Re: [PATCH 2/7] powerpc/traps: Return early in show_signal_msg()
From: LEROY Christophe <hidden>
Date: 2018-07-25 15:42:33
Also in:
lkml
Murilo Opsfelder Araujo [off-list ref] a =C3=A9crit=C2=A0:
Modify logic of show_signal_msg() to return early, if possible. Replace printk_ratelimited() by printk() and a default rate limit burst to limit displaying unhandled signals messages.
Can you explain more the benefits of this change ? Christophe
quoted hunk ↗ jump to hunk
Signed-off-by: Murilo Opsfelder Araujo <redacted> --- arch/powerpc/kernel/traps.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-)diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index cbd3dc365193..4faab4705774 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c@@ -301,6 +301,13 @@ void user_single_step_siginfo(struct task_struct *ts=
k,
quoted hunk ↗ jump to hunk
info->si_addr =3D (void __user *)regs->nip; } +static bool show_unhandled_signals_ratelimited(void) +{ + 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) {@@ -309,11 +316,12 @@ static void show_signal_msg(int signr, struct=20=20=20pt_regs *regs, int code, const char fmt64[] =3D KERN_INFO "%s[%d]: unhandled signal %d " \ "at %016lx nip %016lx lr %016lx code %x\n"; - if (show_unhandled_signals && unhandled_signal(current, signr)) { - printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32, - current->comm, current->pid, signr, - addr, regs->nip, regs->link, code); - } + if (!unhandled_signal(current, signr)) + return; + + printk(regs->msr & MSR_64BIT ? fmt64 : fmt32, + current->comm, current->pid, signr, + addr, regs->nip, regs->link, code); } void _exception_pkey(int signr, struct pt_regs *regs, int code,@@ -326,7 +334,8 @@ void _exception_pkey(int signr, struct pt_regs=20=20=20*regs, int code, return; } - show_signal_msg(signr, regs, code, addr); + if (show_unhandled_signals_ratelimited()) + show_signal_msg(signr, regs, code, addr); if (arch_irqs_disabled() && !arch_irq_disabled_regs(regs)) local_irq_enable(); -- 2.17.1