deepin-kernel/samples/trace_events
Steven Rostedt fd4c1ee32f tracing: Verify event formats that have "%*p.."
[ Upstream commit ea8d7647f9 ]

The trace event verifier checks the formats of trace events to make sure
that they do not point at memory that is not in the trace event itself or
in data that will never be freed. If an event references data that was
allocated when the event triggered and that same data is freed before the
event is read, then the kernel can crash by reading freed memory.

The verifier runs at boot up (or module load) and scans the print formats
of the events and checks their arguments to make sure that dereferenced
pointers are safe. If the format uses "%*p.." the verifier will ignore it,
and that could be dangerous. Cover this case as well.

Also add to the sample code a use case of "%*pbl".

Link: https://lore.kernel.org/all/bcba4d76-2c3f-4d11-baf0-02905db953dd@oracle.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 5013f454a3 ("tracing: Add check of trace event print fmts for dereferencing pointers")
Link: https://lore.kernel.org/20250327195311.2d89ec66@gandalf.local.home
Reported-by: Libo Chen <libo.chen@oracle.com>
Reviewed-by: Libo Chen <libo.chen@oracle.com>
Tested-by: Libo Chen <libo.chen@oracle.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 4d11fac941d83509be4e6a21038281d6d96da50c)
2025-05-09 22:54:58 +08:00
..
Makefile tracing: Add TRACE_CUSTOM_EVENT() macro 2022-03-11 11:49:24 -05:00
trace-events-sample.c tracing: Add __cpumask to denote a trace event field that is a cpumask_t 2022-11-23 19:08:30 -05:00
trace-events-sample.h tracing: Verify event formats that have "%*p.." 2025-05-09 22:54:58 +08:00
trace_custom_sched.c tracing: Add TRACE_CUSTOM_EVENT() macro 2022-03-11 11:49:24 -05:00
trace_custom_sched.h sched/tracing: Append prev_state to tp args instead 2022-05-12 00:37:11 +02:00