[CHECKER] race in 2.5.62/kernel/ptrace.c?

Dawson Engler (engler@csl.stanford.edu)
Sat, 22 Mar 2003 11:47:17 -0800 (PST)


Is the following unlocked use of recalc_sigpending a race?

// 2.5.62/kernel/ptrace.c:339:ptrace_notify:
void ptrace_notify(int exit_code)
{
BUG_ON (!(current->ptrace & PT_PTRACED));

/* Let the debugger run. */
current->exit_code = exit_code;
set_current_state(TASK_STOPPED);
notify_parent(current, SIGCHLD);
schedule();

/*
* Signals sent while we were stopped might set TIF_SIGPENDING.
*/
recalc_sigpending();
}

It seems that recalc_sigpending needs to be protected by
&current->sighand->siglock

E.g.,:

2.5.62/kernel/signal.c:1656:sigprocmask:
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);

2.5.62/kernel/signal.c:2115:sys_sigprocmas

spin_lock_irq(&current->sighand->siglock);
old_set = current->blocked.sig[0];

...

recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);

Or does it not need a lock? (Or am I missing the lock?)
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