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From: Kees Cook <keescook@chromium.org>
To: linux-fsdevel@vger.kernel.org,
	Allen Pais <apais@linux.microsoft.com>
Cc: Kees Cook <keescook@chromium.org>,
	linux-kernel@vger.kernel.org,
	linux-mm@kvack.org,
	viro@zeniv.linux.org.uk,
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	ebiederm@xmission.com,
	mcgrof@kernel.org,
	j.granados@samsung.com,
	allen.lkml@gmail.com
Subject: Re: [PATCH v4] fs/coredump: Enable dynamic configuration of max file note size
Date: Tue,  7 May 2024 10:02:53 -0700
Message-Id: <171510137055.3977159.13112533071742599257.b4-ty@chromium.org>
In-Reply-To: <20240506193700.7884-1-apais@linux.microsoft.com>
References: <20240506193700.7884-1-apais@linux.microsoft.com>
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On Mon, 06 May 2024 19:37:00 +0000, Allen Pais wrote:
> Introduce the capability to dynamically configure the maximum file
> note size for ELF core dumps via sysctl.
> 
> Why is this being done?
> We have observed that during a crash when there are more than 65k mmaps
> in memory, the existing fixed limit on the size of the ELF notes section
> becomes a bottleneck. The notes section quickly reaches its capacity,
> leading to incomplete memory segment information in the resulting coredump.
> This truncation compromises the utility of the coredumps, as crucial
> information about the memory state at the time of the crash might be
> omitted.
> 
> [...]

I adjusted file names, but put it in -next. I had given some confusing
feedback on v3, but I didn't realize until later; apologies for that! The
end result is the sysctl is named kernel.core_file_note_size_limit and
the internal const min/max variables have the _min and _max suffixes.

Applied to for-next/execve, thanks!

[1/1] fs/coredump: Enable dynamic configuration of max file note size
      https://git.kernel.org/kees/c/81e238b1299e

Take care,

-- 
Kees Cook