While running LTP test case access01 the following kernel BUG noticed on linux next 20201124 tag kernel on i386.
git short log: ---------------- git log --oneline next-20201120..next-20201124 -- mm/highmem.c d9927d46febf Merge branch 'akpm-current/current' 72d22a0d0e86 mm: support THPs in zero_user_segments 2a656cad337e mm/highmem: Take kmap_high_get() properly into account
Please find these easy steps to reproduce the kernel build and boot.
step to reproduce: # please install tuxmake # sudo pip3 install -U tuxmake # cd linux-next # tuxmake --runtime docker --target-arch i386 --toolchain gcc-9 --kconfig defconfig --kconfig-add https://builds.tuxbuild.com/1kj7IzwXtISXHWGaaR15CRHM2Zt/config
# Boot the i386 kernel on x86_64 devices. # run LTP # cd /opt/ltp # ./runltp -s access01 # you will notice the below BUG
crash log: ------------- access01.c:243: TPASS: access(accessfile_r, R_OK|W_OK) as root access01.c:243: TPASS: access(accessfile_w, R_OK) as root access01.c:243: TPASS: access(accessfi[ 50.847347] ------------[ cut here ]------------ [ 50.852189] kernel BUG at mm/highmem.c:417! le_w, R_OK|W_OK)[ 50.856437] invalid opcode: 0000 [#1] SMP [ 50.861774] CPU: 2 PID: 628 Comm: loop0 Not tainted 5.10.0-rc5-next-20201124 #2 [ 50.869073] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.2 05/23/2018 [ 50.876457] EIP: zero_user_segments+0x242/0x250 [ 50.880987] Code: e4 fe ff ff 8d 74 26 00 85 c0 0f 84 30 ff ff ff c6 01 00 a8 02 0f 84 25 ff ff ff 31 ff 66 89 7c 01 fe e9 19 ff ff ff 90 0f 0b <0f> 0b 8d b4 26 00 00 00 00 8d 74 26 00 90 3e 8d 74 26 00 55 89 e5 [ 50.899723] EAX: 00000e00 EBX: 00000001 ECX: f6e6f860 EDX: 00000e00 [ 50.905983] ESI: 00000000 EDI: 00000e00 EBP: dec35c7c ESP: dec35c60 [ 50.912237] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010206 [ 50.919015] CR0: 80050033 CR2: 011bcd40 CR3: 163b1000 CR4: 003506d0 [ 50.925272] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 50.931530] DR6: fffe0ff0 DR7: 00000400 [ 50.935360] Call Trace: [ 50.937807] __block_write_begin_int+0x3ec/0x640 [ 50.942426] ? __ext4_get_inode_loc_noinmem+0x80/0x80 [ 50.947478] __block_write_begin+0x15/0x20 [ 50.951566] ? __ext4_get_inode_loc_noinmem+0x80/0x80 [ 50.956611] ext4_da_write_begin+0x170/0x3a0 [ 50.960874] ? __ext4_get_inode_loc_noinmem+0x80/0x80 [ 50.965920] generic_perform_write+0x9c/0x180 [ 50.970279] ext4_buffered_write_iter+0x91/0x170 [ 50.974888] ext4_file_write_iter+0x112/0x910 [ 50.979240] ? check_preempt_wakeup+0x100/0x250 [ 50.983773] ? _cond_resched+0x17/0x30 [ 50.987524] ? __inode_security_revalidate+0x68/0x80 [ 50.992481] do_iter_readv_writev+0x18e/0x1c0 [ 50.996831] ? ext4_dio_supported+0x40/0x40 [ 51.001010] do_iter_write+0x74/0x1b0 [ 51.004665] ? ext4_dio_supported+0x40/0x40 [ 51.008845] vfs_iter_write+0x1b/0x30 [ 51.012510] lo_write_bvec+0x54/0x170 [ 51.016175] loop_queue_work+0x1bd/0x9e0 [ 51.020092] ? finish_task_switch+0x7c/0x3c0 [ 51.024356] ? kthread_worker_fn+0x6e/0x250 [ 51.028535] ? loop_kthread_worker_fn+0x1b/0x20 [ 51.033067] kthread_worker_fn+0xa0/0x250 [ 51.037070] ? lo_rw_aio+0x3c0/0x3c0 [ 51.040640] ? loop_set_status_from_info+0x350/0x350 [ 51.045596] loop_kthread_worker_fn+0x1b/0x20 [ 51.049948] kthread+0xf0/0x120 [ 51.053084] ? loop_set_status_from_info+0x350/0x350 [ 51.058042] ? kthread_park+0xa0/0xa0 [ 51.061701] ret_from_fork+0x1c/0x28 [ 51.065269] Modules linked in: x86_pkg_temp_thermal as root access[ 51.070275] ---[ end trace d002cac2383c24be ]--- [ 51.076150] EIP: zero_user_segments+0x242/0x250 01.c:243: TPASS:[ 51.080778] Code: e4 fe ff ff 8d 74 26 00 85 c0 0f 84 30 ff ff ff c6 01 00 a8 02 0f 84 25 ff ff ff 31 ff 66 89 7c 01 fe e9 19 ff ff ff 90 0f 0b <0f> 0b 8d b4 26 00 00 00 00 8d 74 26 00 90 3e 8d 74 26 00 55 89 e5 [ 51.100815] EAX: 00000e00 EBX: 00000001 ECX: f6e6f860 EDX: 00000e00 access(accessfi[ 51.107174] ESI: 00000000 EDI: 00000e00 EBP: dec35c7c ESP: dec35c60 [ 51.114723] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010206 le_x, R_OK) as r[ 51.121608] CR0: 80050033 CR2: 011bcd40 CR3: 163b1000 CR4: 003506d0 [ 51.129153] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 oot access01.c:[ 51.135518] DR6: fffe0ff0 DR7: 00000400 243: TPASS: access(accessfile_x, W_OK) as root access01.c:243: TPASS: access(accessfile_x, R_OK|W_OK) as root access01.c:243: TPASS: access(accessdir_r/accessfile_r, F_OK) as root
Reported-by: Naresh Kamboju naresh.kamboju@linaro.org
full test log, https://lkft.validation.linaro.org/scheduler/job/1978393#L1593 https://qa-reports.linaro.org/lkft/linux-next-master-sanity/build/next-20201...
metadata: git branch: master git repo: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next git commit: d9137320ac06f526fe3f9a3fdf07a3b14201068a git describe: next-20201124 make_kernelversion: 5.10.0-rc5 kernel-config: https://builds.tuxbuild.com/1kj7IzwXtISXHWGaaR15CRHM2Zt/config