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Message-ID: <4d985bb8b1b9b382cf8e818a8761aa6268d7bc62.camel@perches.com>
Subject: Re: [PATCH] compiler.h: Raise minimum version of GCC to 5.1 for
 arm64
From:   Joe Perches <joe@perches.com>
To:     Masahiro Yamada <masahiroy@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>
Cc:     linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        Will Deacon <will@kernel.org>, Arnd Bergmann <arnd@kernel.org>,
        Russell King <linux@armlinux.org.uk>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Theodore Ts'o <tytso@mit.edu>,
        "Cc: Android Kernel" <kernel-team@android.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Florian Weimer <fweimer@redhat.com>
Date:   Wed, 13 Jan 2021 10:33:43 -0800
In-Reply-To: <CAK7LNASs6dvU6D3jL2GG3jW58fXfaj6VNOe55NJnTB8UPuk2pA@mail.gmail.com>
References: <20210112224832.10980-1-will@kernel.org>
         <161055398865.21762.12236232732054213928.b4-ty@arm.com>
         <CAK7LNASs6dvU6D3jL2GG3jW58fXfaj6VNOe55NJnTB8UPuk2pA@mail.gmail.com>
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On Thu, 2021-01-14 at 02:57 +0900, Masahiro Yamada wrote:
> On Thu, Jan 14, 2021 at 1:08 AM Catalin Marinas <catalin.marinas@arm.com> wrote:
> > 
> > On Tue, 12 Jan 2021 22:48:32 +0000, Will Deacon wrote:
> > > GCC versions >= 4.9 and < 5.1 have been shown to emit memory references
> > > beyond the stack pointer, resulting in memory corruption if an interrupt
> > > is taken after the stack pointer has been adjusted but before the
> > > reference has been executed. This leads to subtle, infrequent data
> > > corruption such as the EXT4 problems reported by Russell King at the
> > > link below.
> > > 
> > > [...]
> > 
> > Applied to arm64 (for-next/fixes), thanks!
> > 
> > [1/1] compiler.h: Raise minimum version of GCC to 5.1 for arm64
> > ??????https://git.kernel.org/arm64/c/1f1244a5ddb7
[]
> Maybe, we can raise the minimal version to gcc 5.1
> for all architectures.

If really raising the required minimum, maybe use 7.1 so kasan v5
and fallthrough are always enabled too.

https://gcc.gnu.org/releases.html

GCC 7.1 	May 2, 2017
GCC 5.1 	April 22, 2015
GCC 4.9.0 	April 22, 2014