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| author |   Tze-nan Wu <Tze-nan.Wu@mediatek.com> | 2024-08-05 13:59:22 +0800 |
|---|---|---|
| committer |   Steven Rostedt (Google) <rostedt@goodmis.org> | 2024-08-07 20:23:12 -0400 |
| commit | bcf86c01ca4676316557dd482c8416ece8c2e143 (patch) | |
| tree | 6c30a42b0ec0aad2c5140015c3dcc47fffa2f960 /tools/perf/scripts/python/export-to-postgresql.py | |
| parent | function_graph: Fix the ret_stack used by ftrace_graph_ret_addr() (diff) | |
| download | linux-rng-bcf86c01ca4676316557dd482c8416ece8c2e143.tar.xz linux-rng-bcf86c01ca4676316557dd482c8416ece8c2e143.zip | |
tracing: Fix overflow in get_free_elt()
"tracing_map->next_elt" in get_free_elt() is at risk of overflowing.
Once it overflows, new elements can still be inserted into the tracing_map
even though the maximum number of elements (`max_elts`) has been reached.
Continuing to insert elements after the overflow could result in the
tracing_map containing "tracing_map->max_size" elements, leaving no empty
entries.
If any attempt is made to insert an element into a full tracing_map using
`__tracing_map_insert()`, it will cause an infinite loop with preemption
disabled, leading to a CPU hang problem.
Fix this by preventing any further increments to "tracing_map->next_elt"
once it reaches "tracing_map->max_elt".
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 08d43a5fa063e ("tracing: Add lock-free tracing_map")
Co-developed-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Link: https://lore.kernel.org/20240805055922.6277-1-Tze-nan.Wu@mediatek.com
Signed-off-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Signed-off-by: Tze-nan Wu <Tze-nan.Wu@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions