This moves the compat_sys_semtimedop function to ipc/sem.c so it
can be shared with 32-bit architectures efficiently. Instead of
copying the timespec back to user space, we take a shortcut and
pass the jiffies value to the low-level implementation directly.
The native sys_semtimedop() function is modified to take a
__kernel_timespec structure, which will be based on a 64-bit
time_t in the future.
There is a small API change here: if multiple errors are present,
and the timespec argument is invalid (bad pointer or bad tv_nsec),
we now return that error before checking any of the other
error conditions. If that is a problem, we need a more sophisticated
approach.
Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
include/linux/syscalls.h | 2 +-
ipc/compat.c | 10 --------
ipc/sem.c | 60 ++++++++++++++++++++++++++++++++++--------------
ipc/syscall.c | 7 ++++++
4 files changed, 51 insertions(+), 28 deletions(-)
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index f3fdc312627b..c2a70a8f907d 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -665,7 +665,7 @@ asmlinkage long sys_semop(int semid, struct sembuf __user
*sops,
asmlinkage long sys_semctl(int semid, int semnum, int cmd, unsigned long arg);
asmlinkage long sys_semtimedop(int semid, struct sembuf __user *sops,
unsigned nsops,
- const struct timespec __user *timeout);
+ const struct __kernel_timespec __user *timeout);
asmlinkage long sys_shmat(int shmid, char __user *shmaddr, int shmflg);
asmlinkage long sys_shmget(key_t key, size_t size, int flag);
asmlinkage long sys_shmdt(char __user *shmaddr);
diff --git a/ipc/compat.c b/ipc/compat.c
index 9b3c85f8a538..2bbdb093d1be 100644
--- a/ipc/compat.c
+++ b/ipc/compat.c
@@ -745,13 +745,3 @@ COMPAT_SYSCALL_DEFINE3(shmctl, int, first, int, second,
void __user *, uptr)
}
return err;
}
-
-COMPAT_SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsems,
- unsigned, nsops,
- const struct compat_timespec __user *, timeout)
-{
- struct timespec __user *ts64;
- if (compat_convert_timespec(&ts64, timeout))
- return -EFAULT;
- return sys_semtimedop(semid, tsems, nsops, ts64);
-}
diff --git a/ipc/sem.c b/ipc/sem.c
index d1a6edd17eba..a6ff6754651c 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -72,6 +72,7 @@
* The worst-case behavior is nevertheless O(N^2) for N wakeups.
*/
+#include <linux/compat.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/init.h>
@@ -1779,8 +1780,9 @@ static int get_queue_result(struct sem_queue *q)
return error;
}
-SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
- unsigned, nsops, const struct timespec __user *, timeout)
+static long semtimedop(int semid, struct sembuf __user * tsops,
+ unsigned nsops, unsigned long jiffies_left,
+ bool timeout)
{
int error = -EINVAL;
struct sem_array *sma;
@@ -1789,7 +1791,6 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf
__user *, tsops,
struct sem_undo *un;
int undos = 0, alter = 0, max, locknum;
struct sem_queue queue;
- unsigned long jiffies_left = 0;
struct ipc_namespace *ns;
struct list_head tasks;
@@ -1808,19 +1809,6 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf
__user *, tsops,
error = -EFAULT;
goto out_free;
}
- if (timeout) {
- struct timespec _timeout;
- if (copy_from_user(&_timeout, timeout, sizeof(*timeout))) {
- error = -EFAULT;
- goto out_free;
- }
- if (_timeout.tv_sec < 0 || _timeout.tv_nsec < 0 ||
- _timeout.tv_nsec >= 1000000000L) {
- error = -EINVAL;
- goto out_free;
- }
- jiffies_left = timespec_to_jiffies(&_timeout);
- }
max = 0;
for (sop = sops; sop < sops + nsops; sop++) {
if (sop->sem_num >= max)
@@ -2014,10 +2002,48 @@ out_free:
return error;
}
+SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
+ unsigned, nsops,
+ const struct __kernel_timespec __user *, timeout)
+{
+ unsigned long jiffies_left = 0;
+
+ if (timeout) {
+ struct timespec64 _timeout;
+ if (get_timespec64(&_timeout, timeout))
+ return -EFAULT;
+ if (_timeout.tv_sec < 0 || _timeout.tv_nsec < 0 ||
+ _timeout.tv_nsec >= 1000000000L)
+ return -EINVAL;
+ jiffies_left = nsecs_to_jiffies(timespec64_to_ns(&_timeout));
+ }
+ return semtimedop(semid, tsops, nsops, jiffies_left, timeout);
+}
+
+#ifdef CONFIG_COMPAT_TIME
+COMPAT_SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
+ unsigned, nsops,
+ const struct compat_timespec __user *, timeout)
+{
+ unsigned long jiffies_left = 0;
+
+ if (timeout) {
+ struct timespec64 _timeout;
+ if (compat_get_timespec64(&_timeout, timeout))
+ return -EFAULT;
+ if (_timeout.tv_sec < 0 || _timeout.tv_nsec < 0 ||
+ _timeout.tv_nsec >= 1000000000L)
+ return -EINVAL;
+ jiffies_left = nsecs_to_jiffies(timespec64_to_ns(&_timeout));
+ }
+ return semtimedop(semid, tsops, nsops, jiffies_left, timeout);
+}
+#endif
+
SYSCALL_DEFINE3(semop, int, semid, struct sembuf __user *, tsops,
unsigned, nsops)
{
- return sys_semtimedop(semid, tsops, nsops, NULL);
+ return semtimedop(semid, tsops, nsops, 0, 0);
}
/* If CLONE_SYSVSEM is set, establish sharing of SEM_UNDO state between
diff --git a/ipc/syscall.c b/ipc/syscall.c
index 52429489cde0..d7b17355d870 100644
--- a/ipc/syscall.c
+++ b/ipc/syscall.c
@@ -7,6 +7,7 @@
#include <linux/unistd.h>
#ifdef __ARCH_WANT_SYS_IPC
+#include <linux/compat_time.h>
#include <linux/errno.h>
#include <linux/ipc.h>
#include <linux/shm.h>
@@ -26,9 +27,15 @@ SYSCALL_DEFINE6(ipc, unsigned int, call, int, first,
unsigned long, second,
return sys_semtimedop(first, (struct sembuf __user *)ptr,
second, NULL);
case SEMTIMEDOP:
+#if defined(CONFIG_ARCH_HAS_COMPAT_TIME) && !defined(CONFIG_64BIT)
+ return compat_sys_semtimedop(first, (struct sembuf __user *)ptr,
+ second,
+ (const struct compat_timespec
__user *)fifth);
+#else
return sys_semtimedop(first, (struct sembuf __user *)ptr,
second,
(const struct timespec __user *)fifth);
+#endif
case SEMGET:
return sys_semget(first, second, third);
--
2.1.0.rc2
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