tracehook_finish_jctl() is needed to avoid the races with SIGKILL
which wakes up UTRACED task, and thus it should be called every time
after the STOPPED/TRACED/UTRACED returns from schedule(), remember
that TASK_UTRACED can be added while the task is STOPPED/UTRACED.
- rename it to tracehook_finish_stop(),jctl no longer matches the
reality.
- change do_signal_state() to call this helper right after schedule(),
otherwise this logic is broken by the upstream changes
- now that utrace doesn't control TASK_TRACED bit, ptrace_stop() must
call this helper too.
Signed-off-by: Oleg Nesterov <oleg(a)redhat.com>
---
include/linux/tracehook.h | 6 +++---
kernel/signal.c | 5 +++--
kernel/utrace.c | 2 +-
3 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
index 7d7bdde..3c7b6b3 100644
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -528,11 +528,11 @@ static inline int tracehook_get_signal(struct task_struct *task,
}
/**
- * tracehook_finish_jctl - report about return from job control stop
+ * tracehook_finish_stop - report about return from STOPPED/TRACED
*
- * This is called by do_signal_stop() after wakeup.
+ * This is called by do_signal_stop() and ptrace_stop after wakeup.
*/
-static inline void tracehook_finish_jctl(void)
+static inline void tracehook_finish_stop(void)
{
if (task_utrace_flags(current))
utrace_finish_stop();
diff --git a/kernel/signal.c b/kernel/signal.c
index 4fcf1c7..a7979ad 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1816,6 +1816,7 @@ static void ptrace_stop(int exit_code, int why, int clear_code,
siginfo_t *info)
read_unlock(&tasklist_lock);
}
+ tracehook_finish_stop();
/*
* While in TASK_TRACED, we were considered "frozen enough".
* Now that we woke up, it's crucial if we're supposed to be
@@ -1952,6 +1953,8 @@ retry:
/* Now we don't run again until woken by SIGCONT or SIGKILL */
schedule();
+ tracehook_finish_stop();
+
spin_lock_irq(¤t->sighand->siglock);
} else {
ptrace_stop(current->group_stop & GROUP_STOP_SIGMASK,
@@ -1974,8 +1977,6 @@ retry:
spin_unlock_irq(¤t->sighand->siglock);
- tracehook_finish_jctl();
-
return 1;
}
diff --git a/kernel/utrace.c b/kernel/utrace.c
index be98607..daa96b9 100644
--- a/kernel/utrace.c
+++ b/kernel/utrace.c
@@ -741,7 +741,7 @@ static bool utrace_reset(struct task_struct *task, struct utrace
*utrace)
void utrace_finish_stop(void)
{
/*
- * If we were task_is_traced() and then SIGKILL'ed, make
+ * If we were task_is_utraced() and then SIGKILL'ed, make
* sure we do nothing until the tracer drops utrace->lock.
*/
if (unlikely(__fatal_signal_pending(current))) {
--
1.5.5.1
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