arm64: use private ratelimit state along with show_unhandled_signals

printk_ratelimit() shares the ratelimiting state with other callers what
may lead to scenarios where at the time we want to print out debug
information we already limited, so nothing appears in the dmesg - this
makes exception-trace quite poor helper in debugging.

Additionally, we have imbalance with some messages limited with global
ratelimit state and other messages limited with their private state
defined via pr_*_ratelimited().

To address this inconsistency show_unhandled_signals_ratelimited()
macro is introduced and caller sites are converted to use it.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 1ef2940df13c..a12251c074a8 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -335,8 +335,7 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
         if (call_undef_hook(regs) == 0)
                 return;
 
-        if (show_unhandled_signals && unhandled_signal(current, SIGILL) &&
-            printk_ratelimit()) {
+        if (show_unhandled_signals_ratelimited() && unhandled_signal(current, SIGILL)) {
                 pr_info("%s[%d]: undefined instruction: pc=%p\n",
                         current->comm, task_pid_nr(current), pc);
                 dump_instr(KERN_INFO, regs);
@@ -363,7 +362,7 @@ asmlinkage long do_ni_syscall(struct pt_regs *regs)
         }
 #endif
 
-        if (show_unhandled_signals && printk_ratelimit()) {
+        if (show_unhandled_signals_ratelimited()) {
                 pr_info("%s[%d]: syscall %d\n", current->comm,
                         task_pid_nr(current), (int)regs->syscallno);
                 dump_instr("", regs);