Re: decompress.c:(.text.FSE_buildDTable_internal+0x2cc): undefined reference to `__clzdi2'

[Paul Cercueil <paul@xxxxxxxxxxxxxxx>]

Hi Nick,

Le mer., janv. 5 2022 at 20:18:27 +0000, Nick Terrell <terrelln@xxxxxx> 
a écrit :
> >  On Jan 5, 2022, at 11:02 AM, kernel test robot <lkp@xxxxxxxxx> 
> > wrote:
> >
> >  tree:   
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 
> > master
> >  head:   c9e6606c7fe92b50a02ce51dda82586ebdf99b48
> >  commit: e0c1b49f5b674cca7b10549c53b3791d0bbc90a8 lib: zstd: Upgrade 
> > to latest upstream zstd version 1.4.10
> >  date:   8 weeks ago
> >  config: mips-randconfig-r025-20220105 
> > (https://download.01.org/0day-ci/archive/20220106/202201060233.mO6P39bM-lkp@xxxxxxxxx/config 
> > )
> >  compiler: mips64el-linux-gcc (GCC) 11.2.0
> >  reproduce (this is a W=1 build):
> >         wget 
> > https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross 
> >  -O ~/bin/make.cross
> >         chmod +x ~/bin/make.cross
> >         # 
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e0c1b49f5b674cca7b10549c53b3791d0bbc90a8
> >         git remote add linus 
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> >         git fetch --no-tags linus master
> >         git checkout e0c1b49f5b674cca7b10549c53b3791d0bbc90a8
> >         # save the config file to linux build tree
> >         mkdir build_dir
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 
> > make.cross O=build_dir ARCH=mips SHELL=/bin/bash
> >
> >  If you fix the issue, kindly add following tag as appropriate
> >  Reported-by: kernel test robot <lkp@xxxxxxxxx>
> >
> >  All errors (new ones prefixed by >>):
> >
> >    mips64el-linux-ld: arch/mips/boot/compressed/decompress.o: in 
> > function `FSE_buildDTable_internal':
> > > >  decompress.c:(.text.FSE_buildDTable_internal+0x2cc): undefined 
> > > > reference to `__clzdi2'
> >    mips64el-linux-ld: arch/mips/boot/compressed/decompress.o: in 
> > function `BIT_initDStream':
> >    decompress.c:(.text.BIT_initDStream+0x7c): undefined reference to 
> > `__clzdi2'
> >    mips64el-linux-ld: decompress.c:(.text.BIT_initDStream+0x158): 
> > undefined reference to `__clzdi2'
> >    mips64el-linux-ld: arch/mips/boot/compressed/decompress.o: in 
> > function `ZSTD_buildFSETable_body_default.constprop.0':
> > > >  
> > > > decompress.c:(.text.ZSTD_buildFSETable_body_default.constprop.0+0x2a8): 
> > > > undefined reference to `__clzdi2'
> >    mips64el-linux-ld: arch/mips/boot/compressed/decompress.o: in 
> > function `FSE_readNCount_body_default':
> > > >  decompress.c:(.text.FSE_readNCount_body_default+0x130): undefined 
> > > > reference to `__ctzdi2'
> > > >  mips64el-linux-ld: 
> > > > decompress.c:(.text.FSE_readNCount_body_default+0x1a4): undefined 
> > > > reference to `__ctzdi2'
> > > >  mips64el-linux-ld: 
> > > > decompress.c:(.text.FSE_readNCount_body_default+0x2e4): undefined 
> > > > reference to `__clzdi2'
> >    mips64el-linux-ld: arch/mips/boot/compressed/decompress.o: in 
> > function `HUF_readStats_body_default':
> > > >  decompress.c:(.text.HUF_readStats_body_default+0x184): undefined 
> > > > reference to `__clzdi2'
> > > >  mips64el-linux-ld: 
> > > > decompress.c:(.text.HUF_readStats_body_default+0x1b4): undefined 
> > > > reference to `__clzdi2'
> >    mips64el-linux-ld: arch/mips/boot/compressed/decompress.o: in 
> > function `ZSTD_DCtx_getParameter':
> > > >  decompress.c:(.text.ZSTD_DCtx_getParameter+0x60): undefined 
> > > > reference to `__clzdi2'
>
> These are complaining about usage of __builtin_c{l,t}z(). The code 
> before this change also used
> __builtin_clz(), so this isn't new. E.g. the call in 
> BIT_initDStream() is present before the change,
> it just moved locations. So these errors aren't new.
>
> This is breaking the MIPS boot code when zstd compressed kernels are 
> enabled, and was
> Introduced in commit a510b61613 [0][1]. The fix is to include the 
> definitions from `lib/clz_ctz.c` [2].
> The same problem was fixed for s390 in this patch [3].
>
> CC: Paul Cercueil

Thanks, I'll send a patch.

Cheers,
-Paul