[PATCH v2 1/5] exec: Only compute current once in flush_old_exec

From: Eric W. Biederman
Date: Sun Mar 08 2020 - 17:37:47 EST



Make it clear that current only needs to be computed once in
flush_old_exec. This may have some efficiency improvements and it
makes the code easier to change.

Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
fs/exec.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index db17be51b112..c3f34791f2f0 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1260,13 +1260,14 @@ void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec)
*/
int flush_old_exec(struct linux_binprm * bprm)
{
+ struct task_struct *me = current;
int retval;

/*
* Make sure we have a private signal table and that
* we are unassociated from the previous thread group.
*/
- retval = de_thread(current);
+ retval = de_thread(me);
if (retval)
goto out;

@@ -1294,10 +1295,10 @@ int flush_old_exec(struct linux_binprm * bprm)
bprm->mm = NULL;

set_fs(USER_DS);
- current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
+ me->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
PF_NOFREEZE | PF_NO_SETAFFINITY);
flush_thread();
- current->personality &= ~bprm->per_clear;
+ me->personality &= ~bprm->per_clear;

/*
* We have to apply CLOEXEC before we change whether the process is
@@ -1305,7 +1306,7 @@ int flush_old_exec(struct linux_binprm * bprm)
* trying to access the should-be-closed file descriptors of a process
* undergoing exec(2).
*/
- do_close_on_exec(current->files);
+ do_close_on_exec(me->files);
return 0;

out:
--
2.25.0