[PATCHv6 28/36] posix-clocks: Add align for timens_offsets
From: Dmitry Safonov <hidden>
Date: 2019-08-15 16:40:05
Also in:
lkml
Subsystem:
the rest · Maintainer:
Linus Torvalds
Align offsets so that time namespace will work for ia32 applications on x86_64 host. Co-developed-by: Andrei Vagin <redacted> Signed-off-by: Andrei Vagin <redacted> Signed-off-by: Dmitry Safonov <redacted> --- include/linux/timens_offsets.h | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/include/linux/timens_offsets.h b/include/linux/timens_offsets.h
index e93aabaa5e45..05da1b0563ce 100644
--- a/include/linux/timens_offsets.h
+++ b/include/linux/timens_offsets.h@@ -2,9 +2,17 @@ #ifndef _LINUX_TIME_OFFSETS_H #define _LINUX_TIME_OFFSETS_H +/* + * Time offsets need align as they're placed on VVAR page, + * which is used by x86_64 and ia32 VDSO code. + * On ia32 offset::tv_sec (u64) has align(4), so re-align offsets + * to the same positions as 64-bit offsets. + * On 64-bit big-endian systems VDSO should convert to timespec64 + * to timespec because of a padding occurring between the fields. + */ struct timens_offsets { - struct timespec64 monotonic; - struct timespec64 boottime; + struct timespec64 monotonic __aligned(8); + struct timespec64 boottime __aligned(8); }; #endif
--
2.22.0