[PATCH 4.14 190/209] futex: Split futex_mm_release() for exit/exec

Greg Kroah-Hartman
2019-12-04T18:09:43Z

From: Thomas Gleixner <tglx@linutronix.de>

commit 150d71584b12809144b8145b817e83b81158ae5f upstream.

To allow separate handling of the futex exit state in the futex exit code
for exit and exec, split futex_mm_release() into two functions and invoke
them from the corresponding exit/exec_mm_release() callsites.

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/20191106224556.332094221@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
include/linux/futex.h | 6 ++++--
kernel/fork.c | 5 ++---
kernel/futex.c | 7 ++++++-
3 files changed, 12 insertions(+), 6 deletions(-)

--- a/include/linux/futex.h
+++ b/include/linux/futex.h
@@ -96,14 +96,16 @@ static inline void futex_exit_done(struc
tsk->futex_state = FUTEX_STATE_DEAD;
}

-void futex_mm_release(struct task_struct *tsk);
+void futex_exit_release(struct task_struct *tsk);
+void futex_exec_release(struct task_struct *tsk);

long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
u32 __user *uaddr2, u32 val2, u32 val3);
#else
static inline void futex_init_task(struct task_struct *tsk) { }
-static inline void futex_mm_release(struct task_struct *tsk) { }
static inline void futex_exit_done(struct task_struct *tsk) { }
+static inline void futex_exit_release(struct task_struct *tsk) { }
+static inline void futex_exec_release(struct task_struct *tsk) { }
#endif

#endif
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1134,9 +1134,6 @@ static int wait_for_vfork_done(struct ta
*/
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);
-
uprobe_free_utask(tsk);

/* Get rid of any cached register state */
@@ -1171,11 +1168,13 @@ static void mm_release(struct task_struc

void exit_mm_release(struct task_struct *tsk, struct mm_struct *mm)
{
+ futex_exit_release(tsk);
mm_release(tsk, mm);
}

void exec_mm_release(struct task_struct *tsk, struct mm_struct *mm)
{
+ futex_exec_release(tsk);
mm_release(tsk, mm);
}

--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -3684,7 +3684,7 @@ static void exit_robust_list(struct task
}
}

-void futex_mm_release(struct task_struct *tsk)
+void futex_exec_release(struct task_struct *tsk)
{
if (unlikely(tsk->robust_list)) {
exit_robust_list(tsk);
@@ -3702,6 +3702,11 @@ void futex_mm_release(struct task_struct
exit_pi_state_list(tsk);
}

+void futex_exit_release(struct task_struct *tsk)
+{
+ futex_exec_release(tsk);
+}
+
long do_futex(u32 __user *uaddr, int op, u32 val, ktime_t *timeout,
u32 __user *uaddr2, u32 val2, u32 val3)
{