[PATCH] perf/x86/intel/pt: Fix base for single entry topa

[PATCH] perf/x86/intel/pt: Fix base for single entry topa

[Jiri Olsa]

Jan reported failing ltp test for pt. It looks like the reason
is commit 38bb8d77d0b9, that did not keep the TOPA_SHIFT for
entry base, adding it back.

[1] https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/tracing/pt_test/pt_test.c

Reported-by: Jan Stancek <jstancek@redhat.com>
Fixes: 38bb8d77d0b9 ("perf/x86/intel/pt: Split ToPA metadata and page layout")
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
---
 arch/x86/events/intel/pt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c
index 74e80ed9c6c4..05e43d0f430b 100644
--- a/arch/x86/events/intel/pt.c
+++ b/arch/x86/events/intel/pt.c
@@ -627,7 +627,7 @@ static struct topa *topa_alloc(int cpu, gfp_t gfp)
 	 * link as the 2nd entry in the table
 	 */
 	if (!intel_pt_validate_hw_cap(PT_CAP_topa_multiple_entries)) {
-		TOPA_ENTRY(&tp->topa, 1)->base = page_to_phys(p);
+		TOPA_ENTRY(&tp->topa, 1)->base = page_to_phys(p) >> TOPA_SHIFT;
 		TOPA_ENTRY(&tp->topa, 1)->end = 1;
 	}
 
-- 
2.21.0

[tip: perf/urgent] perf/x86/intel/pt: Fix base for single entry topa

[tip-bot2 for Jiri Olsa]

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

Commit-ID:     13301c6b16a6d809b331bb88e40ab9ce38238b8b
Gitweb:        https://git.kernel.org/tip/13301c6b16a6d809b331bb88e40ab9ce38238b8b
Author:        Jiri Olsa <jolsa@kernel.org>
AuthorDate:    Sun, 20 Oct 2019 00:07:26 +02:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Sun, 20 Oct 2019 14:42:28 +02:00

perf/x86/intel/pt: Fix base for single entry topa

Jan reported failing ltp test for PT:

  https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/tracing/pt_test/pt_test.c

It looks like the reason is this new commit added in this v5.4 merge window:

  38bb8d77d0b9 ("perf/x86/intel/pt: Split ToPA metadata and page layout")

which did not keep the TOPA_SHIFT for entry base.

Add it back.

Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 38bb8d77d0b9 ("perf/x86/intel/pt: Split ToPA metadata and page layout")
Link: https://lkml.kernel.org/r/20191019220726.12213-1-jolsa@kernel.org
[ Minor changelog edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/events/intel/pt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c
index 74e80ed..05e43d0 100644
--- a/arch/x86/events/intel/pt.c
+++ b/arch/x86/events/intel/pt.c
@@ -627,7 +627,7 @@ static struct topa *topa_alloc(int cpu, gfp_t gfp)
 	 * link as the 2nd entry in the table
 	 */
 	if (!intel_pt_validate_hw_cap(PT_CAP_topa_multiple_entries)) {
-		TOPA_ENTRY(&tp->topa, 1)->base = page_to_phys(p);
+		TOPA_ENTRY(&tp->topa, 1)->base = page_to_phys(p) >> TOPA_SHIFT;
 		TOPA_ENTRY(&tp->topa, 1)->end = 1;
 	}
 

Re: [PATCH] perf/x86/intel/pt: Fix base for single entry topa

[Alexander Shishkin]

Jiri Olsa <jolsa@kernel.org> writes:

> Jan reported failing ltp test for pt. It looks like the reason
> is commit 38bb8d77d0b9, that did not keep the TOPA_SHIFT for
> entry base, adding it back.

Thanks for taking care of that so quickly!

Regards,
--
Alex