diff --git a/fs/exec.c b/fs/exec.c
index 81b85f70e9f3d42abfb69e291ddab03d5c8018c5..c238c258afce31ab9a00c14dbb79e697925e7455 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -966,8 +966,8 @@ EXPORT_SYMBOL(read_code);
/*
* Maps the mm_struct mm into the current task struct.
- * On success, this function returns with the mutex
- * exec_update_mutex locked.
+ * On success, this function returns with exec_update_lock
+ * held for writing.
*/
static int exec_mmap(struct mm_struct *mm)
{
@@ -982,7 +982,7 @@ static int exec_mmap(struct mm_struct *mm)
if (old_mm)
sync_mm_rss(old_mm);
- ret = mutex_lock_killable(&tsk->signal->exec_update_mutex);
+ ret = down_write_killable(&tsk->signal->exec_update_lock);
if (ret)
return ret;
@@ -996,7 +996,7 @@ static int exec_mmap(struct mm_struct *mm)
mmap_read_lock(old_mm);
if (unlikely(old_mm->core_state)) {
mmap_read_unlock(old_mm);
- mutex_unlock(&tsk->signal->exec_update_mutex);
+ up_write(&tsk->signal->exec_update_lock);
return -EINTR;
}
}
@@ -1395,7 +1395,7 @@ int begin_new_exec(struct linux_binprm * bprm)
return 0;
out_unlock:
- mutex_unlock(&me->signal->exec_update_mutex);
+ up_write(&me->signal->exec_update_lock);
out:
return retval;
}
@@ -1436,7 +1436,7 @@ void setup_new_exec(struct linux_binprm * bprm)
* some architectures like powerpc
*/
me->mm->task_size = TASK_SIZE;
- mutex_unlock(&me->signal->exec_update_mutex);
+ up_write(&me->signal->exec_update_lock);
mutex_unlock(&me->signal->cred_guard_mutex);
}
EXPORT_SYMBOL(setup_new_exec);
diff --git a/fs/proc/base.c b/fs/proc/base.c
index b362523a9829ace0f2df2a93a2bd2e8e47a7bdd5..55ce0ee9c5c7342d97ca7a0ac38c3fafd93ef7e9 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -405,11 +405,11 @@ print0:
static int lock_trace(struct task_struct *task)
{
- int err = mutex_lock_killable(&task->signal->exec_update_mutex);
+ int err = down_read_killable(&task->signal->exec_update_lock);
if (err)
return err;
if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
- mutex_unlock(&task->signal->exec_update_mutex);
+ up_read(&task->signal->exec_update_lock);
return -EPERM;
}
return 0;
@@ -417,7 +417,7 @@ static int lock_trace(struct task_struct *task)
static void unlock_trace(struct task_struct *task)
{
- mutex_unlock(&task->signal->exec_update_mutex);
+ up_read(&task->signal->exec_update_lock);
}
#ifdef CONFIG_STACKTRACE
@@ -2930,7 +2930,7 @@ static int do_io_accounting(struct task_struct *task, struct seq_file *m, int wh
unsigned long flags;
int result;
- result = mutex_lock_killable(&task->signal->exec_update_mutex);
+ result = down_read_killable(&task->signal->exec_update_lock);
if (result)
return result;
@@ -2966,7 +2966,7 @@ static int do_io_accounting(struct task_struct *task, struct seq_file *m, int wh
result = 0;
out_unlock:
- mutex_unlock(&task->signal->exec_update_mutex);
+ up_read(&task->signal->exec_update_lock);
return result;
}
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index bd5afa076189748e97564e5e3f02e74e5cb211f6..4e116cd2e5a2395ca91499c2c464fb9d6c5d1626 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -228,12 +228,13 @@ struct signal_struct {
* credential calculations
* (notably. ptrace)
* Deprecated do not use in new code.
- * Use exec_update_mutex instead.
- */
- struct mutex exec_update_mutex; /* Held while task_struct is being
- * updated during exec, and may have
- * inconsistent permissions.
+ * Use exec_update_lock instead.
*/
+ struct rw_semaphore exec_update_lock; /* Held while task_struct is
+ * being updated during exec,
+ * and may have inconsistent
+ * permissions.
+ */
} __randomize_layout;
/*
diff --git a/init/init_task.c b/init/init_task.c
index a56f0abb63e934e3d3de3f9cabf7dd2d9cc760f0..15f6eb93a04fa2f01989c5f5316206e2d00da8d7 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -26,7 +26,7 @@ static struct signal_struct init_signals = {
.multiprocess = HLIST_HEAD_INIT,
.rlim = INIT_RLIMITS,
.cred_guard_mutex = __MUTEX_INITIALIZER(init_signals.cred_guard_mutex),
- .exec_update_mutex = __MUTEX_INITIALIZER(init_signals.exec_update_mutex),
+ .exec_update_lock = __RWSEM_INITIALIZER(init_signals.exec_update_lock),
#ifdef CONFIG_POSIX_TIMERS
.posix_timers = LIST_HEAD_INIT(init_signals.posix_timers),
.cputimer = {
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 19ae6c931c5249b761763dfc53a763a413c0b2a3..55d18791a72de38b77ae29440cf5b0a57b8db37d 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1327,7 +1327,7 @@ static void put_ctx(struct perf_event_context *ctx)
* function.
*
* Lock order:
- * exec_update_mutex
+ * exec_update_lock
* task_struct::perf_event_mutex
* perf_event_context::mutex
* perf_event::child_mutex;
@@ -11959,14 +11959,14 @@ SYSCALL_DEFINE5(perf_event_open,
}
if (task) {
- err = mutex_lock_interruptible(&task->signal->exec_update_mutex);
+ err = down_read_interruptible(&task->signal->exec_update_lock);
if (err)
goto err_file;
/*
* Preserve ptrace permission check for backwards compatibility.
*
- * We must hold exec_update_mutex across this and any potential
+ * We must hold exec_update_lock across this and any potential
* perf_install_in_context() call for this new event to
* serialize against exec() altering our credentials (and the
* perf_event_exit_task() that could imply).
@@ -12129,7 +12129,7 @@ SYSCALL_DEFINE5(perf_event_open,
mutex_unlock(&ctx->mutex);
if (task) {
- mutex_unlock(&task->signal->exec_update_mutex);
+ up_read(&task->signal->exec_update_lock);
put_task_struct(task);
}
@@ -12153,7 +12153,7 @@ err_locked:
mutex_unlock(&ctx->mutex);
err_cred:
if (task)
- mutex_unlock(&task->signal->exec_update_mutex);
+ up_read(&task->signal->exec_update_lock);
err_file:
fput(event_file);
err_context:
@@ -12470,7 +12470,7 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
/*
* When a child task exits, feed back event values to parent events.
*
- * Can be called with exec_update_mutex held when called from
+ * Can be called with exec_update_lock held when called from
* setup_new_exec().
*/
void perf_event_exit_task(struct task_struct *child)
diff --git a/kernel/fork.c b/kernel/fork.c
index 4f44d87b82ef4859178baadaafd846ac749f0ab6..41906a52a7646346167d4979f6b1eaeb6b49a580 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1225,7 +1225,7 @@ struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
struct mm_struct *mm;
int err;
- err = mutex_lock_killable(&task->signal->exec_update_mutex);
+ err = down_read_killable(&task->signal->exec_update_lock);
if (err)
return ERR_PTR(err);
@@ -1235,7 +1235,7 @@ struct mm_struct *mm_access(struct task_struct *task, unsigned int mode)
mmput(mm);
mm = ERR_PTR(-EACCES);
}
- mutex_unlock(&task->signal->exec_update_mutex);
+ up_read(&task->signal->exec_update_lock);
return mm;
}
@@ -1595,7 +1595,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
sig->oom_score_adj_min = current->signal->oom_score_adj_min;
mutex_init(&sig->cred_guard_mutex);
- mutex_init(&sig->exec_update_mutex);
+ init_rwsem(&sig->exec_update_lock);
return 0;
}
diff --git a/kernel/kcmp.c b/kernel/kcmp.c
index 36e58eb5a11dd8c995fa1f6cb85c01d5708f91ca..5353edfad8e11a646a9654d9868dd18e31cb630a 100644
--- a/kernel/kcmp.c
+++ b/kernel/kcmp.c
@@ -70,25 +70,25 @@ get_file_raw_ptr(struct task_struct *task, unsigned int idx)
return file;
}
-static void kcmp_unlock(struct mutex *m1, struct mutex *m2)
+static void kcmp_unlock(struct rw_semaphore *l1, struct rw_semaphore *l2)
{
- if (likely(m2 != m1))
- mutex_unlock(m2);
- mutex_unlock(m1);
+ if (likely(l2 != l1))
+ up_read(l2);
+ up_read(l1);
}
-static int kcmp_lock(struct mutex *m1, struct mutex *m2)
+static int kcmp_lock(struct rw_semaphore *l1, struct rw_semaphore *l2)
{
int err;
- if (m2 > m1)
- swap(m1, m2);
+ if (l2 > l1)
+ swap(l1, l2);
- err = mutex_lock_killable(m1);
- if (!err && likely(m1 != m2)) {
- err = mutex_lock_killable_nested(m2, SINGLE_DEPTH_NESTING);
+ err = down_read_killable(l1);
+ if (!err && likely(l1 != l2)) {
+ err = down_read_killable_nested(l2, SINGLE_DEPTH_NESTING);
if (err)
- mutex_unlock(m1);
+ up_read(l1);
}
return err;
@@ -156,8 +156,8 @@ SYSCALL_DEFINE5(kcmp, pid_t, pid1, pid_t, pid2, int, type,
/*
* One should have enough rights to inspect task details.
*/
- ret = kcmp_lock(&task1->signal->exec_update_mutex,
- &task2->signal->exec_update_mutex);
+ ret = kcmp_lock(&task1->signal->exec_update_lock,
+ &task2->signal->exec_update_lock);
if (ret)
goto err;
if (!ptrace_may_access(task1, PTRACE_MODE_READ_REALCREDS) ||
@@ -212,8 +212,8 @@ SYSCALL_DEFINE5(kcmp, pid_t, pid1, pid_t, pid2, int, type,
}
err_unlock:
- kcmp_unlock(&task1->signal->exec_update_mutex,
- &task2->signal->exec_update_mutex);
+ kcmp_unlock(&task1->signal->exec_update_lock,
+ &task2->signal->exec_update_lock);
err:
put_task_struct(task1);
put_task_struct(task2);
diff --git a/kernel/pid.c b/kernel/pid.c
index 47466d0bbc5b13eef0d5da50193e6f1dc78a3705..ebdf9c60cd0b586b7e6d9f06028bf31bfd9571ab 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -628,7 +628,7 @@ static struct file *__pidfd_fget(struct task_struct *task, int fd)
struct file *file;
int ret;
- ret = mutex_lock_killable(&task->signal->exec_update_mutex);
+ ret = down_read_killable(&task->signal->exec_update_lock);
if (ret)
return ERR_PTR(ret);
@@ -637,7 +637,7 @@ static struct file *__pidfd_fget(struct task_struct *task, int fd)
else
file = ERR_PTR(-EPERM);
- mutex_unlock(&task->signal->exec_update_mutex);
+ up_read(&task->signal->exec_update_lock);
return file ?: ERR_PTR(-EBADF);
}