# git rev-parse -q --verify 1b0df11fde0f14a269a181b3b7f5122415bc5ed7^{commit}
1b0df11fde0f14a269a181b3b7f5122415bc5ed7
already have revision, skipping fetch
# git checkout -q -f -B kisskb 1b0df11fde0f14a269a181b3b7f5122415bc5ed7
# git clean -qxdf
# < git log -1
# commit 1b0df11fde0f14a269a181b3b7f5122415bc5ed7
# Author: Daniel Jordan <daniel.m.jordan@oracle.com>
# Date:   Wed Sep 2 13:07:56 2020 -0400
# 
#     padata: fix possible padata_works_lock deadlock
#     
#     syzbot reports,
#     
#       WARNING: inconsistent lock state
#       5.9.0-rc2-syzkaller #0 Not tainted
#       --------------------------------
#       inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
#       syz-executor.0/26715 takes:
#       (padata_works_lock){+.?.}-{2:2}, at: padata_do_parallel kernel/padata.c:220
#       {IN-SOFTIRQ-W} state was registered at:
#         spin_lock include/linux/spinlock.h:354 [inline]
#         padata_do_parallel kernel/padata.c:220
#         ...
#         __do_softirq kernel/softirq.c:298
#         ...
#         sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1091
#         asm_sysvec_apic_timer_interrupt arch/x86/include/asm/idtentry.h:581
#     
#        Possible unsafe locking scenario:
#     
#              CPU0
#              ----
#         lock(padata_works_lock);
#         <Interrupt>
#           lock(padata_works_lock);
#     
#     padata_do_parallel() takes padata_works_lock with softirqs enabled, so a
#     deadlock is possible if, on the same CPU, the lock is acquired in
#     process context and then softirq handling done in an interrupt leads to
#     the same path.
#     
#     Fix by leaving softirqs disabled while do_parallel holds
#     padata_works_lock.
#     
#     Reported-by: syzbot+f4b9f49e38e25eb4ef52@syzkaller.appspotmail.com
#     Fixes: 4611ce2246889 ("padata: allocate work structures for parallel jobs from a pool")
#     Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
#     Cc: Herbert Xu <herbert@gondor.apana.org.au>
#     Cc: Steffen Klassert <steffen.klassert@secunet.com>
#     Cc: linux-crypto@vger.kernel.org
#     Cc: linux-kernel@vger.kernel.org
#     Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
# < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 1b0df11fde0f14a269a181b3b7f5122415bc5ed7
# < make -s -j 48 ARCH=powerpc O=/kisskb/build/crypto_pseries_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  pseries_defconfig
# < make -s -j 48 ARCH=powerpc O=/kisskb/build/crypto_pseries_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  help
# make -s -j 48 ARCH=powerpc O=/kisskb/build/crypto_pseries_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
# make -s -j 48 ARCH=powerpc O=/kisskb/build/crypto_pseries_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-  
Completed OK
# rm -rf /kisskb/build/crypto_pseries_defconfig_powerpc-gcc4.9
# Build took: 0:02:51.985158