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| author | Oleg Nesterov <oleg@redhat.com> | 2011-04-01 20:13:01 +0200 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2011-04-04 02:11:05 +0200 |
| commit | 321fb561971ba0f10ce18c0f8a4b9fbfc7cef4b9 (patch) | |
| tree | 4123410887b549284ed32cf5e8fb799fd2540c14 /kernel/ptrace.c | |
| parent | ee77f075921730b2b465880f9fd4367003bdab39 (diff) | |
| download | lwn-321fb561971ba0f10ce18c0f8a4b9fbfc7cef4b9.tar.gz lwn-321fb561971ba0f10ce18c0f8a4b9fbfc7cef4b9.zip | |
ptrace: ptrace_check_attach() should not do s/STOPPED/TRACED/
After "ptrace: Clean transitions between TASK_STOPPED and TRACED"
d79fdd6d96f46fabb779d86332e3677c6f5c2a4f, ptrace_check_attach()
should never see a TASK_STOPPED tracee and s/STOPPED/TRACED/ is
no longer legal. Add the warning.
Note: ptrace_check_attach() can be greatly simplified, in particular
it doesn't need tasklist. But I'd prefer another patch for that.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/ptrace.c')
| -rw-r--r-- | kernel/ptrace.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 43485866749a..20d5efdeee02 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -112,16 +112,14 @@ int ptrace_check_attach(struct task_struct *child, int kill) */ read_lock(&tasklist_lock); if ((child->ptrace & PT_PTRACED) && child->parent == current) { - ret = 0; /* * child->sighand can't be NULL, release_task() * does ptrace_unlink() before __exit_signal(). */ spin_lock_irq(&child->sighand->siglock); - if (task_is_stopped(child)) - child->state = TASK_TRACED; - else if (!task_is_traced(child) && !kill) - ret = -ESRCH; + WARN_ON_ONCE(task_is_stopped(child)); + if (task_is_traced(child) || kill) + ret = 0; spin_unlock_irq(&child->sighand->siglock); } read_unlock(&tasklist_lock); |