[glibc] elf: Fix subprocess status handling for tst-dlopen-sgid (bug 32987)

[Florian Weimer]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=35fc356fa3b4f485bd3ba3114c9f774e5df7d3c2

commit 35fc356fa3b4f485bd3ba3114c9f774e5df7d3c2
Author: Florian Weimer <fweimer@redhat.com>
Date:   Wed May 21 08:43:32 2025 +0200

    elf: Fix subprocess status handling for tst-dlopen-sgid (bug 32987)
    
    This should really move into support_capture_subprogram_self_sgid.
    
    Reviewed-by: Sam James <sam@gentoo.org>

Diff:
---
 elf/tst-dlopen-sgid.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/elf/tst-dlopen-sgid.c b/elf/tst-dlopen-sgid.c
index 47829a405e..5688b79f2e 100644
--- a/elf/tst-dlopen-sgid.c
+++ b/elf/tst-dlopen-sgid.c
@@ -26,6 +26,8 @@
 #include <support/check.h>
 #include <support/support.h>
 #include <support/temp_file.h>
+#include <support/test-driver.h>
+#include <sys/wait.h>
 #include <unistd.h>
 
 /* This is the name of our test object.  Use a custom module for
@@ -66,10 +68,16 @@ do_test (void)
     free (from);
   }
 
-  TEST_COMPARE (support_capture_subprogram_self_sgid (magic_argument), 0);
-
   free (libdir);
 
+  int status = support_capture_subprogram_self_sgid (magic_argument);
+
+  if (WEXITSTATUS (status) == EXIT_UNSUPPORTED)
+    return EXIT_UNSUPPORTED;
+
+  if (!WIFEXITED (status))
+    FAIL_EXIT1 ("Unexpected exit status %d from child process\n", status);
+
   return 0;
 }