[PATCH] RISC-V: fix R_RISCV_ADD32/R_RISCV_SUB32 relocations

[PATCH] RISC-V: fix R_RISCV_ADD32/R_RISCV_SUB32 relocations

[Andreas Schwab]

The R_RISCV_ADD32/R_RISCV_SUB32 relocations should add/subtract the
address of the symbol (without overflow check), not its contents.

Signed-off-by: Andreas Schwab <schwab@suse.de>
---
 arch/riscv/kernel/module.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
index 29d265d0cf..46aacf6148 100644
--- a/arch/riscv/kernel/module.c
+++ b/arch/riscv/kernel/module.c
@@ -265,14 +265,14 @@ static int apply_r_riscv_align_rela(struct module *me, u32 *location,
 static int apply_r_riscv_add32_rela(struct module *me, u32 *location,
 				    Elf_Addr v)
 {
-	*(u32 *)location += (*(u32 *)v);
+	*(u32 *)location += (u32)v;
 	return 0;
 }
 
 static int apply_r_riscv_sub32_rela(struct module *me, u32 *location,
 				    Elf_Addr v)
 {
-	*(u32 *)location -= (*(u32 *)v);
+	*(u32 *)location -= (u32)v;
 	return 0;
 }
 
-- 
2.17.1


-- 
Andreas Schwab, SUSE Labs, schwab at suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."

[PATCH] RISC-V: fix R_RISCV_ADD32/R_RISCV_SUB32 relocations

[Palmer Dabbelt]

On Tue, 12 Jun 2018 10:26:36 PDT (-0700), schwab at suse.de wrote:
> The R_RISCV_ADD32/R_RISCV_SUB32 relocations should add/subtract the
> address of the symbol (without overflow check), not its contents.
>
> Signed-off-by: Andreas Schwab <schwab@suse.de>
> ---
>  arch/riscv/kernel/module.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
> index 29d265d0cf..46aacf6148 100644
> --- a/arch/riscv/kernel/module.c
> +++ b/arch/riscv/kernel/module.c
> @@ -265,14 +265,14 @@ static int apply_r_riscv_align_rela(struct module *me, u32 *location,
>  static int apply_r_riscv_add32_rela(struct module *me, u32 *location,
>  				    Elf_Addr v)
>  {
> -	*(u32 *)location += (*(u32 *)v);
> +	*(u32 *)location += (u32)v;
>  	return 0;
>  }
>
>  static int apply_r_riscv_sub32_rela(struct module *me, u32 *location,
>  				    Elf_Addr v)
>  {
> -	*(u32 *)location -= (*(u32 *)v);
> +	*(u32 *)location -= (u32)v;
>  	return 0;
>  }

Oops, sorry I missed those.  The entire relocation set might be worth a 
once-over, as there's a lot of bit twiddling in here and I wouldn't be 
surprised if I missed something else as well.

The RISC-V merge window has closed (I tag on Monday, let it bake until 
Wednesday, and then submit the PR), so I'll target this for my post-RC1 pull 
request.

Thanks!