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uprobes, x86: Fix _TIF_UPROBE vs _TIF_NOTIFY_RESUME

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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>
This commit is contained in:
Andy Lutomirski 2014-11-21 13:26:07 -08:00 committed by Linus Torvalds
parent 90e362f4a7
commit 82975bc6a6
2 changed files with 1 additions and 2 deletions
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2
arch/x86/include/asm/thread_info.h
View File

@ -141,7 +141,7 @@ struct thread_info {
/* Only used for 64 bit */
#define _TIF_DO_NOTIFY_MASK \
(_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \
_TIF_USER_RETURN_NOTIFY)
_TIF_USER_RETURN_NOTIFY | _TIF_UPROBE)
/* flags to check in __switch_to() */
#define _TIF_WORK_CTXSW \

1
kernel/events/uprobes.c
View File

@ -1640,7 +1640,6 @@ bool uprobe_deny_signal(void)
if (__fatal_signal_pending(t) || arch_uprobe_xol_was_trapped(t)) {
utask->state = UTASK_SSTEP_TRAPPED;
set_tsk_thread_flag(t, TIF_UPROBE);
set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
}
}