[PATCH] add semtimedop call to kernel 2.4.19

Mark Fasheh (mfasheh@linux.ucla.edu)
Mon, 4 Nov 2002 11:26:55 -0800


Hello,
Included is a patch against 2.4.19 to allow semaphore operations
with timeouts. The new call functions exactly like semtimedop in Solaris.
Userspace code to use/test this new syscall can be found at:
http://www.exothermic.org/linux/semtimedop.tar.gz
Feedback is greatly appreciated :)
--Mark

If merged, this patch can be attributed to mark.fasheh@oracle.com

diff -urNp linux-2.4.19-orig/arch/i386/kernel/sys_i386.c linux-2.4.19/arch/i386/kernel/sys_i386.c
--- linux-2.4.19-orig/arch/i386/kernel/sys_i386.c 2001-03-19 12:35:09.000000000 -0800
+++ linux-2.4.19/arch/i386/kernel/sys_i386.c 2002-10-30 18:12:15.000000000 -0800
@@ -139,7 +139,11 @@ asmlinkage int sys_ipc (uint call, int f

switch (call) {
case SEMOP:
- return sys_semop (first, (struct sembuf *)ptr, second);
+ return sys_semtimedop (first, (struct sembuf *)ptr, second,
+ NULL);
+ case SEMTIMEDOP:
+ return sys_semtimedop (first, (struct sembuf *)ptr, second,
+ (const struct timespec *)fifth);
case SEMGET:
return sys_semget (first, second, third);
case SEMCTL: {
diff -urNp linux-2.4.19-orig/arch/ia64/ia32/sys_ia32.c linux-2.4.19/arch/ia64/ia32/sys_ia32.c
--- linux-2.4.19-orig/arch/ia64/ia32/sys_ia32.c 2002-08-02 17:39:42.000000000 -0700
+++ linux-2.4.19/arch/ia64/ia32/sys_ia32.c 2002-10-31 13:42:26.000000000 -0800
@@ -2125,6 +2125,7 @@ struct ipc_kludge {
#define SEMOP 1
#define SEMGET 2
#define SEMCTL 3
+#define SEMTIMEDOP 4
#define MSGSND 11
#define MSGRCV 12
#define MSGGET 13
@@ -2552,6 +2553,18 @@ shmctl32 (int first, int second, void *u
return err;
}

+static long
+semtimedop32(int semid, struct sembuf *tsems, int nsems,
+ const struct timespec32 *timeout32)
+{
+ struct timespec t;
+ if (get_user (t.tv_sec, &timeout32->tv_sec) ||
+ get_user (t.tv_nsec, &timeout32->tv_nsec))
+ return -EFAULT;
+
+ return sys_semtimedop(semid, tsems, nsems, &t);
+}
+
asmlinkage long
sys32_ipc (u32 call, int first, int second, int third, u32 ptr, u32 fifth)
{
@@ -2563,7 +2576,10 @@ sys32_ipc (u32 call, int first, int seco
switch (call) {
case SEMOP:
/* struct sembuf is the same on 32 and 64bit :)) */
- return sys_semop(first, (struct sembuf *)AA(ptr), second);
+ return sys_semtimedop(first, (struct sembuf *)AA(ptr), second, NULL);
+ case SEMTIMEDOP:
+ return semtimedop32(first, (struct sembuf *)AA(ptr), second,
+ (const struct timespec32 *)AA(fifth));
case SEMGET:
return sys_semget(first, second, third);
case SEMCTL:
diff -urNp linux-2.4.19-orig/arch/ia64/kernel/entry.S linux-2.4.19/arch/ia64/kernel/entry.S
--- linux-2.4.19-orig/arch/ia64/kernel/entry.S 2002-08-02 17:39:42.000000000 -0700
+++ linux-2.4.19/arch/ia64/kernel/entry.S 2002-10-31 13:44:48.000000000 -0800
@@ -1133,7 +1133,7 @@ sys_call_table:
data8 sys_getdents64
data8 sys_getunwind // 1215
data8 sys_readahead
- data8 ia64_ni_syscall
+ data8 sys_semtimedop
data8 ia64_ni_syscall
data8 ia64_ni_syscall
data8 ia64_ni_syscall // 1220
diff -urNp linux-2.4.19-orig/include/asm-i386/ipc.h linux-2.4.19/include/asm-i386/ipc.h
--- linux-2.4.19-orig/include/asm-i386/ipc.h 1998-12-31 12:05:12.000000000 -0800
+++ linux-2.4.19/include/asm-i386/ipc.h 2002-10-30 18:08:21.000000000 -0800
@@ -14,6 +14,7 @@ struct ipc_kludge {
#define SEMOP 1
#define SEMGET 2
#define SEMCTL 3
+#define SEMTIMEDOP 4
#define MSGSND 11
#define MSGRCV 12
#define MSGGET 13
diff -urNp linux-2.4.19-orig/include/asm-ia64/unistd.h linux-2.4.19/include/asm-ia64/unistd.h
--- linux-2.4.19-orig/include/asm-ia64/unistd.h 2002-08-02 17:39:45.000000000 -0700
+++ linux-2.4.19/include/asm-ia64/unistd.h 2002-10-31 13:54:21.000000000 -0800
@@ -206,6 +206,7 @@
#define __NR_getdents64 1214
#define __NR_getunwind 1215
#define __NR_readahead 1216
+#define __NR_semtimedop 1217
#define __NR_tkill 1229

#if !defined(__ASSEMBLY__) && !defined(ASSEMBLER)
diff -urNp linux-2.4.19-orig/include/linux/sem.h linux-2.4.19/include/linux/sem.h
--- linux-2.4.19-orig/include/linux/sem.h 2001-11-22 11:46:18.000000000 -0800
+++ linux-2.4.19/include/linux/sem.h 2002-10-30 18:07:33.000000000 -0800
@@ -124,6 +124,8 @@ struct sem_undo {
asmlinkage long sys_semget (key_t key, int nsems, int semflg);
asmlinkage long sys_semop (int semid, struct sembuf *sops, unsigned nsops);
asmlinkage long sys_semctl (int semid, int semnum, int cmd, union semun arg);
+asmlinkage long sys_semtimedop (int semid, struct sembuf *sops,
+ unsigned nsops, const struct timespec *timeout);

#endif /* __KERNEL__ */

diff -urNp linux-2.4.19-orig/ipc/sem.c linux-2.4.19/ipc/sem.c
--- linux-2.4.19-orig/ipc/sem.c 2002-08-02 17:39:46.000000000 -0700
+++ linux-2.4.19/ipc/sem.c 2002-10-31 13:35:07.000000000 -0800
@@ -62,6 +62,7 @@
#include <linux/spinlock.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
+#include <linux/time.h>
#include <asm/uaccess.h>
#include "util.h"

@@ -839,6 +840,12 @@ static int alloc_undo(struct sem_array *

asmlinkage long sys_semop (int semid, struct sembuf *tsops, unsigned nsops)
{
+ return sys_semtimedop(semid, tsops, nsops, NULL);
+}
+
+asmlinkage long sys_semtimedop (int semid, struct sembuf *tsops,
+ unsigned nsops, const struct timespec *timeout)
+{
int error = -EINVAL;
struct sem_array *sma;
struct sembuf fast_sops[SEMOPM_FAST];
@@ -846,6 +853,7 @@ asmlinkage long sys_semop (int semid, st
struct sem_undo *un;
int undos = 0, decrease = 0, alter = 0;
struct sem_queue queue;
+ unsigned long jiffies = MAX_SCHEDULE_TIMEOUT;

if (nsops < 1 || semid < 0)
return -EINVAL;
@@ -860,6 +868,19 @@ asmlinkage long sys_semop (int semid, st
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 = timespec_to_jiffies(&_timeout);
+ }
sma = sem_lock(semid);
error=-EINVAL;
if(sma==NULL)
@@ -932,7 +953,7 @@ asmlinkage long sys_semop (int semid, st
current->state = TASK_INTERRUPTIBLE;
sem_unlock(semid);

- schedule();
+ jiffies = schedule_timeout(jiffies);

tmp = sem_lock(semid);
if(tmp==NULL) {
@@ -943,7 +964,7 @@ asmlinkage long sys_semop (int semid, st
goto out_free;
}
/*
- * If queue.status == 1 we where woken up and
+ * If queue.status == 1 we were woken up and
* have to retry else we simply return.
* If an interrupt occurred we have to clean up the
* queue
@@ -957,6 +978,8 @@ asmlinkage long sys_semop (int semid, st
break;
} else {
error = queue.status;
+ if (error == -EINTR && jiffies == 0)
+ error = -EAGAIN;
if (queue.prev) /* got Interrupt */
break;
/* Everything done by update_queue */
diff -urNp linux-2.4.19-orig/ipc/util.c linux-2.4.19/ipc/util.c
--- linux-2.4.19-orig/ipc/util.c 2001-08-12 17:37:53.000000000 -0700
+++ linux-2.4.19/ipc/util.c 2002-10-31 13:37:21.000000000 -0800
@@ -355,6 +355,12 @@ asmlinkage long sys_semop (int semid, st
return -ENOSYS;
}

+asmlinkage long sys_semtimedop (int semid, struct sembuf *sops, unsigned nsops,
+ const struct timespec *timeout)
+{
+ return -ENOSYS;
+}
+
asmlinkage long sys_semctl (int semid, int semnum, int cmd, union semun arg)
{
return -ENOSYS;
-
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