glibc/glibc-RHEL-46736-11.patch

commit 42c810c2cf3554afbdd60885b7da6bb4e702466f
Author: Joseph Myers <josmyers@redhat.com>
Date:   Mon Oct 7 19:44:25 2024 +0000

    Add freopen special-case tests: thread cancellation
    
    Add tests of freopen adding or removing "c" (non-cancelling I/O) from
    the mode string (so completing my planned tests of freopen with
    different features used in the mode strings).  Note that it's in the
    nature of the uncertain time at which cancellation might act (possibly
    during freopen, possibly during subsequent reads) that these can leak
    memory or file descriptors, so these do not include leak tests.
    
    Tested for x86_64.

diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index c920f55ed2119900..09d3622823203f74 100644
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -180,10 +180,12 @@ tests := \
   tst-freopen4 \
   tst-freopen5 \
   tst-freopen6 \
+  tst-freopen7 \
   tst-freopen64-2 \
   tst-freopen64-3 \
   tst-freopen64-4 \
   tst-freopen64-6 \
+  tst-freopen64-7 \
   tst-fseek \
   tst-fwrite \
   tst-getline \
@@ -480,3 +482,6 @@ $(objpfx)tst-setvbuf1-cmp.out: tst-setvbuf1.expect $(objpfx)tst-setvbuf1.out
 
 $(objpfx)tst-printf-round: $(libm)
 $(objpfx)tst-scanf-round: $(libm)
+
+$(objpfx)tst-freopen7: $(shared-thread-library)
+$(objpfx)tst-freopen64-7: $(shared-thread-library)
diff --git a/stdio-common/tst-freopen64-7.c b/stdio-common/tst-freopen64-7.c
new file mode 100644
index 0000000000000000..f34c2805210079b9
--- /dev/null
+++ b/stdio-common/tst-freopen64-7.c
@@ -0,0 +1,2 @@
+#define FREOPEN freopen64
+#include <tst-freopen7-main.c>
diff --git a/stdio-common/tst-freopen7-main.c b/stdio-common/tst-freopen7-main.c
new file mode 100644
index 0000000000000000..965e0b4adce750cc
--- /dev/null
+++ b/stdio-common/tst-freopen7-main.c
@@ -0,0 +1,155 @@
+/* Test freopen cancellation handling.
+   Copyright (C) 2024 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <mcheck.h>
+#include <pthread.h>
+#include <semaphore.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <wchar.h>
+
+#include <support/check.h>
+#include <support/file_contents.h>
+#include <support/support.h>
+#include <support/temp_file.h>
+#include <support/test-driver.h>
+#include <support/xstdio.h>
+#include <support/xthread.h>
+#include <support/xunistd.h>
+
+char *file1, *file2, *file3, *fifo;
+
+sem_t sem;
+
+void *
+test_rc_to_r (void *p)
+{
+  int ret;
+  FILE *fp, *fp2;
+  ret = sem_post (&sem);
+  TEST_VERIFY_EXIT (ret == 0);
+  fp = xfopen (file1, "rc");
+  for (int i = 0; i < 1000000; i++)
+    {
+      fgetc (fp);
+      fseek (fp, 0, SEEK_SET);
+    }
+  fp2 = xfopen (file3, "wc");
+  fputs ("rc_to_r got to freopen", fp2);
+  xfclose (fp2);
+  /* Cancellation should occur at some point from here onwards
+     (possibly leaking memory and file descriptors associated with the
+     FILE).  */
+  fp = FREOPEN (file2, "r", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  for (;;)
+    {
+      fgetc (fp);
+      fseek (fp, 0, SEEK_SET);
+    }
+}
+
+void *
+test_r_to_rc (void *p)
+{
+  int ret;
+  FILE *fp;
+  fp = xfopen (file1, "r");
+  fp = FREOPEN (fifo, "rc", fp);
+  TEST_VERIFY_EXIT (fp != NULL);
+  ret = sem_post (&sem);
+  TEST_VERIFY_EXIT (ret == 0);
+  /* No cancellation should occur for I/O on fifo.  */
+  ret = fgetc (fp);
+  /* At this point, the other thread has called pthread_cancel and
+     then written a byte to the fifo, so this thread is cancelled at
+     the next cancellation point.  */
+  TEST_VERIFY (ret == 'x');
+  xfclose (fp);
+  fp = xfopen (file3, "wc");
+  fputs ("r_to_rc got to fclose", fp);
+  xfclose (fp);
+  pthread_testcancel ();
+  FAIL_EXIT1 ("test_r_to_rc not cancelled\n");
+}
+
+int
+do_test (void)
+{
+  char *temp_dir = support_create_temp_directory ("tst-freopen-cancel");
+  file1 = xasprintf ("%s/file1", temp_dir);
+  support_write_file_string (file1, "file1");
+  add_temp_file (file1);
+  file2 = xasprintf ("%s/file2", temp_dir);
+  support_write_file_string (file2, "file2");
+  add_temp_file (file2);
+  file3 = xasprintf ("%s/file3", temp_dir);
+  support_write_file_string (file3, "file3");
+  add_temp_file (file3);
+  fifo = xasprintf ("%s/fifo", temp_dir);
+  xmkfifo (fifo, 0666);
+  add_temp_file (fifo);
+  int ret;
+  pthread_t thr;
+  void *retval;
+
+  /* Test changing to/from c (cancellation disabled).  */
+
+  verbose_printf ("Testing rc -> r\n");
+  ret = sem_init (&sem, 0, 0);
+  TEST_VERIFY_EXIT (ret == 0);
+  thr = xpthread_create (NULL, test_rc_to_r, NULL);
+  ret = sem_wait (&sem);
+  TEST_VERIFY_EXIT (ret == 0);
+  xpthread_cancel (thr);
+  ret = pthread_join (thr, &retval);
+  TEST_COMPARE (ret, 0);
+  TEST_VERIFY (retval == PTHREAD_CANCELED);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file3, "rc_to_r got to freopen");
+
+  verbose_printf ("Testing r -> rc\n");
+  ret = sem_init (&sem, 0, 0);
+  TEST_VERIFY_EXIT (ret == 0);
+  thr = xpthread_create (NULL, test_r_to_rc, NULL);
+  FILE *fp = xfopen (fifo, "w");
+  ret = sem_wait (&sem);
+  TEST_VERIFY_EXIT (ret == 0);
+  /* This call happens while, or before, the other thread is waiting
+     to read a character from the fifo.  It thus verifies that
+     cancellation does not occur from the fgetc call in that thread
+     (it should instead occur only in pthread_testcancel call),
+     because the expected string is only written to file3 after that
+     thread closes the fifo.  */
+  xpthread_cancel (thr);
+  fputc ('x', fp);
+  xfclose (fp);
+  ret = pthread_join (thr, &retval);
+  TEST_COMPARE (ret, 0);
+  TEST_VERIFY (retval == PTHREAD_CANCELED);
+  TEST_OPEN_AND_COMPARE_FILE_STRING (file3, "r_to_rc got to fclose");
+
+  free (temp_dir);
+  free (file1);
+  free (file2);
+  free (file3);
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/stdio-common/tst-freopen7.c b/stdio-common/tst-freopen7.c
new file mode 100644
index 0000000000000000..03d0de798e3d2616
--- /dev/null
+++ b/stdio-common/tst-freopen7.c
@@ -0,0 +1,2 @@
+#define FREOPEN freopen
+#include <tst-freopen7-main.c>