Enhance setuid-tunables test

Instead of passing GLIBC_TUNABLES via the environment, pass the
environment variable from parent to child.  This allows us to test
multiple variables to ensure better coverage.

The test list currently only includes the case that's already being
tested.  More tests will be added later.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>

2 files changed, 69 insertions, 23 deletions

diff --git a/elf/Makefile b/elf/Makefile
index 0bef49e..de65965 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -1660,8 +1660,6 @@ $(objpfx)tst-nodelete-dlclose.out: $(objpfx)tst-nodelete-dlclose-dso.so \
 
 tst-env-setuid-ENV = MALLOC_CHECK_=2 MALLOC_MMAP_THRESHOLD_=4096 \
 		     LD_HWCAP_MASK=0x1
-tst-env-setuid-tunables-ENV = \
-	GLIBC_TUNABLES=glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096
 
 $(objpfx)tst-debug1: $(libdl)
 $(objpfx)tst-debug1.out: $(objpfx)tst-debug1mod1.so
diff --git a/elf/tst-env-setuid-tunables.c b/elf/tst-env-setuid-tunables.c
index 50bef86..3d52387 100644
--- a/elf/tst-env-setuid-tunables.c
+++ b/elf/tst-env-setuid-tunables.c
@@ -25,35 +25,50 @@
 #include "config.h"
 #undef _LIBC
 
-#define test_parent test_parent_tunables
-#define test_child test_child_tunables
-
-static int test_child_tunables (void);
-static int test_parent_tunables (void);
-
-#include "tst-env-setuid.c"
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <intprops.h>
+#include <array_length.h>
+
+#include <support/check.h>
+#include <support/support.h>
+#include <support/test-driver.h>
+#include <support/capture_subprocess.h>
+
+const char *teststrings[] =
+{
+  "glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096",
+};
 
-#define CHILD_VALSTRING_VALUE "glibc.malloc.mmap_threshold=4096"
-#define PARENT_VALSTRING_VALUE \
-  "glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096"
+const char *resultstrings[] =
+{
+  "glibc.malloc.mmap_threshold=4096",
+};
 
 static int
-test_child_tunables (void)
+test_child (int off)
 {
   const char *val = getenv ("GLIBC_TUNABLES");
 
 #if HAVE_TUNABLES
-  if (val != NULL && strcmp (val, CHILD_VALSTRING_VALUE) == 0)
+  if (val != NULL && strcmp (val, resultstrings[off]) == 0)
     return 0;
 
   if (val != NULL)
-    printf ("Unexpected GLIBC_TUNABLES VALUE %s\n", val);
+    printf ("[%d] Unexpected GLIBC_TUNABLES VALUE %s\n", off, val);
 
   return 1;
 #else
   if (val != NULL)
     {
-      printf ("GLIBC_TUNABLES not cleared\n");
+      printf ("[%d] GLIBC_TUNABLES not cleared\n", off);
       return 1;
     }
   return 0;
@@ -61,15 +76,48 @@ test_child_tunables (void)
 }
 
 static int
-test_parent_tunables (void)
+do_test (int argc, char **argv)
 {
-  const char *val = getenv ("GLIBC_TUNABLES");
+  /* Setgid child process.  */
+  if (argc == 2)
+    {
+      if (getgid () == getegid ())
+	/* This can happen if the file system is mounted nosuid.  */
+	FAIL_UNSUPPORTED ("SGID failed: GID and EGID match (%jd)\n",
+			  (intmax_t) getgid ());
 
-  if (val != NULL && strcmp (val, PARENT_VALSTRING_VALUE) == 0)
-    return 0;
+      int ret = test_child (atoi (argv[1]));
 
-  if (val != NULL)
-    printf ("Unexpected GLIBC_TUNABLES VALUE %s\n", val);
+      if (ret != 0)
+	exit (1);
 
-  return 1;
+      exit (EXIT_SUCCESS);
+    }
+  else
+    {
+      int ret = 0;
+
+      /* Spawn tests.  */
+      for (int i = 0; i < array_length (teststrings); i++)
+	{
+	  char buf[INT_BUFSIZE_BOUND (int)];
+
+	  printf ("Spawned test for %s (%d)\n", teststrings[i], i);
+	  snprintf (buf, sizeof (buf), "%d\n", i);
+	  if (setenv ("GLIBC_TUNABLES", teststrings[i], 1) != 0)
+	    exit (1);
+
+	  int status = support_capture_subprogram_self_sgid (buf);
+
+	  /* Bail out early if unsupported.  */
+	  if (WEXITSTATUS (status) == EXIT_UNSUPPORTED)
+	    return EXIT_UNSUPPORTED;
+
+	  ret |= status;
+	}
+      return ret;
+    }
 }
+
+#define TEST_FUNCTION_ARGV do_test
+#include <support/test-driver.c>