summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2010-02-02 12:37:44 -0800
committerGreg Kroah-Hartman <gregkh@suse.de>2010-04-01 15:55:57 -0700
commit8646c7696b11177ca210f71c24a57872589ee871 (patch)
tree248e22eb59219a578c19295275346fd52749b689
parent38616b6b68bb1f964f86e09548bef944147eaad0 (diff)
downloadlwn-8646c7696b11177ca210f71c24a57872589ee871.tar.gz
lwn-8646c7696b11177ca210f71c24a57872589ee871.zip
Fix 'flush_old_exec()/setup_new_exec()' split
commit 7ab02af428c2d312c0cf8fb0b01cc1eb21131a3d upstream. Commit 221af7f87b9 ("Split 'flush_old_exec' into two functions") split the function at the point of no return - ie right where there were no more error cases to check. That made sense from a technical standpoint, but when we then also combined it with the actual personality setting going in between flush_old_exec() and setup_new_exec(), it needs to be a bit more careful. In particular, we need to make sure that we really flush the old personality bits in the 'flush' stage, rather than later in the 'setup' stage, since otherwise we might be flushing the _new_ personality state that we're just setting up. So this moves the flags and personality flushing (and 'flush_thread()', which is the arch-specific function that generally resets lazy FP state etc) of the old process into flush_old_exec(), so that it doesn't affect any state that execve() is setting up for the new process environment. This was reported by Michal Simek as breaking his Microblaze qemu environment. Reported-and-tested-by: Michal Simek <michal.simek@petalogix.com> Cc: Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
-rw-r--r--fs/exec.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/fs/exec.c b/fs/exec.c
index b7ce707b922d..026ad19e4f9d 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -948,6 +948,11 @@ int flush_old_exec(struct linux_binprm * bprm)
goto out;
bprm->mm = NULL; /* We're using it now */
+
+ current->flags &= ~PF_RANDOMIZE;
+ flush_thread();
+ current->personality &= ~bprm->per_clear;
+
return 0;
out:
@@ -984,9 +989,6 @@ void setup_new_exec(struct linux_binprm * bprm)
tcomm[i] = '\0';
set_task_comm(current, tcomm);
- current->flags &= ~PF_RANDOMIZE;
- flush_thread();
-
/* Set the new mm task size. We have to do that late because it may
* depend on TIF_32BIT which is only updated in flush_thread() on
* some architectures like powerpc
@@ -1002,8 +1004,6 @@ void setup_new_exec(struct linux_binprm * bprm)
set_dumpable(current->mm, suid_dumpable);
}
- current->personality &= ~bprm->per_clear;
-
/*
* Flush performance counters when crossing a
* security domain: