diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-02-26 01:33:31 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 16:15:03 +0300 |
| commit | c29c775a554f7060b6fb31b68f88a3c9087cf1c5 (patch) | |
| tree | b8f5e689c0ac8e8a4acb86c518e29fa45c1947a6 /arch/x86/kernel/traps.c | |
| parent | 6a8dfa8e4053adfcf02ee4d96287943064166beb (diff) | |
| download | linux-c29c775a554f7060b6fb31b68f88a3c9087cf1c5.tar.xz | |
x86/entry: Convert double fault exception to IDTENTRY_DF
Convert #DF to IDTENTRY_DF
- Implement the C entry point with DEFINE_IDTENTRY_DF
- Emit the ASM stub with DECLARE_IDTENTRY_DF on 64bit
- Remove the ASM idtentry in 64bit
- Adjust the 32bit shim code
- Fixup the XEN/PV code
- Remove the old prototypes
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200505135315.583415264@linutronix.de
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 41bb0cb9df84..35298c1df32f 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -319,12 +319,19 @@ __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[]; @@ -381,6 +388,7 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsign #endif nmi_enter(); + instrumentation_begin(); notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV); tsk->thread.error_code = error_code; @@ -424,13 +432,16 @@ 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."); + instrumentation_end(); } DEFINE_IDTENTRY(exc_bounds) |