diff options
Diffstat (limited to 'arch/x86/kernel/traps.c')
| -rw-r--r-- | arch/x86/kernel/traps.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index cc5ba33fcbca..1277562e913b 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -310,12 +310,19 @@ __visible void __noreturn handle_stack_overflow(const char *message, * from the TSS. Returning is, in principle, okay, but changes to regs will * be lost. If, for some reason, we need to return to a context with modified * regs, the shim code could be adjusted to synchronize the registers. + * + * The 32bit #DF shim provides CR2 already as an argument. On 64bit it needs + * to be read before doing anything else. */ -dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsigned long cr2) +DEFINE_IDTENTRY_DF(exc_double_fault) { static const char str[] = "double fault"; struct task_struct *tsk = current; +#ifdef CONFIG_X86_64 + unsigned long address = read_cr2(); +#endif + #ifdef CONFIG_X86_ESPFIX64 extern unsigned char native_irq_return_iret[]; @@ -372,6 +379,7 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsign #endif nmi_enter(); + instr_begin(); notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV); tsk->thread.error_code = error_code; @@ -415,13 +423,16 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsign * stack even if the actual trigger for the double fault was * something else. */ - if ((unsigned long)task_stack_page(tsk) - 1 - cr2 < PAGE_SIZE) - handle_stack_overflow("kernel stack overflow (double-fault)", regs, cr2); + if ((unsigned long)task_stack_page(tsk) - 1 - address < PAGE_SIZE) { + handle_stack_overflow("kernel stack overflow (double-fault)", + regs, address); + } #endif pr_emerg("PANIC: double fault, error_code: 0x%lx\n", error_code); die("double fault", regs, error_code); panic("Machine halted."); + instr_end(); } #endif |