Anju T Sudhakar 110df8bd3e powerpc/perf: Fix kfree memory allocated for nest pmus ... imc_common_cpuhp_mem_free() is the common function for all IMC (In-memory Collection counters) domains to unregister cpuhotplug callback and free memory. Since kfree of memory allocated for nest-imc (per_nest_pmu_arr) is in the common code, all domains (core/nest/thread) can do the kfree in the failure case. This could potentially create a call trace as shown below, where core(/thread/nest) imc pmu initialization fails and in the failure path imc_common_cpuhp_mem_free() free the memory(per_nest_pmu_arr), which is allocated by successfully registered nest units. The call trace is generated in a scenario where core-imc initialization is made to fail and a cpuhotplug is performed in a p9 system. During cpuhotplug ppc_nest_imc_cpu_offline() tries to access per_nest_pmu_arr, which is already freed by core-imc. NIP [c000000000cb6a94] mutex_lock+0x34/0x90 LR [c000000000cb6a88] mutex_lock+0x28/0x90 Call Trace: mutex_lock+0x28/0x90 (unreliable) perf_pmu_migrate_context+0x90/0x3a0 ppc_nest_imc_cpu_offline+0x190/0x1f0 cpuhp_invoke_callback+0x160/0x820 cpuhp_thread_fun+0x1bc/0x270 smpboot_thread_fn+0x250/0x290 kthread+0x1a8/0x1b0 ret_from_kernel_thread+0x5c/0x74 To address this scenario do the kfree(per_nest_pmu_arr) only in case of nest-imc initialization failure, and when there is no other nest units registered. Fixes: 73ce9aec65 ("powerpc/perf: Fix IMC_MAX_PMU macro") Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>		2017-12-13 20:51:22 +11:00
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req-gen	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
8xx-pmu.c
bhrb.S
callchain.c	powerpc/mm: Rename find_linux_pte_or_hugepte()	2017-08-17 23:13:46 +10:00
core-book3s.c	powerpc/perf: Dereference BHRB entries safely	2017-12-13 20:29:20 +11:00
core-fsl-emb.c
e500-pmu.c
e6500-pmu.c
hv-24x7-catalog.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
hv-24x7-domains.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
hv-24x7.c	powerpc/perf/hv-24x7: Fix incorrect comparison in memord	2017-10-22 12:08:31 +02:00
hv-24x7.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
hv-common.c	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
hv-common.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
hv-gpci-requests.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
hv-gpci.c
hv-gpci.h	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
imc-pmu.c	powerpc/perf: Fix kfree memory allocated for nest pmus	2017-12-13 20:51:22 +11:00
isa207-common.c	powerpc/perf: Factor out PPMU_ONLY_COUNT_RUN check code from power8	2017-08-10 22:30:05 +10:00
isa207-common.h	powerpc/perf: Factor out PPMU_ONLY_COUNT_RUN check code from power8	2017-08-10 22:30:05 +10:00
Makefile	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
mpc7450-pmu.c
perf_regs.c	powerpc/perf: Fix oops when kthread execs user process	2017-06-16 21:02:46 +10:00
power4-pmu.c
power5+-pmu.c
power5-pmu.c
power6-pmu.c
power7-events-list.h
power7-pmu.c
power8-events-list.h	powerpc/perf: Add Power8 mem_access event to sysfs	2017-04-19 20:00:23 +10:00
power8-pmu.c	powerpc/perf: Factor out PPMU_ONLY_COUNT_RUN check code from power8	2017-08-10 22:30:05 +10:00
power9-events-list.h	powerpc/perf: Cleanup of PM_BR_CMPL vs. PM_BRU_CMPL in Power9 event list	2017-08-10 22:30:06 +10:00
power9-pmu.c	powerpc/perf: Cleanup of PM_BR_CMPL vs. PM_BRU_CMPL in Power9 event list	2017-08-10 22:30:06 +10:00
ppc970-pmu.c