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authorAndy Lutomirski <luto@kernel.org>2016-08-30 17:27:57 -0700
committerIngo Molnar <mingo@kernel.org>2016-09-08 08:47:20 +0200
commit6271cfdfc0e4731b76921ef02fdd87409d71dfdf (patch)
treeb1af2c82308a83478a5407406b17bad499c3a222 /arch/x86/include/asm/traps.h
parent2b3061c77ce7e429b25a25560ba088e8e7193a67 (diff)
downloadlinux-0-day-6271cfdfc0e4731b76921ef02fdd87409d71dfdf.tar.gz
linux-0-day-6271cfdfc0e4731b76921ef02fdd87409d71dfdf.tar.xz
x86/mm: Improve stack-overflow #PF handling
If we get a page fault indicating kernel stack overflow, invoke handle_stack_overflow(). To prevent us from overflowing the stack again while handling the overflow (because we are likely to have very little stack space left), call handle_stack_overflow() on the double-fault stack. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/6d6cf96b3fb9b4c9aa303817e1dc4de0c7c36487.1472603235.git.luto@kernel.org [ Minor edit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/traps.h')
-rw-r--r--arch/x86/include/asm/traps.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index c3496619740aa..01fd0a7f48cd2 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -117,6 +117,12 @@ extern void ist_exit(struct pt_regs *regs);
extern void ist_begin_non_atomic(struct pt_regs *regs);
extern void ist_end_non_atomic(void);
+#ifdef CONFIG_VMAP_STACK
+void __noreturn handle_stack_overflow(const char *message,
+ struct pt_regs *regs,
+ unsigned long fault_address);
+#endif
+
/* Interrupts/Exceptions */
enum {
X86_TRAP_DE = 0, /* 0, Divide-by-zero */