Re: [linux-next:master 3665/11714] {standard input}:2644: Error: pcrel offset for branch to .LS0015 too far (0x3e)

Re: [linux-next:master 3665/11714] {standard input}:2644: Error: pcrel offset for branch to .LS0015 too far (0x3e)

[Feng Tang]

Add linux-csky list and originally cced people and replace the linux-mm
with linux-kbuild list, which match the discussion better and avoid
email noise for mm people.

On Tue, Jun 22, 2021 at 05:48:18PM +0800, Tang, Feng wrote:
> On Tue, Jun 22, 2021 at 09:49:05AM +0800, kernel test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > head:   889bab4c367a0ef58208fd80fafa74bb6e2dca26
> > commit: cf536e185869d4815d506e777bcca6edd9966a6e [3665/11714] Makefile: extend 32B aligned debug option to 64B aligned
> > config: csky-randconfig-c024-20210622 (attached as .config)
> > compiler: csky-linux-gcc (GCC) 9.3.0
> > 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/next/linux-next.git/commit/?id=cf536e185869d4815d506e777bcca6edd9966a6e
> >         git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> >         git fetch --no-tags linux-next master
> >         git checkout cf536e185869d4815d506e777bcca6edd9966a6e
> >         # save the attached .config to linux build tree
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=csky 

> Thanks for the report. 
> 
> I just reproduced the issue locally, with similar log:
> 
>   CC      drivers/target/target_core_sbc.o
> {standard input}: Assembler messages:
> {standard input}:2644: Error: pcrel offset for branch to .LS0015 too far (0x3e)
> {standard input}:2653: Error: pcrel offset for branch to .LS0015 too far (0x34)
> {standard input}:2659: Error: pcrel offset for branch to .LS0015 too far (0x2c)
> make[2]: *** [scripts/Makefile.build:272: drivers/target/target_core_sbc.o] Error 1
> m
> 
> And when I changed the function align option from 64 to 32, the
> compilation did pass, so this looks to be related with the alignment
> option.
> 
> I'm not very familiar with compiler, and will try to check more.

I did some check and found the error info comes from the assembler
for 'csky' in binutils' gas/config/tc-csky.c, and I could hardly
dive deeper into the code as limited by my knowledge.


> I know it works on x86_64, but don't know how about other
> architectures, and if 'csky' is the only not working one, one
> workaround I can think of is to add kconfig dependency for !csky 

I reused the 0day's reproduce process, and tried on arm64, powerpc64,
and arc, the kernel compilation all succeeded. So maybe we can
add some dependency for this debug option like:

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 3cf48998a374..eb035b31657f 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -415,7 +415,8 @@ config SECTION_MISMATCH_WARN_ONLY
 	  If unsure, say Y.
 
 config DEBUG_FORCE_FUNCTION_ALIGN_64B
-	bool "Force all function address 64B aligned" if EXPERT
+	bool "Force all function address 64B aligned"
+	depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC)
 	help
 	  There are cases that a commit from one domain changes the function
 	  address alignment of other domains, and cause magic performance

Any comments? thanks!

- Feng

> Thanks,
> Feng
> 
> 

Re: [linux-next:master 3665/11714] {standard input}:2644: Error: pcrel offset for branch to .LS0015 too far (0x3e)

[Guo Ren]

On Wed, Jun 23, 2021 at 4:59 PM Feng Tang <feng.tang@intel.com> wrote:
>
> Add linux-csky list and originally cced people and replace the linux-mm
> with linux-kbuild list, which match the discussion better and avoid
> email noise for mm people.
>
> On Tue, Jun 22, 2021 at 05:48:18PM +0800, Tang, Feng wrote:
> > On Tue, Jun 22, 2021 at 09:49:05AM +0800, kernel test robot wrote:
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > > head:   889bab4c367a0ef58208fd80fafa74bb6e2dca26
> > > commit: cf536e185869d4815d506e777bcca6edd9966a6e [3665/11714] Makefile: extend 32B aligned debug option to 64B aligned
> > > config: csky-randconfig-c024-20210622 (attached as .config)
> > > compiler: csky-linux-gcc (GCC) 9.3.0
> > > 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/next/linux-next.git/commit/?id=cf536e185869d4815d506e777bcca6edd9966a6e
> > >         git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> > >         git fetch --no-tags linux-next master
> > >         git checkout cf536e185869d4815d506e777bcca6edd9966a6e
> > >         # save the attached .config to linux build tree
> > >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=csky
>
> > Thanks for the report.
> >
> > I just reproduced the issue locally, with similar log:
> >
> >   CC      drivers/target/target_core_sbc.o
> > {standard input}: Assembler messages:
> > {standard input}:2644: Error: pcrel offset for branch to .LS0015 too far (0x3e)
> > {standard input}:2653: Error: pcrel offset for branch to .LS0015 too far (0x34)
> > {standard input}:2659: Error: pcrel offset for branch to .LS0015 too far (0x2c)
> > make[2]: *** [scripts/Makefile.build:272: drivers/target/target_core_sbc.o] Error 1
> > m
> >
> > And when I changed the function align option from 64 to 32, the
> > compilation did pass, so this looks to be related with the alignment
> > option.
> >
> > I'm not very familiar with compiler, and will try to check more.
>
> I did some check and found the error info comes from the assembler
> for 'csky' in binutils' gas/config/tc-csky.c, and I could hardly
> dive deeper into the code as limited by my knowledge.
>
>
> > I know it works on x86_64, but don't know how about other
> > architectures, and if 'csky' is the only not working one, one
> > workaround I can think of is to add kconfig dependency for !csky
>
> I reused the 0day's reproduce process, and tried on arm64, powerpc64,
> and arc, the kernel compilation all succeeded. So maybe we can
> add some dependency for this debug option like:
>
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 3cf48998a374..eb035b31657f 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -415,7 +415,8 @@ config SECTION_MISMATCH_WARN_ONLY
>           If unsure, say Y.
>
>  config DEBUG_FORCE_FUNCTION_ALIGN_64B
> -       bool "Force all function address 64B aligned" if EXPERT
> +       bool "Force all function address 64B aligned"
> +       depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC)
>         help
>           There are cases that a commit from one domain changes the function
>           address alignment of other domains, and cause magic performance
>
> Any comments? thanks!
Have tried riscv32? I don't think csky is the only problem.

Assembler just follows gcc backend result and also depends on ISA
design. Our condition branch seems not far enough.

Cc: xianmiao_qu@c-sky.com

>
> - Feng
>
> > Thanks,
> > Feng
> >
> >



-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/

Re: [linux-next:master 3665/11714] {standard input}:2644: Error: pcrel offset for branch to .LS0015 too far (0x3e)

[Guo Ren]

On Thu, Jun 24, 2021 at 4:50 PM Feng Tang <feng.tang@intel.com> wrote:
>
> On Thu, Jun 24, 2021 at 04:06:51PM +0800, Guo Ren wrote:
> > On Wed, Jun 23, 2021 at 4:59 PM Feng Tang <feng.tang@intel.com> wrote:
> > >
> > > Add linux-csky list and originally cced people and replace the linux-mm
> > > with linux-kbuild list, which match the discussion better and avoid
> > > email noise for mm people.
> > >
> > > On Tue, Jun 22, 2021 at 05:48:18PM +0800, Tang, Feng wrote:
> > > > On Tue, Jun 22, 2021 at 09:49:05AM +0800, kernel test robot wrote:
> > > > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > > > > head:   889bab4c367a0ef58208fd80fafa74bb6e2dca26
> > > > > commit: cf536e185869d4815d506e777bcca6edd9966a6e [3665/11714] Makefile: extend 32B aligned debug option to 64B aligned
> > > > > config: csky-randconfig-c024-20210622 (attached as .config)
> > > > > compiler: csky-linux-gcc (GCC) 9.3.0
> > > > > 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/next/linux-next.git/commit/?id=cf536e185869d4815d506e777bcca6edd9966a6e
> > > > >         git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> > > > >         git fetch --no-tags linux-next master
> > > > >         git checkout cf536e185869d4815d506e777bcca6edd9966a6e
> > > > >         # save the attached .config to linux build tree
> > > > >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=csky
> > >
> > > > Thanks for the report.
> > > >
> > > > I just reproduced the issue locally, with similar log:
> > > >
> > > >   CC      drivers/target/target_core_sbc.o
> > > > {standard input}: Assembler messages:
> > > > {standard input}:2644: Error: pcrel offset for branch to .LS0015 too far (0x3e)
> > > > {standard input}:2653: Error: pcrel offset for branch to .LS0015 too far (0x34)
> > > > {standard input}:2659: Error: pcrel offset for branch to .LS0015 too far (0x2c)
> > > > make[2]: *** [scripts/Makefile.build:272: drivers/target/target_core_sbc.o] Error 1
> > > > m
> > > >
> > > > And when I changed the function align option from 64 to 32, the
> > > > compilation did pass, so this looks to be related with the alignment
> > > > option.
> > > >
> > > > I'm not very familiar with compiler, and will try to check more.
> > >
> > > I did some check and found the error info comes from the assembler
> > > for 'csky' in binutils' gas/config/tc-csky.c, and I could hardly
> > > dive deeper into the code as limited by my knowledge.
> > >
> > >
> > > > I know it works on x86_64, but don't know how about other
> > > > architectures, and if 'csky' is the only not working one, one
> > > > workaround I can think of is to add kconfig dependency for !csky
> > >
> > > I reused the 0day's reproduce process, and tried on arm64, powerpc64,
> > > and arc, the kernel compilation all succeeded. So maybe we can
> > > add some dependency for this debug option like:
> > >
> > > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> > > index 3cf48998a374..eb035b31657f 100644
> > > --- a/lib/Kconfig.debug
> > > +++ b/lib/Kconfig.debug
> > > @@ -415,7 +415,8 @@ config SECTION_MISMATCH_WARN_ONLY
> > >           If unsure, say Y.
> > >
> > >  config DEBUG_FORCE_FUNCTION_ALIGN_64B
> > > -       bool "Force all function address 64B aligned" if EXPERT
> > > +       bool "Force all function address 64B aligned"
> > > +       depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC)
> > >         help
> > >           There are cases that a commit from one domain changes the function
> > >           address alignment of other domains, and cause magic performance
> > >
> > > Any comments? thanks!
> > Have tried riscv32? I don't think csky is the only problem.
> >
> > Assembler just follows gcc backend result and also depends on ISA
> > design. Our condition branch seems not far enough.
>
> Thanks for the info.
>
> I just used 0day's cross compile env to compile 'riscv32', and it
> succeeded with 64B align option. (the kernel config is attached)
Thx for the info, we'll have a look at it.

>
> Anyway, this debug option is for debug only, and nice to have. If
> it doesn't work on one architecture, I dont' think it means a severe
> problem.
>
> Thanks,
> Feng
>
> > Cc: xianmiao_qu@c-sky.com
> >
> > >
> > > - Feng
> > >
> > > > Thanks,
> > > > Feng
> > > >
> > > >
> >
> >
> >
> > --
> > Best Regards
> >  Guo Ren
> >
> > ML: https://lore.kernel.org/linux-csky/



-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/