Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[linux-imx.git] / kernel / trace / trace_syscalls.c

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 322e16461072575e6d8439208891b5730bd41438..8fd03657bc7d1f684279c46681519e16a1812f87 100644 (file)
--- 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);
 }