[PATCH v2 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 fix the DT color parsing error message by adding the missing
newline and including the domain ID, matching the style of the color
validation error below.

Fixes: 6cdea3444eaf ("xen/arm: add Dom0 cache coloring support")
Signed-off-by: Mykola Kvach <mykola_kvach@xxxxxxxx>
Reviewed-by: Michal Orzel <michal.orzel@xxxxxxx>
---
Changes in v2:
- Include the domain ID in the LLC color parsing error message.
- Add Reviewed-by tag.
---
 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..b5de5787c1 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 "%pd: error parsing LLC color configuration\n", d);
         xfree(colors);
         return err;
     }
-- 
2.43.0