diff options
| -rw-r--r-- | arch/powerpc/include/asm/system.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/kernel/traps.c | 128 |
2 files changed, 74 insertions, 56 deletions
diff --git a/arch/powerpc/include/asm/system.h b/arch/powerpc/include/asm/system.h index e30a13d1ee7..d51c2c20dd2 100644 --- a/arch/powerpc/include/asm/system.h +++ b/arch/powerpc/include/asm/system.h @@ -193,8 +193,8 @@ extern void cacheable_memzero(void *p, unsigned int nb); extern void *cacheable_memcpy(void *, const void *, unsigned int); extern int do_page_fault(struct pt_regs *, unsigned long, unsigned long); extern void bad_page_fault(struct pt_regs *, unsigned long, int); -extern int die(const char *, struct pt_regs *, long); extern void _exception(int, struct pt_regs *, int, unsigned long); +extern void die(const char *, struct pt_regs *, long); extern void _nmask_and_or_msr(unsigned long nmask, unsigned long or_val); #ifdef CONFIG_BOOKE_WDT diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 014f88f03d3..c091527efd8 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -98,18 +98,14 @@ static void pmac_backlight_unblank(void) static inline void pmac_backlight_unblank(void) { } #endif -int die(const char *str, struct pt_regs *regs, long err) +static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED; +static int die_owner = -1; +static unsigned int die_nest_count; +static int die_counter; + +static unsigned __kprobes long oops_begin(struct pt_regs *regs) { - static struct { - raw_spinlock_t lock; - u32 lock_owner; - int lock_owner_depth; - } die = { - .lock = __RAW_SPIN_LOCK_UNLOCKED(die.lock), - .lock_owner = -1, - .lock_owner_depth = 0 - }; - static int die_counter; + int cpu; unsigned long flags; if (debugger(regs)) @@ -117,50 +113,37 @@ int die(const char *str, struct pt_regs *regs, long err) oops_enter(); - if (die.lock_owner != raw_smp_processor_id()) { - console_verbose(); - raw_spin_lock_irqsave(&die.lock, flags); - die.lock_owner = smp_processor_id(); - die.lock_owner_depth = 0; - bust_spinlocks(1); - if (machine_is(powermac)) - pmac_backlight_unblank(); - } else { - local_save_flags(flags); - } - - if (++die.lock_owner_depth < 3) { - printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter); -#ifdef CONFIG_PREEMPT - printk("PREEMPT "); -#endif -#ifdef CONFIG_SMP - printk("SMP NR_CPUS=%d ", NR_CPUS); -#endif -#ifdef CONFIG_DEBUG_PAGEALLOC - printk("DEBUG_PAGEALLOC "); -#endif -#ifdef CONFIG_NUMA - printk("NUMA "); -#endif - printk("%s\n", ppc_md.name ? ppc_md.name : ""); - - if (notify_die(DIE_OOPS, str, regs, err, 255, - SIGSEGV) == NOTIFY_STOP) - return 1; - - print_modules(); - show_regs(regs); - } else { - printk("Recursive die() failure, output suppressed\n"); + /* racy, but better than risking deadlock. */ + raw_local_irq_save(flags); + cpu = smp_processor_id(); + if (!arch_spin_trylock(&die_lock)) { + if (cpu == die_owner) + /* nested oops. should stop eventually */; + else + arch_spin_lock(&die_lock); } + die_nest_count++; + die_owner = cpu; + console_verbose(); + bust_spinlocks(1); + if (machine_is(powermac)) + pmac_backlight_unblank(); + return flags; +} +static void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, + int signr) +{ bust_spinlocks(0); - die.lock_owner = -1; + die_owner = -1; add_taint(TAINT_DIE); + die_nest_count--; oops_exit(); printk("\n"); - raw_spin_unlock_irqrestore(&die.lock, flags); + if (!die_nest_count) + /* Nest count reaches zero, release the lock. */ + arch_spin_unlock(&die_lock); + raw_local_irq_restore(flags); /* * A system reset (0x100) is a request to dump, so we always send @@ -177,6 +160,9 @@ int die(const char *str, struct pt_regs *regs, long err) crash_kexec_secondary(regs); } + if (!signr) + return; + /* * While our oops output is serialised by a spinlock, output * from panic() called below can race and corrupt it. If we @@ -190,15 +176,46 @@ int die(const char *str, struct pt_regs *regs, long err) if (in_interrupt()) panic("Fatal exception in interrupt"); - if (panic_on_oops) panic("Fatal exception"); + do_exit(signr); +} - do_exit(err); +static int __kprobes __die(const char *str, struct pt_regs *regs, long err) +{ + printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter); +#ifdef CONFIG_PREEMPT + printk("PREEMPT "); +#endif +#ifdef CONFIG_SMP + printk("SMP NR_CPUS=%d ", NR_CPUS); +#endif +#ifdef CONFIG_DEBUG_PAGEALLOC + printk("DEBUG_PAGEALLOC "); +#endif +#ifdef CONFIG_NUMA + printk("NUMA "); +#endif + printk("%s\n", ppc_md.name ? ppc_md.name : ""); + + if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP) + return 1; + + print_modules(); + show_regs(regs); return 0; } +void die(const char *str, struct pt_regs *regs, long err) +{ + unsigned long flags = oops_begin(regs); + + if (__die(str, regs, err)) + err = 0; + oops_end(flags, regs, err); +} + void user_single_step_siginfo(struct task_struct *tsk, struct pt_regs *regs, siginfo_t *info) { @@ -217,10 +234,11 @@ void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr) "at %016lx nip %016lx lr %016lx code %x\n"; if (!user_mode(regs)) { - if (die("Exception in kernel mode", regs, signr)) - return; - } else if (show_unhandled_signals && - unhandled_signal(current, signr)) { + die("Exception in kernel mode", regs, signr); + return; + } + + 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); |