Message ID | 20191204095617.20437-1-ahajkova@redhat.com |
---|---|
State | New |
Headers | show |
Series | elf: Add tst-ldconfig-ld_so_conf-update test | expand |
Hi Alexandra, The patch looks good to me, overall. I only have questions and nitpicks, which are as follows: > Test ldconfig after /etc/ld.so.conf update and verify a running process > observes changes to /etc/ld.so.cache. Does this test for a bug that was reported and fixed at some point? If yes, is there a bug number that can be included? Also, looks like the intention of the test is to verify running processes' obseration of cache changes, and not ldconfig itself. Am I right? > diff --git a/elf/Makefile b/elf/Makefile > index b2b3be203f..5a8d60c6a8 100644 > --- a/elf/Makefile > +++ b/elf/Makefile > @@ -162,8 +162,9 @@ tests-static-internal := tst-tls1-static tst-tls2-static \ > CRT-tst-tls1-static-non-pie := $(csu-objpfx)crt1.o > tst-tls1-static-non-pie-no-pie = yes > > -tests-container = \ > - tst-ldconfig-bad-aux-cache > +tests-container := \ > + tst-ldconfig-bad-aux-cache \ > + tst-ldconfig-ld_so_conf-update > > tests := tst-tls9 tst-leaks1 \ > tst-array1 tst-array2 tst-array3 tst-array4 tst-array5 \ > @@ -292,7 +293,8 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \ > tst-auditmanymod4 tst-auditmanymod5 tst-auditmanymod6 \ > tst-auditmanymod7 tst-auditmanymod8 tst-auditmanymod9 \ > tst-initlazyfailmod tst-finilazyfailmod \ > - tst-dlopenfailmod1 tst-dlopenfaillinkmod tst-dlopenfailmod2 > + tst-dlopenfailmod1 tst-dlopenfaillinkmod tst-dlopenfailmod2 \ > + tst-ldconfig-ld-mod > # Most modules build with _ISOMAC defined, but those filtered out > # depend on internal headers. > modules-names-tests = $(filter-out ifuncmod% tst-libc_dlvsym-dso tst-tlsmod%,\ > @@ -1627,3 +1629,6 @@ $(objpfx)tst-dlopenfailmod1.so: \ > $(shared-thread-library) $(objpfx)tst-dlopenfaillinkmod.so > LDFLAGS-tst-dlopenfaillinkmod.so = -Wl,-soname,tst-dlopenfail-missingmod.so > $(objpfx)tst-dlopenfailmod2.so: $(shared-thread-library) > + > +$(objpfx)tst-ldconfig-ld_so_conf-update.out: $(objpfx)tst-ldconfig-ld-mod.so > +$(objpfx)tst-ldconfig-ld_so_conf-update: $(libdl) Looks okay. > diff --git a/elf/tst-ldconfig-ld-mod.c b/elf/tst-ldconfig-ld-mod.c > new file mode 100644 > index 0000000000..acd6609739 > --- /dev/null > +++ b/elf/tst-ldconfig-ld-mod.c > @@ -0,0 +1,8 @@ > +#include <stdio.h> > +#include <stdlib.h> > + > +void > +bar (void) > +{ > + printf ("Called DSO.\n"); > +} Looks okay minus glibc's two space indent. > diff --git a/elf/tst-ldconfig-ld_so_conf-update.c b/elf/tst-ldconfig-ld_so_conf-update.c > new file mode 100644 > index 0000000000..59de51c494 > --- /dev/null > +++ b/elf/tst-ldconfig-ld_so_conf-update.c > @@ -0,0 +1,143 @@ > +/* Test ldconfig after /etc/ld.so.conf update and verify a running process > + observes changes to /etc/ld.so.cache. > + > + Copyright (C) 2019 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; see the file COPYING.LIB. If > + not, see <https://www.gnu.org/licenses/>. */ > + > +#include <stdio.h> > +#include <stdlib.h> > +#include <string.h> > +#include <errno.h> > + > +#include <support/capture_subprocess.h> > +#include <support/check.h> > +#include <support/support.h> > +#include <support/xdlfcn.h> > +#include <support/xstdio.h> > +#include <support/xunistd.h> > + > +#define DSO "libldconfig-ld-mod.so" > +#define DSO_DIR "/tmp/tst-ldconfig" > +#define CONF "/etc/ld.so.conf" Looks okay. > +static void > +execv_wrapper (void *args) > +{ > + char **argv = args; > + > + execv (argv[0], argv); > + FAIL_EXIT1 ("execv: %m"); > +} Perhaps rename to 'run_ldconfig' and drop the use of args? This function is only ever called to run ldconfig, and with the same args each time. > +int > +open_dso (const char *msg) > +{ > + void *dso; > + char *err; > + int ret = 0; > + > + /* RTLD_NOW - all undefined symbols in the library are resolved > + * before dlopen() returns. If this cannot be done, an error > + * is returned. > + * RTLD_GLOBAL - The symbols defined by this library will be made > + * available for symbol resolution of subsequently loaded libraries. */ > + dso = dlopen (DSO, RTLD_NOW | RTLD_GLOBAL); > + if (dso == NULL) > + { > + err = dlerror (); > + printf ("%s dlerror: %s\n", msg, err); > + ret = 1; > + } > + /* Clear any errors. */ > + dlerror (); > + > + return ret; > +} Since we aren't using the "expected" error messages in any way except logging it, and since passing a string is a bit awkward, we could maybe drop this entire function, and replace calls to it with: (for expected failures) TEST_VERIFY_EXIT (dlopen (DSO, RTLD_NOW | RTLD_GLOBAL) == NULL); or (for the final successful call) TEST_VERIFY_EXIT (dlopen (DSO, RTLD_NOW | RTLD_GLOBAL) != NULL); > +/* Create a new directory. > + Copy a test shared object there. > + Try to dlopen it by soname. This should fail. > + (Directory is not searched.) > + Run ldconfig. > + Try to dlopen it again. It should still fail. > + (Directory is still not searched.) > + Add the directory to /etc/ld.so.conf. > + Try to dlopen it again. It should still fail. > + (The loader does not read /etc/ld.so.conf, only /etc/ld.so.cache.) > + Run ldconfig. > + Try to dlopen it again. This should finally succeed. */ Description is clear. There's a missing double space before the last sentence. > +static int > +do_test (void) > +{ > + char *prog = xasprintf ("%s/ldconfig", support_install_rootsbindir); > + char *args[] = { prog, NULL }; Could go into 'run_ldconfig' (i.e. execv_wrapper). > + FILE *fp; > + struct support_capture_subprocess result; Could be declared at point of first use. > + /* Create the needed directories. */ Missing double space. > + xmkdirp ("/var/cache/ldconfig", 0777); > + xmkdirp (DSO_DIR, 0777); > + > + /* Rename the DSO to start with "lib" because there's an undocumented > + filter in ldconfig where it ignores any file that doesn't start with > + "lib" (for regular shared libraries) or "ld-" (for ld-linux-*). */ > + if (rename ("/usr/lib64/tst-ldconfig-ld-mod.so", > + "/tmp/tst-ldconfig/libldconfig-ld-mod.so")) > + FAIL_EXIT1 ("Renaming/moving the DSO failed: %m"); Looks okay. > + /* Open the DSO. We expect this to fail - test_ldconfig directory > + * is not searched. */ The directory you used is tst-ldconfig. > + if (!open_dso ("[Expected] ")) > + FAIL_EXIT1 > + ("We expect dlopen to fail at this point - test dir is not searched."); Could be replaced with that line I suggested earlier: TEST_VERIFY_EXIT (dlopen (DSO, RTLD_NOW | RTLD_GLOBAL) == NULL); > + fp = xfopen (CONF, "a+"); > + if (!fp) > + FAIL_EXIT1 ("creating /etc/ld.so.conf failed: %m"); > + xfclose (fp); Looks okay. > + /* Run ldconfig. */ > + result = support_capture_subprocess (execv_wrapper, args); > + support_capture_subprocess_check (&result, "execv", 0, sc_allow_none); > + > + /* Try to dlopen the same DSO again, we expect this to fail again. */ > + if (!open_dso ("[Expected] ")) > + FAIL_EXIT1 ("We expect dlopen to fail at this point!."); > + > + /* Add test_ldconfig directory to /etc/ld.so.conf. */ > + fp = xfopen (CONF, "w"); > + if (!(fwrite (DSO_DIR, 1, sizeof (DSO_DIR), fp))) > + FAIL_EXIT1 ("updating /etc/ld.so.conf failed: %m"); > + xfclose (fp); > + > + /* Try to dlopen the same DSO again, we expect this to still fail. */ > + if (!open_dso ("[Expected] ")) > + FAIL_EXIT1 ("We expect dlopen to fail at this point!."); > + > + /* Run ldconfig again. */ > + result = support_capture_subprocess (execv_wrapper, args); > + support_capture_subprocess_check (&result, "execv", 0, sc_allow_none); > + support_capture_subprocess_free (&result); > + > + if (open_dso ("[Unexpected] ")) > + FAIL_EXIT1 ("Dlopen failed."); Looks okay minus the one reference to test_ldconfig. Of course, it will change a bit if you go for my dlopen and run_ldconfig suggestions. Cheers, Arjun
diff --git a/elf/Makefile b/elf/Makefile index b2b3be203f..5a8d60c6a8 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -162,8 +162,9 @@ tests-static-internal := tst-tls1-static tst-tls2-static \ CRT-tst-tls1-static-non-pie := $(csu-objpfx)crt1.o tst-tls1-static-non-pie-no-pie = yes -tests-container = \ - tst-ldconfig-bad-aux-cache +tests-container := \ + tst-ldconfig-bad-aux-cache \ + tst-ldconfig-ld_so_conf-update tests := tst-tls9 tst-leaks1 \ tst-array1 tst-array2 tst-array3 tst-array4 tst-array5 \ @@ -292,7 +293,8 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \ tst-auditmanymod4 tst-auditmanymod5 tst-auditmanymod6 \ tst-auditmanymod7 tst-auditmanymod8 tst-auditmanymod9 \ tst-initlazyfailmod tst-finilazyfailmod \ - tst-dlopenfailmod1 tst-dlopenfaillinkmod tst-dlopenfailmod2 + tst-dlopenfailmod1 tst-dlopenfaillinkmod tst-dlopenfailmod2 \ + tst-ldconfig-ld-mod # Most modules build with _ISOMAC defined, but those filtered out # depend on internal headers. modules-names-tests = $(filter-out ifuncmod% tst-libc_dlvsym-dso tst-tlsmod%,\ @@ -1627,3 +1629,6 @@ $(objpfx)tst-dlopenfailmod1.so: \ $(shared-thread-library) $(objpfx)tst-dlopenfaillinkmod.so LDFLAGS-tst-dlopenfaillinkmod.so = -Wl,-soname,tst-dlopenfail-missingmod.so $(objpfx)tst-dlopenfailmod2.so: $(shared-thread-library) + +$(objpfx)tst-ldconfig-ld_so_conf-update.out: $(objpfx)tst-ldconfig-ld-mod.so +$(objpfx)tst-ldconfig-ld_so_conf-update: $(libdl) diff --git a/elf/tst-ldconfig-ld-mod.c b/elf/tst-ldconfig-ld-mod.c new file mode 100644 index 0000000000..acd6609739 --- /dev/null +++ b/elf/tst-ldconfig-ld-mod.c @@ -0,0 +1,8 @@ +#include <stdio.h> +#include <stdlib.h> + +void +bar (void) +{ + printf ("Called DSO.\n"); +} diff --git a/elf/tst-ldconfig-ld_so_conf-update.c b/elf/tst-ldconfig-ld_so_conf-update.c new file mode 100644 index 0000000000..59de51c494 --- /dev/null +++ b/elf/tst-ldconfig-ld_so_conf-update.c @@ -0,0 +1,143 @@ +/* Test ldconfig after /etc/ld.so.conf update and verify a running process + observes changes to /etc/ld.so.cache. + + Copyright (C) 2019 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; see the file COPYING.LIB. If + not, see <https://www.gnu.org/licenses/>. */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> + +#include <support/capture_subprocess.h> +#include <support/check.h> +#include <support/support.h> +#include <support/xdlfcn.h> +#include <support/xstdio.h> +#include <support/xunistd.h> + +#define DSO "libldconfig-ld-mod.so" +#define DSO_DIR "/tmp/tst-ldconfig" +#define CONF "/etc/ld.so.conf" + +static void +execv_wrapper (void *args) +{ + char **argv = args; + + execv (argv[0], argv); + FAIL_EXIT1 ("execv: %m"); +} + +int +open_dso (const char *msg) +{ + void *dso; + char *err; + int ret = 0; + + /* RTLD_NOW - all undefined symbols in the library are resolved + * before dlopen() returns. If this cannot be done, an error + * is returned. + * RTLD_GLOBAL - The symbols defined by this library will be made + * available for symbol resolution of subsequently loaded libraries. */ + dso = dlopen (DSO, RTLD_NOW | RTLD_GLOBAL); + if (dso == NULL) + { + err = dlerror (); + printf ("%s dlerror: %s\n", msg, err); + ret = 1; + } + /* Clear any errors. */ + dlerror (); + + return ret; +} + +/* Create a new directory. + Copy a test shared object there. + Try to dlopen it by soname. This should fail. + (Directory is not searched.) + Run ldconfig. + Try to dlopen it again. It should still fail. + (Directory is still not searched.) + Add the directory to /etc/ld.so.conf. + Try to dlopen it again. It should still fail. + (The loader does not read /etc/ld.so.conf, only /etc/ld.so.cache.) + Run ldconfig. + Try to dlopen it again. This should finally succeed. */ +static int +do_test (void) +{ + char *prog = xasprintf ("%s/ldconfig", support_install_rootsbindir); + char *args[] = { prog, NULL }; + FILE *fp; + struct support_capture_subprocess result; + + /* Create the needed directories. */ + xmkdirp ("/var/cache/ldconfig", 0777); + xmkdirp (DSO_DIR, 0777); + + /* Rename the DSO to start with "lib" because there's an undocumented + filter in ldconfig where it ignores any file that doesn't start with + "lib" (for regular shared libraries) or "ld-" (for ld-linux-*). */ + if (rename ("/usr/lib64/tst-ldconfig-ld-mod.so", + "/tmp/tst-ldconfig/libldconfig-ld-mod.so")) + FAIL_EXIT1 ("Renaming/moving the DSO failed: %m"); + + + /* Open the DSO. We expect this to fail - test_ldconfig directory + * is not searched. */ + if (!open_dso ("[Expected] ")) + FAIL_EXIT1 + ("We expect dlopen to fail at this point - test dir is not searched."); + fp = xfopen (CONF, "a+"); + if (!fp) + FAIL_EXIT1 ("creating /etc/ld.so.conf failed: %m"); + xfclose (fp); + + /* Run ldconfig. */ + result = support_capture_subprocess (execv_wrapper, args); + support_capture_subprocess_check (&result, "execv", 0, sc_allow_none); + + /* Try to dlopen the same DSO again, we expect this to fail again. */ + if (!open_dso ("[Expected] ")) + FAIL_EXIT1 ("We expect dlopen to fail at this point!."); + + /* Add test_ldconfig directory to /etc/ld.so.conf. */ + fp = xfopen (CONF, "w"); + if (!(fwrite (DSO_DIR, 1, sizeof (DSO_DIR), fp))) + FAIL_EXIT1 ("updating /etc/ld.so.conf failed: %m"); + xfclose (fp); + + /* Try to dlopen the same DSO again, we expect this to still fail. */ + if (!open_dso ("[Expected] ")) + FAIL_EXIT1 ("We expect dlopen to fail at this point!."); + + /* Run ldconfig again. */ + result = support_capture_subprocess (execv_wrapper, args); + support_capture_subprocess_check (&result, "execv", 0, sc_allow_none); + support_capture_subprocess_free (&result); + + if (open_dso ("[Unexpected] ")) + FAIL_EXIT1 ("Dlopen failed."); + + free (prog); + return 0; +} + +#include <support/test-driver.c> diff --git a/elf/tst-ldconfig-ld_so_conf-update.root/postclean.req b/elf/tst-ldconfig-ld_so_conf-update.root/postclean.req new file mode 100644 index 0000000000..e69de29bb2 diff --git a/elf/tst-ldconfig-ld_so_conf-update.root/tst-ldconfig-ld_so_conf-update.script b/elf/tst-ldconfig-ld_so_conf-update.root/tst-ldconfig-ld_so_conf-update.script new file mode 100644 index 0000000000..be562ba554 --- /dev/null +++ b/elf/tst-ldconfig-ld_so_conf-update.root/tst-ldconfig-ld_so_conf-update.script @@ -0,0 +1 @@ +cp $B/elf/tst-ldconfig-ld-mod.so $L/tst-ldconfig-ld-mod.so
From: Alexandra Hájková <ahajkova@redhat.com> Test ldconfig after /etc/ld.so.conf update and verify a running process observes changes to /etc/ld.so.cache. The test uses the test-in-container framework. --- elf/Makefile | 11 +- elf/tst-ldconfig-ld-mod.c | 8 + elf/tst-ldconfig-ld_so_conf-update.c | 143 ++++++++++++++++++ .../postclean.req | 0 .../tst-ldconfig-ld_so_conf-update.script | 1 + 5 files changed, 160 insertions(+), 3 deletions(-) create mode 100644 elf/tst-ldconfig-ld-mod.c create mode 100644 elf/tst-ldconfig-ld_so_conf-update.c create mode 100644 elf/tst-ldconfig-ld_so_conf-update.root/postclean.req create mode 100644 elf/tst-ldconfig-ld_so_conf-update.root/tst-ldconfig-ld_so_conf-update.script