perf/x86: Fix missing sample size update on AMD BRS

commit 90befef5a9e820ccccc33181ec14c015980300cc upstream.

It missed to convert a PERF_SAMPLE_BRANCH_STACK user to call the new
perf_sample_save_brstack() helper in order to update the dyn_size.
This affects AMD Zen3 machines with the branch-brs event.

Fixes: eb55b455ef9c ("perf/core: Add perf_sample_save_brstack() helper")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20230427030527.580841-1-namhyung@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index d096b04bf80e80b2c9784cd5380dbe7677f45cd9..9d248703cbddcd6fb7623d22f4a408adee8d97d5 100644 (file)
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1703,10 +1703,8 @@ int x86_pmu_handle_irq(struct pt_regs *regs)
 
                perf_sample_data_init(&data, 0, event->hw.last_period);
 
-               if (has_branch_stack(event)) {
-                       data.br_stack = &cpuc->lbr_stack;
-                       data.sample_flags |= PERF_SAMPLE_BRANCH_STACK;
-               }
+               if (has_branch_stack(event))
+                       perf_sample_save_brstack(&data, event, &cpuc->lbr_stack);
 
                if (perf_event_overflow(event, &data, regs))
                        x86_pmu_stop(event, 0);