From: Christoph Hellwig <hch@infradead.org>
To: Alexandre Ghiti <alex@ghiti.fr>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Albert Ou <aou@eecs.berkeley.edu>,
Kees Cook <keescook@chromium.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Palmer Dabbelt <palmer@sifive.com>,
Will Deacon <will.deacon@arm.com>,
Russell King <linux@armlinux.org.uk>,
Ralf Baechle <ralf@linux-mips.org>,
linux-kernel@vger.kernel.org,
Christoph Hellwig <hch@infradead.org>,
linux-mm@kvack.org, Paul Burton <paul.burton@mips.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
James Hogan <jhogan@kernel.org>,
linux-fsdevel@vger.kernel.org, linux-riscv@lists.infradead.org,
linux-mips@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
Luis Chamberlain <mcgrof@kernel.org>
Subject: Re: [PATCH v2 2/5] arm64, mm: Move generic mmap layout functions to mm
Date: Tue, 9 Apr 2019 23:59:08 -0700 [thread overview]
Message-ID: <20190410065908.GC2942@infradead.org> (raw)
In-Reply-To: <20190404055128.24330-3-alex@ghiti.fr>
On Thu, Apr 04, 2019 at 01:51:25AM -0400, Alexandre Ghiti wrote:
> - fix the case where stack randomization should not be taken into
> account.
Hmm. This sounds a bit vague. It might be better if something
considered a fix is split out to a separate patch with a good
description.
> +config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
> + bool
> + help
> + This allows to use a set of generic functions to determine mmap base
> + address by giving priority to top-down scheme only if the process
> + is not in legacy mode (compat task, unlimited stack size or
> + sysctl_legacy_va_layout).
Given that this is an option that is just selected by other Kconfig
options the help text won't ever be shown. I'd just move it into a
comment bove the definition.
> +#ifdef CONFIG_MMU
> +#ifdef CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
I don't think we need the #ifdef CONFIG_MMU here,
CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT should only be selected
if the MMU is enabled to start with.
> +#ifdef CONFIG_ARCH_HAS_ELF_RANDOMIZE
> +unsigned long arch_mmap_rnd(void)
Now that a bunch of architectures use a version in common code
the arch_ prefix is a bit mislead. Probably not worth changing
here, but some time in the future it could use a new name.
next prev parent reply other threads:[~2019-04-10 6:59 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-04 5:51 [PATCH v2 0/5] Provide generic top-down mmap layout functions Alexandre Ghiti
2019-04-04 5:51 ` [PATCH v2 1/5] mm, fs: Move randomize_stack_top from fs to mm Alexandre Ghiti
2019-04-10 6:54 ` Christoph Hellwig
2019-04-10 7:18 ` Alexandre Ghiti
2019-04-04 5:51 ` [PATCH v2 2/5] arm64, mm: Move generic mmap layout functions " Alexandre Ghiti
2019-04-10 6:59 ` Christoph Hellwig [this message]
2019-04-10 7:32 ` Alexandre Ghiti
2019-04-10 18:27 ` Kees Cook
2019-04-11 7:16 ` Alexandre Ghiti
2019-04-04 5:51 ` [PATCH v2 3/5] arm: Use generic mmap top-down layout Alexandre Ghiti
2019-04-04 5:51 ` [PATCH v2 4/5] mips: " Alexandre Ghiti
2019-04-04 5:51 ` [PATCH v2 5/5] riscv: Make mmap allocation top-down by default Alexandre Ghiti
2019-04-10 6:59 ` Christoph Hellwig
2019-04-10 7:18 ` Alexandre Ghiti
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