From: Greg Kroah-Hartman Date: Fri, 29 Mar 2024 13:08:27 +0000 (+0100) Subject: 5.4-stable patches X-Git-Tag: v6.7.12~148 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7dbc87397aa8177f60e22f530cd5f8e33f000fcc;p=thirdparty%2Fkernel%2Fstable-queue.git 5.4-stable patches added patches: perf-core-fix-reentry-problem-in-perf_output_read_group.patch --- diff --git a/queue-5.4/perf-core-fix-reentry-problem-in-perf_output_read_group.patch b/queue-5.4/perf-core-fix-reentry-problem-in-perf_output_read_group.patch new file mode 100644 index 00000000000..751c15fe899 --- /dev/null +++ b/queue-5.4/perf-core-fix-reentry-problem-in-perf_output_read_group.patch @@ -0,0 +1,80 @@ +From 6b959ba22d34ca793ffdb15b5715457c78e38b1a Mon Sep 17 00:00:00 2001 +From: Yang Jihong +Date: Fri, 2 Sep 2022 16:29:18 +0800 +Subject: perf/core: Fix reentry problem in perf_output_read_group() + +From: Yang Jihong + +commit 6b959ba22d34ca793ffdb15b5715457c78e38b1a upstream. + +perf_output_read_group may respond to IPI request of other cores and invoke +__perf_install_in_context function. As a result, hwc configuration is modified. +causing inconsistency and unexpected consequences. + +Interrupts are not disabled when perf_output_read_group reads PMU counter. +In this case, IPI request may be received from other cores. +As a result, PMU configuration is modified and an error occurs when +reading PMU counter: + + CPU0 CPU1 + __se_sys_perf_event_open + perf_install_in_context + perf_output_read_group smp_call_function_single + for_each_sibling_event(sub, leader) { generic_exec_single + if ((sub != event) && remote_function + (sub->state == PERF_EVENT_STATE_ACTIVE)) | + <----RAISE IPI-----+ + __perf_install_in_context + ctx_resched + event_sched_out + armpmu_del + ... + hwc->idx = -1; // event->hwc.idx is set to -1 + ... + + sub->pmu->read(sub); + armpmu_read + armv8pmu_read_counter + armv8pmu_read_hw_counter + int idx = event->hw.idx; // idx = -1 + u64 val = armv8pmu_read_evcntr(idx); + u32 counter = ARMV8_IDX_TO_COUNTER(idx); // invalid counter = 30 + read_pmevcntrn(counter) // undefined instruction + +Signed-off-by: Yang Jihong +Signed-off-by: Peter Zijlstra (Intel) +Link: https://lkml.kernel.org/r/20220902082918.179248-1-yangjihong1@huawei.com +Signed-off-by: Thadeu Lima de Souza Cascardo +Signed-off-by: Greg Kroah-Hartman +--- + kernel/events/core.c | 9 +++++++++ + 1 file changed, 9 insertions(+) + +--- a/kernel/events/core.c ++++ b/kernel/events/core.c +@@ -6372,9 +6372,16 @@ static void perf_output_read_group(struc + { + struct perf_event *leader = event->group_leader, *sub; + u64 read_format = event->attr.read_format; ++ unsigned long flags; + u64 values[6]; + int n = 0; + ++ /* ++ * Disabling interrupts avoids all counter scheduling ++ * (context switches, timer based rotation and IPIs). ++ */ ++ local_irq_save(flags); ++ + values[n++] = 1 + leader->nr_siblings; + + if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) +@@ -6410,6 +6417,8 @@ static void perf_output_read_group(struc + + __output_copy(handle, values, n * sizeof(u64)); + } ++ ++ local_irq_restore(flags); + } + + #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ diff --git a/queue-5.4/series b/queue-5.4/series index 93754059433..2d6e004da54 100644 --- a/queue-5.4/series +++ b/queue-5.4/series @@ -103,3 +103,4 @@ loop-refactor-loop_set_status-size-calculation.patch loop-factor-out-configuring-loop-from-status.patch loop-check-for-overflow-while-configuring-loop.patch loop-loop_set_status_from_info-check-before-assignment.patch +perf-core-fix-reentry-problem-in-perf_output_read_group.patch