From: "Richard W.M. Jones" <rjones(a)redhat.com&gt; --- .gitignore | 1 + tests/regressions/Makefile.am | 12 +++- tests/regressions/rhbz790721.c | 171 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 183 insertions(+), 1 deletions(-) create mode 100644 tests/regressions/rhbz790721.c diff --git a/.gitignore b/.gitignore index adce922..785e763 100644 --- a/.gitignore +++ b/.gitignore @@ -389,6 +389,7 @@ tests/guests/guest-aux/fedora-packages.db tests/guests/ubuntu.img tests/guests/windows.img tests/regressions/rhbz501893 +tests/regressions/rhbz790721 test-tool/libguestfs-test-tool test-tool/libguestfs-test-tool.1 test-tool/libguestfs-test-tool-helper diff --git a/tests/regressions/Makefile.am b/tests/regressions/Makefile.am index 3aed600..a2a3673 100644 --- a/tests/regressions/Makefile.am +++ b/tests/regressions/Makefile.am @@ -27,6 +27,7 @@ TESTS = \ rhbz602997.sh \ rhbz690819.sh \ rhbz789960.sh \ + rhbz790721 \ test-noexec-stack.pl tests_not_run = \ @@ -40,7 +41,8 @@ TESTS_ENVIRONMENT = \ $(top_builddir)/run check_PROGRAMS = \ - rhbz501893 + rhbz501893 \ + rhbz790721 rhbz501893_SOURCES = rhbz501893.c rhbz501893_CFLAGS = \ @@ -49,6 +51,14 @@ rhbz501893_CFLAGS = \ rhbz501893_LDADD = \ $(top_builddir)/src/libguestfs.la +rhbz790721_SOURCES = rhbz790721.c +rhbz790721_CFLAGS = \ + -pthread \ + -I$(top_srcdir)/src -I$(top_builddir)/src \ + $(WARN_CFLAGS) $(WERROR_CFLAGS) +rhbz790721_LDADD = \ + $(top_builddir)/src/libguestfs.la + EXTRA_DIST = \ $(TESTS) \ $(tests_not_run) \ diff --git a/tests/regressions/rhbz790721.c b/tests/regressions/rhbz790721.c new file mode 100644 index 0000000..b30e3db --- /dev/null +++ b/tests/regressions/rhbz790721.c @@ -0,0 +1,171 @@ +/* libguestfs + * Copyright (C) 2012 Red Hat Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +/* Regression test for RHBZ#790721. + * + * This bug involves locking issues when building the appliance in + * parallel from multiple threads in the same process. We use a read + * lock on the 'checksum' file, and it turns out this causes two + * problems: (1) locks don't have any effect on threads in the same + * process, and (2) because the PID is identical in different threads, + * the file we are trying to overwrite has the same name. + * + * To test this we want to create the appliance repeatedly from + * multiple threads, but we don't really care about launching the full + * qemu (a waste of time and memory for this test). Therefore replace + * qemu with a fake process and just look for the linking error. + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <errno.h> + +#include <pthread.h> + +#include "guestfs.h" + +/* Number of worker threads running the test. */ +#define NR_THREADS 20 + +static pthread_barrier_t barrier; +static void *start_thread (void *); + +int +main (int argc, char *argv[]) +{ + pthread_t thread[NR_THREADS]; + int data[NR_THREADS]; + int i, r, errors; + + /* Ensure error messages are not translated. */ + setenv ("LC_ALL", "C", 1); + + pthread_barrier_init (&barrier, NULL, NR_THREADS); + + /* Create the other threads which will set up their own libguestfs + * handle then wait at a barrier before launching. + */ + for (i = 0; i < NR_THREADS; ++i) { + data[i] = i; + r = pthread_create (&thread[i], NULL, start_thread, &data[i]); + if (r != 0) { + fprintf (stderr, "pthread_create: %s\n", strerror (r)); + exit (EXIT_FAILURE); + } + } + + /* Wait for the threads to exit. */ + errors = 0; + + for (i = 0; i < NR_THREADS; ++i) { + int *ret; + + r = pthread_join (thread[i], (void **) &ret); + if (r != 0) { + fprintf (stderr, "pthread_join: %s\n", strerror (r)); + exit (EXIT_FAILURE); + } + if (*ret == -1) + errors++; + } + + exit (errors == 0 ? EXIT_SUCCESS : EXIT_FAILURE); +} + +static void * +start_thread (void *vi) +{ + int thread_num = *(int *)vi; + guestfs_h *g; + int r; + guestfs_error_handler_cb old_error_cb; + void *old_error_data; + const char *error; + + g = guestfs_create (); + if (g == NULL) { + perror ("guestfs_create"); + *(int *)vi = -1; + pthread_exit (vi); + } + + if (guestfs_add_drive_opts (g, "/dev/null", + GUESTFS_ADD_DRIVE_OPTS_FORMAT, "raw", + GUESTFS_ADD_DRIVE_OPTS_READONLY, 1, + -1) == -1) { + *(int *)vi = -1; + pthread_exit (vi); + } + + /* Fake out qemu. */ + if (guestfs_set_qemu (g, "/bin/true") == -1) { + *(int *)vi = -1; + pthread_exit (vi); + } + + /* Wait for the other threads to finish starting up. */ + r = pthread_barrier_wait (&barrier); + if (r != 0 && r != PTHREAD_BARRIER_SERIAL_THREAD) { + fprintf (stderr, "pthread_barrier_wait: %s\n", strerror (r)); + *(int *)vi = -1; + pthread_exit (vi); + } + + /* Launch the handle. Because of the faked out qemu, we expect this + * will fail with "child process died unexpectedly". We are + * interested in other failures. + */ + old_error_cb = guestfs_get_error_handler (g, &old_error_data); + guestfs_set_error_handler (g, NULL, NULL); + r = guestfs_launch (g); + error = guestfs_last_error (g); + + if (r == 0) { /* This should NOT happen. */ + fprintf (stderr, "rhbz790721: strangeness in test: expected launch to fail, but it didn't!\n"); + *(int *)vi = -1; + pthread_exit (vi); + } + + if (error == NULL) { /* This also should NOT happen. */ + fprintf (stderr, "rhbz790721: strangeness in test: no error message!\n"); + *(int *)vi = -1; + pthread_exit (vi); + } + + /* If this happens, it indicates a bug/race in the appliance + * building code which is what this regression test is designed to + * spot. + */ + if (strcmp (error, "child process died unexpectedly") != 0) { + fprintf (stderr, "rhbz790721: error: %s\n", error); + *(int *)vi = -1; + pthread_exit (vi); + } + + guestfs_set_error_handler (g, old_error_cb, old_error_data); + + /* Close the handle. */ + guestfs_close (g); + + *(int *)vi = 0; + pthread_exit (vi); +} -- 1.7.9