Re: [PATCH] vsprintf: Neaten %pK kptr_restrict, save a bit of codespace

From: Andrew Morton
Date: Wed Jan 19 2011 - 17:50:35 EST


On Thu, 13 Jan 2011 12:21:12 -0800
Joe Perches <joe@xxxxxxxxxxx> wrote:

> If kptr restrictions are on, just set the passed pointer to NULL.
>
> $ size lib/vsprintf.o.*
> text data bss dec hex filename
> 8247 4 2 8253 203d lib/vsprintf.o.new
> 8282 4 2 8288 2060 lib/vsprintf.o.old
>
> Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
>
> ---
>
> lib/vsprintf.c | 14 +++++---------
> 1 files changed, 5 insertions(+), 9 deletions(-)
>
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index d3023df..070d134 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -1047,16 +1047,12 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
> if (spec.field_width == -1)
> spec.field_width = 2 * sizeof(void *);
> return string(buf, end, "pK-error", spec);
> - } else if ((kptr_restrict == 0) ||
> - (kptr_restrict == 1 &&
> - has_capability_noaudit(current, CAP_SYSLOG)))
> - break;
> -
> - if (spec.field_width == -1) {
> - spec.field_width = 2 * sizeof(void *);
> - spec.flags |= ZEROPAD;
> }
> - return number(buf, end, 0, spec);
> + if (!((kptr_restrict == 0) ||
> + (kptr_restrict == 1 &&
> + has_capability_noaudit(current, CAP_SYSLOG))))
> + ptr = NULL;
> + break;
> }
> spec.flags |= SMALL;
> if (spec.field_width == -1) {

This hurts my brain. Does it work?
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