Buildresult: powerpc-fixes/pseries_defconfig+FA_DUMP/powerpc-gcc5 built on Jan 24 2021, 22:41

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Status:	OK
Date/Time:	Jan 24 2021, 22:41
Duration:	0:03:07.699455
Builder:	ka1
Revision:	powerpc/64s: prevent recursive replay_soft_interrupts causing superfluous interrupt (`4025c784c573cab7e3f84746cc82b8033923ec62)`
Target:	powerpc-fixes/pseries_defconfig+FA_DUMP/powerpc-gcc5
Branch:	powerpc-fixes
Compiler:	powerpc-gcc5 (powerpc64-linux-gcc (GCC) 5.5.0 / GNU ld (GNU Binutils) 2.29.1.20170915)
Config:	pseries_defconfig+FA_DUMP (download)
Log:	Download original Possible warnings (2) .config:4079:warning: override: reassigning to symbol CRASH_DUMP .config:4080:warning: override: reassigning to symbol FA_DUMP Full Log # git rev-parse -q --verify 4025c784c573cab7e3f84746cc82b8033923ec62^{commit} 4025c784c573cab7e3f84746cc82b8033923ec62 already have revision, skipping fetch # git checkout -q -f -B kisskb 4025c784c573cab7e3f84746cc82b8033923ec62 # git clean -qxdf # < git log -1 # commit 4025c784c573cab7e3f84746cc82b8033923ec62 # Author: Nicholas Piggin <npiggin@gmail.com> # Date: Sat Jan 23 16:12:44 2021 +1000 # # powerpc/64s: prevent recursive replay_soft_interrupts causing superfluous interrupt # # When an asynchronous interrupt calls irq_exit, it checks for softirqs # that may have been created, and runs them. Running softirqs enables # local irqs, which can replay pending interrupts causing recursion in # replay_soft_interrupts. This abridged trace shows how this can occur: # # ! NIP replay_soft_interrupts # LR interrupt_exit_kernel_prepare # Call Trace: # interrupt_exit_kernel_prepare (unreliable) # interrupt_return # --- interrupt: ea0 at __rb_reserve_next # NIP __rb_reserve_next # LR __rb_reserve_next # Call Trace: # ring_buffer_lock_reserve # trace_function # function_trace_call # ftrace_call # __do_softirq # irq_exit # timer_interrupt # ! replay_soft_interrupts # interrupt_exit_kernel_prepare # interrupt_return # --- interrupt: ea0 at arch_local_irq_restore # # This can not be prevented easily, because softirqs must not block hard # irqs, so it has to be dealt with. # # The recursion is bounded by design in the softirq code because softirq # replay disables softirqs and loops around again to check for new # softirqs created while it ran, so that's not a problem. # # However it does mess up interrupt replay state, causing superfluous # interrupts when the second replay_soft_interrupts clears a pending # interrupt, leaving it still set in the first call in the 'happened' # local variable. # # Fix this by not caching a copy of irqs_happened across interrupt # handler calls. # # Fixes: 3282a3da25bd ("powerpc/64: Implement soft interrupt replay in C") # Signed-off-by: Nicholas Piggin <npiggin@gmail.com> # Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> # Link: https://lore.kernel.org/r/20210123061244.2076145-1-npiggin@gmail.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 4025c784c573cab7e3f84746cc82b8033923ec62 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_defconfig+FA_DUMP_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- pseries_defconfig # Added to kconfig CONFIG_CRASH_DUMP=y # Added to kconfig CONFIG_FA_DUMP=y # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_defconfig+FA_DUMP_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_defconfig+FA_DUMP_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig .config:4079:warning: override: reassigning to symbol CRASH_DUMP .config:4080:warning: override: reassigning to symbol FA_DUMP # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_defconfig+FA_DUMP_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_pseries_defconfig+FA_DUMP_powerpc-gcc5 # Build took: 0:03:07.699455

© Michael Ellerman 2006-2018.