[patch] Fix fileio.exp failuew when run as root user.

[Phil Muldoon <pmuldoon@redhat.com>]

This patch has been carried in the Fedora RPM since 6.8. We are
submitting it for inclusion upstream.

gdb.base/fileio.exp|c fail when this test is executed as a root.  This
test fixes that.

2010-11-19  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.base/fileio.c (ROOTSUBDIR): New macro.
	(main): CHDIR into ROOTSUBDIR.  CHOWN ROOTSUBDIR and CHDIR into
	ROOTSUBDIR if we are being run as root.
	* gdb.base/fileio.exp: Change the startup and finish cleanup.
	Change the test file reference to be into the `fileio.dir' directory.

--

diff --git a/gdb/testsuite/gdb.base/fileio.c b/gdb/testsuite/gdb.base/fileio.c
index 329522f..7c69d4c 100644
--- a/gdb/testsuite/gdb.base/fileio.c
+++ b/gdb/testsuite/gdb.base/fileio.c
@@ -58,6 +58,8 @@ system (const char * string);
 1) Invalid string/command. -  returns 127.  */
 static const char *strerrno (int err);
 
+#define ROOTSUBDIR "fileio.dir"
+
 #define FILENAME    "foo.fileio.test"
 #define RENAMED     "bar.fileio.test"
 #define NONEXISTANT "nofoo.fileio.test"
@@ -542,6 +544,37 @@ strerrno (int err)
 int
 main ()
 {
+  /* ROOTSUBDIR is already prepared by fileio.exp.  We use it for easy cleanup
+     (by fileio.exp) if we are run by multiple users in the same directory.  */
+
+  if (chdir (ROOTSUBDIR) != 0)
+    {
+      printf ("chdir " ROOTSUBDIR ": %s\n", strerror (errno));
+      exit (1);
+    }
+
+  /* These tests
+       Open for write but no write permission returns EACCES
+       Unlinking a file in a directory w/o write access returns EACCES
+     fail if we are being run as root - drop the privileges here.  */
+
+  if (geteuid () == 0)
+    {
+      uid_t uid = 99;
+
+      if (chown (".", uid, uid) != 0)
+	{
+	  printf ("chown %d.%d " ROOTSUBDIR ": %s\n", (int) uid, (int) uid,
+		  strerror (errno));
+	  exit (1);
+	}
+      if (setuid (uid) || geteuid () == 0)
+	{
+	  printf ("setuid %d: %s\n", (int) uid, strerror (errno));
+	  exit (1);
+	}
+    }
+
   /* Don't change the order of the calls.  They partly depend on each other */
   test_open ();
   test_write ();
diff --git a/gdb/testsuite/gdb.base/fileio.exp b/gdb/testsuite/gdb.base/fileio.exp
index d6242d0..ddb853c 100644
--- a/gdb/testsuite/gdb.base/fileio.exp
+++ b/gdb/testsuite/gdb.base/fileio.exp
@@ -42,8 +42,8 @@ if [get_compiler_info ${binfile}] {
     return -1;
 }
 
-remote_exec build {sh -xc test\ -r\ dir2.fileio.test\ &&\ chmod\ -f\ +w\ dir2.fileio.test}
-remote_exec build {sh -xc rm\ -rf\ *.fileio.test}
+remote_exec build {sh -xc rm\ -rf\ fileio.dir}
+remote_exec build {sh -xc mkdir\ -m777\ fileio.dir}
 
 set oldtimeout $timeout
 set timeout [expr "$timeout + 60"]
@@ -85,7 +85,7 @@ gdb_test continue \
 
 gdb_test "continue" ".*" ""
 
-catch "system \"chmod -f -w nowrt.fileio.test\""
+catch "system \"chmod -f -w fileio.dir/nowrt.fileio.test\""
 
 gdb_test continue \
 "Continuing\\..*open 5:.*EACCES$stop_msg" \
@@ -250,8 +250,8 @@ gdb_test continue \
 send_gdb "quit\n"
 send_gdb "y\n"
 
-remote_exec build {sh -xc test\ -r\ dir2.fileio.test\ &&\ chmod\ -f\ +w\ dir2.fileio.test}
-remote_exec build {sh -xc rm\ -rf\ *.fileio.test}
+remote_exec build {sh -xc test\ -r\ fileio.dir/dir2.fileio.test\ &&\ chmod\ -f\ +w\ fileio.dir/dir2.fileio.test}
+remote_exec build {sh -xc rm\ -rf\ fileio.dir}
 
 set timeout $oldtimeout
 return 0