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Diffstat (limited to 'ipc')
-rw-r--r--ipc/sem.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/ipc/sem.c b/ipc/sem.c
index cddd5b5fde51..b3757ea0694b 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -92,7 +92,14 @@
/* One semaphore structure for each semaphore in the system. */
struct sem {
int semval; /* current value */
- int sempid; /* pid of last operation */
+ /*
+ * PID of the process that last modified the semaphore. For
+ * Linux, specifically these are:
+ * - semop
+ * - semctl, via SETVAL and SETALL.
+ * - at task exit when performing undo adjustments (see exit_sem).
+ */
+ int sempid;
spinlock_t lock; /* spinlock for fine-grained semtimedop */
struct list_head pending_alter; /* pending single-sop operations */
/* that alter the semaphore */
@@ -1444,8 +1451,10 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
goto out_unlock;
}
- for (i = 0; i < nsems; i++)
+ for (i = 0; i < nsems; i++) {
sma->sem_base[i].semval = sem_io[i];
+ sma->sem_base[i].sempid = task_tgid_vnr(current);
+ }
ipc_assert_locked_object(&sma->sem_perm);
list_for_each_entry(un, &sma->list_id, list_id) {