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authorThomas Gleixner <tglx@linutronix.de>2019-11-06 22:55:38 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-11-29 10:10:10 +0100
commit7d7e93588fe2843e7bac3b258a8ad91049b2c4b5 (patch)
tree9a4adadb23873e11f3c776c0c0660b2a70a30b49
parent52507cfaffe900c4d23931e9863bd54b4b980d65 (diff)
exit/exec: Seperate mm_release()
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>
-rw-r--r--fs/exec.c2
-rw-r--r--include/linux/sched/mm.h6
-rw-r--r--kernel/exit.c2
-rw-r--r--kernel/fork.c12
4 files changed, 17 insertions, 5 deletions
diff --git a/fs/exec.c b/fs/exec.c
index 555e93c7dec8..c27231234764 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1015,7 +1015,7 @@ 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/mm.h b/include/linux/sched/mm.h
index e6770012db18..c49257a3b510 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -117,8 +117,10 @@ 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_MEMCG
extern void mm_update_next_owner(struct mm_struct *mm);
diff --git a/kernel/exit.c b/kernel/exit.c
index d11bdcaac2e1..cd893b530902 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -437,7 +437,7 @@ static void exit_mm(void)
struct mm_struct *mm = current->mm;
struct core_state *core_state;
- mm_release(current, mm);
+ exit_mm_release(current, mm);
if (!mm)
return;
sync_mm_rss(mm);
diff --git a/kernel/fork.c b/kernel/fork.c
index 93750abf3917..04b86e66e8dd 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1283,7 +1283,7 @@ 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);
@@ -1320,6 +1320,16 @@ 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);
+}
+
/**
* dup_mm() - duplicates an existing mm structure
* @tsk: the task_struct with which the new mm will be associated.