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Message-Id: <20230804081514.120171-1-tianruidong@linux.alibaba.com>
Date: Fri, 4 Aug 2023 16:15:13 +0800
From: Ruidong Tian <tianruidong@...ux.alibaba.com>
To: linux-kernel@...r.kernel.org
Cc: tianruidong@...ux.alibaba.com, alexander.shishkin@...ux.intel.com,
coresight@...ts.linaro.org, linux-arm-kernel@...ts.infradead.org,
mike.leach@...aro.org, suzuki.poulose@....com, james.clark@....com
Subject: [PATCH v3 0/1] coresight: tmc: Explicit type conversions to
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
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