X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=arch%2Ftile%2Fgxio%2Fmpipe.c;h=320ff5e6e61ed5ff9849f3ce30c4a9fac69343e9;hb=bceb7efa6a7e656bfaa67b6f54925e7db75bcd52;hp=5301a9ffbae10917d1a7bd38ffd0ea136d8def6c;hpb=f1da3458e9d915d72b0dd30a7c41c3aff8f03589;p=cascardo%2Flinux.git

diff --git a/arch/tile/gxio/mpipe.c b/arch/tile/gxio/mpipe.c
index 5301a9ffbae1..320ff5e6e61e 100644
--- a/arch/tile/gxio/mpipe.c
+++ b/arch/tile/gxio/mpipe.c
@@ -29,6 +29,32 @@
 /* HACK: Avoid pointless "shadow" warnings. */
 #define link link_shadow
 
+/**
+ * strscpy - Copy a C-string into a sized buffer, but only if it fits
+ * @dest: Where to copy the string to
+ * @src: Where to copy the string from
+ * @size: size of destination buffer
+ *
+ * Use this routine to avoid copying too-long strings.
+ * The routine returns the total number of bytes copied
+ * (including the trailing NUL) or zero if the buffer wasn't
+ * big enough.  To ensure that programmers pay attention
+ * to the return code, the destination has a single NUL
+ * written at the front (if size is non-zero) when the
+ * buffer is not big enough.
+ */
+static size_t strscpy(char *dest, const char *src, size_t size)
+{
+	size_t len = strnlen(src, size) + 1;
+	if (len > size) {
+		if (size)
+			dest[0] = '\0';
+		return 0;
+	}
+	memcpy(dest, src, len);
+	return len;
+}
+
 int gxio_mpipe_init(gxio_mpipe_context_t *context, unsigned int mpipe_index)
 {
 	char file[32];
@@ -511,8 +537,8 @@ int gxio_mpipe_link_instance(const char *link_name)
 	if (!context)
 		return GXIO_ERR_NO_DEVICE;
 
-	strncpy(name.name, link_name, sizeof(name.name));
-	name.name[GXIO_MPIPE_LINK_NAME_LEN - 1] = '\0';
+	if (strscpy(name.name, link_name, sizeof(name.name)) == 0)
+		return GXIO_ERR_NO_DEVICE;
 
 	return gxio_mpipe_info_instance_aux(context, name);
 }
@@ -529,7 +555,8 @@ int gxio_mpipe_link_enumerate_mac(int idx, char *link_name, uint8_t *link_mac)
 
 	rv = gxio_mpipe_info_enumerate_aux(context, idx, &name, &mac);
 	if (rv >= 0) {
-		strncpy(link_name, name.name, sizeof(name.name));
+		if (strscpy(link_name, name.name, sizeof(name.name)) == 0)
+			return GXIO_ERR_INVAL_MEMORY_SIZE;
 		memcpy(link_mac, mac.mac, sizeof(mac.mac));
 	}
 
@@ -545,8 +572,8 @@ int gxio_mpipe_link_open(gxio_mpipe_link_t *link,
 	_gxio_mpipe_link_name_t name;
 	int rv;
 
-	strncpy(name.name, link_name, sizeof(name.name));
-	name.name[GXIO_MPIPE_LINK_NAME_LEN - 1] = '\0';
+	if (strscpy(name.name, link_name, sizeof(name.name)) == 0)
+		return GXIO_ERR_NO_DEVICE;
 
 	rv = gxio_mpipe_link_open_aux(context, name, flags);
 	if (rv < 0)