diff options
| author | Andrei Vagin <avagin@gmail.com> | 2019-03-28 20:44:13 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-04 09:21:23 +0200 |
| commit | 107cfb99c81f37a8df6dc4726495db7b5e22967f (patch) | |
| tree | f6447ff8b36a5e0257663f79230772c437e559d6 /include | |
| parent | 87eaf3d8ac51577c6123b43245e547c94c54dc06 (diff) | |
ptrace: take into account saved_sigmask in PTRACE{GET,SET}SIGMASK
[ Upstream commit fcfc2aa0185f4a731d05a21e9f359968fdfd02e7 ]
There are a few system calls (pselect, ppoll, etc) which replace a task
sigmask while they are running in a kernel-space
When a task calls one of these syscalls, the kernel saves a current
sigmask in task->saved_sigmask and sets a syscall sigmask.
On syscall-exit-stop, ptrace traps a task before restoring the
saved_sigmask, so PTRACE_GETSIGMASK returns the syscall sigmask and
PTRACE_SETSIGMASK does nothing, because its sigmask is replaced by
saved_sigmask, when the task returns to user-space.
This patch fixes this problem. PTRACE_GETSIGMASK returns saved_sigmask
if it's set. PTRACE_SETSIGMASK drops the TIF_RESTORE_SIGMASK flag.
Link: http://lkml.kernel.org/r/20181120060616.6043-1-avagin@gmail.com
Fixes: 29000caecbe8 ("ptrace: add ability to get/set signal-blocked mask")
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/sched/signal.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index 13789d10a50e..76b8399b17f6 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -417,10 +417,20 @@ static inline void set_restore_sigmask(void) set_thread_flag(TIF_RESTORE_SIGMASK); WARN_ON(!test_thread_flag(TIF_SIGPENDING)); } + +static inline void clear_tsk_restore_sigmask(struct task_struct *tsk) +{ + clear_tsk_thread_flag(tsk, TIF_RESTORE_SIGMASK); +} + static inline void clear_restore_sigmask(void) { clear_thread_flag(TIF_RESTORE_SIGMASK); } +static inline bool test_tsk_restore_sigmask(struct task_struct *tsk) +{ + return test_tsk_thread_flag(tsk, TIF_RESTORE_SIGMASK); +} static inline bool test_restore_sigmask(void) { return test_thread_flag(TIF_RESTORE_SIGMASK); @@ -438,6 +448,10 @@ static inline void set_restore_sigmask(void) current->restore_sigmask = true; WARN_ON(!test_thread_flag(TIF_SIGPENDING)); } +static inline void clear_tsk_restore_sigmask(struct task_struct *tsk) +{ + tsk->restore_sigmask = false; +} static inline void clear_restore_sigmask(void) { current->restore_sigmask = false; @@ -446,6 +460,10 @@ static inline bool test_restore_sigmask(void) { return current->restore_sigmask; } +static inline bool test_tsk_restore_sigmask(struct task_struct *tsk) +{ + return tsk->restore_sigmask; +} static inline bool test_and_clear_restore_sigmask(void) { if (!current->restore_sigmask) |