Package v4l2loopback-dkms fails to install in 20.04.1

Asked by Dave Dixon

What can I do to fix this?

Ubuntu release 20.04.1. Sudo apt install v4l2loopback-dkms fails with

Loading new v4l2loopback-0.12.3 DKMS files...
Building for 5.4.0-42-generic
Building initial module for 5.4.0-42-generic
Error! Bad return status for module build on kernel: 5.4.0-42-generic (x86_64)
Consult /var/lib/dkms/v4l2loopback/0.12.3/build/make.log for more information.
dpkg: error processing package v4l2loopback-dkms (--configure):
installed v4l2loopback-dkms package post-installation script subprocess returne
d error exit status 10
Errors were encountered while processing:
v4l2loopback-dkms
E: Sub-process /usr/bin/dpkg returned an error code (1)

Question information

Language:
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Status:
Solved
For:
Ubuntu v4l2loopback Edit question
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Solved by:
Dave Dixon
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Revision history for this message
Manfred Hampl (m-hampl) said :
#1

Consult /var/lib/dkms/v4l2loopback/0.12.3/build/make.log for more information.

Are there any useful messages in /var/lib/dkms/v4l2loopback/0.12.3/build/make.log

?

For diagnistic purposes please provide the output of the commands

uname -a
lsb_release -crid
apt-cache policy v4l2loopback-dkms

Revision history for this message
Dave Dixon (ddixon-swcp) said :
#2

uname -a
--------------
Linux <node> 5.4.0-42-generic #46-Ubuntu SMP Fri Jul 10 00:24:02 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

lsb_release -crid
-------------------------
Distributor ID: Ubuntu
Description: Ubuntu 20.04.1 LTS
Release: 20.04
Codename: focal

apt-cache policy v4l2loopback-dkms
-------------------------------------------------------
v4l2loopback-dkms:
v4l2loopback-dkms:
  Installed: 0.12.3-1
  Candidate: 0.12.3-1
  Version table:
 *** 0.12.3-1 500
        500 http://us.archive.ubuntu.com/ubuntu focal/universe amd64 Packages
        500 http://us.archive.ubuntu.com/ubuntu focal/universe i386 Packages
        100 /var/lib/dpkg/status

/var/lib/dkms/v4l2loopback/0.12.3/build/make.log
---------------------------------------------------------------------------
DKMS make.log for v4l2loopback-0.12.3 for kernel 5.4.0-42-generic (x86_64)
Mon 17 Aug 2020 09:09:42 AM MDT
Building v4l2-loopback driver...
make -C /lib/modules/5.4.0-42-generic/build M=/var/lib/dkms/v4l2loopback/0.12.3/build modules
make[1]: Entering directory '/usr/src/linux-headers-5.4.0-42-generic'
  CC [M] /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.o
In file included from <command-line>:0:0:
./arch/x86/include/asm/page_64.h: In function ‘clear_page’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:256:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\
  ^
./arch/x86/include/asm/page_64.h:49:2: note: in expansion of macro ‘alternative_call_2’
  alternative_call_2(clear_page_orig,
  ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:128:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldinstr2\n" \
  ^
./arch/x86/include/asm/alternative.h:168:2: note: in expansion of macro ‘OLDINSTR_2’
  OLDINSTR_2(oldinstr, 1, 2) \
  ^
./arch/x86/include/asm/alternative.h:256:23: note: in expansion of macro ‘ALTERNATIVE_2’
  asm_inline volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\
                       ^
./arch/x86/include/asm/page_64.h:49:2: note: in expansion of macro ‘alternative_call_2’
  alternative_call_2(clear_page_orig,
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:256:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\
  ^
./arch/x86/include/asm/page_64.h:49:2: note: in expansion of macro ‘alternative_call_2’
  alternative_call_2(clear_page_orig,
  ^
./arch/x86/include/asm/segment.h: In function ‘vdso_read_cpunode’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:240:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
  ^
./arch/x86/include/asm/segment.h:266:2: note: in expansion of macro ‘alternative_io’
  alternative_io ("lsl %[seg],%[p]",
  ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:240:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
                       ^
./arch/x86/include/asm/segment.h:266:2: note: in expansion of macro ‘alternative_io’
  alternative_io ("lsl %[seg],%[p]",
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:240:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
  ^
./arch/x86/include/asm/segment.h:266:2: note: in expansion of macro ‘alternative_io’
  alternative_io ("lsl %[seg],%[p]",
  ^
./arch/x86/include/asm/special_insns.h: In function ‘clflushopt’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:240:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
  ^
./arch/x86/include/asm/special_insns.h:205:2: note: in expansion of macro ‘alternative_io’
  alternative_io(".byte " __stringify(NOP_DS_PREFIX) "; clflush %P0",
  ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:240:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
                       ^
./arch/x86/include/asm/special_insns.h:205:2: note: in expansion of macro ‘alternative_io’
  alternative_io(".byte " __stringify(NOP_DS_PREFIX) "; clflush %P0",
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:240:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
  ^
./arch/x86/include/asm/special_insns.h:205:2: note: in expansion of macro ‘alternative_io’
  alternative_io(".byte " __stringify(NOP_DS_PREFIX) "; clflush %P0",
  ^
./arch/x86/include/asm/processor.h: In function ‘prefetch’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:221:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
  ^
./arch/x86/include/asm/processor.h:795:2: note: in expansion of macro ‘alternative_input’
  alternative_input(BASE_PREFETCH, "prefetchnta %P1",
  ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:221:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
                       ^
./arch/x86/include/asm/processor.h:795:2: note: in expansion of macro ‘alternative_input’
  alternative_input(BASE_PREFETCH, "prefetchnta %P1",
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:221:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
  ^
./arch/x86/include/asm/processor.h:795:2: note: in expansion of macro ‘alternative_input’
  alternative_input(BASE_PREFETCH, "prefetchnta %P1",
  ^
./arch/x86/include/asm/processor.h: In function ‘prefetchw’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:221:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
  ^
./arch/x86/include/asm/processor.h:807:2: note: in expansion of macro ‘alternative_input’
  alternative_input(BASE_PREFETCH, "prefetchw %P1",
  ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:221:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
                       ^
./arch/x86/include/asm/processor.h:807:2: note: in expansion of macro ‘alternative_input’
  alternative_input(BASE_PREFETCH, "prefetchw %P1",
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:221:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
  ^
./arch/x86/include/asm/processor.h:807:2: note: in expansion of macro ‘alternative_input’
  alternative_input(BASE_PREFETCH, "prefetchw %P1",
  ^
./include/linux/thread_info.h: In function ‘copy_overflow’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:93:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_NO_CUT_HERE | BUGFLAG_TAINT(taint));\
   ^
./include/asm-generic/bug.h:124:3: note: in expansion of macro ‘__WARN_printf’
   __WARN_printf(TAINT_WARN, format); \
   ^
./include/linux/thread_info.h:134:2: note: in expansion of macro ‘WARN’
  WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:93:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_NO_CUT_HERE | BUGFLAG_TAINT(taint));\
   ^
./include/asm-generic/bug.h:124:3: note: in expansion of macro ‘__WARN_printf’
   __WARN_printf(TAINT_WARN, format); \
   ^
./include/linux/thread_info.h:134:2: note: in expansion of macro ‘WARN’
  WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:93:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_NO_CUT_HERE | BUGFLAG_TAINT(taint));\
   ^
./include/asm-generic/bug.h:124:3: note: in expansion of macro ‘__WARN_printf’
   __WARN_printf(TAINT_WARN, format); \
   ^
./include/linux/thread_info.h:134:2: note: in expansion of macro ‘WARN’
  WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
  ^
./include/linux/thread_info.h: In function ‘check_copy_size’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/thread_info.h:150:6: note: in expansion of macro ‘WARN_ON_ONCE’
  if (WARN_ON_ONCE(bytes > INT_MAX))
      ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/thread_info.h:150:6: note: in expansion of macro ‘WARN_ON_ONCE’
  if (WARN_ON_ONCE(bytes > INT_MAX))
      ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/thread_info.h:150:6: note: in expansion of macro ‘WARN_ON_ONCE’
  if (WARN_ON_ONCE(bytes > INT_MAX))
      ^
In file included from <command-line>:0:0:
./include/linux/rcupdate.h: In function ‘rcu_head_after_call_rcu’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/rcupdate.h:893:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(func != (rcu_callback_t)~0L);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/rcupdate.h:893:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(func != (rcu_callback_t)~0L);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/rcupdate.h:893:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(func != (rcu_callback_t)~0L);
  ^
./include/linux/ktime.h: In function ‘ktime_divns’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/ktime.h:171:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON(div < 0);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/ktime.h:171:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON(div < 0);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/ktime.h:171:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON(div < 0);
  ^
./include/linux/srcu.h: In function ‘srcu_read_unlock’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/srcu.h:179:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(idx & ~0x1);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/srcu.h:179:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(idx & ~0x1);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/srcu.h:179:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(idx & ~0x1);
  ^
./include/linux/page-flags.h: In function ‘ClearPageCompound’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/asm-generic/bug.h:62:57: note: in expansion of macro ‘BUG’
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                                         ^
./include/linux/page-flags.h:565:2: note: in expansion of macro ‘BUG_ON’
  BUG_ON(!PageHead(page));
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/asm-generic/bug.h:62:57: note: in expansion of macro ‘BUG’
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                                         ^
./include/linux/page-flags.h:565:2: note: in expansion of macro ‘BUG_ON’
  BUG_ON(!PageHead(page));
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/asm-generic/bug.h:62:57: note: in expansion of macro ‘BUG’
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                                         ^
./include/linux/page-flags.h:565:2: note: in expansion of macro ‘BUG_ON’
  BUG_ON(!PageHead(page));
  ^
./include/asm-generic/fixmap.h: In function ‘virt_to_fix’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/asm-generic/bug.h:62:57: note: in expansion of macro ‘BUG’
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                                         ^
./include/asm-generic/fixmap.h:38:2: note: in expansion of macro ‘BUG_ON’
  BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/asm-generic/bug.h:62:57: note: in expansion of macro ‘BUG’
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                                         ^
./include/asm-generic/fixmap.h:38:2: note: in expansion of macro ‘BUG_ON’
  BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/asm-generic/bug.h:62:57: note: in expansion of macro ‘BUG’
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                                         ^
./include/asm-generic/fixmap.h:38:2: note: in expansion of macro ‘BUG_ON’
  BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);
  ^
./arch/x86/include/asm/apic.h: In function ‘native_apic_mem_write’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:240:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
  ^
./arch/x86/include/asm/apic.h:107:2: note: in expansion of macro ‘alternative_io’
  alternative_io("movl %0, %P1", "xchgl %0, %P1", X86_BUG_11AP,
  ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:240:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
                       ^
./arch/x86/include/asm/apic.h:107:2: note: in expansion of macro ‘alternative_io’
  alternative_io("movl %0, %P1", "xchgl %0, %P1", X86_BUG_11AP,
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:240:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) \
  ^
./arch/x86/include/asm/apic.h:107:2: note: in expansion of macro ‘alternative_io’
  alternative_io("movl %0, %P1", "xchgl %0, %P1", X86_BUG_11AP,
  ^
In file included from ./arch/x86/include/asm/smp.h:13:0,
                 from ./arch/x86/include/asm/mmzone_64.h:11,
                 from ./arch/x86/include/asm/mmzone.h:5,
                 from ./include/linux/mmzone.h:971,
                 from ./include/linux/gfp.h:6,
                 from ./include/linux/mm.h:10,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:18:
./arch/x86/include/asm/apic.h:105:16: warning: unused variable ‘addr’ [-Wunused-variable]
  volatile u32 *addr = (volatile u32 *)(APIC_BASE + reg);
                ^
In file included from <command-line>:0:0:
./arch/x86/include/asm/smap.h: In function ‘clac’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/smap.h:47:2: note: in expansion of macro ‘alternative’
  alternative("", __ASM_CLAC, X86_FEATURE_SMAP);
  ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:204:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
                       ^
./arch/x86/include/asm/smap.h:47:2: note: in expansion of macro ‘alternative’
  alternative("", __ASM_CLAC, X86_FEATURE_SMAP);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/smap.h:47:2: note: in expansion of macro ‘alternative’
  alternative("", __ASM_CLAC, X86_FEATURE_SMAP);
  ^
./arch/x86/include/asm/smap.h: In function ‘stac’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/smap.h:53:2: note: in expansion of macro ‘alternative’
  alternative("", __ASM_STAC, X86_FEATURE_SMAP);
  ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:204:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
                       ^
./arch/x86/include/asm/smap.h:53:2: note: in expansion of macro ‘alternative’
  alternative("", __ASM_STAC, X86_FEATURE_SMAP);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/smap.h:53:2: note: in expansion of macro ‘alternative’
  alternative("", __ASM_STAC, X86_FEATURE_SMAP);
  ^
./arch/x86/include/asm/uaccess_64.h: In function ‘copy_user_generic’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:256:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\
  ^
./arch/x86/include/asm/uaccess_64.h:37:2: note: in expansion of macro ‘alternative_call_2’
  alternative_call_2(copy_user_generic_unrolled,
  ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:128:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldinstr2\n" \
  ^
./arch/x86/include/asm/alternative.h:168:2: note: in expansion of macro ‘OLDINSTR_2’
  OLDINSTR_2(oldinstr, 1, 2) \
  ^
./arch/x86/include/asm/alternative.h:256:23: note: in expansion of macro ‘ALTERNATIVE_2’
  asm_inline volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\
                       ^
./arch/x86/include/asm/uaccess_64.h:37:2: note: in expansion of macro ‘alternative_call_2’
  alternative_call_2(copy_user_generic_unrolled,
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:256:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\
  ^
./arch/x86/include/asm/uaccess_64.h:37:2: note: in expansion of macro ‘alternative_call_2’
  alternative_call_2(copy_user_generic_unrolled,
  ^
./arch/x86/include/asm/uaccess_64.h: In function ‘raw_copy_from_user’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:74:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:204:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
                       ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:74:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:74:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:80:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:204:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
                       ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:80:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:80:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:86:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:204:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
                       ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:86:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:86:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:92:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:204:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
                       ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:92:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:92:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:98:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:204:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
                       ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:98:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:98:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:108:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:204:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
                       ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:108:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess_64.h:108:3: note: in expansion of macro ‘__uaccess_begin_nospec’
   __uaccess_begin_nospec();
   ^
./arch/x86/include/asm/uaccess.h: In function ‘user_access_begin’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess.h:716:2: note: in expansion of macro ‘__uaccess_begin_nospec’
  __uaccess_begin_nospec();
  ^
In file included from ./arch/x86/include/asm/barrier.h:5:0,
                 from ./include/linux/compiler.h:256,
                 from ./include/linux/export.h:42,
                 from ./include/linux/linkage.h:7,
                 from ./include/linux/preempt.h:10,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/alternative.h:108:2: error: expected identifier or ‘(’ before string constant
  "# ALT: oldnstr\n" \
  ^
./arch/x86/include/asm/alternative.h:159:2: note: in expansion of macro ‘OLDINSTR’
  OLDINSTR(oldinstr, 1) \
  ^
./arch/x86/include/asm/alternative.h:204:23: note: in expansion of macro ‘ALTERNATIVE’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
                       ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess.h:716:2: note: in expansion of macro ‘__uaccess_begin_nospec’
  __uaccess_begin_nospec();
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/alternative.h:204:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")
  ^
./arch/x86/include/asm/barrier.h:52:26: note: in expansion of macro ‘alternative’
 #define barrier_nospec() alternative("", "lfence", X86_FEATURE_LFENCE_RDTSC)
                          ^
./arch/x86/include/asm/uaccess.h:125:2: note: in expansion of macro ‘barrier_nospec’
  barrier_nospec(); \
  ^
./arch/x86/include/asm/uaccess.h:716:2: note: in expansion of macro ‘__uaccess_begin_nospec’
  __uaccess_begin_nospec();
  ^
./include/linux/xarray.h: In function ‘xa_mk_value’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/xarray.h:54:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON((long)v < 0);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/xarray.h:54:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON((long)v < 0);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/xarray.h:54:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON((long)v < 0);
  ^
./include/linux/iocontext.h: In function ‘get_io_context_active’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/iocontext.h:132:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(atomic_long_read(&ioc->refcount) <= 0);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/iocontext.h:132:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(atomic_long_read(&ioc->refcount) <= 0);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/iocontext.h:132:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(atomic_long_read(&ioc->refcount) <= 0);
  ^
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/iocontext.h:133:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(atomic_read(&ioc->active_ref) <= 0);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/iocontext.h:133:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(atomic_read(&ioc->active_ref) <= 0);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/iocontext.h:133:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(atomic_read(&ioc->active_ref) <= 0);
  ^
./include/linux/iocontext.h: In function ‘ioc_task_link’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/iocontext.h:142:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(atomic_read(&ioc->nr_tasks) <= 0);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/iocontext.h:142:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(atomic_read(&ioc->nr_tasks) <= 0);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/iocontext.h:142:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(atomic_read(&ioc->nr_tasks) <= 0);
  ^
./include/linux/quota.h: In function ‘make_kqid’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/linux/quota.h:114:3: note: in expansion of macro ‘BUG’
   BUG();
   ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/linux/quota.h:114:3: note: in expansion of macro ‘BUG’
   BUG();
   ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/linux/quota.h:114:3: note: in expansion of macro ‘BUG’
   BUG();
   ^
./include/linux/quota.h: In function ‘make_kqid_invalid’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/linux/quota.h:141:3: note: in expansion of macro ‘BUG’
   BUG();
   ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/linux/quota.h:141:3: note: in expansion of macro ‘BUG’
   BUG();
   ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/linux/quota.h:141:3: note: in expansion of macro ‘BUG’
   BUG();
   ^
./include/linux/fs.h: In function ‘filemap_nr_thps_inc’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/fs.h:2848:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(1);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/fs.h:2848:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(1);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/fs.h:2848:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(1);
  ^
./include/linux/fs.h: In function ‘filemap_nr_thps_dec’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/fs.h:2857:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(1);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/fs.h:2857:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(1);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/fs.h:2857:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(1);
  ^
./include/linux/fs.h: In function ‘i_readcount_dec’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/asm-generic/bug.h:62:57: note: in expansion of macro ‘BUG’
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                                         ^
./include/linux/fs.h:2964:2: note: in expansion of macro ‘BUG_ON’
  BUG_ON(!atomic_read(&inode->i_readcount));
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/asm-generic/bug.h:62:57: note: in expansion of macro ‘BUG’
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                                         ^
./include/linux/fs.h:2964:2: note: in expansion of macro ‘BUG_ON’
  BUG_ON(!atomic_read(&inode->i_readcount));
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/asm-generic/bug.h:62:57: note: in expansion of macro ‘BUG’
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                                         ^
./include/linux/fs.h:2964:2: note: in expansion of macro ‘BUG_ON’
  BUG_ON(!atomic_read(&inode->i_readcount));
  ^
./include/linux/mm.h: In function ‘try_get_page’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/mm.h:1041:6: note: in expansion of macro ‘WARN_ON_ONCE’
  if (WARN_ON_ONCE(page_ref_count(page) <= 0))
      ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/mm.h:1041:6: note: in expansion of macro ‘WARN_ON_ONCE’
  if (WARN_ON_ONCE(page_ref_count(page) <= 0))
      ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/mm.h:1041:6: note: in expansion of macro ‘WARN_ON_ONCE’
  if (WARN_ON_ONCE(page_ref_count(page) <= 0))
      ^
./include/linux/mm.h: In function ‘page_memcg_rcu’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/mm.h:1305:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(!rcu_read_lock_held());
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/mm.h:1305:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(!rcu_read_lock_held());
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/mm.h:1305:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(!rcu_read_lock_held());
  ^
./include/linux/kernfs.h: In function ‘kernfs_enable_ns’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/kernfs.h:305:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/kernfs.h:305:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/kernfs.h:305:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR);
  ^
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/kernfs.h:306:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(!RB_EMPTY_ROOT(&kn->dir.children));
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/kernfs.h:306:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(!RB_EMPTY_ROOT(&kn->dir.children));
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/kernfs.h:306:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(!RB_EMPTY_ROOT(&kn->dir.children));
  ^
./include/linux/kobject.h: In function ‘kobject_has_children’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/kobject.h:134:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(kref_read(&kobj->kref) == 0);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/kobject.h:134:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(kref_read(&kobj->kref) == 0);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:98:3: note: in expansion of macro ‘__WARN_FLAGS’
   __WARN_FLAGS(BUGFLAG_ONCE | \
   ^
./include/linux/kobject.h:134:2: note: in expansion of macro ‘WARN_ON_ONCE’
  WARN_ON_ONCE(kref_read(&kobj->kref) == 0);
  ^
./include/linux/slab.h: In function ‘kmalloc_index’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/linux/slab.h:386:2: note: in expansion of macro ‘BUG’
  BUG();
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/linux/slab.h:386:2: note: in expansion of macro ‘BUG’
  BUG();
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/linux/slab.h:386:2: note: in expansion of macro ‘BUG’
  BUG();
  ^
./include/linux/sched/signal.h: In function ‘signal_set_stop_flags’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/sched/signal.h:252:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON(sig->flags & (SIGNAL_GROUP_EXIT|SIGNAL_GROUP_COREDUMP));
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/sched/signal.h:252:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON(sig->flags & (SIGNAL_GROUP_EXIT|SIGNAL_GROUP_COREDUMP));
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/sched/signal.h:252:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON(sig->flags & (SIGNAL_GROUP_EXIT|SIGNAL_GROUP_COREDUMP));
  ^
./include/linux/sched/signal.h: In function ‘restore_saved_sigmask_unless’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/sched/signal.h:482:3: note: in expansion of macro ‘WARN_ON’
   WARN_ON(!test_thread_flag(TIF_SIGPENDING));
   ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/sched/signal.h:482:3: note: in expansion of macro ‘WARN_ON’
   WARN_ON(!test_thread_flag(TIF_SIGPENDING));
   ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/sched/signal.h:482:3: note: in expansion of macro ‘WARN_ON’
   WARN_ON(!test_thread_flag(TIF_SIGPENDING));
   ^
./include/media/media-entity.h: In function ‘media_entity_enum_set’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:466:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
      ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:466:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
      ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:466:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
      ^
./include/media/media-entity.h: In function ‘media_entity_enum_clear’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:481:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
      ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:481:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
      ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:481:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
      ^
./include/media/media-entity.h: In function ‘media_entity_enum_test’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:498:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
      ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:498:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
      ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:498:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
      ^
./include/media/media-entity.h: In function ‘media_entity_enum_test_and_set’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:517:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
      ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:517:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
      ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:517:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(entity->internal_idx >= ent_enum->idx_max))
      ^
./include/media/media-entity.h: In function ‘media_entity_enum_intersects’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:548:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON(ent_enum1->idx_max != ent_enum2->idx_max);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:548:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON(ent_enum1->idx_max != ent_enum2->idx_max);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-entity.h:548:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON(ent_enum1->idx_max != ent_enum2->idx_max);
  ^
./include/linux/acpi.h: In function ‘acpi_free_fwnode_static’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/acpi.h:65:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(!is_acpi_static_node(fwnode)))
      ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/acpi.h:65:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(!is_acpi_static_node(fwnode)))
      ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/linux/acpi.h:65:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(!is_acpi_static_node(fwnode)))
      ^
./include/linux/scatterlist.h: In function ‘sg_assign_page’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/asm-generic/bug.h:62:57: note: in expansion of macro ‘BUG’
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                                         ^
./include/linux/scatterlist.h:95:2: note: in expansion of macro ‘BUG_ON’
  BUG_ON((unsigned long) page & (SG_CHAIN | SG_END));
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/asm-generic/bug.h:62:57: note: in expansion of macro ‘BUG’
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                                         ^
./include/linux/scatterlist.h:95:2: note: in expansion of macro ‘BUG_ON’
  BUG_ON((unsigned long) page & (SG_CHAIN | SG_END));
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
./include/asm-generic/bug.h:62:57: note: in expansion of macro ‘BUG’
 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                                         ^
./include/linux/scatterlist.h:95:2: note: in expansion of macro ‘BUG_ON’
  BUG_ON((unsigned long) page & (SG_CHAIN | SG_END));
  ^
./include/media/v4l2-subdev.h: In function ‘v4l2_subdev_get_try_format’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/v4l2-subdev.h:938:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(pad >= sd->entity.num_pads))
      ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/v4l2-subdev.h:938:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(pad >= sd->entity.num_pads))
      ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/v4l2-subdev.h:938:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(pad >= sd->entity.num_pads))
      ^
./include/media/v4l2-subdev.h: In function ‘v4l2_subdev_get_try_crop’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/v4l2-subdev.h:956:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(pad >= sd->entity.num_pads))
      ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/v4l2-subdev.h:956:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(pad >= sd->entity.num_pads))
      ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/v4l2-subdev.h:956:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(pad >= sd->entity.num_pads))
      ^
./include/media/v4l2-subdev.h: In function ‘v4l2_subdev_get_try_compose’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/v4l2-subdev.h:974:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(pad >= sd->entity.num_pads))
      ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/v4l2-subdev.h:974:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(pad >= sd->entity.num_pads))
      ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/v4l2-subdev.h:974:6: note: in expansion of macro ‘WARN_ON’
  if (WARN_ON(pad >= sd->entity.num_pads))
      ^
./include/media/media-request.h: In function ‘media_request_unlock_for_access’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-request.h:116:7: note: in expansion of macro ‘WARN_ON’
  if (!WARN_ON(!req->access_count))
       ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-request.h:116:7: note: in expansion of macro ‘WARN_ON’
  if (!WARN_ON(!req->access_count))
       ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-request.h:116:7: note: in expansion of macro ‘WARN_ON’
  if (!WARN_ON(!req->access_count))
       ^
./include/media/media-request.h: In function ‘media_request_unlock_for_update’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-request.h:164:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON(req->updating_count <= 0);
  ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-request.h:164:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON(req->updating_count <= 0);
  ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:79:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \
  ^
./include/asm-generic/bug.h:90:19: note: in expansion of macro ‘__WARN_FLAGS’
 #define __WARN() __WARN_FLAGS(BUGFLAG_TAINT(TAINT_WARN))
                   ^
./include/asm-generic/bug.h:115:3: note: in expansion of macro ‘__WARN’
   __WARN(); \
   ^
./include/media/media-request.h:164:2: note: in expansion of macro ‘WARN_ON’
  WARN_ON(req->updating_count <= 0);
  ^
/var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c: In function ‘vidioc_queryctrl’:
././include/linux/compiler_types.h:210:24: error: expected ‘(’ before ‘__inline’
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
/var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:1157:3: note: in expansion of macro ‘BUG’
   BUG();
   ^
In file included from ./include/linux/bug.h:5:0,
                 from ./include/linux/thread_info.h:12,
                 from ./arch/x86/include/asm/preempt.h:7,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/vmalloc.h:5,
                 from /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:17:
./arch/x86/include/asm/bug.h:35:22: error: expected identifier or ‘(’ before string constant
  asm_inline volatile("1:\t" ins "\n" \
                      ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
/var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:1157:3: note: in expansion of macro ‘BUG’
   BUG();
   ^
In file included from <command-line>:0:0:
././include/linux/compiler_types.h:210:24: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
 #define asm_inline asm __inline
                        ^
./arch/x86/include/asm/bug.h:35:2: note: in expansion of macro ‘asm_inline’
  asm_inline volatile("1:\t" ins "\n" \
  ^
./arch/x86/include/asm/bug.h:73:2: note: in expansion of macro ‘_BUG_FLAGS’
  _BUG_FLAGS(ASM_UD2, 0); \
  ^
/var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.c:1157:3: note: in expansion of macro ‘BUG’
   BUG();
   ^
make[2]: *** [scripts/Makefile.build:275: /var/lib/dkms/v4l2loopback/0.12.3/build/v4l2loopback.o] Error 1
make[1]: *** [Makefile:1731: /var/lib/dkms/v4l2loopback/0.12.3/build] Error 2
make[1]: Leaving directory '/usr/src/linux-headers-5.4.0-42-generic'
make: *** [Makefile:43: v4l2loopback.ko] Error 2

Revision history for this message
Manfred Hampl (m-hampl) said :
#3

Maybe a C compiler that doesn't understand "#define asm_inline asm __inline"

What is the output of the command

gcc --version

Revision history for this message
Dave Dixon (ddixon-swcp) said :
#4

gcc --version
------------------
gcc (Ubuntu 4.9.3-13ubuntu2) 4.9.3
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Revision history for this message
Manfred Hampl (m-hampl) said :
#5

This is an old version of the C compiler (from Ubuntu xenial, 18.04)
You should install a current one (or select the newer one if you have more than one installed)

What is the output of the command

dpkg -l | grep gcc-

Revision history for this message
Dave Dixon (ddixon-swcp) said :
#6

dpkg -l | grep gcc-
---------------------------
ii gcc-10-base:amd64 10.1.0-2ubuntu1~18.04 amd64 GCC, the GNU Compiler Collection (base package)
ii gcc-10-base:i386 10.1.0-2ubuntu1~18.04 i386 GCC, the GNU Compiler Collection (base package)
ii gcc-4.8 4.8.5-4ubuntu8 amd64 GNU C compiler
ii gcc-4.8-base:amd64 4.8.5-4ubuntu8 amd64 GCC, the GNU Compiler Collection (base package)
ii gcc-4.9 4.9.3-13ubuntu2 amd64 GNU C compiler
ii gcc-4.9-base:amd64 4.9.3-13ubuntu2 amd64 GCC, the GNU Compiler Collection (base package)
ii gcc-7 7.5.0-6ubuntu2 amd64 GNU C compiler
ii gcc-7-base:amd64 7.5.0-6ubuntu2 amd64 GCC, the GNU Compiler Collection (base package)
ii gcc-8-base:amd64 8.4.0-3ubuntu2 amd64 GCC, the GNU Compiler Collection (base package)
ii gcc-8-base:i386 8.4.0-3ubuntu2 i386 GCC, the GNU Compiler Collection (base package)
ii gcc-9-base:amd64 9.3.0-10ubuntu2 amd64 GCC, the GNU Compiler Collection (base package)
ii gcc-avr 1:5.4.0+Atmel3.6.1-2build1 amd64 GNU C compiler (cross compiler for avr)
ii lib32gcc-s1 10.1.0-2ubuntu1~18.04 amd64 GCC support library (32 bit Version)
ii libgcc-4.8-dev:amd64 4.8.5-4ubuntu8 amd64 GCC support library (development files)
ii libgcc-4.9-dev:amd64 4.9.3-13ubuntu2 amd64 GCC support library (development files)
ii libgcc-7-dev:amd64 7.5.0-6ubuntu2 amd64 GCC support library (development files)
ii libgcc-s1:amd64 10.1.0-2ubuntu1~18.04 amd64 GCC support library
ii libgcc-s1:i386 10.1.0-2ubuntu1~18.04 i386 GCC support library

Revision history for this message
Dave Dixon (ddixon-swcp) said :
#7

I ran update-alternatives, selected gcc-7, and reinstalled v4l2loopback-dkms. The installation may not have completed successfully. I get

Can't load /var/lib/shim-signed/mok/.rnd into RNG
139771503281472:error:2406F079:random number generator:RAND_load_file:Cannot open file:../crypto/rand/randfile.c:98:Filename=/var/lib/shim-signed/mok/.rnd
Generating a RSA private key
....................++++
.........................++++
writing new private key to '/var/lib/shim-signed/mok/MOK.priv'
-----
Done.

At any rate,

sudo modprobe v4l2loopback
modprobe: ERROR: could not insert 'v4l2loopback': Operation not permitted

v4l2loopback
v4l2loopback: command not found

Revision history for this message
Manfred Hampl (m-hampl) said :
#8

This now is a problem with secure boot.

The Ubuntu-provided kernel modules are signed with a key that is already registered.

If you compile a kernel module yourself, then you have two possibilities:
1. switch off signature checking as part of secure boot
or
2. Create your own signature key, sign the kernel module with that key and register the key in the system.

"writing new private key to '/var/lib/shim-signed/mok/MOK.priv'"
This is already one of the steps, but there are other steps missing:
copy that key to the U>EFI are (with mokutil command), and then reboot the system and activate the key.
see https://wiki.ubuntu.com/UEFI/SecureBoot/DKMS

Revision history for this message
Manfred Hampl (m-hampl) said :
#9

And the command to execute is

v4l2loopback-ctl

Revision history for this message
Dave Dixon (ddixon-swcp) said :
#10

In the course of all this I discovered that my gcc installation was broken in many ways. After a few passes with aptitude I got everything in sync. Then I instaledl gcc 9.3 (same as Ubuntu kernel) and compiled v4l2loopback with no error messages, reboot to MOK, or anything weird. I am now able to modprobe v4l2loopback.

Thanks very much for your help. Two lessons learned:

1. After many years and without intentional manipulation, maintaining multiple versions of gcc can result in a dependency nightmare. Multiple LTS version upgrades along the way didn't catch the problems.

2. Compile with the same version of gcc as the OS kernel. It's old advice, but good advice!

Thanks again!