| Message ID | 87a5brf2kd.fsf@oldenburg.str.redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | elf: Fix handling of symbol versions which hash to zero (bug 29190) | expand |
On Thu, 16 Jan 2025, Florian Weimer wrote: > This was found through code inspection. No application impact is > known. > > Tested on i686-linux-gnu and x86_64-linux.gnu. > > Joseph, do we need to adjust the hash collision tests after this fix > goes in? The tests should work fine as-is (they avoid testing symbol versions that hash to 0 because of this issue), but it would also be reasonable to expand tst-hash-collision3 to include symbol versions that hash to 0, given this fix.
Am Donnerstag, 16. Januar 2025, 11:58:10 Mitteleuropäische Normalzeit schrieb Florian Weimer: > This was found through code inspection. No application impact is > known. > > Tested on i686-linux-gnu and x86_64-linux.gnu. > I guess it's time to re-visit this now for 2.42 ?
* Andreas K. Huettel: > Am Donnerstag, 16. Januar 2025, 11:58:10 Mitteleuropäische Normalzeit schrieb Florian Weimer: >> This was found through code inspection. No application impact is >> known. >> >> Tested on i686-linux-gnu and x86_64-linux.gnu. >> > > I guess it's time to re-visit this now for 2.42 ? Indeed. Adhemerval marked it as Accepted in Patchwork, I think, but I don't think it's been reviewed. Thanks, Florian
On 10/02/25 14:30, Florian Weimer wrote: > * Andreas K. Huettel: > >> Am Donnerstag, 16. Januar 2025, 11:58:10 Mitteleuropäische Normalzeit schrieb Florian Weimer: >>> This was found through code inspection. No application impact is >>> known. >>> >>> Tested on i686-linux-gnu and x86_64-linux.gnu. >>> >> >> I guess it's time to re-visit this now for 2.42 ? > > Indeed. Adhemerval marked it as Accepted in Patchwork, I think, but > I don't think it's been reviewed. I think I have marked it wrongly as accepted, I will try to review this.
On 16/01/25 07:58, Florian Weimer wrote: > This was found through code inspection. No application impact is > known. > > Tested on i686-linux-gnu and x86_64-linux.gnu. > > Joseph, do we need to adjust the hash collision tests after this fix > goes in? > > Thanks, > Florian > > --- > elf/Makefile | 26 +++++++++++++++++ > elf/dl-lookup.c | 22 ++++++++++---- > elf/dl-version.c | 7 +++++ > elf/tst-version-hash-zero-linkmod.c | 22 ++++++++++++++ > elf/tst-version-hash-zero-linkmod.map | 7 +++++ > elf/tst-version-hash-zero-mod.c | 20 +++++++++++++ > elf/tst-version-hash-zero-mod.map | 13 +++++++++ > elf/tst-version-hash-zero-refmod.c | 23 +++++++++++++++ > elf/tst-version-hash-zero.c | 55 +++++++++++++++++++++++++++++++++++ > 9 files changed, 189 insertions(+), 6 deletions(-) > > diff --git a/elf/Makefile b/elf/Makefile > index 4b1d0d8741..8382e672a1 100644 > --- a/elf/Makefile > +++ b/elf/Makefile > @@ -497,6 +497,7 @@ tests += \ > tst-unique2 \ > tst-unwind-ctor \ > tst-unwind-main \ > + tst-version-hash-zero \ > unload3 \ > unload4 \ > unload5 \ > @@ -1033,6 +1034,9 @@ modules-names += \ > tst-unique2mod1 \ > tst-unique2mod2 \ > tst-unwind-ctor-lib \ > + tst-version-hash-zero-linkmod \ > + tst-version-hash-zero-mod \ > + tst-version-hash-zero-refmod \ > unload2dep \ > unload2mod \ > unload3mod1 \ > @@ -3392,3 +3396,25 @@ $(objpfx)tst-nolink-libc-2: $(objpfx)tst-nolink-libc.o > -Wl,--dynamic-linker=$(objpfx)ld.so > $(objpfx)tst-nolink-libc-2.out: $(objpfx)tst-nolink-libc-2 $(objpfx)ld.so > $< > $@ 2>&1; $(evaluate-test) > + > +$(objpfx)tst-version-hash-zero.out: \ > + $(objpfx)tst-version-hash-zero-mod.so \ > + $(objpfx)tst-version-hash-zero-refmod.so > +$(objpfx)tst-version-hash-zero-mod.so: $(objpfx)tst-version-hash-zero-mod.os \ > + tst-version-hash-zero-mod.map > + $(LINK.o) -shared -o $@ $(LDFLAGS.so) $< \ > + -Wl,--version-script=tst-version-hash-zero-mod.map > +# The run-time test module tst-version-hash-zero-refmod.so is linked > +# to a stub module, tst-version-hash-zero-linkmod.so, to produce an > +# expected relocation error. > +$(objpfx)tst-version-hash-zero-refmod.so: \ > + $(objpfx)tst-version-hash-zero-linkmod.so > +$(objpfx)tst-version-hash-zero-linkmod.so:\ > + $(objpfx)tst-version-hash-zero-linkmod.os \ > + tst-version-hash-zero-linkmod.map > + $(LINK.o) -shared -o $@ $(LDFLAGS.so) $< \ > + -Wl,--version-script=tst-version-hash-zero-linkmod.map \ > + -Wl,--soname=tst-version-hash-zero-mod.so > +$(objpfx)tst-version-hash-zero-refmod.so: \ > + $(objpfx)tst-version-hash-zero-linkmod.so > +tst-version-hash-zero-refmod.so-no-z-defs = yes This triggers some warnings with make: Makefile:3410: warning: overriding recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-mod.so' ../Makerules:722: warning: ignoring old recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-mod.so' Makefile:3420: warning: overriding recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-linkmod.so' ../Makerules:722: warning: ignoring old recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-linkmod.so' Makefile:3410: warning: overriding recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-mod.so' ../Makerules:722: warning: ignoring old recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-mod.so' Makefile:3420: warning: overriding recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-linkmod.so' ../Makerules:722: warning: ignoring old recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-linkmod.so' Would be possible to the version script with LDFLAGS-* rule? > diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c > index ece647f009..2f5cd674f5 100644 > --- a/elf/dl-lookup.c > +++ b/elf/dl-lookup.c > @@ -100,12 +100,22 @@ check_match (const char *const undef_name, > /* We can match the version information or use the > default one if it is not hidden. */ > ElfW(Half) ndx = verstab[symidx] & 0x7fff; > - if ((map->l_versions[ndx].hash != version->hash > - || strcmp (map->l_versions[ndx].name, version->name)) > - && (version->hidden || map->l_versions[ndx].hash > - || (verstab[symidx] & 0x8000))) > - /* It's not the version we want. */ > - return NULL; > + if (map->l_versions[ndx].hash == version->hash > + && strcmp (map->l_versions[ndx].name, version->name) == 0) > + /* This is an exact version match. Return the symbol below. */ > + ; > + else > + { > + if (!version->hidden > + && map->l_versions[ndx].name[0] == '\0' > + && (verstab[symidx] & 0x8000) == 0 > + && (*num_versions)++ == 0) > + /* This is the global default version. Store it as a > + fallback match. */ > + *versioned_sym = sym; > + > + return NULL; > + } > } > } > else Ok. > diff --git a/elf/dl-version.c b/elf/dl-version.c > index d414bd1e18..2fbf4942b9 100644 > --- a/elf/dl-version.c > +++ b/elf/dl-version.c > @@ -357,6 +357,13 @@ _dl_check_map_versions (struct link_map *map, int verbose, int trace_mode) > ent = (ElfW(Verdef) *) ((char *) ent + ent->vd_next); > } > } > + > + /* The empty string has ELF hash zero. This avoids a NULL check > + before the version string comparison in check_match in > + dl-lookup.c. */ > + for (unsigned int i = 0; i < map->l_nversions; ++i) > + if (map->l_versions[i].name == NULL) > + map->l_versions[i].name = ""; > } > > /* When there is a DT_VERNEED entry with libc.so on DT_NEEDED, issue Would the test trigger this? I tried to comment this out and at least with valgrind tst-version-hash-zero does not trigger any invalid memory access. > diff --git a/elf/tst-version-hash-zero-linkmod.c b/elf/tst-version-hash-zero-linkmod.c > new file mode 100644 > index 0000000000..f71574bd2d > --- /dev/null > +++ b/elf/tst-version-hash-zero-linkmod.c > @@ -0,0 +1,22 @@ > +/* Stub module for linking tst-version-hash-zero-refmod.so. > + Copyright (C) 2025 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/>. */ > + > +/* The version script assigns a different symbol version for the stub > + module. Loading the module with the incorrect version is expected > + to fail. */ > +#include "tst-version-hash-zero-mod.c" Ok. > diff --git a/elf/tst-version-hash-zero-linkmod.map b/elf/tst-version-hash-zero-linkmod.map > new file mode 100644 > index 0000000000..2dba7c22d7 > --- /dev/null > +++ b/elf/tst-version-hash-zero-linkmod.map > @@ -0,0 +1,7 @@ > +Base { > + local: *; > +}; > + > +OTHER_VERSION { > + global: global_variable; > +} Base; > diff --git a/elf/tst-version-hash-zero-mod.c b/elf/tst-version-hash-zero-mod.c > new file mode 100644 > index 0000000000..f99c020746 > --- /dev/null > +++ b/elf/tst-version-hash-zero-mod.c > @@ -0,0 +1,20 @@ > +/* Test module with a zero version symbol hash. > + Copyright (C) 2025 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/>. */ > + > +/* The symbol version is assigned by version script. */ > +int global_variable; > diff --git a/elf/tst-version-hash-zero-mod.map b/elf/tst-version-hash-zero-mod.map > new file mode 100644 > index 0000000000..41eaff7914 > --- /dev/null > +++ b/elf/tst-version-hash-zero-mod.map > @@ -0,0 +1,13 @@ > +Base { > + local: *; > +}; > + > +/* Define the version so that tst-version-hash-zero-refmod.so passes > + the initial symbol version check. */ > +OTHER_VERSION { > +} Base; > + > +/* This version string hashes to zero. */ > +PPPPPPPPPPPP { > + global: global_variable; > +} Base; > diff --git a/elf/tst-version-hash-zero-refmod.c b/elf/tst-version-hash-zero-refmod.c > new file mode 100644 > index 0000000000..29a9caaa40 > --- /dev/null > +++ b/elf/tst-version-hash-zero-refmod.c > @@ -0,0 +1,23 @@ > +/* Test module that triggers a relocation failure in tst-version-hash-zero. > + Copyright (C) 2025 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/>. */ > + > +/* This is bound to global_variable@@OTHER_VERSION via > + tst-version-hash-zero-linkmod.so, but at run time, only > + global_variable@PPPPPPPPPPPP exists. */ > +extern int global_variable; > +int *pointer_variable = &global_variable; > diff --git a/elf/tst-version-hash-zero.c b/elf/tst-version-hash-zero.c > new file mode 100644 > index 0000000000..ad391bf202 > --- /dev/null > +++ b/elf/tst-version-hash-zero.c > @@ -0,0 +1,55 @@ > +/* Symbols with version hash zero should not match any version (bug 29190). > + Copyright (C) 2025 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 <support/check.h> > +#include <support/xdlfcn.h> > +#include <stddef.h> > +#include <string.h> > + > +static int > +do_test (void) > +{ > + void *handle = xdlopen ("tst-version-hash-zero-mod.so", RTLD_NOW); > + > + /* This used to crash because some struct r_found_version entries > + with hash zero did not have valid version strings. */ > + TEST_VERIFY (xdlvsym (handle, "global_variable", "PPPPPPPPPPPP") != NULL); > + > + /* Consistency check. */ > + TEST_VERIFY (xdlsym (handle, "global_variable") > + == xdlvsym (handle, "global_variable", "PPPPPPPPPPPP")); > + > + /* This symbol version is supposed to be missing. */ > + TEST_VERIFY (dlvsym (handle, "global_variable", "OTHER_VERSION") == NULL); > + > + /* tst-version-hash-zero-refmod.so references > + global_variable@@OTHER_VERSION and is expected to fail to load. > + dlvsym sets the hidden flag during lookup. Relocation does not, > + so this exercises a different failure case. */ > + TEST_VERIFY (dlopen ("tst-version-hash-zero-refmod.so", RTLD_NOW) == NULL); > + const char *message = dlerror (); > + if (strstr (message, This is strictly invalid is dlopen does not fail (and the below test is not TEST_VERIFY_EXIT). Maybe use 'message == NULL || ...' here. > + ": undefined symbol: global_variable, version OTHER_VERSION") > + == NULL) > + FAIL_EXIT1 ("unexpected dlopen failure: %s", message); > + > + xdlclose (handle); > + return 0; > +} > + > +#include <support/test-driver.c> > > base-commit: a402cae36d95a2141703df324b5de5b581868c5c >
* Adhemerval Zanella Netto: > This triggers some warnings with make: > > Makefile:3410: warning: overriding recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-mod.so' > ../Makerules:722: warning: ignoring old recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-mod.so' > Makefile:3420: warning: overriding recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-linkmod.so' > ../Makerules:722: warning: ignoring old recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-linkmod.so' > Makefile:3410: warning: overriding recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-mod.so' > ../Makerules:722: warning: ignoring old recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-mod.so' > Makefile:3420: warning: overriding recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-linkmod.so' > ../Makerules:722: warning: ignoring old recipe for target '/mnt/projects/glibc/build/aarch64-linux-gnu/elf/tst-version-hash-zero-linkmod.so' > > Would be possible to the version script with LDFLAGS-* rule? It will lose the dependency and miss some required rebuilds. But I think it may be the only way to do this without warnings in the current build system. >> diff --git a/elf/dl-version.c b/elf/dl-version.c >> index d414bd1e18..2fbf4942b9 100644 >> --- a/elf/dl-version.c >> +++ b/elf/dl-version.c >> @@ -357,6 +357,13 @@ _dl_check_map_versions (struct link_map *map, int verbose, int trace_mode) >> ent = (ElfW(Verdef) *) ((char *) ent + ent->vd_next); >> } >> } >> + >> + /* The empty string has ELF hash zero. This avoids a NULL check >> + before the version string comparison in check_match in >> + dl-lookup.c. */ >> + for (unsigned int i = 0; i < map->l_nversions; ++i) >> + if (map->l_versions[i].name == NULL) >> + map->l_versions[i].name = ""; >> } >> >> /* When there is a DT_VERNEED entry with libc.so on DT_NEEDED, issue > > Would the test trigger this? I tried to comment this out and at least > with valgrind tst-version-hash-zero does not trigger any invalid > memory access. This can only happen if there is a gap in the version indexes, so testing this would require binary patching. We could error out in this case, I think. Maybe as a separate change? >> diff --git a/elf/tst-version-hash-zero.c b/elf/tst-version-hash-zero.c >> new file mode 100644 >> index 0000000000..ad391bf202 >> --- /dev/null >> +++ b/elf/tst-version-hash-zero.c >> @@ -0,0 +1,55 @@ >> + /* tst-version-hash-zero-refmod.so references >> + global_variable@@OTHER_VERSION and is expected to fail to load. >> + dlvsym sets the hidden flag during lookup. Relocation does not, >> + so this exercises a different failure case. */ >> + TEST_VERIFY (dlopen ("tst-version-hash-zero-refmod.so", RTLD_NOW) == NULL); >> + const char *message = dlerror (); >> + if (strstr (message, > > This is strictly invalid is dlopen does not fail (and the below test is > not TEST_VERIFY_EXIT). Maybe use 'message == NULL || ...' here. I'll switch to TEST_VERIFY_EXIT. Thanks, Florian
diff --git a/elf/Makefile b/elf/Makefile index 4b1d0d8741..8382e672a1 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -497,6 +497,7 @@ tests += \ tst-unique2 \ tst-unwind-ctor \ tst-unwind-main \ + tst-version-hash-zero \ unload3 \ unload4 \ unload5 \ @@ -1033,6 +1034,9 @@ modules-names += \ tst-unique2mod1 \ tst-unique2mod2 \ tst-unwind-ctor-lib \ + tst-version-hash-zero-linkmod \ + tst-version-hash-zero-mod \ + tst-version-hash-zero-refmod \ unload2dep \ unload2mod \ unload3mod1 \ @@ -3392,3 +3396,25 @@ $(objpfx)tst-nolink-libc-2: $(objpfx)tst-nolink-libc.o -Wl,--dynamic-linker=$(objpfx)ld.so $(objpfx)tst-nolink-libc-2.out: $(objpfx)tst-nolink-libc-2 $(objpfx)ld.so $< > $@ 2>&1; $(evaluate-test) + +$(objpfx)tst-version-hash-zero.out: \ + $(objpfx)tst-version-hash-zero-mod.so \ + $(objpfx)tst-version-hash-zero-refmod.so +$(objpfx)tst-version-hash-zero-mod.so: $(objpfx)tst-version-hash-zero-mod.os \ + tst-version-hash-zero-mod.map + $(LINK.o) -shared -o $@ $(LDFLAGS.so) $< \ + -Wl,--version-script=tst-version-hash-zero-mod.map +# The run-time test module tst-version-hash-zero-refmod.so is linked +# to a stub module, tst-version-hash-zero-linkmod.so, to produce an +# expected relocation error. +$(objpfx)tst-version-hash-zero-refmod.so: \ + $(objpfx)tst-version-hash-zero-linkmod.so +$(objpfx)tst-version-hash-zero-linkmod.so:\ + $(objpfx)tst-version-hash-zero-linkmod.os \ + tst-version-hash-zero-linkmod.map + $(LINK.o) -shared -o $@ $(LDFLAGS.so) $< \ + -Wl,--version-script=tst-version-hash-zero-linkmod.map \ + -Wl,--soname=tst-version-hash-zero-mod.so +$(objpfx)tst-version-hash-zero-refmod.so: \ + $(objpfx)tst-version-hash-zero-linkmod.so +tst-version-hash-zero-refmod.so-no-z-defs = yes diff --git a/elf/dl-lookup.c b/elf/dl-lookup.c index ece647f009..2f5cd674f5 100644 --- a/elf/dl-lookup.c +++ b/elf/dl-lookup.c @@ -100,12 +100,22 @@ check_match (const char *const undef_name, /* We can match the version information or use the default one if it is not hidden. */ ElfW(Half) ndx = verstab[symidx] & 0x7fff; - if ((map->l_versions[ndx].hash != version->hash - || strcmp (map->l_versions[ndx].name, version->name)) - && (version->hidden || map->l_versions[ndx].hash - || (verstab[symidx] & 0x8000))) - /* It's not the version we want. */ - return NULL; + if (map->l_versions[ndx].hash == version->hash + && strcmp (map->l_versions[ndx].name, version->name) == 0) + /* This is an exact version match. Return the symbol below. */ + ; + else + { + if (!version->hidden + && map->l_versions[ndx].name[0] == '\0' + && (verstab[symidx] & 0x8000) == 0 + && (*num_versions)++ == 0) + /* This is the global default version. Store it as a + fallback match. */ + *versioned_sym = sym; + + return NULL; + } } } else diff --git a/elf/dl-version.c b/elf/dl-version.c index d414bd1e18..2fbf4942b9 100644 --- a/elf/dl-version.c +++ b/elf/dl-version.c @@ -357,6 +357,13 @@ _dl_check_map_versions (struct link_map *map, int verbose, int trace_mode) ent = (ElfW(Verdef) *) ((char *) ent + ent->vd_next); } } + + /* The empty string has ELF hash zero. This avoids a NULL check + before the version string comparison in check_match in + dl-lookup.c. */ + for (unsigned int i = 0; i < map->l_nversions; ++i) + if (map->l_versions[i].name == NULL) + map->l_versions[i].name = ""; } /* When there is a DT_VERNEED entry with libc.so on DT_NEEDED, issue diff --git a/elf/tst-version-hash-zero-linkmod.c b/elf/tst-version-hash-zero-linkmod.c new file mode 100644 index 0000000000..f71574bd2d --- /dev/null +++ b/elf/tst-version-hash-zero-linkmod.c @@ -0,0 +1,22 @@ +/* Stub module for linking tst-version-hash-zero-refmod.so. + Copyright (C) 2025 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/>. */ + +/* The version script assigns a different symbol version for the stub + module. Loading the module with the incorrect version is expected + to fail. */ +#include "tst-version-hash-zero-mod.c" diff --git a/elf/tst-version-hash-zero-linkmod.map b/elf/tst-version-hash-zero-linkmod.map new file mode 100644 index 0000000000..2dba7c22d7 --- /dev/null +++ b/elf/tst-version-hash-zero-linkmod.map @@ -0,0 +1,7 @@ +Base { + local: *; +}; + +OTHER_VERSION { + global: global_variable; +} Base; diff --git a/elf/tst-version-hash-zero-mod.c b/elf/tst-version-hash-zero-mod.c new file mode 100644 index 0000000000..f99c020746 --- /dev/null +++ b/elf/tst-version-hash-zero-mod.c @@ -0,0 +1,20 @@ +/* Test module with a zero version symbol hash. + Copyright (C) 2025 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/>. */ + +/* The symbol version is assigned by version script. */ +int global_variable; diff --git a/elf/tst-version-hash-zero-mod.map b/elf/tst-version-hash-zero-mod.map new file mode 100644 index 0000000000..41eaff7914 --- /dev/null +++ b/elf/tst-version-hash-zero-mod.map @@ -0,0 +1,13 @@ +Base { + local: *; +}; + +/* Define the version so that tst-version-hash-zero-refmod.so passes + the initial symbol version check. */ +OTHER_VERSION { +} Base; + +/* This version string hashes to zero. */ +PPPPPPPPPPPP { + global: global_variable; +} Base; diff --git a/elf/tst-version-hash-zero-refmod.c b/elf/tst-version-hash-zero-refmod.c new file mode 100644 index 0000000000..29a9caaa40 --- /dev/null +++ b/elf/tst-version-hash-zero-refmod.c @@ -0,0 +1,23 @@ +/* Test module that triggers a relocation failure in tst-version-hash-zero. + Copyright (C) 2025 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/>. */ + +/* This is bound to global_variable@@OTHER_VERSION via + tst-version-hash-zero-linkmod.so, but at run time, only + global_variable@PPPPPPPPPPPP exists. */ +extern int global_variable; +int *pointer_variable = &global_variable; diff --git a/elf/tst-version-hash-zero.c b/elf/tst-version-hash-zero.c new file mode 100644 index 0000000000..ad391bf202 --- /dev/null +++ b/elf/tst-version-hash-zero.c @@ -0,0 +1,55 @@ +/* Symbols with version hash zero should not match any version (bug 29190). + Copyright (C) 2025 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 <support/check.h> +#include <support/xdlfcn.h> +#include <stddef.h> +#include <string.h> + +static int +do_test (void) +{ + void *handle = xdlopen ("tst-version-hash-zero-mod.so", RTLD_NOW); + + /* This used to crash because some struct r_found_version entries + with hash zero did not have valid version strings. */ + TEST_VERIFY (xdlvsym (handle, "global_variable", "PPPPPPPPPPPP") != NULL); + + /* Consistency check. */ + TEST_VERIFY (xdlsym (handle, "global_variable") + == xdlvsym (handle, "global_variable", "PPPPPPPPPPPP")); + + /* This symbol version is supposed to be missing. */ + TEST_VERIFY (dlvsym (handle, "global_variable", "OTHER_VERSION") == NULL); + + /* tst-version-hash-zero-refmod.so references + global_variable@@OTHER_VERSION and is expected to fail to load. + dlvsym sets the hidden flag during lookup. Relocation does not, + so this exercises a different failure case. */ + TEST_VERIFY (dlopen ("tst-version-hash-zero-refmod.so", RTLD_NOW) == NULL); + const char *message = dlerror (); + if (strstr (message, + ": undefined symbol: global_variable, version OTHER_VERSION") + == NULL) + FAIL_EXIT1 ("unexpected dlopen failure: %s", message); + + xdlclose (handle); + return 0; +} + +#include <support/test-driver.c>