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From: Jann Horn <jannh@google.com>
To: enkechen@cisco.com
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H . Peter Anvin" <hpa@zytor.com>,
	"the arch/x86 maintainers" <x86@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Arnd Bergmann <arnd@arndb.de>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Khalid Aziz <khalid.aziz@oracle.com>,
	Kate Stewart <kstewart@linuxfoundation.org>,
	deller@gmx.de, Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Andrew Morton <akpm@linux-foundation.org>,
	christian@brauner.io, Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Dave.Martin@arm.com, mchehab+samsung@kernel.org,
	Michal Hocko <mhocko@kernel.org>, Rik van Riel <riel@surriel.com>,
	"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
	guro@fb.com, Marcos Souza <marcos.souza.org@gmail.com>,
	Oleg Nesterov <oleg@redhat.com>,
	linux@dominikbrodowski.net, Cyrill Gorcunov <gorcunov@openvz.org>,
	yang.shi@linux.alibaba.com, Kees Cook <keescook@chromium.org>,
	kernel list <linux-kernel@vger.kernel.org>,
	linux-arch <linux-arch@vger.kernel.org>,
	Victor Kamensky <kamensky@cisco.com>,
	xe-linux-external@cisco.com, sstrogin@cisco.com
Subject: Re: [PATCH] kernel/signal: Signal-based pre-coredump notification
Date: Mon, 22 Oct 2018 17:40:28 +0200	[thread overview]
Message-ID: <CAG48ez27=w0oWFTYUeFc72-0DL0tf=NOzGCeZgtxFOePPPE5cA@mail.gmail.com> (raw)
In-Reply-To: <2631f765-8d7a-45ea-6aa4-d8a9bb00d56f@cisco.com>

On Sat, Oct 20, 2018 at 1:01 AM Enke Chen <enkechen@cisco.com> wrote:
> Regarding the security considerations, it seems simpler and more secure to
> just clear the "pre-coredump signal" cross execve(2), and let the new program
> decide for itself.  What do you think?

I don't have a problem with these semantics.

I could imagine someone being unhappy about the theoretical race
window if they want to perform an in-place reexecution of a running
service, but I don't know whether anyone actually cares about that.

> Changes to prctl(2):
>
> DESCRIPTION
>
>        PR_SET_PREDUMP_SIG (since Linux 4.20.x)
>               This allows the calling process to receive a signal (arg2,
>               if nonzero) from a child process prior to the coredump of
>               the child process. arg2 must be SIGUSR1, or SIGUSR2, or
>               SIGCHLD, or 0 (for clear).
>
>               When SIGCHLD is specified, the signal code is set to
>               CLD_PREDUMP in such an SIGCHLD signal.
>
>               The value of the pre-coredump signal is cleared across
>               execve(2), or for the child of a fork(2).
>
>        PR_GET_PREDUMP_SIG (since Linux 4.20.x)
>               Return the current value of the pre-coredump signal for the
>               calling process, in the location pointed to by (int *) arg2.

  reply	other threads:[~2018-10-22 15:40 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-13  0:33 [PATCH] kernel/signal: Signal-based pre-coredump notification Enke Chen
2018-10-13  6:40 ` Greg Kroah-Hartman
2018-10-15 18:16   ` Enke Chen
2018-10-15 18:43     ` Greg Kroah-Hartman
2018-10-15 18:49       ` Enke Chen
2018-10-15 18:58         ` Greg Kroah-Hartman
2018-10-13 10:44 ` Christian Brauner
2018-10-15 18:39   ` Enke Chen
2018-10-13 18:27 ` Jann Horn
2018-10-15 18:36   ` Enke Chen
2018-10-15 18:54     ` Jann Horn
2018-10-15 19:23       ` Enke Chen
2018-10-19 23:01       ` Enke Chen
2018-10-22 15:40         ` Jann Horn [this message]
2018-10-22 20:48           ` Enke Chen
2018-10-15 12:05 ` Oleg Nesterov
2018-10-15 18:54   ` Enke Chen
2018-10-15 19:17   ` Enke Chen
2018-10-15 19:26     ` Enke Chen
2018-10-16 14:14     ` Oleg Nesterov
2018-10-16 15:09       ` Eric W. Biederman
2018-10-17  0:39       ` Enke Chen
2018-10-15 21:21 ` Alan Cox
2018-10-15 21:31   ` Enke Chen
2018-10-15 23:28 ` Eric W. Biederman
2018-10-16  0:33   ` valdis.kletnieks
2018-10-16  0:54   ` Enke Chen
2018-10-16 15:26     ` Eric W. Biederman
2018-10-22 21:09 ` [PATCH v2] " Enke Chen
2018-10-23  9:23   ` Oleg Nesterov
2018-10-23 19:43     ` Enke Chen
2018-10-23 21:40       ` Enke Chen
2018-10-24 13:52       ` Oleg Nesterov
2018-10-24 21:56         ` Enke Chen
2018-10-24  5:39   ` [PATCH v3] " Enke Chen
2018-10-24 14:02     ` Oleg Nesterov
2018-10-24 22:02       ` Enke Chen
2018-10-25 22:56     ` [PATCH v4] " Enke Chen
2018-10-26  8:28       ` Oleg Nesterov
2018-10-26 22:23         ` Enke Chen
2018-10-29 11:18           ` Oleg Nesterov
2018-10-29 21:08             ` Enke Chen
2018-10-29 22:31             ` [PATCH v5] " Enke Chen
2018-10-30 16:46               ` Oleg Nesterov
2018-10-31  0:25                 ` Enke Chen
2018-11-22  0:37                 ` Andrew Morton
2018-11-22  1:09                   ` Enke Chen
2018-11-22  1:18                     ` Enke Chen
2018-11-22  1:33                     ` Andrew Morton
2018-11-22  4:57                       ` Enke Chen
2018-11-12 23:22               ` Enke Chen
2018-11-27 22:54               ` [PATCH v5 1/2] " Enke Chen
2018-11-28 15:19                 ` Dave Martin
2018-11-29  0:15                   ` Enke Chen
2018-11-29 11:55                     ` Dave Martin
2018-11-30  0:27                       ` Enke Chen
2018-11-30 12:03                       ` Oleg Nesterov
2018-12-05  6:47                       ` Jann Horn
2018-12-04 22:37                     ` Andrew Morton
2018-12-06 17:29                       ` Oleg Nesterov
2018-10-25 22:56     ` [PATCH] selftests/prctl: selftest for pre-coredump signal notification Enke Chen
2018-11-27 22:54       ` [PATCH v5 2/2] " Enke Chen
2018-10-24 13:29   ` [PATCH v2] kernel/signal: Signal-based pre-coredump notification Eric W. Biederman
2018-10-24 23:50     ` Enke Chen
2018-10-25 12:23       ` Eric W. Biederman
2018-10-25 20:45         ` Enke Chen
2018-10-25 21:24         ` Enke Chen
2018-10-25 21:56         ` Enke Chen
2018-10-25 13:45     ` Jann Horn
2018-10-25 20:21       ` Eric W. Biederman

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