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From:   "Eric W. Biederman" <ebiederm@xmission.com>
To:     Oleg Nesterov <oleg@redhat.com>
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Date:   Thu, 05 May 2022 12:53:45 -0500
In-Reply-To: <20220505152801.GC13929@redhat.com> (Oleg Nesterov's message of
        "Thu, 5 May 2022 17:28:03 +0200")
Message-ID: <87zgjv6f2u.fsf@email.froward.int.ebiederm.org>
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Subject: Re: [PATCH v3 08/11] ptrace: Admit ptrace_stop can generate
 spuriuos SIGTRAPs
Precedence: bulk

Oleg Nesterov <oleg@redhat.com> writes:

> On 05/04, Eric W. Biederman wrote:
>>
>> -static int ptrace_stop(int exit_code, int why, int clear_code,
>> -			unsigned long message, kernel_siginfo_t *info)
>> +static int ptrace_stop(int exit_code, int why, unsigned long message,
>> +		       kernel_siginfo_t *info)
>
> Forgot to mention... but in general I like this change.
>
> In particular, I like the fact it kills the ugly "int clear_code" arg
> which looks as if it solves the problems with the exiting tracer, but
> actually it doesn't. And we do not really care, imo.

Further either this change is necessary or we need to take siglock in
the !current->ptrace path in "ptrace: Don't change __state" so that
JOBCTL_TRACED can be cleared.

So I vote for deleting code, and making ptrace_stop easier to reason
about.

Eric