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authorMathieu Desnoyers <mathieu.desnoyers@efficios.com>2024-10-09 03:07:16 +0200
committerSteven Rostedt (Google) <rostedt@goodmis.org>2024-10-09 23:09:36 +0200
commita3204c740a59bebb3b37a294d83f4e353303a52c (patch)
treeb93dbe4003eb4daa32abccb1b999beb4b695ca18
parenttracing: Allow system call tracepoints to handle page faults (diff)
downloadlinux-a3204c740a59bebb3b37a294d83f4e353303a52c.tar.xz
linux-a3204c740a59bebb3b37a294d83f4e353303a52c.zip
tracing/ftrace: Add might_fault check to syscall probes
Add a might_fault() check to validate that the ftrace sys_enter/sys_exit probe callbacks are indeed called from a context where page faults can be handled. Cc: Michael Jeanson <mjeanson@efficios.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Yonghong Song <yhs@fb.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com> Cc: bpf@vger.kernel.org Cc: Joel Fernandes <joel@joelfernandes.org> Link: https://lore.kernel.org/20241009010718.2050182-7-mathieu.desnoyers@efficios.com Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-rw-r--r--include/trace/trace_events.h1
-rw-r--r--kernel/trace/trace_syscalls.c2
2 files changed, 3 insertions, 0 deletions
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 63071aa5923d..4f22136fd465 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -446,6 +446,7 @@ __DECLARE_EVENT_CLASS(call, PARAMS(proto), PARAMS(args), PARAMS(tstruct), \
static notrace void \
trace_event_raw_event_##call(void *__data, proto) \
{ \
+ might_fault(); \
preempt_disable_notrace(); \
do_trace_event_raw_event_##call(__data, args); \
preempt_enable_notrace(); \
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index b1cc19806f3d..6d6bbd56ed92 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -303,6 +303,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id)
* Syscall probe called with preemption enabled, but the ring
* buffer and per-cpu data require preemption to be disabled.
*/
+ might_fault();
guard(preempt_notrace)();
syscall_nr = trace_get_syscall_nr(current, regs);
@@ -348,6 +349,7 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
* Syscall probe called with preemption enabled, but the ring
* buffer and per-cpu data require preemption to be disabled.
*/
+ might_fault();
guard(preempt_notrace)();
syscall_nr = trace_get_syscall_nr(current, regs);