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-rw-r--r--kernel/trace/trace_syscalls.c26
1 files changed, 9 insertions, 17 deletions
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 322e164..8fd0365 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -175,7 +175,7 @@ print_syscall_exit(struct trace_iterator *iter, int flags,
entry = syscall_nr_to_meta(syscall);
if (!entry) {
- trace_seq_printf(s, "\n");
+ trace_seq_putc(s, '\n');
return TRACE_TYPE_HANDLED;
}
@@ -566,15 +566,15 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
if (!sys_data)
return;
+ head = this_cpu_ptr(sys_data->enter_event->perf_events);
+ if (hlist_empty(head))
+ return;
+
/* get the size after alignment with the u32 buffer size field */
size = sizeof(unsigned long) * sys_data->nb_args + sizeof(*rec);
size = ALIGN(size + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
- if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
- "perf buffer not large enough"))
- return;
-
rec = (struct syscall_trace_enter *)perf_trace_buf_prepare(size,
sys_data->enter_event->event.type, regs, &rctx);
if (!rec)
@@ -583,8 +583,6 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
rec->nr = syscall_nr;
syscall_get_arguments(current, regs, 0, sys_data->nb_args,
(unsigned long *)&rec->args);
-
- head = this_cpu_ptr(sys_data->enter_event->perf_events);
perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
}
@@ -642,18 +640,14 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
if (!sys_data)
return;
+ head = this_cpu_ptr(sys_data->exit_event->perf_events);
+ if (hlist_empty(head))
+ return;
+
/* We can probably do that at build time */
size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64));
size -= sizeof(u32);
- /*
- * Impossible, but be paranoid with the future
- * How to put this check outside runtime?
- */
- if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE,
- "exit event has grown above perf buffer size"))
- return;
-
rec = (struct syscall_trace_exit *)perf_trace_buf_prepare(size,
sys_data->exit_event->event.type, regs, &rctx);
if (!rec)
@@ -661,8 +655,6 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
rec->nr = syscall_nr;
rec->ret = syscall_get_return_value(current, regs);
-
- head = this_cpu_ptr(sys_data->exit_event->perf_events);
perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
}
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