lkml.org 
[lkml]   [2023]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[PATCH v3 0/1] coresight: tmc: Explicit type conversions to
Date
Perf cs_etm session executed unexpectedly when AUX buffer > 1G.

perf record -C 0 -m ,2G -e cs_etm// -- <workload>
[ perf record: Captured and wrote 2.615 MB perf.data ]

Perf only collect about 2M perf data rather than 2G. This is becasuse
the operation, "nr_pages << PAGE_SHIFT", in coresight tmc driver, will
overflow when nr_pages >= 0x80000(correspond to 1G AUX buffer). The
overflow cause buffer allocation to fail, and TMC driver will alloc
minimal buffer size(1M). You can just get about 2M perf data(1M AUX
buffer + perf data header) at least.

Explicit convert nr_pages to 64 bit in tmc driver to avoid overflow.

Changes in V2:
Suzuki K Poulose:
Add another 2 places where needed to fix.

Changes in V1:
James Clark:
Use a more accurate commit message.

Ruidong Tian (1):
coresight: tmc: Explicit type conversions to prevent integer overflow

drivers/hwtracing/coresight/coresight-tmc-etf.c | 2 +-
drivers/hwtracing/coresight/coresight-tmc-etr.c | 5 +++--
drivers/hwtracing/coresight/coresight-tmc.h | 2 +-
3 files changed, 5 insertions(+), 4 deletions(-)

--
2.33.1

\
 
 \ /
  Last update: 2023-08-04 10:16    [W:0.056 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site