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

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Message-ID: <Y+ppd3YEM0BB6O5l@xhacker>
Date:   Tue, 14 Feb 2023 00:46:47 +0800
From:   Jisheng Zhang <jszhang@...nel.org>
To:     Samuel Holland <samuel@...lland.org>
Cc:     Heiko Stuebner <heiko@...ech.de>,
        Palmer Dabbelt <palmer@...belt.com>,
        linux-riscv@...ts.infradead.org,
        Andrew Jones <ajones@...tanamicro.com>,
        Christoph Muellner <christoph.muellner@...ll.eu>,
        Conor Dooley <conor.dooley@...rochip.com>,
        Guo Ren <guoren@...nel.org>,
        Heiko Stuebner <heiko.stuebner@...ll.eu>,
        Nathan Chancellor <nathan@...nel.org>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] riscv: Fix early alternative patching

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@...lland.org>

Reviewed-by: Jisheng Zhang <jszhang@...nel.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
>