# git rev-parse -q --verify 60b7ed54a41b550d50caf7f2418db4a7e75b5bdc^{commit} 60b7ed54a41b550d50caf7f2418db4a7e75b5bdc already have revision, skipping fetch # git checkout -q -f -B kisskb 60b7ed54a41b550d50caf7f2418db4a7e75b5bdc # git clean -qxdf # < git log -1 # commit 60b7ed54a41b550d50caf7f2418db4a7e75b5bdc # Author: Athira Rajeev # Date: Thu Jun 17 13:55:06 2021 -0400 # # powerpc/perf: Fix crash in perf_instruction_pointer() when ppmu is not set # # On systems without any specific PMU driver support registered, running # perf record causes Oops. # # The relevant portion from call trace: # # BUG: Kernel NULL pointer dereference on read at 0x00000040 # Faulting instruction address: 0xc0021f0c # Oops: Kernel access of bad area, sig: 11 [#1] # BE PAGE_SIZE=4K PREEMPT CMPCPRO # SAF3000 DIE NOTIFICATION # CPU: 0 PID: 442 Comm: null_syscall Not tainted 5.13.0-rc6-s3k-dev-01645-g7649ee3d2957 #5164 # NIP: c0021f0c LR: c00e8ad8 CTR: c00d8a5c # NIP perf_instruction_pointer+0x10/0x60 # LR perf_prepare_sample+0x344/0x674 # Call Trace: # perf_prepare_sample+0x7c/0x674 (unreliable) # perf_event_output_forward+0x3c/0x94 # __perf_event_overflow+0x74/0x14c # perf_swevent_hrtimer+0xf8/0x170 # __hrtimer_run_queues.constprop.0+0x160/0x318 # hrtimer_interrupt+0x148/0x3b0 # timer_interrupt+0xc4/0x22c # Decrementer_virt+0xb8/0xbc # # During perf record session, perf_instruction_pointer() is called to # capture the sample IP. This function in core-book3s accesses # ppmu->flags. If a platform specific PMU driver is not registered, ppmu # is set to NULL and accessing its members results in a crash. Fix this # crash by checking if ppmu is set. # # Fixes: 2ca13a4cc56c ("powerpc/perf: Use regs->nip when SIAR is zero") # Cc: stable@vger.kernel.org # v5.11+ # Reported-by: Christophe Leroy # Signed-off-by: Athira Rajeev # Tested-by: Christophe Leroy # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/1623952506-1431-1-git-send-email-atrajeev@linux.vnet.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 60b7ed54a41b550d50caf7f2418db4a7e75b5bdc # < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_le_defconfig+NO_NUMA_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- pseries_le_defconfig # Added to kconfig CONFIG_NUMA=n # < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_le_defconfig+NO_NUMA_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_le_defconfig+NO_NUMA_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pseries_le_defconfig+NO_NUMA_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_le_defconfig+NO_NUMA_powerpc-gcc5 # Build took: 0:01:55.465115