powerpc/traps: Avoid rate limit messages from show unhandled signals

In the recent commit to add an explicit ratelimit state when showing
unhandled signals, commit 35a52a10c3ac ("powerpc/traps: Use an
explicit ratelimit state for show_signal_msg()"), I put the check of
show_unhandled_signals and the ratelimit state before the call to
unhandled_signal() so as to avoid unnecessarily calling the latter
when show_unhandled_signals is false.

However that causes us to check the ratelimit state on every call, so
if we take a lot of *handled* signals that has the effect of making
the ratelimit code print warnings that callbacks have been suppressed
when they haven't.

So rearrange the code so that we check show_unhandled_signals first,
then call unhandled_signal() and finally check the ratelimit state.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 070e96f1773a464b1aebf7c316e2de1028dd6c2f..c85adb8582713075426ab05b537c6910d19d467a 100644 (file)
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -315,22 +315,21 @@ void user_single_step_siginfo(struct task_struct *tsk,
        info->si_addr = (void __user *)regs->nip;
 }
 
-static bool show_unhandled_signals_ratelimited(void)
+static void show_signal_msg(int signr, struct pt_regs *regs, int code,
+                           unsigned long addr)
 {
        static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
                                      DEFAULT_RATELIMIT_BURST);
-       return show_unhandled_signals && __ratelimit(&rs);
-}
 
-static void show_signal_msg(int signr, struct pt_regs *regs, int code,
-                           unsigned long addr)
-{
-       if (!show_unhandled_signals_ratelimited())
+       if (!show_unhandled_signals)
                return;
 
        if (!unhandled_signal(current, signr))
                return;
 
+       if (!__ratelimit(&rs))
+               return;
+
        pr_info("%s[%d]: %s (%d) at %lx nip %lx lr %lx code %x",
                current->comm, current->pid, signame(signr), signr,
                addr, regs->nip, regs->link, code);