diff options
| -rw-r--r-- | ChangeLog | 25 | ||||
| -rw-r--r-- | elf/Makefile | 16 | ||||
| -rw-r--r-- | elf/Versions | 4 | ||||
| -rw-r--r-- | elf/dl-libc.c | 73 | ||||
| -rw-r--r-- | elf/tst-libc_dlvsym-dso.c | 25 | ||||
| -rw-r--r-- | elf/tst-libc_dlvsym-static.c | 32 | ||||
| -rw-r--r-- | elf/tst-libc_dlvsym.c | 34 | ||||
| -rw-r--r-- | elf/tst-libc_dlvsym.h | 125 | ||||
| -rw-r--r-- | include/dlfcn.h | 2 |
9 files changed, 330 insertions, 6 deletions
@@ -1,3 +1,28 @@ +2018-01-04 Florian Weimer <fweimer@redhat.com> + + Add support for calling dlvsym from libc.so. + * include/dlfcn.h (__libc_dlvsym): Declare. + * elf/Makefile (tests-static-internal): Add + tst-libc_dlvsym-static. + (tests-internal): Add tst-libc_dlvsym. + (modules-names): Add tst-libc_dlvsym-dso. + (tst-libc_dlvsym, tst-libc_dlvsym-static): Link with libdl. + (tst-libc_dlvsym-dso.so): Link with libdl, libsupport. + (tst-libc_dlvsym.out, tst-libc_dlvsym-static.out): The shared + object tst-libc_dlvsym-dso.so needs to be built before running + these tests. + (tst-libc_dlvsym-static-ENV): Set LD_LIBRARY_PATH. + * elf/Versions: Export __libc_dlvsym. + * elf/dl-libc.c (struct do_dlvsym_args): New. + (do_dlvsym, __libc_dlvsym): New functions. + (struct dl_open_hook, _dl_open_hook): Add dlvsym member. + (_dl_open_hook2): New variable. + (__libc_register_dl_open_hook): Set it. + * elf/tst-libc_dlvsym-dso.c: New file. + * elf/tst-libc_dlvsym-static.c: Likewise. + * elf/tst-libc_dlvsym.c: Likewise. + * elf/tst-libc_dlvsym.h: Likewise. + 2018-01-03 Samuel Thibault <samuel.thibault@ens-lyon.org> * support/support_enter_mount_namespace.c [!CLONE_NEWNS]: Do not diff --git a/elf/Makefile b/elf/Makefile index 8967ac2685..2a432d8bee 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -151,7 +151,7 @@ tests-static-normal := tst-leaks1-static tst-array1-static tst-array5-static \ tst-linkall-static tst-env-setuid tst-env-setuid-tunables tests-static-internal := tst-tls1-static tst-tls2-static \ tst-ptrguard1-static tst-stackguard1-static \ - tst-tls1-static-non-pie + tst-tls1-static-non-pie tst-libc_dlvsym-static CRT-tst-tls1-static-non-pie := $(csu-objpfx)crt1.o tst-tls1-static-non-pie-no-pie = yes @@ -192,7 +192,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \ tests-internal += loadtest unload unload2 circleload1 \ neededtest neededtest2 neededtest3 neededtest4 \ tst-tls3 tst-tls6 tst-tls7 tst-tls8 tst-dlmopen2 \ - tst-ptrguard1 tst-stackguard1 + tst-ptrguard1 tst-stackguard1 tst-libc_dlvsym ifeq ($(build-hardcoded-path-in-tests),yes) tests += tst-dlopen-aout tst-dlopen-aout-no-pie = yes @@ -272,7 +272,7 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \ tst-audit12mod1 tst-audit12mod2 tst-audit12mod3 tst-auditmod12 \ tst-latepthreadmod $(tst-tls-many-dynamic-modules) \ tst-nodelete-dlclose-dso tst-nodelete-dlclose-plugin \ - tst-main1mod + tst-main1mod tst-libc_dlvsym-dso ifeq (yes,$(have-mtls-dialect-gnu2)) tests += tst-gnu2-tls1 modules-names += tst-gnu2-tls1mod @@ -1436,3 +1436,13 @@ CRT-tst-main1 := $(csu-objpfx)crt1.o tst-main1-no-pie = yes LDLIBS-tst-main1 = $(libsupport) tst-main1mod.so-no-z-defs = yes + +# Both the main program and the DSO for tst-libc_dlvsym need to link +# against libdl. +$(objpfx)tst-libc_dlvsym: $(libdl) +$(objpfx)tst-libc_dlvsym-dso.so: $(libsupport) $(libdl) +$(objpfx)tst-libc_dlvsym.out: $(objpfx)tst-libc_dlvsym-dso.so +$(objpfx)tst-libc_dlvsym-static: $(common-objpfx)dlfcn/libdl.a +tst-libc_dlvsym-static-ENV = \ + LD_LIBRARY_PATH=$(objpfx):$(common-objpfx):$(common-objpfx)dlfcn +$(objpfx)tst-libc_dlvsym-static.out: $(objpfx)tst-libc_dlvsym-dso.so diff --git a/elf/Versions b/elf/Versions index 79ffaf73d2..3b09901f6c 100644 --- a/elf/Versions +++ b/elf/Versions @@ -23,9 +23,9 @@ libc { GLIBC_PRIVATE { # functions used in other libraries _dl_addr; - _dl_open_hook; + _dl_open_hook; _dl_open_hook2; _dl_sym; _dl_vsym; - __libc_dlclose; __libc_dlopen_mode; __libc_dlsym; + __libc_dlclose; __libc_dlopen_mode; __libc_dlsym; __libc_dlvsym; # Internal error handling support. Interposes the functions in ld.so. _dl_signal_exception; _dl_catch_exception; diff --git a/elf/dl-libc.c b/elf/dl-libc.c index c6818e0313..fc01f5514d 100644 --- a/elf/dl-libc.c +++ b/elf/dl-libc.c @@ -20,6 +20,7 @@ #include <dlfcn.h> #include <stdlib.h> #include <ldsodefs.h> +#include <dl-hash.h> extern int __libc_argc attribute_hidden; extern char **__libc_argv attribute_hidden; @@ -78,6 +79,15 @@ struct do_dlsym_args const ElfW(Sym) *ref; }; +struct do_dlvsym_args +{ + /* dlvsym is like dlsym. */ + struct do_dlsym_args dlsym; + + /* But dlvsym needs a version as well. */ + struct r_found_version version; +}; + static void do_dlopen (void *ptr) { @@ -99,6 +109,18 @@ do_dlsym (void *ptr) } static void +do_dlvsym (void *ptr) +{ + struct do_dlvsym_args *args = ptr; + args->dlsym.ref = NULL; + args->dlsym.loadbase + = GLRO(dl_lookup_symbol_x) (args->dlsym.name, args->dlsym.map, + &args->dlsym.ref, + args->dlsym.map->l_local_scope, + &args->version, 0, 0, NULL); +} + +static void do_dlclose (void *ptr) { GLRO(dl_close) ((struct link_map *) ptr); @@ -112,6 +134,7 @@ struct dl_open_hook void *(*dlopen_mode) (const char *name, int mode); void *(*dlsym) (void *map, const char *name); int (*dlclose) (void *map); + void *(*dlvsym) (void *map, const char *name, const char *version); }; #ifdef SHARED @@ -119,6 +142,15 @@ extern struct dl_open_hook *_dl_open_hook; libc_hidden_proto (_dl_open_hook); struct dl_open_hook *_dl_open_hook __attribute__ ((nocommon)); libc_hidden_data_def (_dl_open_hook); + +/* The dlvsym member was added retroactively to struct dl_open_hook. + Static applications which have it will set _dl_open_hook2 in + addition to _dl_open_hook. */ +extern struct dl_open_hook *_dl_open_hook2; +libc_hidden_proto (_dl_open_hook2); +struct dl_open_hook *_dl_open_hook2 __attribute__ ((nocommon)); +libc_hidden_data_def (_dl_open_hook2); + #else static void do_dlsym_private (void *ptr) @@ -142,7 +174,8 @@ static struct dl_open_hook _dl_open_hook = { .dlopen_mode = __libc_dlopen_mode, .dlsym = __libc_dlsym, - .dlclose = __libc_dlclose + .dlclose = __libc_dlclose, + .dlvsym = __libc_dlvsym, }; #endif @@ -192,6 +225,11 @@ __libc_register_dl_open_hook (struct link_map *map) hook = (struct dl_open_hook **) __libc_dlsym_private (map, "_dl_open_hook"); if (hook != NULL) *hook = &_dl_open_hook; + + /* For dlvsym support. */ + hook = (struct dl_open_hook **) __libc_dlsym_private (map, "_dl_open_hook2"); + if (hook != NULL) + *hook = &_dl_open_hook; } #endif @@ -211,6 +249,39 @@ __libc_dlsym (void *map, const char *name) } libc_hidden_def (__libc_dlsym) +/* Replacement for dlvsym. MAP must be a real map. This function + returns NULL without setting the dlerror value in case of static + dlopen from an old binary. */ +void * +__libc_dlvsym (void *map, const char *name, const char *version) +{ +#ifdef SHARED + if (!rtld_active ()) + { + /* The static application is too old and does not provide the + dlvsym hook. */ + if (_dl_open_hook2 == NULL) + return NULL; + return _dl_open_hook2->dlvsym (map, name, version); + } +#endif + + struct do_dlvsym_args args; + args.dlsym.map = map; + args.dlsym.name = name; + + /* See _dl_vsym in dl-sym.c. */ + args.version.name = version; + args.version.hidden = 1; + args.version.hash = _dl_elf_hash (version); + args.version.filename = NULL; + + return (dlerror_run (do_dlvsym, &args) ? NULL + : (void *) (DL_SYMBOL_ADDRESS (args.dlsym.loadbase, + args.dlsym.ref))); +} +libc_hidden_def (__libc_dlvsym) + int __libc_dlclose (void *map) { diff --git a/elf/tst-libc_dlvsym-dso.c b/elf/tst-libc_dlvsym-dso.c new file mode 100644 index 0000000000..d74c1ead61 --- /dev/null +++ b/elf/tst-libc_dlvsym-dso.c @@ -0,0 +1,25 @@ +/* Compare dlvsym and __libc_dlvsym results. Shared object code. + Copyright (C) 2017 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 + <http://www.gnu.org/licenses/>. */ + +#include "tst-libc_dlvsym.h" + +void +compare_vsyms_global (void) +{ + compare_vsyms (); +} diff --git a/elf/tst-libc_dlvsym-static.c b/elf/tst-libc_dlvsym-static.c new file mode 100644 index 0000000000..955f28d754 --- /dev/null +++ b/elf/tst-libc_dlvsym-static.c @@ -0,0 +1,32 @@ +/* Compare dlvsym and __libc_dlvsym results. Static version. + Copyright (C) 2017 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 + <http://www.gnu.org/licenses/>. */ + +#include <support/xdlfcn.h> + +static int +do_test (void) +{ + void *handle = xdlopen ("tst-libc_dlvsym-dso.so", RTLD_LAZY); + void (*compare) (void) = xdlsym (handle, "compare_vsyms_global"); + compare (); + xdlclose (handle); + + return 0; +} + +#include <support/test-driver.c> diff --git a/elf/tst-libc_dlvsym.c b/elf/tst-libc_dlvsym.c new file mode 100644 index 0000000000..864db4ee6a --- /dev/null +++ b/elf/tst-libc_dlvsym.c @@ -0,0 +1,34 @@ +/* Compare dlvsym and __libc_dlvsym results. Dynamic version. + Copyright (C) 2017 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 + <http://www.gnu.org/licenses/>. */ + +#include "tst-libc_dlvsym.h" + +static int +do_test (void) +{ + compare_vsyms (); + + void *handle = xdlopen ("tst-libc_dlvsym-dso.so", RTLD_LAZY); + void (*compare) (void) = xdlsym (handle, "compare_vsyms_global"); + compare (); + xdlclose (handle); + + return 0; +} + +#include <support/test-driver.c> diff --git a/elf/tst-libc_dlvsym.h b/elf/tst-libc_dlvsym.h new file mode 100644 index 0000000000..6b1d8d5b3a --- /dev/null +++ b/elf/tst-libc_dlvsym.h @@ -0,0 +1,125 @@ +/* Compare dlvsym and __libc_dlvsym results. Common code. + Copyright (C) 2017 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 + <http://www.gnu.org/licenses/>. */ + +/* compare_vsyms is the main entry point for these tests. + + Indirectly, It calls __libc_dlvsym (from libc.so; internal + interface) and dlvsym (from libdl.so; public interface) to compare + the results for a selected set of symbols in libc.so which + typically have more than one symbol version. The two functions are + implemented by somewhat different code, and this test checks that + their results are the same. + + The versions are generated to range from GLIBC_2.0 to GLIBC_2.Y, + with Y being the current __GLIBC_MINOR__ version plus two. In + addition, there is a list of special symbol versions of the form + GLIBC_2.Y.Z, which were used for some releases. + + Comparing the two dlvsym results at versions which do not actually + exist does not test much, but it will not contribute to false test + failures, either. */ + +#include <array_length.h> +#include <gnu/lib-names.h> +#include <stdbool.h> +#include <stdio.h> +#include <support/check.h> +#include <support/xdlfcn.h> + +/* Run consistency check for versioned symbol NAME@VERSION. NB: We + may execute in a shared object, so exit on error for proper error + reporting. */ +static void +compare_vsyms_0 (void *libc_handle, const char *name, const char *version, + bool *pfound) +{ + void *dlvsym_address = dlvsym (libc_handle, name, version); + void *libc_dlvsym_address + = __libc_dlvsym (libc_handle, name, version); + if (dlvsym_address != libc_dlvsym_address) + FAIL_EXIT1 ("%s@%s mismatch: %p != %p", + name, version, dlvsym_address, libc_dlvsym_address); + if (dlvsym_address != NULL) + *pfound = true; +} + + +/* Run consistency check for versioned symbol NAME at multiple symbol + version. */ +static void +compare_vsyms_1 (void *libc_handle, const char *name) +{ + bool found = false; + + /* Historic versions which do not follow the usual GLIBC_2.Y + pattern, to increase test coverage. Not all architectures have + those, but probing additional versions does not hurt. */ + static const char special_versions[][12] = + { + "GLIBC_2.1.1", + "GLIBC_2.1.2", + "GLIBC_2.1.3", + "GLIBC_2.1.4", + "GLIBC_2.2.1", + "GLIBC_2.2.2", + "GLIBC_2.2.3", + "GLIBC_2.2.4", + "GLIBC_2.2.5", + "GLIBC_2.2.6", + "GLIBC_2.3.2", + "GLIBC_2.3.3", + "GLIBC_2.3.4", + }; + for (int i = 0; i < array_length (special_versions); ++i) + compare_vsyms_0 (libc_handle, name, special_versions[i], &found); + + /* Iterate to an out-of-range version, to cover some unused symbols + as well. */ + for (int minor_version = 0; minor_version <= __GLIBC_MINOR__ + 2; + ++minor_version) + { + char version[30]; + snprintf (version, sizeof (version), "GLIBC_%d.%d", + __GLIBC__, minor_version); + compare_vsyms_0 (libc_handle, name, version, &found); + } + + if (!found) + FAIL_EXIT1 ("symbol %s not found at any version", name); +} + +/* Run consistency checks for various symbols which usually have + multiple versions. */ +static void +compare_vsyms (void) +{ + /* The minor version loop in compare_vsyms_1 needs updating in case + we ever switch to glibc 3.0. */ + if (__GLIBC__ != 2) + FAIL_EXIT1 ("unexpected glibc major version: %d", __GLIBC__); + + /* __libc_dlvsym does not recognize the special RTLD_* handles, so + obtain an explicit handle for libc.so. */ + void *libc_handle = xdlopen (LIBC_SO, RTLD_LAZY | RTLD_NOLOAD); + + compare_vsyms_1 (libc_handle, "_sys_errlist"); + compare_vsyms_1 (libc_handle, "_sys_siglist"); + compare_vsyms_1 (libc_handle, "quick_exit"); + + xdlclose (libc_handle); +} diff --git a/include/dlfcn.h b/include/dlfcn.h index 526086f1a0..12ef913e19 100644 --- a/include/dlfcn.h +++ b/include/dlfcn.h @@ -35,9 +35,11 @@ extern char **__libc_argv attribute_hidden; __libc_dlopen_mode (name, RTLD_LAZY | __RTLD_DLOPEN) extern void *__libc_dlopen_mode (const char *__name, int __mode); extern void *__libc_dlsym (void *__map, const char *__name); +extern void *__libc_dlvsym (void *map, const char *name, const char *version); extern int __libc_dlclose (void *__map); libc_hidden_proto (__libc_dlopen_mode) libc_hidden_proto (__libc_dlsym) +libc_hidden_proto (__libc_dlvsym) libc_hidden_proto (__libc_dlclose) /* Locate shared object containing the given address. */ |