futex: Split futex_mm_release() for exit/exec

BugLink: https://bugs.launchpad.net/bugs/1855787
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: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/include/linux/futex.h b/include/linux/futex.h
index 35703ec3a2556e7e4e4e942e435749a8ead758ab..fb698e25f210a7f729d277d0e975ab8e375ee653 100644 (file)
--- a/include/linux/futex.h
+++ b/include/linux/futex.h
@@ -96,14 +96,16 @@ 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) { }
 #endif
 
 #endif

diff --git a/kernel/fork.c b/kernel/fork.c
index 0f72642eb75adc722649051fa17a4b73a6c79201..ea0c6e9104568bd1e49acef9a34a9a276569a063 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1168,9 +1168,6 @@ 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 */
@@ -1205,11 +1202,13 @@ 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 10c75096d601c1dbb78d2e951c9856523b7bcffe..d84d317f6e1fca2db14a6f73ed43dcf5e9077c2f 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -3684,7 +3684,7 @@ 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);
@@ -3702,6 +3702,11 @@ 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)
 {