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From: Christian Brauner <christian@brauner.io>
To: Florian Weimer <fweimer@redhat.com>
Cc: ebiederm@xmission.com, linux-kernel@vger.kernel.org,
	serge@hallyn.com, jannh@google.com, luto@kernel.org,
	akpm@linux-foundation.org, oleg@redhat.com, cyphar@cyphar.com,
	viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org,
	linux-api@vger.kernel.org, dancol@google.com,
	timmurray@google.com, linux-man@vger.kernel.org
Subject: Re: [PATCH] procfd_signal.2: document procfd_signal syscall
Date: Thu, 29 Nov 2018 10:12:05 +1300
Message-ID: <E81EDAAC-F9E3-4D3A-AEE8-09E266D7FEDB@brauner.io> (raw)
In-Reply-To: <87in0g7waf.fsf@oldenburg.str.redhat.com>

On November 29, 2018 9:59:52 AM GMT+13:00, Florian Weimer <fweimer@redhat.com> wrote:
>* Christian Brauner:
>
>> +.\" Copyright (C) 2018 Christian Brauner <christian@brauner.io>
>
>The text seems to be largely derived from rt_sigqueueinfo, so I'm not
>sure if this appropriate here.
>
>> +the null signal (0) can be used to check if a process with a given
>> +PID exists.
>
>What does this mean if hte process is identified by file descriptor?
>
>> +.PP
>> +The optional
>> +.I info
>> +argument specifies the data to accompany the signal.
>> +This argument is a pointer to a structure of type
>> +.IR siginfo_t ,
>> +described in
>> +.BR sigaction (2)
>> +(and defined by including
>> +.IR <sigaction.h> ).
>> +The caller should set the following fields in this structure:
>> +.TP
>> +.I si_code
>> +This must be one of the
>> +.B SI_*
>> +codes in the Linux kernel source file
>> +.IR include/asm-generic/siginfo.h ,
>> +with the restriction that the code must be negative
>> +(i.e., cannot be
>> +.BR SI_USER ,
>> +which is used by the kernel to indicate a signal sent by
>> +.BR kill (2))
>> +and cannot (since Linux 2.6.39) be
>
>Obsolete reference in this context.
>
>> +.TP
>> +.B ESRCH
>> +The process or process group does not exist.
>> +Note that an existing process might be a zombie,
>> +a process that has terminated execution, but
>> +has not yet been
>> +.BR wait (2)ed
>> +for.
>
>Again: What does this mean if the process identified by a descriptor?
>Does a process in zombie state exist in this sense or not?
>
>Thanks,
>Florian

Updating the document is on my Todo.
Florian, can you take a look at the actual patch too, please?

      reply index

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-19 10:32 [PATCH v1 0/2] proc: allow signaling processes via file descriptors Christian Brauner
2018-11-19 10:32 ` [PATCH v1 1/2] proc: get process file descriptor from /proc/<pid> Christian Brauner
2018-11-19 15:32   ` Andy Lutomirski
2018-11-19 18:20     ` Christian Brauner
2018-11-19 10:32 ` [PATCH v1 2/2] signal: add procfd_signal() syscall Christian Brauner
2018-11-19 15:45   ` Andy Lutomirski
2018-11-19 15:57     ` Daniel Colascione
2018-11-19 18:39     ` Christian Brauner
2018-11-19 15:59   ` Daniel Colascione
2018-11-19 18:29     ` Christian Brauner
2018-11-19 19:02       ` Eric W. Biederman
2018-11-19 19:31         ` Christian Brauner
2018-11-19 19:39           ` Daniel Colascione
2018-11-19 17:10   ` Eugene Syromiatnikov
2018-11-19 18:23     ` Christian Brauner
2018-11-19 17:14   ` Eugene Syromiatnikov
2018-11-19 20:28   ` Aleksa Sarai
2018-11-19 20:55     ` Christian Brauner
2018-11-19 21:13       ` Christian Brauner
2018-11-19 21:18       ` Aleksa Sarai
2018-11-19 21:20         ` Christian Brauner
2018-11-19 21:21         ` Christian Brauner
2018-11-19 21:25           ` Aleksa Sarai
2018-11-19 21:26           ` Daniel Colascione
2018-11-19 21:36             ` Aleksa Sarai
2018-11-19 21:37             ` Christian Brauner
2018-11-19 21:41               ` Daniel Colascione
2018-11-20  4:59                 ` Eric W. Biederman
2018-11-20 10:31                   ` Christian Brauner
2018-11-21 21:39                     ` Serge E. Hallyn
2018-11-19 21:23         ` Aleksa Sarai
2018-11-22  7:41           ` Serge E. Hallyn
2018-11-19 22:39   ` Tycho Andersen
2018-11-19 22:49     ` Daniel Colascione
2018-11-19 23:07       ` Tycho Andersen
2018-11-20  0:27         ` Andy Lutomirski
2018-11-20  0:32           ` Christian Brauner
2018-11-20  0:34             ` Andy Lutomirski
2018-11-20  0:49           ` Daniel Colascione
2018-11-22  7:48     ` Serge E. Hallyn
2018-11-19 23:35   ` kbuild test robot
2018-11-19 23:37   ` kbuild test robot
2018-11-19 23:45     ` Christian Brauner
2018-11-28 21:45   ` Joey Pabalinas
2018-11-28 22:05     ` Christian Brauner
2018-11-28 23:02       ` Joey Pabalinas
2018-11-19 10:32 ` [PATCH] procfd_signal.2: document procfd_signal syscall Christian Brauner
2018-11-20 13:29   ` Michael Kerrisk (man-pages)
2018-11-28 20:59   ` Florian Weimer
2018-11-28 21:12     ` Christian Brauner [this message]

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