[PATCH v3 08/11] ptrace: Admit ptrace_stop can generate spuriuos SIGTRAPs

[Eric W. Biederman]

Oleg Nesterov <oleg at 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