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-rw-r--r--include/linux/sem.h1
-rw-r--r--ipc/sem.c37
2 files changed, 31 insertions, 7 deletions
diff --git a/include/linux/sem.h b/include/linux/sem.h
index 55e17f6..976ce3a 100644
--- a/include/linux/sem.h
+++ b/include/linux/sem.h
@@ -12,7 +12,6 @@ struct task_struct;
struct sem_array {
struct kern_ipc_perm ____cacheline_aligned_in_smp
sem_perm; /* permissions .. see ipc.h */
- time_t sem_otime; /* last semop time */
time_t sem_ctime; /* last change time */
struct sem *sem_base; /* ptr to first semaphore in array */
struct list_head pending_alter; /* pending operations */
diff --git a/ipc/sem.c b/ipc/sem.c
index 6291257..51352e1 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -99,6 +99,7 @@ struct sem {
/* that alter the semaphore */
struct list_head pending_const; /* pending single-sop operations */
/* that do not alter the semaphore*/
+ time_t sem_otime; /* candidate for sem_otime */
} ____cacheline_aligned_in_smp;
/* One queue for each sleeping process in the system. */
@@ -911,8 +912,14 @@ static void do_smart_update(struct sem_array *sma, struct sembuf *sops, int nsop
}
}
}
- if (otime)
- sma->sem_otime = get_seconds();
+ if (otime) {
+ if (sops == NULL) {
+ sma->sem_base[0].sem_otime = get_seconds();
+ } else {
+ sma->sem_base[sops[0].sem_num].sem_otime =
+ get_seconds();
+ }
+ }
}
@@ -1058,6 +1065,21 @@ static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in,
}
}
+static time_t get_semotime(struct sem_array *sma)
+{
+ int i;
+ time_t res;
+
+ res = sma->sem_base[0].sem_otime;
+ for (i = 1; i < sma->sem_nsems; i++) {
+ time_t to = sma->sem_base[i].sem_otime;
+
+ if (to > res)
+ res = to;
+ }
+ return res;
+}
+
static int semctl_nolock(struct ipc_namespace *ns, int semid,
int cmd, int version, void __user *p)
{
@@ -1131,9 +1153,9 @@ static int semctl_nolock(struct ipc_namespace *ns, int semid,
goto out_unlock;
kernel_to_ipc64_perm(&sma->sem_perm, &tbuf.sem_perm);
- tbuf.sem_otime = sma->sem_otime;
- tbuf.sem_ctime = sma->sem_ctime;
- tbuf.sem_nsems = sma->sem_nsems;
+ tbuf.sem_otime = get_semotime(sma);
+ tbuf.sem_ctime = sma->sem_ctime;
+ tbuf.sem_nsems = sma->sem_nsems;
rcu_read_unlock();
if (copy_semid_to_user(p, &tbuf, version))
return -EFAULT;
@@ -2025,6 +2047,9 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it)
{
struct user_namespace *user_ns = seq_user_ns(s);
struct sem_array *sma = it;
+ time_t sem_otime;
+
+ sem_otime = get_semotime(sma);
return seq_printf(s,
"%10d %10d %4o %10u %5u %5u %5u %5u %10lu %10lu\n",
@@ -2036,7 +2061,7 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it)
from_kgid_munged(user_ns, sma->sem_perm.gid),
from_kuid_munged(user_ns, sma->sem_perm.cuid),
from_kgid_munged(user_ns, sma->sem_perm.cgid),
- sma->sem_otime,
+ sem_otime,
sma->sem_ctime);
}
#endif
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