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* [PATCH v2] RISC-V: Make R_RISCV_SUB6 conforms to riscv ABI standard
@ 2022-11-21 12:00 zengxiao
  2022-11-23  2:52 ` Nelson Chu
  0 siblings, 1 reply; 3+ messages in thread
From: zengxiao @ 2022-11-21 12:00 UTC (permalink / raw)
  To: binutils; +Cc: shihua, nelson, palmer, kito.cheng, Xiao Zeng

From: Xiao Zeng <zengxiao@eswincomputing.com>

The R_RISCV_SUB6 only the lower 6 bits of the code are valid, which
can be found in 8.5. Relocations of:
https://github.com/riscv-non-isa/riscv-elf-psabi-doc/releases/download/v1.0-rc4/riscv-abi.pdf

bfd/ChangeLog:

        * elfnn-riscv.c (riscv_elf_relocate_section): Take the R_RISCV_SUB6
	lower 6 bits as the significant bit.
        * elfxx-riscv.c (riscv_elf_add_sub_reloc): Likewise.
---
 bfd/elfnn-riscv.c | 4 ++++
 bfd/elfxx-riscv.c | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/bfd/elfnn-riscv.c b/bfd/elfnn-riscv.c
index 0570a971b5a..a02aa64786e 100644
--- a/bfd/elfnn-riscv.c
+++ b/bfd/elfnn-riscv.c
@@ -2427,6 +2427,10 @@ riscv_elf_relocate_section (bfd *output_bfd,
 	  break;
 
 	case R_RISCV_SUB6:
+	  relocation = (old_value & ~howto->dst_mask)
+		       | (((old_value & howto->dst_mask) - relocation)
+			  & howto->dst_mask);
+	  break;
 	case R_RISCV_SUB8:
 	case R_RISCV_SUB16:
 	case R_RISCV_SUB32:
diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
index afbde56b9e5..2db24acf7a5 100644
--- a/bfd/elfxx-riscv.c
+++ b/bfd/elfxx-riscv.c
@@ -994,6 +994,10 @@ riscv_elf_add_sub_reloc (bfd *abfd,
       relocation = old_value + relocation;
       break;
     case R_RISCV_SUB6:
+      relocation = (old_value & ~howto->dst_mask)
+		    | (((old_value & howto->dst_mask) - relocation)
+		      & howto->dst_mask);
+      break;
     case R_RISCV_SUB8:
     case R_RISCV_SUB16:
     case R_RISCV_SUB32:
-- 
2.34.1


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] RISC-V: Make R_RISCV_SUB6 conforms to riscv ABI standard
  2022-11-21 12:00 [PATCH v2] RISC-V: Make R_RISCV_SUB6 conforms to riscv ABI standard zengxiao
@ 2022-11-23  2:52 ` Nelson Chu
  2022-11-23  9:05   ` Xiao Zeng
  0 siblings, 1 reply; 3+ messages in thread
From: Nelson Chu @ 2022-11-23  2:52 UTC (permalink / raw)
  To: zengxiao; +Cc: binutils, shihua, palmer, kito.cheng

Thanks for fixing this.  We also need to add the out-of-range check
for R_RISCV_SUB6 in the riscv_elf_add_sub_reloc, and the overflow
checks for all ADD/SUB/SET relocations, but since they can be added in
the later patches, so I committed this one after passing the
riscv-gnu-toolchain regressions.

Thanks
Nelson

On Mon, Nov 21, 2022 at 8:02 PM <zengxiao@eswincomputing.com> wrote:
>
> From: Xiao Zeng <zengxiao@eswincomputing.com>
>
> The R_RISCV_SUB6 only the lower 6 bits of the code are valid, which
> can be found in 8.5. Relocations of:
> https://github.com/riscv-non-isa/riscv-elf-psabi-doc/releases/download/v1.0-rc4/riscv-abi.pdf
>
> bfd/ChangeLog:
>
>         * elfnn-riscv.c (riscv_elf_relocate_section): Take the R_RISCV_SUB6
>         lower 6 bits as the significant bit.
>         * elfxx-riscv.c (riscv_elf_add_sub_reloc): Likewise.
> ---
>  bfd/elfnn-riscv.c | 4 ++++
>  bfd/elfxx-riscv.c | 4 ++++
>  2 files changed, 8 insertions(+)
>
> diff --git a/bfd/elfnn-riscv.c b/bfd/elfnn-riscv.c
> index 0570a971b5a..a02aa64786e 100644
> --- a/bfd/elfnn-riscv.c
> +++ b/bfd/elfnn-riscv.c
> @@ -2427,6 +2427,10 @@ riscv_elf_relocate_section (bfd *output_bfd,
>           break;
>
>         case R_RISCV_SUB6:
> +         relocation = (old_value & ~howto->dst_mask)
> +                      | (((old_value & howto->dst_mask) - relocation)
> +                         & howto->dst_mask);
> +         break;

The old_value needs to be defined, but it's easy enough to add, so I fixed it.

>         case R_RISCV_SUB8:
>         case R_RISCV_SUB16:
>         case R_RISCV_SUB32:
> diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
> index afbde56b9e5..2db24acf7a5 100644
> --- a/bfd/elfxx-riscv.c
> +++ b/bfd/elfxx-riscv.c
> @@ -994,6 +994,10 @@ riscv_elf_add_sub_reloc (bfd *abfd,
>        relocation = old_value + relocation;
>        break;
>      case R_RISCV_SUB6:
> +      relocation = (old_value & ~howto->dst_mask)
> +                   | (((old_value & howto->dst_mask) - relocation)
> +                     & howto->dst_mask);
> +      break;
>      case R_RISCV_SUB8:
>      case R_RISCV_SUB16:
>      case R_RISCV_SUB32:
> --
> 2.34.1
>

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] RISC-V: Make R_RISCV_SUB6 conforms to riscv ABI standard
  2022-11-23  2:52 ` Nelson Chu
@ 2022-11-23  9:05   ` Xiao Zeng
  0 siblings, 0 replies; 3+ messages in thread
From: Xiao Zeng @ 2022-11-23  9:05 UTC (permalink / raw)
  To: Nelson Chu; +Cc: binutils, shihua, palmer, kito.cheng

On Wed, Nov 23, 2022 at 12:00:00 AM  Nelson Chu <nelson@rivosinc.com> wrote:
>
>Thanks for fixing this.  We also need to add the out-of-range check
>for R_RISCV_SUB6 in the riscv_elf_add_sub_reloc, and the overflow
>checks for all ADD/SUB/SET relocations, but since they can be added in
>the later patches, so I committed this one after passing the
>riscv-gnu-toolchain regressions. 

OK. In the next patch, I will solve this problem.

>
>Thanks
>Nelson
>
>On Mon, Nov 21, 2022 at 8:02 PM <zengxiao@eswincomputing.com> wrote:
>>
>> From: Xiao Zeng <zengxiao@eswincomputing.com>
>>
>> The R_RISCV_SUB6 only the lower 6 bits of the code are valid, which
>> can be found in 8.5. Relocations of:
>> https://github.com/riscv-non-isa/riscv-elf-psabi-doc/releases/download/v1.0-rc4/riscv-abi.pdf
>>
>> bfd/ChangeLog:
>>
>>         * elfnn-riscv.c (riscv_elf_relocate_section): Take the R_RISCV_SUB6
>>         lower 6 bits as the significant bit.
>>         * elfxx-riscv.c (riscv_elf_add_sub_reloc): Likewise.
>> ---
>>  bfd/elfnn-riscv.c | 4 ++++
>>  bfd/elfxx-riscv.c | 4 ++++
>>  2 files changed, 8 insertions(+)
>>
>> diff --git a/bfd/elfnn-riscv.c b/bfd/elfnn-riscv.c
>> index 0570a971b5a..a02aa64786e 100644
>> --- a/bfd/elfnn-riscv.c
>> +++ b/bfd/elfnn-riscv.c
>> @@ -2427,6 +2427,10 @@ riscv_elf_relocate_section (bfd *output_bfd,
>>           break;
>>
>>         case R_RISCV_SUB6:
>> +         relocation = (old_value & ~howto->dst_mask)
>> +                      | (((old_value & howto->dst_mask) - relocation)
>> +                         & howto->dst_mask);
>> +         break;
>
>The old_value needs to be defined, but it's easy enough to add, so I fixed it. 

Thanks Nelson

>
>>         case R_RISCV_SUB8:
>>         case R_RISCV_SUB16:
>>         case R_RISCV_SUB32:
>> diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
>> index afbde56b9e5..2db24acf7a5 100644
>> --- a/bfd/elfxx-riscv.c
>> +++ b/bfd/elfxx-riscv.c
>> @@ -994,6 +994,10 @@ riscv_elf_add_sub_reloc (bfd *abfd,
>>        relocation = old_value + relocation;
>>        break;
>>      case R_RISCV_SUB6:
>> +      relocation = (old_value & ~howto->dst_mask)
>> +                   | (((old_value & howto->dst_mask) - relocation)
>> +                     & howto->dst_mask);
>> +      break;
>>      case R_RISCV_SUB8:
>>      case R_RISCV_SUB16:
>>      case R_RISCV_SUB32:
>> --
>> 2.34.1
>> 

Thanks
Xiao

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2022-11-23  9:05 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2022-11-21 12:00 [PATCH v2] RISC-V: Make R_RISCV_SUB6 conforms to riscv ABI standard zengxiao
2022-11-23  2:52 ` Nelson Chu
2022-11-23  9:05   ` Xiao Zeng

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