Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 82975bc6 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Linus Torvalds
Browse files

uprobes, x86: Fix _TIF_UPROBE vs _TIF_NOTIFY_RESUME 



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: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarAndy Lutomirski <luto@amacapital.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 90e362f4

arch/x86/include/asm/thread_info.h

+1 −1
Original line number Original line Diff line number Diff line
@@ -141,7 +141,7 @@ struct thread_info { 
/* Only used for 64 bit */

/* Only used for 64 bit */

#define _TIF_DO_NOTIFY_MASK						\

#define _TIF_DO_NOTIFY_MASK						\

	(_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME |	\

	(_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME |	\

	 _TIF_USER_RETURN_NOTIFY)

	 _TIF_USER_RETURN_NOTIFY | _TIF_UPROBE)





/* flags to check in __switch_to() */

/* flags to check in __switch_to() */

#define _TIF_WORK_CTXSW							\

#define _TIF_WORK_CTXSW							\

kernel/events/uprobes.c

+0 −1
Original line number Original line Diff line number Diff line
@@ -1640,7 +1640,6 @@ bool uprobe_deny_signal(void) 
		if (__fatal_signal_pending(t) || arch_uprobe_xol_was_trapped(t)) {

		if (__fatal_signal_pending(t) || arch_uprobe_xol_was_trapped(t)) {

			utask->state = UTASK_SSTEP_TRAPPED;

			utask->state = UTASK_SSTEP_TRAPPED;

			set_tsk_thread_flag(t, TIF_UPROBE);

			set_tsk_thread_flag(t, TIF_UPROBE);

			set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);

		}

		}

	}

	}