Re: [PATCH 3/5] x86: simplify early command line parsing

Borislav Petkov
2016-01-06T17:10:52Z

On Tue, Dec 22, 2015 at 02:52:41PM -0800, Dave Hansen wrote:
>
> From: Dave Hansen <dave.hansen@linux.intel.com>
>
> __cmdline_find_option_bool() tries to account for both
> NULL-terminated and non-NULL-terminated strings. It keeps 'pos'
> to look for the end of the buffer and also looks for '!c' in a
> bunch of places to look for NULL termination.
>
> But, it also calls strlen(). You can't call strlen on a
> non-NULL-terminated string.
>
> If !strlen(cmdline), then cmdline[0]=='\0'. In that case, we
> will go in to the while() loop, set c='\0', hit st_wordstart,
> notice !c, and will immediately return 0.
>
> So, remove the strlen(). It is unnecessary and unsafe.
>
> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Borislav Petkov <bp@suse.de>
> Cc: H. Peter Anvin <hpa@zytor.com>
> Cc: linux-kernel@vger.kernel.org
> Cc: fenghua.yu@intel.com
> Cc: yu-cheng.yu@intel.com
> ---
>
> b/arch/x86/lib/cmdline.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff -puN arch/x86/lib/cmdline.c~x86-early-command-line-non-term arch/x86/lib/cmdline.c
> --- a/arch/x86/lib/cmdline.c~x86-early-command-line-non-term 2015-12-22 11:56:59.454186167 -0800
> +++ b/arch/x86/lib/cmdline.c 2015-12-22 11:56:59.457186302 -0800
> @@ -39,9 +39,6 @@ int cmdline_find_option_bool(const char
> if (!cmdline)
> return -1; /* No command line */
>
> - if (!strlen(cmdline))
> - return 0;
> -

Patch 1 adds the strlen(), this patch removes it. Please merge both patches.

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Regards/Gruss,
Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
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