linux-kernel - Re: [PATCH] Add VDSO time function support for x86 32-bit kernel

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]

Date:	Wed, 12 Dec 2012 15:34:36 -0800
From:	"H. Peter Anvin" <hpa@...or.com>
To:	stefani@...bold.net
CC:	linux-kernel@...r.kernel.org, x86@...nel.org, tglx@...utronix.de,
	mingo@...hat.com, ak@...ux.intel.com, aarcange@...hat.com,
	john.stultz@...aro.org, luto@...capital.net
Subject: Re: [PATCH] Add VDSO time function support for x86 32-bit kernel

On 12/12/2012 12:19 PM, stefani@...bold.net wrote:
> diff --git a/arch/x86/vdso/vdso32/vclock_gettime.c b/arch/x86/vdso/vdso32/vclock_gettime.c
> new file mode 100644
> index 0000000..c9a1909
> --- /dev/null
> +++ b/arch/x86/vdso/vdso32/vclock_gettime.c
> @@ -0,0 +1,7 @@
> +/*
> + * since vgtod layout differs between X86_64 and x86_32, it is not possible to
> + * provide a 32 bit vclock with a 64 bit kernel
> + */
> +#ifdef CONFIG_X86_32
> +#include "../vclock_gettime.c"
> +#endif

This is where this goes fail.  Sorry, it is not acceptable to introduce 
an ABI on x86-32 without providing it also on x86-64 in compatibility mode.

I also don't believe it is not possible... it might require some more 
cleverness; perhaps we need to do the 32-bit vgtod in such a way that it 
*is* compatible with 64 bits.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/