[PATCH v2 3/3] boot: android: rework bootargs concatenation

[Nicolas Belin]

Rework the bootargs concatenation allocating more accurately
the length that is needed.
Do not forget an extra byte for the null termination byte as,
in some cases, the allocation was 1 byte short.

Fixes: 86f4695b ("image: Fix Android boot image support")
Signed-off-by: Nicolas Belin <nbe...@baylibre.com>
---
 boot/image-android.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/boot/image-android.c b/boot/image-android.c
index 
362a5c7435a3a8bcf7b674b96e31069a91a892b5..61ac312db7ad9ba6c55727469dd4ded61824c67c
 100644
--- a/boot/image-android.c
+++ b/boot/image-android.c
@@ -287,37 +287,40 @@ int android_image_get_kernel(const void *hdr,
               kernel_addr, DIV_ROUND_UP(img_data.kernel_size, 1024));
 
        int len = 0;
+       char *bootargs = env_get("bootargs");
+
+       if (bootargs)
+               len += strlen(bootargs);
+
        if (*img_data.kcmdline) {
                printf("Kernel command line: %s\n", img_data.kcmdline);
-               len += strlen(img_data.kcmdline);
+               len += strlen(img_data.kcmdline) + (len ? 1 : 0); /* +1 for 
extra space */
        }
 
        if (*img_data.kcmdline_extra) {
                printf("Kernel extra command line: %s\n", 
img_data.kcmdline_extra);
-               len += strlen(img_data.kcmdline_extra);
+               len += strlen(img_data.kcmdline_extra) + (len ? 1 : 0); /* +1 
for extra space */
        }
 
-       char *bootargs = env_get("bootargs");
-       if (bootargs)
-               len += strlen(bootargs);
-
-       char *newbootargs = malloc(len + 2);
+       char *newbootargs = malloc(len + 1); /* +1 for the '\0' */
        if (!newbootargs) {
                puts("Error: malloc in android_image_get_kernel failed!\n");
                return -ENOMEM;
        }
-       *newbootargs = '\0';
+       *newbootargs = '\0'; /* set to Null in case no components below are 
present */
 
-       if (bootargs) {
+       if (bootargs)
                strcpy(newbootargs, bootargs);
-               strcat(newbootargs, " ");
-       }
 
-       if (*img_data.kcmdline)
+       if (*img_data.kcmdline) {
+               if (*newbootargs) /* If there is something in newbootargs, a 
space is needed */
+                       strcat(newbootargs, " ");
                strcat(newbootargs, img_data.kcmdline);
+       }
 
        if (*img_data.kcmdline_extra) {
-               strcat(newbootargs, " ");
+               if (*newbootargs) /* If there is something in newbootargs, a 
space is needed */
+                       strcat(newbootargs, " ");
                strcat(newbootargs, img_data.kcmdline_extra);
        }
 

-- 
2.34.1