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Diffstat (limited to 'kernel/sys.c')
-rw-r--r--kernel/sys.c108
1 files changed, 71 insertions, 37 deletions
diff --git a/kernel/sys.c b/kernel/sys.c
index f006632c2ba..5a9d6b07501 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -525,7 +525,7 @@ asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
}
if (new_egid != old_egid)
{
- current->mm->dumpable = 0;
+ current->mm->dumpable = suid_dumpable;
smp_wmb();
}
if (rgid != (gid_t) -1 ||
@@ -556,7 +556,7 @@ asmlinkage long sys_setgid(gid_t gid)
{
if(old_egid != gid)
{
- current->mm->dumpable=0;
+ current->mm->dumpable = suid_dumpable;
smp_wmb();
}
current->gid = current->egid = current->sgid = current->fsgid = gid;
@@ -565,7 +565,7 @@ asmlinkage long sys_setgid(gid_t gid)
{
if(old_egid != gid)
{
- current->mm->dumpable=0;
+ current->mm->dumpable = suid_dumpable;
smp_wmb();
}
current->egid = current->fsgid = gid;
@@ -596,7 +596,7 @@ static int set_user(uid_t new_ruid, int dumpclear)
if(dumpclear)
{
- current->mm->dumpable = 0;
+ current->mm->dumpable = suid_dumpable;
smp_wmb();
}
current->uid = new_ruid;
@@ -653,7 +653,7 @@ asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
if (new_euid != old_euid)
{
- current->mm->dumpable=0;
+ current->mm->dumpable = suid_dumpable;
smp_wmb();
}
current->fsuid = current->euid = new_euid;
@@ -703,7 +703,7 @@ asmlinkage long sys_setuid(uid_t uid)
if (old_euid != uid)
{
- current->mm->dumpable = 0;
+ current->mm->dumpable = suid_dumpable;
smp_wmb();
}
current->fsuid = current->euid = uid;
@@ -748,7 +748,7 @@ asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
if (euid != (uid_t) -1) {
if (euid != current->euid)
{
- current->mm->dumpable = 0;
+ current->mm->dumpable = suid_dumpable;
smp_wmb();
}
current->euid = euid;
@@ -798,7 +798,7 @@ asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
if (egid != (gid_t) -1) {
if (egid != current->egid)
{
- current->mm->dumpable = 0;
+ current->mm->dumpable = suid_dumpable;
smp_wmb();
}
current->egid = egid;
@@ -845,7 +845,7 @@ asmlinkage long sys_setfsuid(uid_t uid)
{
if (uid != old_fsuid)
{
- current->mm->dumpable = 0;
+ current->mm->dumpable = suid_dumpable;
smp_wmb();
}
current->fsuid = uid;
@@ -875,7 +875,7 @@ asmlinkage long sys_setfsgid(gid_t gid)
{
if (gid != old_fsgid)
{
- current->mm->dumpable = 0;
+ current->mm->dumpable = suid_dumpable;
smp_wmb();
}
current->fsgid = gid;
@@ -894,35 +894,69 @@ asmlinkage long sys_times(struct tms __user * tbuf)
*/
if (tbuf) {
struct tms tmp;
- struct task_struct *tsk = current;
- struct task_struct *t;
cputime_t utime, stime, cutime, cstime;
- read_lock(&tasklist_lock);
- utime = tsk->signal->utime;
- stime = tsk->signal->stime;
- t = tsk;
- do {
- utime = cputime_add(utime, t->utime);
- stime = cputime_add(stime, t->stime);
- t = next_thread(t);
- } while (t != tsk);
-
- /*
- * While we have tasklist_lock read-locked, no dying thread
- * can be updating current->signal->[us]time. Instead,
- * we got their counts included in the live thread loop.
- * However, another thread can come in right now and
- * do a wait call that updates current->signal->c[us]time.
- * To make sure we always see that pair updated atomically,
- * we take the siglock around fetching them.
- */
- spin_lock_irq(&tsk->sighand->siglock);
- cutime = tsk->signal->cutime;
- cstime = tsk->signal->cstime;
- spin_unlock_irq(&tsk->sighand->siglock);
- read_unlock(&tasklist_lock);
+#ifdef CONFIG_SMP
+ if (thread_group_empty(current)) {
+ /*
+ * Single thread case without the use of any locks.
+ *
+ * We may race with release_task if two threads are
+ * executing. However, release task first adds up the
+ * counters (__exit_signal) before removing the task
+ * from the process tasklist (__unhash_process).
+ * __exit_signal also acquires and releases the
+ * siglock which results in the proper memory ordering
+ * so that the list modifications are always visible
+ * after the counters have been updated.
+ *
+ * If the counters have been updated by the second thread
+ * but the thread has not yet been removed from the list
+ * then the other branch will be executing which will
+ * block on tasklist_lock until the exit handling of the
+ * other task is finished.
+ *
+ * This also implies that the sighand->siglock cannot
+ * be held by another processor. So we can also
+ * skip acquiring that lock.
+ */
+ utime = cputime_add(current->signal->utime, current->utime);
+ stime = cputime_add(current->signal->utime, current->stime);
+ cutime = current->signal->cutime;
+ cstime = current->signal->cstime;
+ } else
+#endif
+ {
+
+ /* Process with multiple threads */
+ struct task_struct *tsk = current;
+ struct task_struct *t;
+ read_lock(&tasklist_lock);
+ utime = tsk->signal->utime;
+ stime = tsk->signal->stime;
+ t = tsk;
+ do {
+ utime = cputime_add(utime, t->utime);
+ stime = cputime_add(stime, t->stime);
+ t = next_thread(t);
+ } while (t != tsk);
+
+ /*
+ * While we have tasklist_lock read-locked, no dying thread
+ * can be updating current->signal->[us]time. Instead,
+ * we got their counts included in the live thread loop.
+ * However, another thread can come in right now and
+ * do a wait call that updates current->signal->c[us]time.
+ * To make sure we always see that pair updated atomically,
+ * we take the siglock around fetching them.
+ */
+ spin_lock_irq(&tsk->sighand->siglock);
+ cutime = tsk->signal->cutime;
+ cstime = tsk->signal->cstime;
+ spin_unlock_irq(&tsk->sighand->siglock);
+ read_unlock(&tasklist_lock);
+ }
tmp.tms_utime = cputime_to_clock_t(utime);
tmp.tms_stime = cputime_to_clock_t(stime);
tmp.tms_cutime = cputime_to_clock_t(cutime);
@@ -1652,7 +1686,7 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
error = 1;
break;
case PR_SET_DUMPABLE:
- if (arg2 != 0 && arg2 != 1) {
+ if (arg2 < 0 || arg2 > 2) {
error = -EINVAL;
break;
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-02-02 10:51:25 +0000