The following commit has been merged into the perf/urgent branch of tip:

Commit-ID:     0ba6502ce167fc3d598c08c2cc3b4ed7ca5aa251
Gitweb:        https://git.kernel.org/tip/0ba6502ce167fc3d598c08c2cc3b4ed7ca5aa251
Author:        Dapeng Mi <dapeng1.mi@linux.intel.com>
AuthorDate:    Tue, 28 Oct 2025 14:42:14 +08:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 29 Oct 2025 10:29:52 +01:00

perf/x86/intel: Fix KASAN global-out-of-bounds warning

When running "perf mem record" command on CWF, the below KASAN
global-out-of-bounds warning is seen.

  ==================================================================
  BUG: KASAN: global-out-of-bounds in cmt_latency_data+0x176/0x1b0
  Read of size 4 at addr ffffffffb721d000 by task dtlb/9850

  Call Trace:

   kasan_report+0xb8/0xf0
   cmt_latency_data+0x176/0x1b0
   setup_arch_pebs_sample_data+0xf49/0x2560
   intel_pmu_drain_arch_pebs+0x577/0xb00
   handle_pmi_common+0x6c4/0xc80

The issue is caused by below code in __grt_latency_data(). The code
tries to access x86_hybrid_pmu structure which doesn't exist on
non-hybrid platform like CWF.

        WARN_ON_ONCE(hybrid_pmu(event->pmu)->pmu_type == hybrid_big)

So add is_hybrid() check before calling this WARN_ON_ONCE to fix the
global-out-of-bounds access issue.

Fixes: 090262439f66 ("perf/x86/intel: Rename model-specific pebs_latency_data functions")
Reported-by: Xudong Hao <xudong.hao@intel.com>
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Zide Chen <zide.chen@intel.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20251028064214.1451968-1-dapeng1.mi@linux.intel.com
---
 arch/x86/events/intel/ds.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index c0b7ac1..01bc59e 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -317,7 +317,8 @@ static u64 __grt_latency_data(struct perf_event *event, u64 status,
 {
 	u64 val;
 
-	WARN_ON_ONCE(hybrid_pmu(event->pmu)->pmu_type == hybrid_big);
+	WARN_ON_ONCE(is_hybrid() &&
+		     hybrid_pmu(event->pmu)->pmu_type == hybrid_big);
 
 	dse &= PERF_PEBS_DATA_SOURCE_GRT_MASK;
 	val = hybrid_var(event->pmu, pebs_data_source)[dse];