1 files changed, 3 insertions, 21 deletions
diff --git a/diagnose_usb/diagnose_usb.cpp b/diagnose_usb/diagnose_usb.cpp
index 5716323ce..35edb5e05 100644
--- a/diagnose_usb/diagnose_usb.cpp
+++ b/diagnose_usb/diagnose_usb.cpp
@@ -19,9 +19,7 @@
 #include <errno.h>
 #include <unistd.h>
 
-#include <algorithm>
 #include <string>
-#include <vector>
 
 #include <android-base/stringprintf.h>
 
@@ -47,25 +45,9 @@ static std::string GetUdevProblem() {
         return "";
     }
 
-    int ngroups = getgroups(0, nullptr);
-    if (ngroups < 0) {
-        perror("failed to get groups list size");
-        return "";
-    }
-
-    std::vector<gid_t> groups(ngroups);
-    ngroups = getgroups(groups.size(), groups.data());
-    if (ngroups < 0) {
-        perror("failed to get groups list");
-        return "";
-    }
-
-    groups.resize(ngroups);
-
-    // getgroups(2) indicates that the egid may not be included so we check it additionally just
-    // to be sure.
-    if (std::find(groups.begin(), groups.end(), plugdev_group->gr_gid) != groups.end() ||
-        getegid() == plugdev_group->gr_gid) {
+    // getgroups(2) indicates that the GNU group_member(3) may not check the egid so we check it
+    // additionally just to be sure.
+    if (group_member(plugdev_group->gr_gid) || getegid() == plugdev_group->gr_gid) {
         // The user is in plugdev so the problem is likely with the udev rules.
         return "missing udev rules? user is in the plugdev group";
     }