fw_cfg: Fix -boot bootsplash error checking

fw_cfg_bootsplash() gets option parameter "splash-time"
with qemu_opt_get(), then converts it to an integer by hand.
It neglects to check that conversion for errors. This is
needlessly complicated and error-prone. But as "splash-time
not specified" is not the same as "splash-time=T" for any T,
we need use qemu_opt_get() to check if splash time exists.
This patch also make the qemu exit when finding or loading
splash file failed.

Signed-off-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <1542777026-2788-2-git-send-email-liq3ea@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

1 files changed, 13 insertions, 22 deletions

diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index 9c4409b..ad91abd 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -117,47 +117,38 @@ error:
 
 static void fw_cfg_bootsplash(FWCfgState *s)
 {
-    int boot_splash_time = -1;
     const char *boot_splash_filename = NULL;
-    char *p;
+    const char *boot_splash_time = NULL;
     char *filename, *file_data;
     gsize file_size;
     int file_type;
-    const char *temp;
 
     /* get user configuration */
     QemuOptsList *plist = qemu_find_opts("boot-opts");
     QemuOpts *opts = QTAILQ_FIRST(&plist->head);
-    if (opts != NULL) {
-        temp = qemu_opt_get(opts, "splash");
-        if (temp != NULL) {
-            boot_splash_filename = temp;
-        }
-        temp = qemu_opt_get(opts, "splash-time");
-        if (temp != NULL) {
-            p = (char *)temp;
-            boot_splash_time = strtol(p, &p, 10);
-        }
-    }
+    boot_splash_filename = qemu_opt_get(opts, "splash");
+    boot_splash_time = qemu_opt_get(opts, "splash-time");
 
     /* insert splash time if user configurated */
-    if (boot_splash_time >= 0) {
+    if (boot_splash_time) {
+        int64_t bst_val = qemu_opt_get_number(opts, "splash-time", -1);
         /* validate the input */
-        if (boot_splash_time > 0xffff) {
-            error_report("splash time is big than 65535, force it to 65535.");
-            boot_splash_time = 0xffff;
+        if (bst_val < 0 || bst_val > 0xffff) {
+            error_report("splash-time is invalid,"
+                         "it should be a value between 0 and 65535");
+            exit(1);
         }
         /* use little endian format */
-        qemu_extra_params_fw[0] = (uint8_t)(boot_splash_time & 0xff);
-        qemu_extra_params_fw[1] = (uint8_t)((boot_splash_time >> 8) & 0xff);
+        qemu_extra_params_fw[0] = (uint8_t)(bst_val & 0xff);
+        qemu_extra_params_fw[1] = (uint8_t)((bst_val >> 8) & 0xff);
         fw_cfg_add_file(s, "etc/boot-menu-wait", qemu_extra_params_fw, 2);
     }
 
     /* insert splash file if user configurated */
-    if (boot_splash_filename != NULL) {
+    if (boot_splash_filename) {
         filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, boot_splash_filename);
         if (filename == NULL) {
-            error_report("failed to find file '%s'.", boot_splash_filename);
+            error_report("failed to find file '%s'", boot_splash_filename);
             return;
         }