Commit aa5d1b81 authored Jul 24, 2017 by Kees Cook Committed by Ingo Molnar Jul 25, 2017

x86/asm: Add ASM_UNREACHABLE

This creates an unreachable annotation in asm for CONFIG_STACK_VALIDATION=y.
While here, adjust earlier uses of \t\n into \n\t.

Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Elena Reshetova <elena.reshetova@intel.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Hans Liljestrand <ishkamiel@gmail.com>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: Jann Horn <jannh@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Serge E. Hallyn <serge@hallyn.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arozansk@redhat.com
Cc: axboe@kernel.dk
Cc: kernel-hardening@lists.openwall.com
Cc: linux-arch <linux-arch@vger.kernel.org>
Link: http://lkml.kernel.org/r/1500921349-10803-3-git-send-email-keescook@chromium.org

Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent df340524

include/linux/compiler-gcc.h

+9 −4

Original line number	Diff line number	Diff line
		@@ -203,11 +203,16 @@

		#ifdef CONFIG_STACK_VALIDATION
		#define annotate_unreachable() ({ \
		asm("%c0:\t\n" \
		".pushsection .discard.unreachable\t\n" \
		".long %c0b - .\t\n" \
		".popsection\t\n" : : "i" (__LINE__)); \
		asm("%c0:\n\t" \
		".pushsection .discard.unreachable\n\t" \
		".long %c0b - .\n\t" \
		".popsection\n\t" : : "i" (__LINE__)); \
		})
		#define ASM_UNREACHABLE \
		"999:\n\t" \
		".pushsection .discard.unreachable\n\t" \
		".long 999b - .\n\t" \
		".popsection\n\t"
		#else
		#define annotate_unreachable()
		#endif

include/linux/compiler.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -185,6 +185,9 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
		#endif

		/* Unreachable code */
		#ifndef ASM_UNREACHABLE
		# define ASM_UNREACHABLE
		#endif
		#ifndef unreachable
		# define unreachable() do { } while (1)
		#endif

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