linux-kernel - Re: [PATCH] RISC-V: Always define XIP

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <b674bc91-8228-9236-f3ec-8f65bb5620c8@ghiti.fr>
Date:   Wed, 28 Apr 2021 04:25:55 -0400
From:   Alex Ghiti <alex@...ti.fr>
To:     Palmer Dabbelt <palmer@...belt.com>,
        linux-riscv@...ts.infradead.org
Cc:     Paul Walmsley <paul.walmsley@...ive.com>, aou@...s.berkeley.edu,
        akpm@...ux-foundation.org, Atish Patra <Atish.Patra@....com>,
        Anup Patel <Anup.Patel@....com>, wangkefeng.wang@...wei.com,
        rppt@...nel.org, vitaly.wool@...sulko.com, greentime.hu@...ive.com,
        0x7f454c46@...il.com, chenhuang5@...wei.com,
        linux-kernel@...r.kernel.org, kernel-team@...roid.com,
        Palmer Dabbelt <palmerdabbelt@...gle.com>,
        Guenter Roeck <linux@...ck-us.net>
Subject: Re: [PATCH] RISC-V: Always define XIP_FIXUP

Le 4/27/21 à 11:34 PM, Palmer Dabbelt a écrit :
> From: Palmer Dabbelt <palmerdabbelt@...gle.com>
> 
> XIP depends on MMU, but XIP_FIXUP is defined throughout the kernel in
> order to avoid excessive ifdefs.  This just makes sure to always define
> XIP_FIXIP, which will fix MMU=n builds.

A small typo here.

> 
> Fixes: 44c922572952 ("RISC-V: enable XIP")
> Reported-by: Guenter Roeck <linux@...ck-us.net>
> Signed-off-by: Palmer Dabbelt <palmerdabbelt@...gle.com>
> ---
>   arch/riscv/include/asm/pgtable.h | 24 ++++++++++++------------
>   1 file changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index 2f1384e14e31..fd749351f432 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -73,18 +73,6 @@
>   #endif
>   #define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
>   
> -#ifdef CONFIG_XIP_KERNEL
> -#define XIP_OFFSET		SZ_8M
> -#define XIP_FIXUP(addr) ({							\
> -	uintptr_t __a = (uintptr_t)(addr);					\
> -	(__a >= CONFIG_XIP_PHYS_ADDR && __a < CONFIG_XIP_PHYS_ADDR + SZ_16M) ?	\
> -		__a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - XIP_OFFSET :\
> -		__a;								\
> -	})
> -#else
> -#define XIP_FIXUP(addr)		(addr)
> -#endif /* CONFIG_XIP_KERNEL */
> -
>   #endif
>   
>   #ifndef __ASSEMBLY__
> @@ -101,6 +89,18 @@
>   #include <asm/pgtable-32.h>
>   #endif /* CONFIG_64BIT */
>   
> +#ifdef CONFIG_XIP_KERNEL
> +#define XIP_OFFSET		SZ_8M


XIP_OFFSET is used in head.S and then this breaks XIP_KERNEL. XIP_OFFSET 
must live outside the ifndef __ASSEMBLY__.


> +#define XIP_FIXUP(addr) ({							\
> +	uintptr_t __a = (uintptr_t)(addr);					\
> +	(__a >= CONFIG_XIP_PHYS_ADDR && __a < CONFIG_XIP_PHYS_ADDR + SZ_16M) ?	\
> +		__a - CONFIG_XIP_PHYS_ADDR + CONFIG_PHYS_RAM_BASE - XIP_OFFSET :\
> +		__a;								\
> +	})
> +#else
> +#define XIP_FIXUP(addr)		(addr)
> +#endif /* CONFIG_XIP_KERNEL */
> +
>   #ifdef CONFIG_MMU
>   /* Number of entries in the page global directory */
>   #define PTRS_PER_PGD    (PAGE_SIZE / sizeof(pgd_t))
> 

Thank you for doing that!

Alex