Building older mips kernels with different versions of binutils; possible patch for 3.2 and 3.4

From: Guenter Roeck <linux@roeck-us.net>
To: stable <stable@vger.kernel.org>,
	Linux MIPS Mailing List <linux-mips@linux-mips.org>,
	Ben Hutchings <ben@decadent.org.uk>,
	Li Zefan <lizefan@huawei.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Building older mips kernels with different versions of binutils; possible patch for 3.2 and 3.4
Date: Sun, 15 May 2016 19:56:35 -0700	[thread overview]
Message-ID: <573936E3.3050003@roeck-us.net> (raw)

Hi folks,

building mips images with a consistent infrastructure is becoming more and more difficult.
Current state is as follows.

Binutils/	2.22	2.24	2.25
Kernel
3.2		X	-	-
3.4		X	-	-
3.10		X	X	-
3.14		X	X	-
3.16		X	X	-
3.18		X	X	(X) [1]
4.1		X	X	(X)
4.4		X	X	(X)
4.5		X	X	(X)
4.6		X	X	(X)
next		-	X	(X)

[1] (at least) allnoconfig fails to build with binutils 2.25 (2.25.1, more specifically).

I used the following toolchains for the above tests:
- Poky 1.3 (binutils 2.22)
- Poky 2.0 (binutils 2.25.1)
- gcc-4.6.3-nolibc from kernel.org (binutils 2.22)
- gcc-4.9.0-nolibc from kernel.org (binutils 2.24)

For 3.4 and 3.2 kernels to build with binutils v2.24, it would be necessary to
apply patch c02263063362 ("MIPS: Refactor 'clear_page' and 'copy_page' functions").
It applies cleanly to 3.4, but has a Makefile conflict in 3.2. It might
make sense to apply this patch to both releases. Would this be possible ?
This way, we would have at least one toolchain which can build all 3.2+ kernels.

Thanks,
Guenter