diff options
Diffstat (limited to 'arch/x86/mm/extable.c')
| -rw-r--r-- | arch/x86/mm/extable.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index fd9eb98c4f58..aaeda3ffaafe 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -125,6 +125,20 @@ void __init early_fixup_exception(struct pt_regs *regs, int trapnr) if (regs->cs != __KERNEL_CS) goto fail; + /* + * The full exception fixup machinery is available as soon as + * the early IDT is loaded. This means that it is the + * responsibility of extable users to either function correctly + * when handlers are invoked early or to simply avoid causing + * exceptions before they're ready to handle them. + * + * This is better than filtering which handlers can be used, + * because refusing to call a handler here is guaranteed to + * result in a hard-to-debug panic. + * + * Keep in mind that not all vectors actually get here. Early + * fage faults, for example, are special. + */ if (fixup_exception(regs, trapnr)) return; |