Re: [STABLE BACKPORT v2 4.4.y, 4.9.y and 4.14.y] compiler.h: Raise minimum version of GCC to 5.1 for arm64

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Jan 25, 2021 at 01:24:25PM +0000, Will Deacon wrote:
> commit dca5244d2f5b94f1809f0c02a549edf41ccd5493 upstream.
> 
> 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.
> 
> Life is too short for buggy compilers, so raise the minimum GCC version
> required by arm64 to 5.1.
> 
> Reported-by: Russell King <linux@armlinux.org.uk>
> Suggested-by: Arnd Bergmann <arnd@kernel.org>
> Signed-off-by: Will Deacon <will@kernel.org>
> Tested-by: Nathan Chancellor <natechancellor@gmail.com>
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
> Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: <stable@vger.kernel.org> # 4.4.y, 4.9.y and 4.14.y only
> Cc: Theodore Ts'o <tytso@mit.edu>
> Cc: Florian Weimer <fweimer@redhat.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Nick Desaulniers <ndesaulniers@google.com>
> Cc: Nathan Chancellor <natechancellor@gmail.com>
> Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
> Link: https://lore.kernel.org/r/20210105154726.GD1551@shell.armlinux.org.uk
> Link: https://lore.kernel.org/r/20210112224832.10980-1-will@kernel.org
> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
> [will: backport to 4.4.y/4.9.y/4.14.y; add __clang__ check]
> Link: https://lore.kernel.org/r/CA+G9fYuzE9WMSB7uGjV4gTzK510SHEdJb_UXQCzsQ5MqA=h9SA@mail.gmail.com
> Signed-off-by: Will Deacon <will@kernel.org>
> ---
>  include/linux/compiler-gcc.h | 6 ++++++
>  1 file changed, 6 insertions(+)

Thanks, now queued up, let's try this again :)

greg k-h