Messages in this thread | | | Date | Wed, 15 Aug 2012 19:56:51 +0200 | From | Oleg Nesterov <> | Subject | Re: yama_ptrace_access_check(): possible recursive locking detected |
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On 08/15, Peter Zijlstra wrote: > > On Wed, 2012-08-15 at 15:01 +0200, Oleg Nesterov wrote: > > BTW, set_task_comm()->wmb() and memset() should die. There are > > not needed afaics, and the comment is misleading. > > As long as we guarantee there's always a terminating '\0',
Yes, but we already have this guarantee?
Unless of course some buggy code does something wrong with task->comm[], but nobody should do this.
IOW, task->comm[TASK_COMM_LEN - 1] is always 0, no?
> now strlcpy() > doesn't pad the result,
afaics set_task_comm()->strlcpy() doesn't change the last byte too.
> however if we initialize the ->comm to all 0s in > fork()
fork() is special, yes. ->comm is copied by dup_task_struct() and the new task_struct can have everything in ->comm. But nobody can see the new task yet, and nobody can play with its ->comm.
Or I misunderstood?
> That barrier is indeed completely pointless as there's no pairing > barrier anywhere.
Yes, agreed.
Oleg.
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