Messages in this thread Patch in this message | | | Date | Sun, 21 Mar 2010 19:48:01 +0100 | From | Oleg Nesterov <> | Subject | [PATCH] check_unshare_flags: kill the bogus CLONE_SIGHAND/sig->count check |
| |
check_unshare_flags(CLONE_SIGHAND) adds CLONE_THREAD to *flags_ptr if the task is multithreaded to ensure unshare_thread() will fail.
Not only this is a bit strange way to return the error, this is absolutely meaningless. If signal->count > 1 then sighand->count must be also > 1, and unshare_sighand() will fail anyway.
In fact, all CLONE_THREAD/SIGHAND/VM checks inside sys_unshare() do not look right. Fortunately this code doesn't really work anyway.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> ---
kernel/fork.c | 8 -------- 1 file changed, 8 deletions(-)
--- 34-rc1/kernel/fork.c~UNSHARE_DONT_USE_SIG_COUNT 2010-03-21 18:37:31.000000000 +0100 +++ 34-rc1/kernel/fork.c 2010-03-21 19:08:06.000000000 +0100 @@ -1519,14 +1519,6 @@ static void check_unshare_flags(unsigned *flags_ptr |= CLONE_SIGHAND; /* - * If unsharing signal handlers and the task was created - * using CLONE_THREAD, then must unshare the thread - */ - if ((*flags_ptr & CLONE_SIGHAND) && - (atomic_read(¤t->signal->count) > 1)) - *flags_ptr |= CLONE_THREAD; - - /* * If unsharing namespace, must also unshare filesystem information. */ if (*flags_ptr & CLONE_NEWNS)
| |