Hi Fengguang,
On 01/05/2016 06:30 AM, Fengguang Wu wrote:
Hi Guenter,
On Tue, Jan 05, 2016 at 06:02:47AM -0800, Guenter Roeck wrote:
On 01/05/2016 12:22 AM, Fengguang Wu wrote:
On Tue, Jan 05, 2016 at 12:09:14AM -0800, Guenter Roeck wrote:
On 01/04/2016 11:23 PM, kbuild test robot wrote:
Hi Guenter,
First bad commit (maybe != root cause):
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
master
head: 168309855a7d1e16db751e9c647119fe2d2dc878
commit: 398c7500a1f5f74e207bd2edca1b1721b3cc1f1e MIPS: VDSO: Fix build error
with binutils 2.24 and earlier
date: 6 days ago
config: mips-jmr3927_defconfig (attached as .config)
reproduce:
wget
https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross
-O ~/bin/make.cross
chmod +x ~/bin/make.cross
git checkout 398c7500a1f5f74e207bd2edca1b1721b3cc1f1e
# save the attached .config to linux build tree
make.cross ARCH=mips
All errors (new ones prefixed by >>):
arch/mips/vdso/gettimeofday.c:1:0: error: '-march=r3900' requires '-mfp32'
/*
^
AFAICS this is using the mips cross compiler version 4.9.0 from kernel.org [1],
which in turn uses binutils 2.24. At least this is what make.cross tries to
install.
Oops, sorry. I'm now using the debian MIPS cross compiler 5.2.1 ...
make.cross has not been updated yet.
No problem. FWIW, I tested my patch with the compiler from Yocto 2.0, which
uses gcc 5.2.0 and binutils 2.25.1, with no problem.
Do you have directions on how to install a debian cross compiler into a Ubuntu
system ?
Alternatively, what version of binutils does the mips cross compiler use ?
These are the installed version in my Debian:
||/ Name Version Architecture
Description
+++-====================================-=======================-=======================-=============================================================================
ii gcc-5-mips-linux-gnu 5.2.1-16cross1 amd64
GNU C compiler
ii gcc-5-mipsel-linux-gnu 5.2.1-16cross1 amd64
GNU C compiler
ii binutils-mips-linux-gnu 2.25-8 amd64
GNU binary utilities, for mips-linux-gnu target
ii binutils-mipsel-linux-gnu 2.25-8 amd64
GNU binary utilities, for mipsel-linux-gnu target
You may check if these packages are available on Ubuntu. Anyway the
Unfortunately it looks like they are not available.
versions are close to yours. This is interesting, I'll do more checks.
The problem is an interesting one: Due to my patch,
arch/mips/vdso/gettimeofday.c
actually compiles with your toolchain (as it should, since its binutils version
is >= 2.25). Previously that was not the case. In other words, my patch exposes
a previously existing problem.
The underlying problem seems to be that your toolchain, as the error suggests,
does not support '-march=r3900' (which is set with the affected configuration)
without '-mfp32'. This may be a problem only for gettimeofday.c because that
file is compiled with different options than everything else. I _suspect_
the reason to be that -msoft-float and -Wa,-msoft-float are dropped from the
gettimeofday compile options, but I am not sure. Ralf and/or Alex (copying)
may have a better understanding of the problem.
Thanks,
Guenter
Thanks,
Fengguang
I downloaded it and used it to compile both the attached configuration as well
as jmr3927_defconfig. Both are building just fine for me. On top of that,
arch/mips/vdso/gettimeofday.c should not build in the first place with binutils
2.24
(and doesn't build for me).
What am I missing ?
Guenter
---
[1]
https://www.kernel.org/pub/tools/crosstool/files/bin/x86_64/4.9.0/x86_64-gcc-4.9.0-nolibc_mips-linux.tar.xz
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/