Commit 58ab4e89 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by Luis Henriques

uprobes, x86: Fix _TIF_UPROBE vs _TIF_NOTIFY_RESUME

commit 82975bc6 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: 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>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent 6d90a2f6
...@@ -141,7 +141,7 @@ struct thread_info { ...@@ -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 \
......
...@@ -1639,7 +1639,6 @@ bool uprobe_deny_signal(void) ...@@ -1639,7 +1639,6 @@ 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);
} }
} }
......
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