From: Steven Rostedt <[email protected]> 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) <[email protected]> --- Changes since v3: https://lore.kernel.org/[email protected] - 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
