diff options
Diffstat (limited to 'arch/x86_64/kernel/traps.c')
| -rw-r--r-- | arch/x86_64/kernel/traps.c | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c index 2700b1375c1..cea335e8746 100644 --- a/arch/x86_64/kernel/traps.c +++ b/arch/x86_64/kernel/traps.c @@ -102,6 +102,8 @@ static inline void preempt_conditional_cli(struct pt_regs *regs) { if (regs->eflags & X86_EFLAGS_IF) local_irq_disable(); + /* Make sure to not schedule here because we could be running + on an exception stack. */ preempt_enable_no_resched(); } @@ -385,6 +387,7 @@ void out_of_line_bug(void) static DEFINE_SPINLOCK(die_lock); static int die_owner = -1; +static unsigned int die_nest_count; unsigned __kprobes long oops_begin(void) { @@ -399,6 +402,7 @@ unsigned __kprobes long oops_begin(void) else spin_lock(&die_lock); } + die_nest_count++; die_owner = cpu; console_verbose(); bust_spinlocks(1); @@ -409,7 +413,13 @@ void __kprobes oops_end(unsigned long flags) { die_owner = -1; bust_spinlocks(0); - spin_unlock_irqrestore(&die_lock, flags); + die_nest_count--; + if (die_nest_count) + /* We still own the lock */ + local_irq_restore(flags); + else + /* Nest count reaches zero, release the lock. */ + spin_unlock_irqrestore(&die_lock, flags); if (panic_on_oops) panic("Oops"); } @@ -464,6 +474,8 @@ void __kprobes die_nmi(char *str, struct pt_regs *regs) panic("nmi watchdog"); printk("console shuts up ...\n"); oops_end(flags); + nmi_exit(); + local_irq_enable(); do_exit(SIGSEGV); } @@ -473,8 +485,6 @@ static void __kprobes do_trap(int trapnr, int signr, char *str, { struct task_struct *tsk = current; - conditional_sti(regs); - tsk->thread.error_code = error_code; tsk->thread.trap_no = trapnr; @@ -511,6 +521,7 @@ asmlinkage void do_##name(struct pt_regs * regs, long error_code) \ if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ == NOTIFY_STOP) \ return; \ + conditional_sti(regs); \ do_trap(trapnr, signr, str, regs, error_code, NULL); \ } @@ -525,6 +536,7 @@ asmlinkage void do_##name(struct pt_regs * regs, long error_code) \ if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ == NOTIFY_STOP) \ return; \ + conditional_sti(regs); \ do_trap(trapnr, signr, str, regs, error_code, &info); \ } @@ -538,7 +550,17 @@ DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS) DO_ERROR(11, SIGBUS, "segment not present", segment_not_present) DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0) DO_ERROR(18, SIGSEGV, "reserved", reserved) -DO_ERROR(12, SIGBUS, "stack segment", stack_segment) + +/* Runs on IST stack */ +asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code) +{ + if (notify_die(DIE_TRAP, "stack segment", regs, error_code, + 12, SIGBUS) == NOTIFY_STOP) + return; + preempt_conditional_sti(regs); + do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL); + preempt_conditional_cli(regs); +} asmlinkage void do_double_fault(struct pt_regs * regs, long error_code) { @@ -672,8 +694,9 @@ asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code) if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) { return; } + preempt_conditional_sti(regs); do_trap(3, SIGTRAP, "int3", regs, error_code, NULL); - return; + preempt_conditional_cli(regs); } /* Help handler running on IST stack to switch back to user stack |