[PATCH] Use libnss_files.so for tests posix/bug-ga2 and resolv/tst-leaks2 [BZ #26821]
Stefan Liebler
stli@linux.ibm.com
Thu Nov 19 12:28:29 GMT 2020
The tests posix/bug-ga2-mem and resolv/mtrace-tst-leaks2 are failing on
fedora 33 as mtrace reports memory leaks.
The /etc/nsswitch.conf differs between
Fedora 32: hosts: files dns myhostname
Fedora 33: hosts: files resolve [!UNAVAIL=return] myhostname dns
Therefore /lib64/libnss_resolve.so.2 (from systemd) and the dependencies
libgcc_s.so.1 and libpthread.so.0 are loaded.
Usually all malloc'ed resources from getaddrinfo / gethostbyname are freed
and the libraries are dlclose'd in nss/nsswitch.c:libc_freeres_fn (free_mem).
Unfortunately, /lib64/libnss_resolve.so.2 is marked with DF_1_NODELETE.
As this library is not unmapped, you'll see "Memory not freed".
Therefore those tests are now only rely on libnss_files.so by preparing
a chroot with all required configuration files and executing the test in
a subprocess.
This patch also added support for /etc/services and /etc/nsswitch.conf
in struct support_chroot_configuration.
Note:
We can't use __nss_configure_lookup as it would lead to not setting up
nsswitch.c:service_table before calling __getservbyname_r / __gethostbyname_r.
nsswitch.c:nss_load_library would then add resources to default_table which
are not freed by nsswitch.c:libc_freeres_fn (free_mem)
---
posix/Makefile | 1 +
posix/bug-ga2.c | 68 +++++++++++++++++++++++++++++++++++-----
resolv/Makefile | 1 +
resolv/tst-leaks2.c | 63 +++++++++++++++++++++++++++++++++----
support/namespace.h | 4 +++
support/support_chroot.c | 9 +++++-
6 files changed, 132 insertions(+), 14 deletions(-)
diff --git a/posix/Makefile b/posix/Makefile
index 693082ed28..0ef4e7f4be 100644
--- a/posix/Makefile
+++ b/posix/Makefile
@@ -361,6 +361,7 @@ $(objpfx)bug-ga2-mem.out: $(objpfx)bug-ga2.out
$(common-objpfx)malloc/mtrace $(objpfx)bug-ga2.mtrace > $@; \
$(evaluate-test)
+$(objpfx)bug-ga2: $(libdl)
bug-ga2-ENV = MALLOC_TRACE=$(objpfx)bug-ga2.mtrace
bug-glob2-ENV = MALLOC_TRACE=$(objpfx)bug-glob2.mtrace
diff --git a/posix/bug-ga2.c b/posix/bug-ga2.c
index 5ea759b8ce..889f100358 100644
--- a/posix/bug-ga2.c
+++ b/posix/bug-ga2.c
@@ -1,16 +1,46 @@
/* Test case by Sam Varshavchik <mrsam@courier-mta.com>. */
#include <mcheck.h>
#include <netdb.h>
-#include <stdio.h>
+#include <stdlib.h>
#include <string.h>
+#include <dlfcn.h>
+#include <gnu/lib-names.h>
+#include <support/check.h>
+#include <support/namespace.h>
+#include <support/test-driver.h>
+#include <support/xunistd.h>
-int
-main (void)
+struct support_chroot *chroot_env;
+
+static void
+prepare (int argc, char **argv)
+{
+ /* Generate a /etc/nsswitch.conf instead of using __nss_configure_lookup
+ as it would lead to not setting up nsswitch.c:service_table before calling
+ __getservbyname_r. nss_load_library would then add resources to
+ default_table which are not freed by
+ nss/nsswitch.c:libc_freeres_fn (free_mem). */
+ chroot_env = support_chroot_create
+ ((struct support_chroot_configuration)
+ {
+ .nsswitch_conf =
+ "services: files\n"
+ "hosts: files\n",
+ .host_conf = "multi on\n",
+ .hosts = "192.0.2.1 www.gnu.org\n",
+ .services = "http 80/tcp\n"
+ });
+}
+
+static void
+subprocess_test (void *closure)
{
struct addrinfo hints, *res;
int i, ret;
mtrace ();
+ xchroot (chroot_env->path_chroot);
+
for (i = 0; i < 100; i++)
{
memset (&hints, 0, sizeof (hints));
@@ -20,11 +50,35 @@ main (void)
ret = getaddrinfo ("www.gnu.org", "http", &hints, &res);
if (ret)
- {
- printf ("%s\n", gai_strerror (ret));
- return 1;
- }
+ FAIL_EXIT1 ("%s\n", gai_strerror (ret));
+
freeaddrinfo (res);
}
+
+ /* Ensure that the resources malloc'ed by getaddrinfo are freed by
+ nss/nsswitch.c:libc_freeres_fn (free_mem). */
+ exit (EXIT_SUCCESS);
+}
+
+
+static int
+do_test (void)
+{
+ support_become_root ();
+ if (!support_can_chroot ())
+ return EXIT_UNSUPPORTED;
+
+ /* Load the libraries now as those are not available in chroot. */
+ if (dlopen (LIBNSS_FILES_SO, RTLD_LAZY) == NULL)
+ FAIL_EXIT1 ("could not load " LIBNSS_FILES_SO ": %s", dlerror ());
+
+ /* Run the chroot'ing test in a subprocess in order to be able to delete the
+ temporary files. */
+ support_isolate_in_subprocess (subprocess_test, NULL);
+
+ support_chroot_free (chroot_env);
return 0;
}
+
+#define PREPARE prepare
+#include <support/test-driver.c>
diff --git a/resolv/Makefile b/resolv/Makefile
index dbd8f8bf4f..533d36eebf 100644
--- a/resolv/Makefile
+++ b/resolv/Makefile
@@ -157,6 +157,7 @@ $(objpfx)mtrace-tst-leaks.out: $(objpfx)tst-leaks.out
$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks.mtrace > $@; \
$(evaluate-test)
+$(objpfx)tst-leaks2: $(libdl)
tst-leaks2-ENV = MALLOC_TRACE=$(objpfx)tst-leaks2.mtrace
$(objpfx)mtrace-tst-leaks2.out: $(objpfx)tst-leaks2.out
$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks2.mtrace > $@; \
diff --git a/resolv/tst-leaks2.c b/resolv/tst-leaks2.c
index a2f5db3adc..8f7a807572 100644
--- a/resolv/tst-leaks2.c
+++ b/resolv/tst-leaks2.c
@@ -21,20 +21,71 @@
#include <mcheck.h>
#include <netdb.h>
#include <resolv.h>
+#include <stdlib.h>
+#include <dlfcn.h>
+#include <gnu/lib-names.h>
+#include <support/check.h>
+#include <support/namespace.h>
+#include <support/test-driver.h>
+#include <support/xunistd.h>
-static int
-do_test (void)
+struct support_chroot *chroot_env;
+
+static void
+prepare (int argc, char **argv)
+{
+ /* Generate a /etc/nsswitch.conf file instead of using __nss_configure_lookup
+ as it would lead to not setting up nsswitch.c:service_table before calling
+ __gethostbyname_r. nss_load_library would then add resources to
+ default_table which are not freed by
+ nss/nsswitch.c:libc_freeres_fn (free_mem) */
+ chroot_env = support_chroot_create
+ ((struct support_chroot_configuration)
+ {
+ .nsswitch_conf = "hosts: files\n",
+ .host_conf = "multi on\n",
+ .hosts = "192.0.2.1 www.gnu.org\n",
+ });
+}
+
+static void
+subprocess_test (void *closure)
{
mtrace ();
+ xchroot (chroot_env->path_chroot);
+
for (int i = 0; i < 20; ++i)
{
res_init ();
- gethostbyname ("www.gnu.org");
+ if (gethostbyname ("www.gnu.org") == NULL)
+ FAIL_EXIT1 ("%s\n", hstrerror (h_errno));
}
+
+ /* Ensure that the resources malloc'ed by gethostbyname are freed by
+ nss/nsswitch.c:libc_freeres_fn (free_mem). */
+ exit (EXIT_SUCCESS);
+}
+
+
+static int
+do_test (void)
+{
+ support_become_root ();
+ if (!support_can_chroot ())
+ return EXIT_UNSUPPORTED;
+
+ /* Load the libraries now as those are not available in chroot. */
+ if (dlopen (LIBNSS_FILES_SO, RTLD_LAZY) == NULL)
+ FAIL_EXIT1 ("could not load " LIBNSS_FILES_SO ": %s", dlerror ());
+
+ /* Run the chroot'ing test in a subprocess in order to be able to delete the
+ temporary files. */
+ support_isolate_in_subprocess (subprocess_test, NULL);
+
+ support_chroot_free (chroot_env);
return 0;
}
-#define TEST_FUNCTION do_test ()
#define TIMEOUT 30
-/* This defines the `main' function and some more. */
-#include <test-skeleton.c>
+#define PREPARE prepare
+#include <support/test-driver.c>
diff --git a/support/namespace.h b/support/namespace.h
index 5210343877..1c74dcaa4b 100644
--- a/support/namespace.h
+++ b/support/namespace.h
@@ -75,6 +75,8 @@ struct support_chroot_configuration
const char *hosts; /* /etc/hosts. */
const char *host_conf; /* /etc/host.conf. */
const char *aliases; /* /etc/aliases. */
+ const char *services; /* /etc/services. */
+ const char *nsswitch_conf; /* /etc/nsswitch.conf. */
};
/* The result of the creation of a chroot. */
@@ -92,6 +94,8 @@ struct support_chroot
char *path_hosts; /* /etc/hosts. */
char *path_host_conf; /* /etc/host.conf. */
char *path_aliases; /* /etc/aliases. */
+ char *path_services; /* /etc/services. */
+ char *path_nsswitch_conf; /* /etc/nsswitch.conf. */
};
/* Create a chroot environment. The returned data should be freed
diff --git a/support/support_chroot.c b/support/support_chroot.c
index 4f435c1ac1..e6cabd30c5 100644
--- a/support/support_chroot.c
+++ b/support/support_chroot.c
@@ -24,6 +24,8 @@
#include <support/test-driver.h>
#include <support/xunistd.h>
+extern const char *__progname;
+
/* If CONTENTS is not NULL, write it to the file at DIRECTORY/RELPATH,
and store the name in *ABSPATH. If CONTENTS is NULL, store NULL in
*ABSPATH. */
@@ -45,7 +47,7 @@ struct support_chroot *
support_chroot_create (struct support_chroot_configuration conf)
{
struct support_chroot *chroot = xmalloc (sizeof (*chroot));
- chroot->path_chroot = support_create_temp_directory ("tst-resolv-res_init-");
+ chroot->path_chroot = support_create_temp_directory (__progname);
/* Create the /etc directory in the chroot environment. */
char *path_etc = xasprintf ("%s/etc", chroot->path_chroot);
@@ -57,6 +59,9 @@ support_chroot_create (struct support_chroot_configuration conf)
write_file (path_etc, "hosts", conf.hosts, &chroot->path_hosts);
write_file (path_etc, "host.conf", conf.host_conf, &chroot->path_host_conf);
write_file (path_etc, "aliases", conf.aliases, &chroot->path_aliases);
+ write_file (path_etc, "services", conf.services, &chroot->path_services);
+ write_file (path_etc, "nsswitch.conf", conf.nsswitch_conf,
+ &chroot->path_nsswitch_conf);
free (path_etc);
@@ -79,5 +84,7 @@ support_chroot_free (struct support_chroot *chroot)
free (chroot->path_hosts);
free (chroot->path_host_conf);
free (chroot->path_aliases);
+ free (chroot->path_services);
+ free (chroot->path_nsswitch_conf);
free (chroot);
}
--
2.28.0
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