Uptime (Android): fix implementation

Regression of 41fed1d

Author: CarterLi

src/detection/uptime/uptime_linux.c

@@ -6,20 +6,32 @@
 
 const char* ffDetectUptime(FFUptimeResult* result)
 {
+    #ifndef __ANDROID__ // cat: /proc/uptime: Permission denied
+    
     // #620
     char buf[64];
     ssize_t nRead = ffReadFileData("/proc/uptime", sizeof(buf) - 1, buf);
-    if(nRead < 0)
-        return "ffReadFileData(\"/proc/uptime\", sizeof(buf) - 1, buf) failed";
-    buf[nRead] = '\0';
+    if(nRead > 0)
+    {
+        buf[nRead] = '\0';
 
-    char *err = NULL;
-    double sec = strtod(buf, &err);
-    if(err != buf)
-        result->uptime = (uint64_t) (sec * 1000);
-    else
-        return "strtod(buf, &err) failed";
+        char *err = NULL;
+        double sec = strtod(buf, &err);
+        if(err != buf)
+        {
+            result->uptime = (uint64_t) (sec * 1000);
+            result->bootTime = ffTimeGetNow() + result->uptime;
+            return NULL;
+        }
+    }
 
+    #endif
+
+    struct timespec uptime;
+    if (clock_gettime(CLOCK_BOOTTIME, &uptime) != 0)
+        return "clock_gettime(CLOCK_BOOTTIME) failed";
+
+    result->uptime = (uint64_t) uptime.tv_sec * 1000 + (uint64_t) uptime.tv_nsec / 1000000;
     result->bootTime = ffTimeGetNow() + result->uptime;
 
     return NULL;