diff mbox series

[04/12] exit/exec: Seperate mm_release()

Message ID 20210201151214.2193508-5-lee.jones@linaro.org
State New
Headers show
Series Futex back-port from v4.9 | expand

Commit Message

Lee Jones Feb. 1, 2021, 3:12 p.m. UTC 
From: Thomas Gleixner <tglx@linutronix.de>


commit 4610ba7ad877fafc0a25a30c6c82015304120426 upstream.

mm_release() contains the futex exit handling. mm_release() is called from
do_exit()->exit_mm() and from exec()->exec_mm().

In the exit_mm() case PF_EXITING and the futex state is updated. In the
exec_mm() case these states are not touched.

As the futex exit code needs further protections against exit races, this
needs to be split into two functions.

Preparatory only, no functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Reviewed-by: Ingo Molnar <mingo@kernel.org>

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

Link: https://lkml.kernel.org/r/20191106224556.240518241@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Lee Jones <lee.jones@linaro.org>

---
 fs/exec.c             |  2 +-
 include/linux/sched.h |  6 ++++--
 kernel/exit.c         |  2 +-
 kernel/fork.c         | 12 +++++++++++-
 4 files changed, 17 insertions(+), 5 deletions(-)

-- 
2.25.1
diff mbox series

Patch

diff --git a/fs/exec.c b/fs/exec.c
index 46cc0c072246d..ce111af5784be 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -875,7 +875,7 @@  static int exec_mmap(struct mm_struct *mm)
 	/* Notify parent that we're no longer interested in the old VM */
 	tsk = current;
 	old_mm = current->mm;
-	mm_release(tsk, old_mm);
+	exec_mm_release(tsk, old_mm);
 
 	if (old_mm) {
 		sync_mm_rss(old_mm);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index bdd41a0127d10..aba34bba5e9e3 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2647,8 +2647,10 @@  extern struct mm_struct *get_task_mm(struct task_struct *task);
  * succeeds.
  */
 extern struct mm_struct *mm_access(struct task_struct *task, unsigned int mode);
-/* Remove the current tasks stale references to the old mm_struct */
-extern void mm_release(struct task_struct *, struct mm_struct *);
+/* Remove the current tasks stale references to the old mm_struct on exit() */
+extern void exit_mm_release(struct task_struct *, struct mm_struct *);
+/* Remove the current tasks stale references to the old mm_struct on exec() */
+extern void exec_mm_release(struct task_struct *, struct mm_struct *);
 
 #ifdef CONFIG_HAVE_COPY_THREAD_TLS
 extern int copy_thread_tls(unsigned long, unsigned long, unsigned long,
diff --git a/kernel/exit.c b/kernel/exit.c
index 274a3c3834a15..a098d76a9877e 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -389,7 +389,7 @@  static void exit_mm(struct task_struct *tsk)
 	struct mm_struct *mm = tsk->mm;
 	struct core_state *core_state;
 
-	mm_release(tsk, mm);
+	exit_mm_release(tsk, mm);
 	if (!mm)
 		return;
 	sync_mm_rss(mm);
diff --git a/kernel/fork.c b/kernel/fork.c
index d0ab6aff5efdc..43a50072dd5b4 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -887,7 +887,7 @@  static int wait_for_vfork_done(struct task_struct *child,
  * restoring the old one. . .
  * Eric Biederman 10 January 1998
  */
-void mm_release(struct task_struct *tsk, struct mm_struct *mm)
+static void mm_release(struct task_struct *tsk, struct mm_struct *mm)
 {
 	/* Get rid of any futexes when releasing the mm */
 	futex_mm_release(tsk);
@@ -924,6 +924,16 @@  void mm_release(struct task_struct *tsk, struct mm_struct *mm)
 		complete_vfork_done(tsk);
 }
 
+void exit_mm_release(struct task_struct *tsk, struct mm_struct *mm)
+{
+	mm_release(tsk, mm);
+}
+
+void exec_mm_release(struct task_struct *tsk, struct mm_struct *mm)
+{
+	mm_release(tsk, mm);
+}
+
 /*
  * Allocate a new mm structure and copy contents from the
  * mm structure of the passed in task structure.