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From: Oleg Nesterov <oleg@tv-sign.ru>
To: Pierre Morel <pmorel@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-kernel@vger.kernel.org, Roland McGrath <roland@redhat.com>,
	Heiko Carstens <heicars2@linux.vnet.ibm.com>,
	sameske@linux.vnet.ibm.com,
	Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: Re: [RFC] [Patch 1/1] [Self Ptrace] System call notification with self_ptrace
Date: Mon, 25 Aug 2008 20:54:03 +0400	[thread overview]
Message-ID: <20080825165403.GA604@tv-sign.ru> (raw)
In-Reply-To: <48B26083.8080506@linux.vnet.ibm.com>

On 08/25, Pierre Morel wrote:
>
> @@ -550,6 +550,23 @@ asmlinkage long sys_ptrace(long request,
>  		goto out;
>  	}
>
> +	if (request == PTRACE_SELF_ON) {
> +		task_lock(current);
> +		set_thread_flag(TIF_SYSCALL_TRACE);
> +		current->ptrace |= PT_SELF;

I didn't read the whole patch, but this sets PT_SELF without PT_PTRACED
(and without ptrace_attach).

We have some "->ptrace != 0" checks which can misunderstand this. Just
for example, suppose that the task does sys_ptrace(PTRACE_SELF_ON) and
then its parent dies. I guess in that case forget_original_parent()
will hit BUG_ON(p->ptrace), no?

Oleg.


  parent reply	other threads:[~2008-08-25 16:49 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-08-25  7:34 [RFC] [Patch 1/1] [Self Ptrace] System call notification with self_ptrace Pierre Morel
2008-08-25 16:33 ` Dave Hansen
2008-08-26 12:33   ` Pierre Morel
2008-08-25 16:54 ` Oleg Nesterov [this message]
2008-08-26 14:04   ` Pierre Morel
2008-08-26 16:27     ` Oleg Nesterov
2008-08-27 14:32       ` Pierre Morel
2008-08-27 16:24         ` Oleg Nesterov
2008-08-28 12:03           ` Pierre Morel
2008-08-28 12:32             ` Oleg Nesterov
2008-08-28 13:24               ` Pierre Morel

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