futex: Split futex_mm_release() for exit/exec

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>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>

diff --git a/include/linux/futex.h b/include/linux/futex.h
index 025ad96bcf9d4ab48efea8d69e1a3d0e4671a74e..6414cfaf88e0c25676e4b0b968e66edb52298155 100644 (file)
--- a/include/linux/futex.h
+++ b/include/linux/futex.h
@@ -93,14 +93,16 @@ static inline void futex_exit_done(struct task_struct *tsk)
        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) { }
 static inline long do_futex(u32 __user *uaddr, int op, u32 val,
                            ktime_t *timeout, u32 __user *uaddr2,
                            u32 val2, u32 val3)

diff --git a/kernel/fork.c b/kernel/fork.c
index 3ab3d52118541aeb705ff8e7adcdb391322daf84..7125d768b3ea52dc8c98c42396dd5009255be4b8 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1291,9 +1291,6 @@ static int wait_for_vfork_done(struct task_struct *child,
  */
 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 */
@@ -1328,11 +1325,13 @@ static void mm_release(struct task_struct *tsk, struct mm_struct *mm)
 
 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);
 }
 

diff --git a/kernel/futex.c b/kernel/futex.c
index df824306c227cf8aab5717d5754ae7719fe02924..f29606305ab985916d562862bc1b1774b1aa5b4d 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -3661,7 +3661,7 @@ static void exit_robust_list(struct task_struct *curr)
        }
 }
 
-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);
@@ -3679,6 +3679,11 @@ void futex_mm_release(struct task_struct *tsk)
                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)
 {