[PATCH] Re: [Xen-staging] [xen-unstable] [XEN] Avoid use of GNU-specific memmem().

[Alex Williamson <alex.williamson@hp.com>]

On Thu, 2007-01-04 at 10:18 +0000, Xen staging patchbot-unstable wrote:
> # HG changeset patch
> # User kfraser@localhost.localdomain
> # Date 1167905854 0
> # Node ID bdbfbfdfbd64ddedc775d55f1a9e842847fea7b2
> # Parent  60f91c9f1a248491e2f216d009a27a4c7e5e67d4
> [XEN] Avoid use of GNU-specific memmem().

> --- a/xen/tools/symbols.c	Wed Jan 03 23:53:27 2007 +0000
> +++ b/xen/tools/symbols.c	Thu Jan 04 10:17:34 2007 +0000
> @@ -350,6 +350,14 @@ static void build_initial_tok_table(void
>  	table_cnt = pos;
>  }
>  
> +static void *memmem_pvt(void *h, size_t hlen, void *n, size_t nlen)
> +{
> +	char *p;
> +	for (p = h; (p - (char *)h) <= (hlen - nlen); p++)
> +		if (!memcmp(p, n, nlen)) return p;
> +	return NULL;
> +}

   size_t is unsigned, (hlen - nlen) can wrap and cause a segfault.  The
patch below fixes it.  Thanks,

	Alex

Signed-off-by: Alex Williamson <alex.williamson@hp.com>
---

diff -r a8930b548048 xen/tools/symbols.c
--- a/xen/tools/symbols.c	Fri Jan 05 14:36:55 2007 -0700
+++ b/xen/tools/symbols.c	Fri Jan 05 14:58:21 2007 -0700
@@ -353,7 +353,7 @@ static void *memmem_pvt(void *h, size_t 
 static void *memmem_pvt(void *h, size_t hlen, void *n, size_t nlen)
 {
 	char *p;
-	for (p = h; (p - (char *)h) <= (hlen - nlen); p++)
+	for (p = h; (p - (char *)h) <= (long)(hlen - nlen); p++)
 		if (!memcmp(p, n, nlen)) return p;
 	return NULL;
 }