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From:   Bernd Edlinger <bernd.edlinger@hotmail.de>
To:     "Eric W. Biederman" <ebiederm@xmission.com>
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Subject: Re: [PATCH v2 4/5] exec: Move exec_mmap right after de_thread in
 flush_old_exec
Thread-Topic: [PATCH v2 4/5] exec: Move exec_mmap right after de_thread in
 flush_old_exec
Thread-Index: AQHV9ZIq8LqSeoOzkk+o9CTpCnOInKhAqHsA
Date:   Mon, 9 Mar 2020 19:34:59 +0000
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On 3/8/20 10:38 PM, Eric W. Biederman wrote:
> 
> I have read through the code in exec_mmap and I do not see anything
> that depends on sighand or the sighand lock, or on signals in anyway
> so this should be safe.
> 
> This rearrangement of code has two siginficant benefits.  It makes
                                        ^ typo: significant

> the determination of passing the point of no return by testing bprm->mm
> accurate.  All failures prior to that point in flush_old_exec are
> either truly recoverable or they are fatal.
> 
> Futher this consolidates all of the possible indefinite waits for   ^ typo: Further

> userspace together at the top of flush_old_exec.  The possible wait
> for a ptracer on PTRACE_EVENT_EXIT, the possible wait for a page fault
> to be resolved in clear_child_tid, and the possible wait for a page
> fault in exit_robust_list.
> 
> This consolidation allows the creation of a mutex to replace
> cred_guard_mutex that is not held of possible indefinite userspace

can you also reword this "held of" thing here as well?


Thanks
Bernd.