[glibc/ibm/2.32/master] Enhance setuid-tunables test

[Tulio Magno Quites Machado Filho <tuliom@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=36ae20e6764fc0eb1ef126c41e40f14ecedc4031

commit 36ae20e6764fc0eb1ef126c41e40f14ecedc4031
Author: Siddhesh Poyarekar <siddhesh@sourceware.org>
Date:   Tue Mar 16 12:37:54 2021 +0530

    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>
    
    (cherry picked from commit 061fe3f8add46a89b7453e87eabb9c4695005ced)

Diff:
---
 elf/Makefile                  |  2 -
 elf/tst-env-setuid-tunables.c | 90 +++++++++++++++++++++++++++++++++----------
 2 files changed, 69 insertions(+), 23 deletions(-)

diff --git a/elf/Makefile b/elf/Makefile
index 355e70037b..3ba7f4ecfc 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -1632,8 +1632,6 @@ $(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 971d5892b1..91db3d7555 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>