[PATCH 2/2] xen/common: llc-coloring: reject empty color tokens

[Mykola Kvach <xakep.amatop@xxxxxxxxx>]

From: Mykola Kvach <mykola_kvach@xxxxxxxx>

parse_color_config() currently accepts delimiters where a color value
is expected because simple_strtoul() returns zero without advancing the
input pointer. This makes strings such as ",2-6", "-10,19-20" or
"1,,2" look as if an empty value was color 0.

Also add the missing newline to the DT color parsing error message.

Fixes: 6cdea3444eaf ("xen/arm: add Dom0 cache coloring support")
Signed-off-by: Mykola Kvach <mykola_kvach@xxxxxxxx>
---
 xen/common/llc-coloring.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/xen/common/llc-coloring.c b/xen/common/llc-coloring.c
index 2606cb0977..5d00d4b40e 100644
--- a/xen/common/llc-coloring.c
+++ b/xen/common/llc-coloring.c
@@ -64,14 +64,21 @@ static int __init parse_color_config(const char *buf, 
unsigned int colors[],
 
     while ( *s != '\0' )
     {
+        const char *endp;
         unsigned int color, start, end;
 
-        start = simple_strtoul(s, &s, 0);
+        start = simple_strtoul(s, &endp, 0);
+        if ( endp == s )
+            goto fail;
+        s = endp;
 
         if ( *s == '-' )    /* Range */
         {
             s++;
-            end = simple_strtoul(s, &s, 0);
+            end = simple_strtoul(s, &endp, 0);
+            if ( endp == s )
+                goto fail;
+            s = endp;
         }
         else                /* Single value */
             end = start;
@@ -334,7 +341,7 @@ int __init domain_set_llc_colors_from_str(struct domain *d, 
const char *str)
     err = parse_color_config(str, colors, max_nr_colors, &num_colors);
     if ( err )
     {
-        printk(XENLOG_ERR "Error parsing LLC color configuration");
+        printk(XENLOG_ERR "Error parsing LLC color configuration\n");
         xfree(colors);
         return err;
     }
-- 
2.43.0