On 11/12/17 9:18 AM, Fengguang Wu wrote:
On Sun, Nov 12, 2017 at 09:14:14AM +0800, Alexei Starovoitov wrote:
On 11/12/17 8:23 AM, kbuild test robot wrote:
tree:
https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git
master
head: 7c5556decd0a629e9ee02e93653f75ba7b7da03c
commit: 638f5b90d46016372a8e3e0a434f199cc5e12b8c [488/665] bpf:
reduce verifier memory consumption
config: mips-64r6el_defconfig (attached as .config)
compiler: mips64el-linux-gnuabi64-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
git checkout 638f5b90d46016372a8e3e0a434f199cc5e12b8c
# save the attached .config to linux build tree
make.cross ARCH=mips
All errors (new ones prefixed by >>):
kernel/bpf/verifier.o: In function `realloc_verifier_state.isra.19':
verifier.c:(.text+0x36fc): undefined reference to `__multi3'
that's a known issue with gcc 7 on mips that is "optimizing"
normal 64-bit multiply into 128-bit variant.
Nothing to fix on the kernel side.
Good to know that! Do you think it a good idea to blacklist __multi3
errors in mips builds?
I would do so. yes.
Though digging further this function was added to
arch/sparc/lib/multi3.S
since gcc doing the same "optimization" there.
Adding asm code doesn't look right to me. I'd rather push
gcc folks to avoid such codegen.
