diff options
Diffstat (limited to 'arch/x86/kernel/traps_64.c')
| -rw-r--r-- | arch/x86/kernel/traps_64.c | 65 |
1 files changed, 42 insertions, 23 deletions
diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c index 71c2629997b..22fe62a24ed 100644 --- a/arch/x86/kernel/traps_64.c +++ b/arch/x86/kernel/traps_64.c @@ -7,10 +7,8 @@ */ /* - * 'Traps.c' handles hardware traps and faults after we have saved some - * state in 'entry.S'. + * Handle hardware traps and faults. */ -#include <linux/moduleparam.h> #include <linux/interrupt.h> #include <linux/kallsyms.h> #include <linux/spinlock.h> @@ -41,18 +39,21 @@ #include <asm/stacktrace.h> #include <asm/processor.h> +#include <asm/kmemcheck.h> #include <asm/debugreg.h> #include <asm/atomic.h> #include <asm/system.h> #include <asm/unwind.h> +#include <asm/traps.h> #include <asm/desc.h> #include <asm/i387.h> + +#include <mach_traps.h> + #include <asm/pgalloc.h> #include <asm/proto.h> #include <asm/pda.h> -#include <asm/traps.h> -#include <mach_traps.h> static int ignore_nmis; @@ -73,8 +74,6 @@ static inline void preempt_conditional_cli(struct pt_regs *regs) { if (regs->flags & X86_EFLAGS_IF) local_irq_disable(); - /* Make sure to not schedule here because we could be running - on an exception stack. */ dec_preempt_count(); } @@ -228,9 +227,12 @@ gp_in_kernel: static notrace __kprobes void mem_parity_error(unsigned char reason, struct pt_regs *regs) { - printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n", - reason); - printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n"); + printk(KERN_EMERG + "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", + reason, smp_processor_id()); + + printk(KERN_EMERG + "You have some hardware problem, likely on the PCI bus.\n"); #if defined(CONFIG_EDAC) if (edac_handler_set()) { @@ -275,19 +277,18 @@ unknown_nmi_error(unsigned char reason, struct pt_regs *regs) if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP) return; - printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n", - reason); - printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n"); + printk(KERN_EMERG + "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", + reason, smp_processor_id()); + printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n"); if (panic_on_unrecovered_nmi) panic("NMI: Not continuing"); printk(KERN_EMERG "Dazed and confused, but trying to continue\n"); } -/* Runs on IST stack. This code must keep interrupts off all the time. - Nested NMIs are prevented by the CPU. */ -asmlinkage notrace __kprobes void default_do_nmi(struct pt_regs *regs) +static notrace __kprobes void default_do_nmi(struct pt_regs *regs) { unsigned char reason = 0; int cpu; @@ -348,7 +349,7 @@ void restart_nmi(void) acpi_nmi_enable(); } -/* runs on IST stack. */ +/* May run on IST stack. */ dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code) { if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) @@ -381,7 +382,30 @@ asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) return regs; } -/* runs on IST stack. */ +/* + * Our handling of the processor debug registers is non-trivial. + * We do not clear them on entry and exit from the kernel. Therefore + * it is possible to get a watchpoint trap here from inside the kernel. + * However, the code in ./ptrace.c has ensured that the user can + * only set watchpoints on userspace addresses. Therefore the in-kernel + * watchpoint trap can only occur in code which is reading/writing + * from user space. Such code must not hold kernel locks (since it + * can equally take a page fault), therefore it is safe to call + * force_sig_info even though that claims and releases locks. + * + * Code in ./signal.c ensures that the debug control register + * is restored before we deliver any signal, and therefore that + * user code runs with the correct debug control register even though + * we clear it here. + * + * Being careful here means that we don't have to be as careful in a + * lot of more complicated places (task switching can be a bit lazy + * about restoring all the debug state, and ptrace doesn't have to + * find every occurrence of the TF bit that could be saved away even + * by user code) + * + * May run on IST stack. + */ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) { struct task_struct *tsk = current; @@ -525,11 +549,6 @@ dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code) math_error((void __user *)regs->ip); } -asmlinkage void bad_intr(void) -{ - printk("bad interrupt"); -} - static void simd_math_error(void __user *ip) { struct task_struct *task; |