[PATCH 3/3] exec: Rename the flag called_exec_mmap point_of_no_return

Eric W. Biederman
2020-04-07T01:35:14Z

Update the comments and make the code easier to understand by
renaming this flag.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
fs/exec.c | 12 ++++++------
include/linux/binfmts.h | 6 +++---
2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index 28c87020da9b..a61987d6dc33 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1300,12 +1300,12 @@ int flush_old_exec(struct linux_binprm * bprm)
goto out;

/*
- * After setting bprm->called_exec_mmap (to mark that current is
- * using the prepared mm now), we have nothing left of the original
- * process. If anything from here on returns an error, the check
- * in search_binary_handler() will SEGV current.
+ * With the new mm installed it is completely impossible to
+ * fail and return to the original process. If anything from
+ * here on returns an error, the check in
+ * search_binary_handler() will SEGV current.
*/
- bprm->called_exec_mmap = 1;
+ bprm->point_of_no_return = true;
bprm->mm = NULL;

#ifdef CONFIG_POSIX_TIMERS
@@ -1694,7 +1694,7 @@ int search_binary_handler(struct linux_binprm *bprm)

read_lock(&binfmt_lock);
put_binfmt(fmt);
- if (retval < 0 && bprm->called_exec_mmap) {
+ if (retval < 0 && bprm->point_of_no_return) {
/* we got to flush_old_exec() and failed after it */
read_unlock(&binfmt_lock);
force_sigsegv(SIGSEGV);
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index 6f564b9ad882..8f479dad7931 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -46,10 +46,10 @@ struct linux_binprm {
*/
secureexec:1,
/*
- * Set by flush_old_exec, when exec_mmap has been called.
- * This is past the point of no return.
+ * Set when errors can no longer be returned to the
+ * original userspace.
*/
- called_exec_mmap:1;
+ point_of_no_return:1;
#ifdef __alpha__
unsigned int taso:1;
#endif
--
2.25.0