From: Steven Rostedt <rostedt@kernel.org>
To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
linux-perf-users@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Namhyung Kim <namhyung@kernel.org>,
Takaya Saeki <takayas@google.com>,
Tom Zanussi <zanussi@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ian Rogers <irogers@google.com>,
Douglas Raillard <douglas.raillard@arm.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Jiri Olsa <jolsa@kernel.org>,
Adrian Hunter <adrian.hunter@intel.com>,
Ingo Molnar <mingo@redhat.com>
Subject: [PATCH v4 03/13] perf: tracing: Simplify perf_sysenter_enable/disable() with guards
Date: Mon, 20 Oct 2025 20:51:58 -0400 [thread overview]
Message-ID: <20251021005232.758121204@kernel.org> (raw)
In-Reply-To: 20251021005155.705735078@kernel.org
From: Steven Rostedt <rostedt@goodmis.org>
Use guard(mutex)(&syscall_trace_lock) for perf_sysenter_enable() and
perf_sysenter_disable() as well as for the perf_sysexit_enable() and
perf_sysexit_disable(). This will make it easier to update these functions
with other code that has early exit handling.
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
Changes since v3: https://lore.kernel.org/20251015173548.540984239@kernel.org
- Fixed return value of perf_sysenter_enable() and perf_sysexit_enable()
to not return undefined value (kernel test robot)
kernel/trace/trace_syscalls.c | 48 ++++++++++++++++-------------------
1 file changed, 22 insertions(+), 26 deletions(-)
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 98670006ebeb..de2b6e285fc5 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -1009,22 +1009,21 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
static int perf_sysenter_enable(struct trace_event_call *call)
{
- int ret = 0;
int num;
num = ((struct syscall_metadata *)call->data)->syscall_nr;
- mutex_lock(&syscall_trace_lock);
- if (!sys_perf_refcount_enter)
- ret = register_trace_sys_enter(perf_syscall_enter, NULL);
- if (ret) {
- pr_info("event trace: Could not activate syscall entry trace point");
- } else {
- set_bit(num, enabled_perf_enter_syscalls);
- sys_perf_refcount_enter++;
+ guard(mutex)(&syscall_trace_lock);
+ if (!sys_perf_refcount_enter) {
+ int ret = register_trace_sys_enter(perf_syscall_enter, NULL);
+ if (ret) {
+ pr_info("event trace: Could not activate syscall entry trace point");
+ return ret;
+ }
}
- mutex_unlock(&syscall_trace_lock);
- return ret;
+ set_bit(num, enabled_perf_enter_syscalls);
+ sys_perf_refcount_enter++;
+ return 0;
}
static void perf_sysenter_disable(struct trace_event_call *call)
@@ -1033,12 +1032,11 @@ static void perf_sysenter_disable(struct trace_event_call *call)
num = ((struct syscall_metadata *)call->data)->syscall_nr;
- mutex_lock(&syscall_trace_lock);
+ guard(mutex)(&syscall_trace_lock);
sys_perf_refcount_enter--;
clear_bit(num, enabled_perf_enter_syscalls);
if (!sys_perf_refcount_enter)
unregister_trace_sys_enter(perf_syscall_enter, NULL);
- mutex_unlock(&syscall_trace_lock);
}
static int perf_call_bpf_exit(struct trace_event_call *call, struct pt_regs *regs,
@@ -1115,22 +1113,21 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
static int perf_sysexit_enable(struct trace_event_call *call)
{
- int ret = 0;
int num;
num = ((struct syscall_metadata *)call->data)->syscall_nr;
- mutex_lock(&syscall_trace_lock);
- if (!sys_perf_refcount_exit)
- ret = register_trace_sys_exit(perf_syscall_exit, NULL);
- if (ret) {
- pr_info("event trace: Could not activate syscall exit trace point");
- } else {
- set_bit(num, enabled_perf_exit_syscalls);
- sys_perf_refcount_exit++;
+ guard(mutex)(&syscall_trace_lock);
+ if (!sys_perf_refcount_exit) {
+ int ret = register_trace_sys_exit(perf_syscall_exit, NULL);
+ if (ret) {
+ pr_info("event trace: Could not activate syscall exit trace point");
+ return ret;
+ }
}
- mutex_unlock(&syscall_trace_lock);
- return ret;
+ set_bit(num, enabled_perf_exit_syscalls);
+ sys_perf_refcount_exit++;
+ return 0;
}
static void perf_sysexit_disable(struct trace_event_call *call)
@@ -1139,12 +1136,11 @@ static void perf_sysexit_disable(struct trace_event_call *call)
num = ((struct syscall_metadata *)call->data)->syscall_nr;
- mutex_lock(&syscall_trace_lock);
+ guard(mutex)(&syscall_trace_lock);
sys_perf_refcount_exit--;
clear_bit(num, enabled_perf_exit_syscalls);
if (!sys_perf_refcount_exit)
unregister_trace_sys_exit(perf_syscall_exit, NULL);
- mutex_unlock(&syscall_trace_lock);
}
#endif /* CONFIG_PERF_EVENTS */
--
2.51.0
next prev parent reply other threads:[~2025-10-21 0:52 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-21 0:51 [PATCH v4 00/13] tracing: Show contents of syscall trace event user space fields Steven Rostedt
2025-10-21 0:51 ` [PATCH v4 01/13] tracing: Make trace_user_fault_read() exposed to rest of tracing Steven Rostedt
2025-10-21 0:51 ` [PATCH v4 02/13] tracing: Have syscall trace events read user space string Steven Rostedt
2025-10-21 0:51 ` Steven Rostedt [this message]
2025-10-21 0:51 ` [PATCH v4 04/13] perf: tracing: Have perf system calls read user space Steven Rostedt
2025-10-21 0:52 ` [PATCH v4 05/13] tracing: Have system call events record user array data Steven Rostedt
2025-10-21 0:52 ` [PATCH v4 06/13] tracing: Display some syscall arrays as strings Steven Rostedt
2025-10-21 0:52 ` [PATCH v4 07/13] tracing: Allow syscall trace events to read more than one user parameter Steven Rostedt
2025-10-21 0:52 ` [PATCH v4 08/13] tracing: Add a config and syscall_user_buf_size file to limit amount written Steven Rostedt
2025-10-21 0:52 ` [PATCH v4 09/13] tracing: Show printable characters in syscall arrays Steven Rostedt
2025-10-21 0:52 ` [PATCH v4 10/13] tracing: Add trace_seq_pop() and seq_buf_pop() Steven Rostedt
2025-10-21 0:52 ` [PATCH v4 11/13] tracing: Add parsing of flags to the sys_enter_openat trace event Steven Rostedt
2025-10-21 0:52 ` [PATCH v4 12/13] tracing: Check for printable characters when printing field dyn strings Steven Rostedt
2025-10-21 0:52 ` [PATCH v4 13/13] tracing: Have persistent ring buffer print syscalls normally Steven Rostedt
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