hotplug: fix firmware loading

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

diff --git a/plug/hotplug.c b/plug/hotplug.c
index 075062b..b50c04e 100644 (file)
--- a/plug/hotplug.c
+++ b/plug/hotplug.c
@@ -161,10 +161,10 @@ static void handle_firmware(struct blob_attr *msg, struct blob_attr *data)
        char *dir = blobmsg_get_string(blobmsg_data(data));
        char *file = hotplug_msg_find_var(msg, "FIRMWARE");
        char *dev = hotplug_msg_find_var(msg, "DEVPATH");
-       void *fw_data;
-       struct stat s;
+       struct stat s = { 0 };
        char *path, loadpath[256], syspath[256];
-       int fw, load, sys, len;
+       int fw, src, load, len;
+       static char buf[4096];
 
        DEBUG(2, "Firmware request for %s/%s\n", dir, file);
 
@@ -173,35 +173,24 @@ static void handle_firmware(struct blob_attr *msg, struct blob_attr *data)
                exit(-1);
        }
 
-       path = malloc(strlen(dir) + strlen(file) + 2);
-       if (!path) {
-               ERROR("Failed to allocate memory\n");
-               exit(-1);
-       }
+       path = alloca(strlen(dir) + strlen(file) + 2);
        sprintf(path, "%s/%s", dir, file);
 
        if (stat(path, &s)) {
                ERROR("Could not find firmware %s\n", path);
-               exit(-1);
-       }
-
-       fw_data = malloc(s.st_size);
-       if (!fw_data) {
-               ERROR("Failed to allocate firmware data memory\n");
-               exit(-1);
+               src = -1;
+               s.st_size = 0;
+               goto send_to_kernel;
        }
 
-       fw = open(path, O_RDONLY);
-       if (!fw) {
+       src = open(path, O_RDONLY);
+       if (src < 0) {
                ERROR("Failed to open %s\n", path);
-               exit(-1);
-       }
-       if (read(fw, fw_data, s.st_size) != s.st_size) {
-               ERROR("Failed to read firmware data\n");
-               exit(-1);
+               s.st_size = 0;
+               goto send_to_kernel;
        }
-       close(fw);
 
+send_to_kernel:
        snprintf(loadpath, sizeof(loadpath), "/sys/%s/loading", dev);
        load = open(loadpath, O_WRONLY);
        if (!load) {
@@ -212,19 +201,23 @@ static void handle_firmware(struct blob_attr *msg, struct blob_attr *data)
        close(load);
 
        snprintf(syspath, sizeof(syspath), "/sys/%s/data", dev);
-       sys = open(syspath, O_WRONLY);
-       if (!sys) {
+       fw = open(syspath, O_WRONLY);
+       if (fw < 0) {
                ERROR("Failed to open %s\n", syspath);
                exit(-1);
        }
 
        len = s.st_size;
-       while (len > 4096) {
-               write(fw, fw_data, 4096);
-               len -= 4096;
+       while (len) {
+               len = read(src, buf, sizeof(buf));
+               if (len <= 0)
+                       break;
+
+               write(fw, buf, len);
        }
-       if (len)
-               write(fw, fw_data, len);
+
+       if (src >= 0)
+               close(src);
        close(fw);
 
        load = open(loadpath, O_WRONLY);