uprobes, x86: Fix _TIF_UPROBE vs _TIF_NOTIFY_RESUME
authorAndy Lutomirski <luto@amacapital.net>
Fri, 21 Nov 2014 21:26:07 +0000 (13:26 -0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 6 Dec 2014 23:05:46 +0000 (15:05 -0800)
commit0061b518b1b85224bd697f2474d72b18b67a8d53
tree2841996ee43966711e6ff4dcf1c5fe1a54cff088
parent0b15c16c4f4a7c62c3c0f99b7ef8ddfcdab2ae66
uprobes, x86: Fix _TIF_UPROBE vs _TIF_NOTIFY_RESUME

commit 82975bc6a6df743b9a01810fb32cb65d0ec5d60b upstream.

x86 call do_notify_resume on paranoid returns if TIF_UPROBE is set but
not on non-paranoid returns.  I suspect that this is a mistake and that
the code only works because int3 is paranoid.

Setting _TIF_NOTIFY_RESUME in the uprobe code was probably a workaround
for the x86 bug.  With that bug fixed, we can remove _TIF_NOTIFY_RESUME
from the uprobes code.

Reported-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/include/asm/thread_info.h
kernel/events/uprobes.c