Re: [tip:core/rseq 25/39] include/linux/rseq_entry.h:132:3: error: invalid operand for instruction

Re: [tip:core/rseq 25/39] include/linux/rseq_entry.h:132:3: error: invalid operand for instruction

[Thomas Gleixner]

On Tue, Nov 25 2025 at 01:37, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/rseq
> head:   21782b3a5cd40892cb2995aa1ec3e74dd1112f1d
> commit: abc850e7616c91ebaa3f5ba3617ab0a104d45039 [25/39] rseq: Provide and use rseq_update_user_cs()
> config: powerpc-randconfig-002-20251124 (https://download.01.org/0day-ci/archive/20251125/202511250134.i0Jm8d7I-lkp@intel.com/config)
> compiler: clang version 16.0.6 (https://github.com/llvm/llvm-project 7cbf1a2591520c2491aa35339f227775f4d3adf6)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251125/202511250134.i0Jm8d7I-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202511250134.i0Jm8d7I-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
>    In file included from kernel/rseq.c:75:
>>> include/linux/rseq_entry.h:132:3: error: invalid operand for instruction
>                    unsafe_get_user(start_ip, &ucs->start_ip, efault);
>                    ^
>    include/linux/uaccess.h:606:2: note: expanded from macro 'unsafe_get_user'
>            arch_unsafe_get_user(x, ptr, local_label);      \
>            ^
>    arch/powerpc/include/asm/uaccess.h:458:2: note: expanded from macro 'arch_unsafe_get_user'
>            __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \
>            ^
>    arch/powerpc/include/asm/uaccess.h:282:2: note: expanded from macro '__get_user_size_goto'
>            __get_user_size_allowed(x, ptr, size, __gus_retval);    \
>            ^
>    arch/powerpc/include/asm/uaccess.h:273:10: note: expanded from macro '__get_user_size_allowed'
>            case 8: __get_user_asm2(x, (u64 __user *)ptr, retval);  break;  \
>                    ^
>    arch/powerpc/include/asm/uaccess.h:256:4: note: expanded from macro '__get_user_asm2'
>                    "       li %1+1,0\n"                    \
>                     ^
>    <inline asm>:7:5: note: instantiated into assembly here
>            li 31+1,0

Definitely not a problem of tip core/rseq. It just ends up in
__get_user_asm2() and then the compiler gets unhappy about the PowerPC
inline assembly for whatever reason.

Thanks,

        tglx
 

Re: [tip:core/rseq 25/39] include/linux/rseq_entry.h:132:3: error: invalid operand for instruction

[Philip Li]

On Mon, Nov 24, 2025 at 08:15:46PM +0100, Thomas Gleixner wrote:
> On Tue, Nov 25 2025 at 01:37, kernel test robot wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/rseq
> > head:   21782b3a5cd40892cb2995aa1ec3e74dd1112f1d
> > commit: abc850e7616c91ebaa3f5ba3617ab0a104d45039 [25/39] rseq: Provide and use rseq_update_user_cs()
> > config: powerpc-randconfig-002-20251124 (https://download.01.org/0day-ci/archive/20251125/202511250134.i0Jm8d7I-lkp@intel.com/config)
> > compiler: clang version 16.0.6 (https://github.com/llvm/llvm-project 7cbf1a2591520c2491aa35339f227775f4d3adf6)
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251125/202511250134.i0Jm8d7I-lkp@intel.com/reproduce)
> >
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202511250134.i0Jm8d7I-lkp@intel.com/
> >
> > All errors (new ones prefixed by >>):
> >
> >    In file included from kernel/rseq.c:75:
> >>> include/linux/rseq_entry.h:132:3: error: invalid operand for instruction
> >                    unsafe_get_user(start_ip, &ucs->start_ip, efault);
> >                    ^
> >    include/linux/uaccess.h:606:2: note: expanded from macro 'unsafe_get_user'
> >            arch_unsafe_get_user(x, ptr, local_label);      \
> >            ^
> >    arch/powerpc/include/asm/uaccess.h:458:2: note: expanded from macro 'arch_unsafe_get_user'
> >            __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \
> >            ^
> >    arch/powerpc/include/asm/uaccess.h:282:2: note: expanded from macro '__get_user_size_goto'
> >            __get_user_size_allowed(x, ptr, size, __gus_retval);    \
> >            ^
> >    arch/powerpc/include/asm/uaccess.h:273:10: note: expanded from macro '__get_user_size_allowed'
> >            case 8: __get_user_asm2(x, (u64 __user *)ptr, retval);  break;  \
> >                    ^
> >    arch/powerpc/include/asm/uaccess.h:256:4: note: expanded from macro '__get_user_asm2'
> >                    "       li %1+1,0\n"                    \
> >                     ^
> >    <inline asm>:7:5: note: instantiated into assembly here
> >            li 31+1,0
> 
> Definitely not a problem of tip core/rseq. It just ends up in
> __get_user_asm2() and then the compiler gets unhappy about the PowerPC
> inline assembly for whatever reason.

Thanks, got it, I will configure the bot to avoid sending further report
for this.

> 
> Thanks,
> 
>         tglx
>  
> 
> 

Re: [tip:core/rseq 25/39] include/linux/rseq_entry.h:132:3: error: invalid operand for instruction

[Christophe Leroy (CS GROUP)]

Le 24/11/2025 à 20:15, Thomas Gleixner a écrit :
> On Tue, Nov 25 2025 at 01:37, kernel test robot wrote:
>> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/rseq
>> head:   21782b3a5cd40892cb2995aa1ec3e74dd1112f1d
>> commit: abc850e7616c91ebaa3f5ba3617ab0a104d45039 [25/39] rseq: Provide and use rseq_update_user_cs()
>> config: powerpc-randconfig-002-20251124 (https://download.01.org/0day-ci/archive/20251125/202511250134.i0Jm8d7I-lkp@intel.com/config)
>> compiler: clang version 16.0.6 (https://github.com/llvm/llvm-project 7cbf1a2591520c2491aa35339f227775f4d3adf6)
>> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251125/202511250134.i0Jm8d7I-lkp@intel.com/reproduce)
>>
>> If you fix the issue in a separate patch/commit (i.e. not just a new version of
>> the same patch/commit), kindly add following tags
>> | Reported-by: kernel test robot <lkp@intel.com>
>> | Closes: https://lore.kernel.org/oe-kbuild-all/202511250134.i0Jm8d7I-lkp@intel.com/
>>
>> All errors (new ones prefixed by >>):
>>
>>     In file included from kernel/rseq.c:75:
>>>> include/linux/rseq_entry.h:132:3: error: invalid operand for instruction
>>                     unsafe_get_user(start_ip, &ucs->start_ip, efault);
>>                     ^
>>     include/linux/uaccess.h:606:2: note: expanded from macro 'unsafe_get_user'
>>             arch_unsafe_get_user(x, ptr, local_label);      \
>>             ^
>>     arch/powerpc/include/asm/uaccess.h:458:2: note: expanded from macro 'arch_unsafe_get_user'
>>             __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \
>>             ^
>>     arch/powerpc/include/asm/uaccess.h:282:2: note: expanded from macro '__get_user_size_goto'
>>             __get_user_size_allowed(x, ptr, size, __gus_retval);    \
>>             ^
>>     arch/powerpc/include/asm/uaccess.h:273:10: note: expanded from macro '__get_user_size_allowed'
>>             case 8: __get_user_asm2(x, (u64 __user *)ptr, retval);  break;  \
>>                     ^
>>     arch/powerpc/include/asm/uaccess.h:256:4: note: expanded from macro '__get_user_asm2'
>>                     "       li %1+1,0\n"                    \
>>                      ^
>>     <inline asm>:7:5: note: instantiated into assembly here
>>             li 31+1,0
> 
> Definitely not a problem of tip core/rseq. It just ends up in
> __get_user_asm2() and then the compiler gets unhappy about the PowerPC
> inline assembly for whatever reason.

I see it is a CLANG build.

CLANG might be less flexible, can you test with following change ?

diff --git a/arch/powerpc/include/asm/uaccess.h 
b/arch/powerpc/include/asm/uaccess.h
index 4f5a46a77fa2..33d5f7ade254 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -253,7 +253,7 @@ __gus_failed:								\
  		".section .fixup,\"ax\"\n"		\
  		"4:	li %0,%3\n"			\
  		"	li %1,0\n"			\
-		"	li %1+1,0\n"			\
+		"	li %L1,0\n"			\
  		"	b 3b\n"				\
  		".previous\n"				\
  		EX_TABLE(1b, 4b)			\


Thanks
Christophe

Re: [tip:core/rseq 25/39] include/linux/rseq_entry.h:132:3: error: invalid operand for instruction

[Nathan Chancellor]

On Tue, Nov 25, 2025 at 08:38:40AM +0100, Christophe Leroy (CS GROUP) wrote:
> 
> 
> Le 24/11/2025 à 20:15, Thomas Gleixner a écrit :
> > On Tue, Nov 25 2025 at 01:37, kernel test robot wrote:
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/rseq
> > > head:   21782b3a5cd40892cb2995aa1ec3e74dd1112f1d
> > > commit: abc850e7616c91ebaa3f5ba3617ab0a104d45039 [25/39] rseq: Provide and use rseq_update_user_cs()
> > > config: powerpc-randconfig-002-20251124 (https://download.01.org/0day-ci/archive/20251125/202511250134.i0Jm8d7I-lkp@intel.com/config)
> > > compiler: clang version 16.0.6 (https://github.com/llvm/llvm-project 7cbf1a2591520c2491aa35339f227775f4d3adf6)
> > > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251125/202511250134.i0Jm8d7I-lkp@intel.com/reproduce)
> > > 
> > > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > > the same patch/commit), kindly add following tags
> > > | Reported-by: kernel test robot <lkp@intel.com>
> > > | Closes: https://lore.kernel.org/oe-kbuild-all/202511250134.i0Jm8d7I-lkp@intel.com/
> > > 
> > > All errors (new ones prefixed by >>):
> > > 
> > >     In file included from kernel/rseq.c:75:
> > > > > include/linux/rseq_entry.h:132:3: error: invalid operand for instruction
> > >                     unsafe_get_user(start_ip, &ucs->start_ip, efault);
> > >                     ^
> > >     include/linux/uaccess.h:606:2: note: expanded from macro 'unsafe_get_user'
> > >             arch_unsafe_get_user(x, ptr, local_label);      \
> > >             ^
> > >     arch/powerpc/include/asm/uaccess.h:458:2: note: expanded from macro 'arch_unsafe_get_user'
> > >             __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \
> > >             ^
> > >     arch/powerpc/include/asm/uaccess.h:282:2: note: expanded from macro '__get_user_size_goto'
> > >             __get_user_size_allowed(x, ptr, size, __gus_retval);    \
> > >             ^
> > >     arch/powerpc/include/asm/uaccess.h:273:10: note: expanded from macro '__get_user_size_allowed'
> > >             case 8: __get_user_asm2(x, (u64 __user *)ptr, retval);  break;  \
> > >                     ^
> > >     arch/powerpc/include/asm/uaccess.h:256:4: note: expanded from macro '__get_user_asm2'
> > >                     "       li %1+1,0\n"                    \
> > >                      ^
> > >     <inline asm>:7:5: note: instantiated into assembly here
> > >             li 31+1,0
> > 
> > Definitely not a problem of tip core/rseq. It just ends up in
> > __get_user_asm2() and then the compiler gets unhappy about the PowerPC
> > inline assembly for whatever reason.
> 
> I see it is a CLANG build.
> 
> CLANG might be less flexible, can you test with following change ?

That avoids the error for me. I notice that this does not reproduce
beyond clang-16 for me so I am going to bisect LLVM to see what fixes
this error.

> diff --git a/arch/powerpc/include/asm/uaccess.h
> b/arch/powerpc/include/asm/uaccess.h
> index 4f5a46a77fa2..33d5f7ade254 100644
> --- a/arch/powerpc/include/asm/uaccess.h
> +++ b/arch/powerpc/include/asm/uaccess.h
> @@ -253,7 +253,7 @@ __gus_failed:								\
>  		".section .fixup,\"ax\"\n"		\
>  		"4:	li %0,%3\n"			\
>  		"	li %1,0\n"			\
> -		"	li %1+1,0\n"			\
> +		"	li %L1,0\n"			\
>  		"	b 3b\n"				\
>  		".previous\n"				\
>  		EX_TABLE(1b, 4b)			\
> 
> 
> Thanks
> Christophe

Re: [tip:core/rseq 25/39] include/linux/rseq_entry.h:132:3: error: invalid operand for instruction

[Nathan Chancellor]

On Tue, Nov 25, 2025 at 04:18:34PM -0700, Nathan Chancellor wrote:
> That avoids the error for me. I notice that this does not reproduce
> beyond clang-16 for me so I am going to bisect LLVM to see what fixes
> this error.

Oh, it is because of commit e2ffa15b9baa ("kbuild: Disable
CC_HAS_ASM_GOTO_OUTPUT on clang < 17"). Prior to that change, all
supported versions of clang would use the CONFIG_CC_HAS_ASM_GOTO_OUTPUT
blocks in arch/powerpc/include/asm/uaccess.h, whereas now clang-15 and
clang-16 will use the variants without asm goto with outputs.

Cheers,
Nathan