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>
This commit is contained in:
Kees Cook 2017-07-12 14:35:58 -07:00 committed by Linus Torvalds
parent 3e2c044a54
commit e2ae8ab4b5
2 changed files with 2 additions and 7 deletions

View File

@ -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 */

View File

@ -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 */