On Tue, Mar 10, 2020 at 09:34:03PM +0100, Bernd Edlinger wrote:
On 3/10/20 9:29 PM, Kees Cook wrote:
On Sun, Mar 08, 2020 at 04:36:17PM -0500, Eric W. Biederman wrote:
This makes the code clearer and makes it easier to implement a mutex that is not taken over any locations that may block indefinitely waiting for userspace.
Signed-off-by: "Eric W. Biederman" ebiederm@xmission.com
fs/exec.c | 39 ++++++++++++++++++++++++++------------- 1 file changed, 26 insertions(+), 13 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c index c3f34791f2f0..ff74b9a74d34 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1194,6 +1194,23 @@ static int de_thread(struct task_struct *tsk) flush_itimer_signals(); #endif
Semi-related (existing behavior): in de_thread(), what keeps the thread group from changing? i.e.:
if (thread_group_empty(tsk)) goto no_thread_group; /* * Kill all other threads in the thread group. */ spin_lock_irq(lock);... kill other threads under lock ...
Why is the thread_group_emtpy() test not under lock?
A new thread cannot created when only one thread is executing, right?
*face palm* Yes, of course. :) I'm thinking too hard.