riscv: Fix alternatives issues on for-next

[PATCH 1/2] riscv: Fix early alternative patching

Posted by Samuel Holland 2 years, 12 months ago

Now that the text to patch is located using a relative offset from the
alternative entry, the text address should be computed without applying
the kernel mapping offset, both before and after VM setup.

Fixes: 8d23e94a4433 ("riscv: switch to relative alternative entries")
Signed-off-by: Samuel Holland <samuel@sholland.org>
---

 arch/riscv/errata/thead/errata.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c
index c0bea5c94128..1dd90a5f86f0 100644
--- a/arch/riscv/errata/thead/errata.c
+++ b/arch/riscv/errata/thead/errata.c
@@ -102,9 +102,7 @@ void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct al
 
 			/* On vm-alternatives, the mmu isn't running yet */
 			if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
-				memcpy((void *)__pa_symbol(oldptr),
-				       (void *)__pa_symbol(altptr),
-				       alt->alt_len);
+				memcpy(oldptr, altptr, alt->alt_len);
 			else
 				patch_text_nosync(oldptr, altptr, alt->alt_len);
 		}
-- 
2.37.4

Re: [PATCH 1/2] riscv: Fix early alternative patching

Posted by Jisheng Zhang 2 years, 12 months ago

On Sat, Feb 11, 2023 at 08:15:32PM -0600, Samuel Holland wrote:
> Now that the text to patch is located using a relative offset from the
> alternative entry, the text address should be computed without applying
> the kernel mapping offset, both before and after VM setup.

Good catch!
> 
> Fixes: 8d23e94a4433 ("riscv: switch to relative alternative entries")
> Signed-off-by: Samuel Holland <samuel@sholland.org>

Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
> ---
> 
>  arch/riscv/errata/thead/errata.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c
> index c0bea5c94128..1dd90a5f86f0 100644
> --- a/arch/riscv/errata/thead/errata.c
> +++ b/arch/riscv/errata/thead/errata.c
> @@ -102,9 +102,7 @@ void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct al
>  
>  			/* On vm-alternatives, the mmu isn't running yet */
>  			if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
> -				memcpy((void *)__pa_symbol(oldptr),
> -				       (void *)__pa_symbol(altptr),
> -				       alt->alt_len);
> +				memcpy(oldptr, altptr, alt->alt_len);
>  			else
>  				patch_text_nosync(oldptr, altptr, alt->alt_len);
>  		}
> -- 
> 2.37.4
>

Re: [PATCH 1/2] riscv: Fix early alternative patching

Posted by Guo Ren 2 years, 12 months ago

On Sun, Feb 12, 2023 at 10:15 AM Samuel Holland <samuel@sholland.org> wrote:
>
> Now that the text to patch is located using a relative offset from the
> alternative entry, the text address should be computed without applying
> the kernel mapping offset, both before and after VM setup.
>
> Fixes: 8d23e94a4433 ("riscv: switch to relative alternative entries")
> Signed-off-by: Samuel Holland <samuel@sholland.org>
> ---
>
>  arch/riscv/errata/thead/errata.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c
> index c0bea5c94128..1dd90a5f86f0 100644
> --- a/arch/riscv/errata/thead/errata.c
> +++ b/arch/riscv/errata/thead/errata.c
> @@ -102,9 +102,7 @@ void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct al
>
>                         /* On vm-alternatives, the mmu isn't running yet */
>                         if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
> -                               memcpy((void *)__pa_symbol(oldptr),
> -                                      (void *)__pa_symbol(altptr),
> -                                      alt->alt_len);
> +                               memcpy(oldptr, altptr, alt->alt_len);
>                         else
>                                 patch_text_nosync(oldptr, altptr, alt->alt_len);
>                 }
> --
> 2.37.4
>
Reviewed-by: Guo Ren <guoren@kernel.org>

-- 
Best Regards
 Guo Ren

Re: [PATCH 1/2] riscv: Fix early alternative patching

Posted by Conor Dooley 2 years, 12 months ago

On Sat, Feb 11, 2023 at 08:15:32PM -0600, Samuel Holland wrote:
> Now that the text to patch is located using a relative offset from the
> alternative entry, the text address should be computed without applying
> the kernel mapping offset, both before and after VM setup.
> 
> Fixes: 8d23e94a4433 ("riscv: switch to relative alternative entries")

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>

> Signed-off-by: Samuel Holland <samuel@sholland.org>
> ---
> 
>  arch/riscv/errata/thead/errata.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/arch/riscv/errata/thead/errata.c b/arch/riscv/errata/thead/errata.c
> index c0bea5c94128..1dd90a5f86f0 100644
> --- a/arch/riscv/errata/thead/errata.c
> +++ b/arch/riscv/errata/thead/errata.c
> @@ -102,9 +102,7 @@ void __init_or_module thead_errata_patch_func(struct alt_entry *begin, struct al
>  
>  			/* On vm-alternatives, the mmu isn't running yet */
>  			if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
> -				memcpy((void *)__pa_symbol(oldptr),
> -				       (void *)__pa_symbol(altptr),
> -				       alt->alt_len);
> +				memcpy(oldptr, altptr, alt->alt_len);
>  			else
>  				patch_text_nosync(oldptr, altptr, alt->alt_len);
>  		}
> -- 
> 2.37.4
>