[Qemu-trivial] [PATCH] cutils: refine strtol error handling in parse_debug_env

[Paolo Bonzini]

Avoid truncation of a 64-bit long to a 32-bit int, and check for errno
(especially ERANGE).

Signed-off-by: Paolo Bonzini <address@hidden>
---
        v1->v2: clear errno before strtol
---
 util/cutils.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/util/cutils.c b/util/cutils.c
index dbe7412..9312e45 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -523,16 +523,17 @@ int parse_debug_env(const char *name, int max, int 
initial)
 {
     char *debug_env = getenv(name);
     char *inv = NULL;
-    int debug;
+    long debug;
 
     if (!debug_env) {
         return initial;
     }
+    errno = 0;
     debug = strtol(debug_env, &inv, 10);
     if (inv == debug_env) {
         return initial;
     }
-    if (debug < 0 || debug > max) {
+    if (debug < 0 || debug > max || errno != 0) {
         fprintf(stderr, "warning: %s not in [0, %d]", name, max);
         return initial;
     }
-- 
1.8.3.1