diff options
authorDavid Howells <dhowells@redhat.com>2013-03-13 14:59:47 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-03-13 15:21:49 -0700
commitca044f9a9ed492f0f7e52df999c10ca6f7cfc5c0 (patch)
parent29ba06b9ed51d49dea6c79c3c16b961d661262bd (diff)
UAPI: fix endianness conditionals in linux/raid/md_p.h
In the UAPI header files, __BIG_ENDIAN and __LITTLE_ENDIAN must be compared against __BYTE_ORDER in preprocessor conditionals where these are exposed to userspace (that is they're not inside __KERNEL__ conditionals). However, in the main kernel the norm is to check for "defined(__XXX_ENDIAN)" rather than comparing against __BYTE_ORDER and this has incorrectly leaked into the userspace headers. The definition of struct mdp_superblock_s in linux/raid/md_p.h is wrong in this way. Note that userspace will likely interpret the ordering of the fields incorrectly as the big-endian variant on a little-endian machines - depending on header inclusion order. [!!!] NOTE [!!!] This patch may adversely change the userspace API. It might be better to fix the ordering of events_hi, events_lo, cp_events_hi and cp_events_lo in struct mdp_superblock_s / typedef mdp_super_t. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: NeilBrown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 4 insertions, 2 deletions
diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h
index ee753536ab70..fe1a5406d4d9 100644
--- a/include/uapi/linux/raid/md_p.h
+++ b/include/uapi/linux/raid/md_p.h
@@ -145,16 +145,18 @@ typedef struct mdp_superblock_s {
__u32 failed_disks; /* 4 Number of failed disks */
__u32 spare_disks; /* 5 Number of spare disks */
__u32 sb_csum; /* 6 checksum of the whole superblock */
-#ifdef __BIG_ENDIAN
+#if defined(__BYTE_ORDER) ? __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN)
__u32 events_hi; /* 7 high-order of superblock update count */
__u32 events_lo; /* 8 low-order of superblock update count */
__u32 cp_events_hi; /* 9 high-order of checkpoint update count */
__u32 cp_events_lo; /* 10 low-order of checkpoint update count */
+#elif defined(__BYTE_ORDER) ? __BYTE_ORDER == __LITTLE_ENDIAN : defined(__LITTLE_ENDIAN)
__u32 events_lo; /* 7 low-order of superblock update count */
__u32 events_hi; /* 8 high-order of superblock update count */
__u32 cp_events_lo; /* 9 low-order of checkpoint update count */
__u32 cp_events_hi; /* 10 high-order of checkpoint update count */
+#error unspecified endianness
__u32 recovery_cp; /* 11 recovery checkpoint sector count */
/* There are only valid for minor_version > 90 */

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