# git rev-parse -q --verify 1174ea047a350ba2e1294131aa14046675ab45fd^{commit}
1174ea047a350ba2e1294131aa14046675ab45fd
already have revision, skipping fetch
# git checkout -q -f -B kisskb 1174ea047a350ba2e1294131aa14046675ab45fd
# git clean -qxdf
# < git log -1
# commit 1174ea047a350ba2e1294131aa14046675ab45fd
# Author: Benjamin Gray <bgray@linux.ibm.com>
# Date:   Fri Sep 15 13:46:04 2023 +1000
# 
#     powerpc/dexcr: Move HASHCHK trap handler
#     
#     Syzkaller reported a sleep in atomic context bug relating to the HASHCHK
#     handler logic:
#     
#       BUG: sleeping function called from invalid context at arch/powerpc/kernel/traps.c:1518
#       in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 25040, name: syz-executor
#       preempt_count: 0, expected: 0
#       RCU nest depth: 0, expected: 0
#       no locks held by syz-executor/25040.
#       irq event stamp: 34
#       hardirqs last  enabled at (33): [<c000000000048b38>] prep_irq_for_enabled_exit arch/powerpc/kernel/interrupt.c:56 [inline]
#       hardirqs last  enabled at (33): [<c000000000048b38>] interrupt_exit_user_prepare_main+0x148/0x600 arch/powerpc/kernel/interrupt.c:230
#       hardirqs last disabled at (34): [<c00000000003e6a4>] interrupt_enter_prepare+0x144/0x4f0 arch/powerpc/include/asm/interrupt.h:176
#       softirqs last  enabled at (0): [<c000000000281954>] copy_process+0x16e4/0x4750 kernel/fork.c:2436
#       softirqs last disabled at (0): [<0000000000000000>] 0x0
#       CPU: 15 PID: 25040 Comm: syz-executor Not tainted 6.5.0-rc5-00001-g3ccdff6bb06d #3
#       Hardware name: IBM,9105-22A POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1040.00 (NL1040_021) hv:phyp pSeries
#       Call Trace:
#       [c0000000a8247ce0] [c00000000032b0e4] __might_resched+0x3b4/0x400 kernel/sched/core.c:10189
#       [c0000000a8247d80] [c0000000008c7dc8] __might_fault+0xa8/0x170 mm/memory.c:5853
#       [c0000000a8247dc0] [c00000000004160c] do_program_check+0x32c/0xb20 arch/powerpc/kernel/traps.c:1518
#       [c0000000a8247e50] [c000000000009b2c] program_check_common_virt+0x3bc/0x3c0
#     
#     To determine if a trap was caused by a HASHCHK instruction, we inspect
#     the user instruction that triggered the trap. However this may sleep
#     if the page needs to be faulted in (get_user_instr() reaches
#     __get_user(), which calls might_fault() and triggers the bug message).
#     
#     Move the HASHCHK handler logic to after we allow IRQs, which is fine
#     because we are only interested in HASHCHK if it's a user space trap.
#     
#     Fixes: 5bcba4e6c13f ("powerpc/dexcr: Handle hashchk exception")
#     Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://msgid.link/20230915034604.45393-1-bgray@linux.ibm.com
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 1174ea047a350ba2e1294131aa14046675ab45fd
# make -s -j 160 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc866_ads_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  mpc866_ads_defconfig
# < make -s -j 160 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc866_ads_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  help
# make -s -j 160 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc866_ads_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
# make -s -j 160 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc866_ads_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_mpc866_ads_defconfig_powerpc-gcc5
# Build took: 0:00:24.787488