This is a note to let you know that I've just added the patch titled sparc64: Fix pcr_ops initialization and usage bugs. to the 3.16-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: sparc64-fix-pcr_ops-initialization-and-usage-bugs.patch and it can be found in the queue-3.16 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Oct 28 11:19:22 CST 2014 From: "David S. Miller" <davem@xxxxxxxxxxxxx> Date: Mon, 11 Aug 2014 15:38:46 -0700 Subject: sparc64: Fix pcr_ops initialization and usage bugs. From: "David S. Miller" <davem@xxxxxxxxxxxxx> [ Upstream commit 8bccf5b313180faefce38e0d1140f76e0f327d28 ] Christopher reports that perf_event_print_debug() can crash in uniprocessor builds. The crash is due to pcr_ops being NULL. This happens because pcr_arch_init() is only invoked by smp_cpus_done() which only executes in SMP builds. init_hw_perf_events() is closely intertwined with pcr_ops being setup properly, therefore: 1) Call pcr_arch_init() early on from init_hw_perf_events(), instead of from smp_cpus_done(). 2) Do not hook up a PMU type if pcr_ops is NULL after pcr_arch_init(). 3) Move init_hw_perf_events to a later initcall so that it we will be sure to invoke pcr_arch_init() after all cpus are brought up. Finally, guard the one naked sequence of pcr_ops dereferences in __global_pmu_self() with an appropriate NULL check. Reported-by: Christopher Alexander Tobias Schulze <cat.schulze@xxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/sparc/kernel/perf_event.c | 7 +++++-- arch/sparc/kernel/process_64.c | 3 +++ arch/sparc/kernel/smp_64.c | 1 - 3 files changed, 8 insertions(+), 3 deletions(-) --- a/arch/sparc/kernel/perf_event.c +++ b/arch/sparc/kernel/perf_event.c @@ -1671,9 +1671,12 @@ static bool __init supported_pmu(void) static int __init init_hw_perf_events(void) { + int err; + pr_info("Performance events: "); - if (!supported_pmu()) { + err = pcr_arch_init(); + if (err || !supported_pmu()) { pr_cont("No support for PMU type '%s'\n", sparc_pmu_type); return 0; } @@ -1685,7 +1688,7 @@ static int __init init_hw_perf_events(vo return 0; } -early_initcall(init_hw_perf_events); +pure_initcall(init_hw_perf_events); void perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs) --- a/arch/sparc/kernel/process_64.c +++ b/arch/sparc/kernel/process_64.c @@ -312,6 +312,9 @@ static void __global_pmu_self(int this_c struct global_pmu_snapshot *pp; int i, num; + if (!pcr_ops) + return; + pp = &global_cpu_snapshot[this_cpu].pmu; num = 1; --- a/arch/sparc/kernel/smp_64.c +++ b/arch/sparc/kernel/smp_64.c @@ -1383,7 +1383,6 @@ void __cpu_die(unsigned int cpu) void __init smp_cpus_done(unsigned int max_cpus) { - pcr_arch_init(); } void smp_send_reschedule(int cpu) Patches currently in stable-queue which might be from davem@xxxxxxxxxxxxx are queue-3.16/sparc64-adjust-vmalloc-region-size-based-upon-available-virtual-address-bits.patch queue-3.16/sparc64-fix-fpu-register-corruption-with-aes-crypto-offload.patch queue-3.16/sparc64-move-request_irq-from-ldc_bind-to-ldc_alloc.patch queue-3.16/sparc32-dma_alloc_coherent-must-honour-gfp-flags.patch queue-3.16/sparc64-kill-unnecessary-tables-and-increase-max_banks.patch queue-3.16/sparc-let-memset-return-the-address-argument.patch queue-3.16/sparc64-use-kernel-page-tables-for-vmemmap.patch queue-3.16/sparc64-sparse-irq.patch queue-3.16/sparc64-fix-physical-memory-management-regressions-with-large-max_phys_bits.patch queue-3.16/sparc64-fix-lockdep-warnings-on-reboot-on-ultra-5.patch queue-3.16/sparc64-switch-to-4-level-page-tables.patch queue-3.16/sparc64-sun4v-tlb-error-power-off-events.patch queue-3.16/sparc-bpf_jit-fix-support-for-ldx-stx-mem-and-skf_ad_vlan_tag.patch queue-3.16/sparc64-increase-size-of-boot-string-to-1024-bytes.patch queue-3.16/sparc64-find_node-adjustment.patch queue-3.16/sparc64-fix-reversed-start-end-in-flush_tlb_kernel_range.patch queue-3.16/sparc64-increase-max_phys_address_bits-to-53.patch queue-3.16/sparc64-define-va-hole-at-run-time-rather-than-at-compile-time.patch queue-3.16/sparc64-fix-register-corruption-in-top-most-kernel-stack-frame-during-boot.patch queue-3.16/sparc64-do-not-disable-interrupts-in-nmi_cpu_busy.patch queue-3.16/sparc64-support-m6-and-m7-for-building-cpu-distribution-map.patch queue-3.16/sparc64-cpu-hardware-caps-support-for-sparc-m6-and-m7.patch queue-3.16/sparc64-do-not-define-thread-fpregs-save-area-as-zero-length-array.patch queue-3.16/sparc-bpf_jit-fix-loads-from-negative-offsets.patch queue-3.16/sparc64-t5-pmu.patch queue-3.16/sparc64-adjust-ktsb-assembler-to-support-larger-physical-addresses.patch queue-3.16/sparc64-implement-__get_user_pages_fast.patch queue-3.16/sparc64-fix-corrupted-thread-fault-code.patch queue-3.16/sparc64-fix-hibernation-code-refrence-to-page_offset.patch queue-3.16/sparc64-correctly-recognise-m6-and-m7-cpu-type.patch queue-3.16/sparc64-fix-pcr_ops-initialization-and-usage-bugs.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html