Comment 13 for bug 1857074

On Tue, Jan 14, 2020 at 8:35 AM Juerg Haefliger
<email address hidden> wrote:
>
> We certainly want this:
>
> commit 71c751f2a43fa03fae3cf5f0067ed3001a397013
> Author: Mark Rutland <email address hidden>
> Date: Mon Apr 23 11:41:33 2018 +0100
>
> arm64: add sentinel to kpti_safe_list

Agreed, nice catch. Unfortunately, even with that, I'm still seeing
the crash (see below). Attached is the backport of the above I used on
top of 4.15.0-74.84, in case you find I did it wrong.

bestovius login: [ 95.760101] kernel BUG at fs/buffer.c:1240!
[ 95.764335] Internal error: Oops - BUG: 0 [#1] SMP
[ 95.769171] Modules linked in: nls_iso8859_1 thunderx_edac
thunderx_zip cavium_rng_vf shpchp cavium_rng gpio_keys uio_pdrv_genirq
ipmi_ssif uio ipmi_devintf ipmi_msghandler sch_fq_codel ib_iser
rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi
scsi_transport_iscsi ip_tables x_tables autofs4 btrfs zstd_compress
raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor
async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear nicvf
nicpf ast i2c_algo_bit ttm drm_kms_helper syscopyarea sysfillrect
aes_ce_blk sysimgblt thunder_bgx fb_sys_fops aes_ce_cipher crc32_ce
drm crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce ahci libahci
thunder_xcv i2c_thunderx mdio_thunder thunderx_mmc mdio_cavium
aes_neon_bs aes_neon_blk crypto_simd cryptd aes_arm64
[ 95.837496] Process curl (pid: 1848, stack limit = 0x000000004a994c79)
[ 95.844086] CPU: 1 PID: 1848 Comm: curl Not tainted 4.15.18 #1
[ 95.849972] Hardware name: Cavium ThunderX CRB/To be filled by
O.E.M., BIOS 5.11 12/12/2012
[ 95.858403] pstate: 20400085 (nzCv daIf +PAN -UAO)
[ 95.863243] pc : __find_get_block+0x2e8/0x398
[ 95.867640] lr : __getblk_gfp+0x3c/0x2a8
[ 95.871596] sp : ffff00001fe23970
[ 95.874939] x29: ffff00001fe23970 x28: ffff801ff29d8400
[ 95.880302] x27: 000000000000000b x26: 0000000000000010
[ 95.885665] x25: 0000000003880020 x24: 0000000000000001
[ 95.891027] x23: 0000000000000008 x22: ffff801f25098000
[ 95.896390] x21: ffff801f25098000 x20: 0000000003880020
[ 95.901752] x19: 0000000000001000 x18: 0000fffff5966764
[ 95.907115] x17: 0000000000000000 x16: 0000000000000000
[ 95.912477] x15: 000032d49d85d7a0 x14: 002e941340578278
[ 95.917840] x13: 0000fffff5965d60 x12: 0000000000000000
[ 95.923202] x11: ffff000009578c08 x10: 0000000000000040
[ 95.928565] x9 : ffff801f69456ca8 x8 : ffff801f2526ac00
[ 95.933927] x7 : ffff0000083bb9a8 x6 : 0000000000000010
[ 95.939290] x5 : 000000000000001c x4 : 0000000000000100
[ 95.944653] x3 : 0000000000000008 x2 : 0000000000001000
[ 95.950016] x1 : 0000000003880020 x0 : 0000000000000080
[ 95.955378] Call trace:
[ 95.957846] __find_get_block+0x2e8/0x398
[ 95.961892] __getblk_gfp+0x3c/0x2a8
[ 95.965502] __ext4_get_inode_loc+0xe4/0x418
[ 95.969810] ext4_reserve_inode_write+0x5c/0xf8
[ 95.974381] ext4_mark_inode_dirty+0x5c/0x228
[ 95.978777] ext4_da_write_end+0x2c4/0x2e8
[ 95.982912] generic_perform_write+0x108/0x1b0
[ 95.987397] __generic_file_write_iter+0x14c/0x1c0
[ 95.992232] ext4_file_write_iter+0x120/0x3d0
[ 95.996629] new_sync_write+0xd8/0x138
[ 96.000411] __vfs_write+0x74/0x80
[ 96.003842] vfs_write+0xac/0x1b0
[ 96.007185] SyS_write+0x74/0xf0
[ 96.012674] el0_svc_naked+0x30/0x34
[ 96.018502] Code: 17ffffe7 a90363b7 a9046bb9 f9002bbb (d4210000)
[ 96.026896] ---[ end trace 04e2c614fd4c593c ]---