Commit e2ae8ab4 authored Jul 12, 2017 by Kees Cook Committed by Linus Torvalds Jul 12, 2017

kexec_file: adjust declaration of kexec_purgatory

Defining kexec_purgatory as a zero-length char array upsets compile time
size checking.  Since this is built on a per-arch basis, define it as an
unsized char array (like is done for other similar things, e.g.  linker
sections).  This silences the warning generated by the future
CONFIG_FORTIFY_SOURCE, which did not like the memcmp() of a "0 byte"
array.  This drops the __weak and uses an extern instead, since both
users define kexec_purgatory.

Link: http://lkml.kernel.org/r/1497903987-21002-4-git-send-email-keescook@chromium.org


Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 3e2c044a

kernel/kexec_file.c

+0 −7

Original line number	Diff line number	Diff line
		@@ -26,13 +26,6 @@
		#include <linux/vmalloc.h>
		#include "kexec_internal.h"

		/*
		* Declare these symbols weak so that if architecture provides a purgatory,
		* these will be overridden.
		*/
		char __weak kexec_purgatory[0];
		size_t __weak kexec_purgatory_size = 0;

		static int kexec_calculate_store_digests(struct kimage *image);

		/* Architectures can provide this probe function */

kernel/kexec_internal.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -17,6 +17,8 @@ extern struct mutex kexec_mutex;
		#ifdef CONFIG_KEXEC_FILE
		#include <linux/purgatory.h>
		void kimage_file_post_load_cleanup(struct kimage *image);
		extern char kexec_purgatory[];
		extern size_t kexec_purgatory_size;
		#else /* CONFIG_KEXEC_FILE */
		static inline void kimage_file_post_load_cleanup(struct kimage *image) { }
		#endif /* CONFIG_KEXEC_FILE */

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