path: root/ipc/compat.c
diff options
authorH. Peter Anvin <>2014-02-01 18:54:11 -0800
committerH. Peter Anvin <>2014-02-02 14:09:12 -0800
commit81993e81a994504f4c8b97d3410c9a052cdbcc9d (patch)
tree7471cde617f11dad2f29187daa764e1d119a9731 /ipc/compat.c
parent5cb480f6b488128140c940abff3c36f524a334a8 (diff)
compat: Get rid of (get|put)_compat_time(val|spec)
We have two APIs for compatiblity timespec/val, with confusingly similar names. compat_(get|put)_time(val|spec) *do* handle the case where COMPAT_USE_64BIT_TIME is set, whereas (get|put)_compat_time(val|spec) do not. This is an accident waiting to happen. Clean it up by favoring the full-service version; the limited version is replaced with double-underscore versions static to kernel/compat.c. A common pattern is to convert a struct timespec to kernel format in an allocation on the user stack. Unfortunately it is open-coded in several places. Since this allocation isn't actually needed if COMPAT_USE_64BIT_TIME is true (since user format == kernel format) encapsulate that whole pattern into the function compat_convert_timespec(). An equivalent function should be written for struct timeval if it is needed in the future. Finally, get rid of compat_(get|put)_timeval_convert(): each was only used once, and the latter was not even doing what the function said (no conversion actually was being done.) Moving the conversion into compat_sys_settimeofday() itself makes the code much more similar to sys_settimeofday() itself. v3: Remove unused compat_convert_timeval(). v2: Drop bogus "const" in the destination argument for compat_convert_time*(). Cc: Mauro Carvalho Chehab <> Cc: Alexander Viro <> Cc: Hans Verkuil <> Cc: Andrew Morton <> Cc: Heiko Carstens <> Cc: Manfred Spraul <> Cc: Mateusz Guzik <> Cc: Rafael Aquini <> Cc: Davidlohr Bueso <> Cc: Stephen Rothwell <> Cc: Dan Carpenter <> Cc: Arnd Bergmann <> Cc: Thomas Gleixner <> Cc: Ingo Molnar <> Cc: Linus Torvalds <> Cc: Catalin Marinas <> Cc: Will Deacon <> Tested-by: H.J. Lu <> Signed-off-by: H. Peter Anvin <>
Diffstat (limited to 'ipc/compat.c')
1 files changed, 3 insertions, 9 deletions
diff --git a/ipc/compat.c b/ipc/compat.c
index f486b0096a67..1048522479e5 100644
--- a/ipc/compat.c
+++ b/ipc/compat.c
@@ -752,14 +752,8 @@ long compat_sys_shmctl(int first, int second, void __user *uptr)
long compat_sys_semtimedop(int semid, struct sembuf __user *tsems,
unsigned nsops, const struct compat_timespec __user *timeout)
- struct timespec __user *ts64 = NULL;
- if (timeout) {
- struct timespec ts;
- ts64 = compat_alloc_user_space(sizeof(*ts64));
- if (get_compat_timespec(&ts, timeout))
- return -EFAULT;
- if (copy_to_user(ts64, &ts, sizeof(ts)))
- return -EFAULT;
- }
+ struct timespec __user *ts64;
+ if (compat_convert_timespec(&ts64, timeout))
+ return -EFAULT;
return sys_semtimedop(semid, tsems, nsops, ts64);