check_unshare_flags: kill the bogus CLONE_SIGHAND/sig->count check
authorOleg Nesterov <oleg@redhat.com>
Wed, 26 May 2010 21:43:21 +0000 (14:43 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 27 May 2010 16:12:47 +0000 (09:12 -0700)
commit6e1be45aa6ba6a36c0312f65ecf311135c73001d
tree3ea540e0ee249259e40e26c38215981b466075ad
parent97101eb41d0d3c97543878ce40e0b8a8b2747ed7
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>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Veaceslav Falico <vfalico@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/fork.c