This is a note to let you know that I've just added the patch titled
perf/x86/intel/pt: Fix sampling using single range output
to the 5.10-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:
perf-x86-intel-pt-fix-sampling-using-single-range-output.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ce0d998be9274dd3a3d971cbeaa6fe28fd2c3062 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Date: Sat, 12 Nov 2022 17:15:08 +0200
Subject: perf/x86/intel/pt: Fix sampling using single range output
From: Adrian Hunter <adrian.hunter@xxxxxxxxx>
commit ce0d998be9274dd3a3d971cbeaa6fe28fd2c3062 upstream.
Deal with errata TGL052, ADL037 and RPL017 "Trace May Contain Incorrect
Data When Configured With Single Range Output Larger Than 4KB" by
disabling single range output whenever larger than 4KB.
Fixes: 670638477aed ("perf/x86/intel/pt: Opportunistically use single range output mode")
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20221112151508.13768-1-adrian.hunter@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/events/intel/pt.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/arch/x86/events/intel/pt.c
+++ b/arch/x86/events/intel/pt.c
@@ -1247,6 +1247,15 @@ static int pt_buffer_try_single(struct p
if (1 << order != nr_pages)
goto out;
+ /*
+ * Some processors cannot always support single range for more than
+ * 4KB - refer errata TGL052, ADL037 and RPL017. Future processors might
+ * also be affected, so for now rather than trying to keep track of
+ * which ones, just disable it for all.
+ */
+ if (nr_pages > 1)
+ goto out;
+
buf->single = true;
buf->nr_pages = nr_pages;
ret = 0;
Patches currently in stable-queue which might be from adrian.hunter@xxxxxxxxx are
queue-5.10/mmc-sdhci-esdhc-imx-use-the-correct-host-caps-for-mm.patch
queue-5.10/perf-x86-intel-pt-fix-sampling-using-single-range-output.patch
