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X-Microsoft-Antispam-Message-Info-Original: LMgO/mYoJBfMt2z67b3jKG54ewsP5hVNTSc3h1lze23TuBwduM90YPUEqzUBuXzN8mxeCzVGp+KjfEBg+mvLYrfwABX9g3W1nl78+yfSydJDUYFkf+nfNc5IdG6Rkk68oABDy/iOjk7uKo0BTQ1C3Hk3D5npoJY5SvIApYZiQzcaO3wnZVAQMrsQiT2AdFJPmF/JBZtR40z6mfxnaJWFxZjDIRPXrocPqmUC+YbtrY5La8Z1ppZMUMJIgWEe7rWrRS9DIfZ12eu4OfuuWlN2vmPHkgGeBo+3/8Yo+ZQA5WThgHf+F9lGD3NVueCMY3pp7HmSgvJQY4/uxknDh5ueyTN/edBn1jT99EkiNjNwq36+cqCwlwg5xV9C+K58VjZBnxz7Y9apoGd2CHhaeVhEDU35eFbCNwy8jeTNA1BvGGbNhBwm9Ctxp+RsE/9dXsy6TSZNxytDs0dlw2+ORJD2XQF1aTf+y8eg8qvz9RfokC4= x-ms-exchange-transport-forked: True MIME-Version: 1.0 Original-Authentication-Results: spf=none (sender IP is ) smtp.mailfrom=David.Kilroy@arm.com; Return-Path: David.Kilroy@arm.com X-MS-Exchange-Transport-CrossTenantHeadersStripped: AM5EUR03FT051.eop-EUR03.prod.protection.outlook.com X-MS-Office365-Filtering-Correlation-Id-Prvs: 0c2cd21b-7cc0-4d24-21eb-08d7781672dd There are two fixes that are needed to be able to dlopen filter objects. First _dl_map_object_deps cannot assume that map will be at the beginning of l_searchlist.r_list[], as filtees are inserted before map. Secondly dl_open_worker needs to ensure that filtees get relocated. In _dl_map_object_deps: * avoiding removing relocatiion dependencies of map by setting l_reserved to 0 and otherwise processing the rest of the search list. * ensure that map remains at the beginning of l_initfini - the list of things that need initialisation (and destruction). Do this by splitting the copy up. This may not be required, but matches the initialization order without dlopen. Modify dl_open_worker to relocate the objects in new->l_inifini. new->l_initfini is constructed in _dl_map_object_deps, and lists the objects that need initialization and destruction. Originally the list of objects in new->l_next are relocated. All of these objects should also be included in new->l_initfini (both lists are populated with dependencies in _dl_map_object_deps). We can't use new->l_prev to pick up filtees, as during a recursive dlopen from an interposed malloc call, l->prev can contain objects that are not ready for relocation. Add tests to verify that symbols resolve to the filtee implementation when filter objects are used, both as a normal link and when dlopen'd. Tested by running the testsuite on x86_64. --- elf/Makefile | 12 ++++++++++-- elf/dl-deps.c | 35 ++++++++++++++++++++++++++--------- elf/dl-open.c | 11 +++++++---- elf/tst-filterobj-dlopen.c | 39 +++++++++++++++++++++++++++++++++++++++ elf/tst-filterobj-flt.c | 24 ++++++++++++++++++++++++ elf/tst-filterobj-lib.c | 24 ++++++++++++++++++++++++ elf/tst-filterobj-lib.h | 18 ++++++++++++++++++ elf/tst-filterobj.c | 36 ++++++++++++++++++++++++++++++++++++ 8 files changed, 184 insertions(+), 15 deletions(-) create mode 100644 elf/tst-filterobj-dlopen.c create mode 100644 elf/tst-filterobj-flt.c create mode 100644 elf/tst-filterobj-lib.c create mode 100644 elf/tst-filterobj-lib.h create mode 100644 elf/tst-filterobj.c diff --git a/elf/Makefile b/elf/Makefile index 0debea7..69f11c7 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -199,7 +199,8 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \ tst-debug1 tst-main1 tst-absolute-sym tst-absolute-zero tst-big-note \ tst-unwind-ctor tst-unwind-main tst-audit13 \ tst-sonamemove-link tst-sonamemove-dlopen tst-dlopen-tlsmodid \ - tst-dlopen-self tst-auditmany tst-initfinilazyfail tst-dlopenfail + tst-dlopen-self tst-auditmany tst-initfinilazyfail tst-dlopenfail \ + tst-filterobj tst-filterobj-dlopen # reldep9 tests-internal += loadtest unload unload2 circleload1 \ neededtest neededtest2 neededtest3 neededtest4 \ @@ -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-filterobj-flt tst-filterobj-lib # 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 +1629,9 @@ $(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: $(shared-thread-library) + +LDFLAGS-tst-filterobj-flt.so = -Wl,--filter=$(objpfx)tst-filterobj-lib.so +$(objpfx)tst-filterobj: $(objpfx)tst-filterobj-flt.so | $(objpfx)tst-filterobj-lib.so +$(objpfx)tst-filterobj-dlopen: $(libdl) | $(objpfx)tst-filterobj-lib.so +$(objpfx)tst-filterobj.out: $(objpfx)tst-filterobj-lib.so +$(objpfx)tst-filterobj-dlopen.out: $(objpfx)tst-filterobj-lib.so diff --git a/elf/dl-deps.c b/elf/dl-deps.c index c29b988..bb85c83 100644 --- a/elf/dl-deps.c +++ b/elf/dl-deps.c @@ -550,13 +550,14 @@ Filters not supported with LD_TRACE_PRELINKING")); } /* Maybe we can remove some relocation dependencies now. */ - assert (map->l_searchlist.r_list[0] == map); struct link_map_reldeps *l_reldeps = NULL; if (map->l_reldeps != NULL) { - for (i = 1; i < nlist; ++i) + for (i = 0; i < nlist; ++i) map->l_searchlist.r_list[i]->l_reserved = 1; + /* Avoid removing relocation dependencies of the main binary. */ + map->l_reserved = 0; struct link_map **list = &map->l_reldeps->list[0]; for (i = 0; i < map->l_reldeps->act; ++i) if (list[i]->l_reserved) @@ -581,16 +582,32 @@ Filters not supported with LD_TRACE_PRELINKING")); } } - for (i = 1; i < nlist; ++i) + for (i = 0; i < nlist; ++i) map->l_searchlist.r_list[i]->l_reserved = 0; } - /* Sort the initializer list to take dependencies into account. The binary - itself will always be initialize last. */ - memcpy (l_initfini, map->l_searchlist.r_list, - nlist * sizeof (struct link_map *)); - /* We can skip looking for the binary itself which is at the front of - the search list. */ + /* Sort the initializer list to take dependencies into account. Always + initialize the binary itself last. First, find it in the search list. */ + for (i = 0; i < nlist; ++i) + if (map->l_searchlist.r_list[i] == map) + break; + assert (i < nlist); + if (i > 0) + { + /* Copy the binary into position 0. */ + memcpy (l_initfini, &map->l_searchlist.r_list[i], + sizeof (struct link_map *)); + /* Copy the filtees. */ + memcpy (&l_initfini[1], map->l_searchlist.r_list, + i * sizeof (struct link_map *)); + /* Copy the remainder. */ + memcpy (&l_initfini[i + 1], &map->l_searchlist.r_list[i + 1], + (nlist - i - 1) * sizeof (struct link_map *)); + } + else + memcpy (l_initfini, map->l_searchlist.r_list, + nlist * sizeof (struct link_map *)); + _dl_sort_maps (&l_initfini[1], nlist - 1, NULL, false); /* Terminate the list of dependencies. */ diff --git a/elf/dl-open.c b/elf/dl-open.c index df9f29a..9996fe9 100644 --- a/elf/dl-open.c +++ b/elf/dl-open.c @@ -637,22 +637,25 @@ dl_open_worker (void *a) allows IFUNC relocations to work and it also means copy relocation of dependencies are if necessary overwritten. */ unsigned int nmaps = 0; - struct link_map *l = new; + unsigned int j = 0; + struct link_map *l = new->l_initfini[0]; do { if (! l->l_real->l_relocated) ++nmaps; - l = l->l_next; + l = new->l_initfini[++j]; } while (l != NULL); + /* Stack allocation is limited by the number of loaded objects. */ struct link_map *maps[nmaps]; nmaps = 0; - l = new; + j = 0; + l = new->l_initfini[0]; do { if (! l->l_real->l_relocated) maps[nmaps++] = l; - l = l->l_next; + l = new->l_initfini[++j]; } while (l != NULL); _dl_sort_maps (maps, nmaps, NULL, false); diff --git a/elf/tst-filterobj-dlopen.c b/elf/tst-filterobj-dlopen.c new file mode 100644 index 0000000..81eed0f --- /dev/null +++ b/elf/tst-filterobj-dlopen.c @@ -0,0 +1,39 @@ +/* Test for BZ16272, dlopen'ing a filter object. + Ensure that symbols from the filter object resolve to the filtee. + + 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; if not, see + . */ + +#include +#include "support/check.h" +#include "support/xdlfcn.h" + +static int do_test (void) +{ + void *lib = xdlopen ("tst-filterobj-flt.so", RTLD_LAZY); + char *(*fn)(void) = xdlsym (lib, "get_text"); + const char* text = fn (); + + printf ("%s\n", text); + + /* Verify the text matches what we expect from the filtee */ + TEST_COMPARE_STRING (text, "Hello from filtee (PASS)"); + + return 0; +} + +#include "support/test-driver.c" diff --git a/elf/tst-filterobj-flt.c b/elf/tst-filterobj-flt.c new file mode 100644 index 0000000..b4e10b2 --- /dev/null +++ b/elf/tst-filterobj-flt.c @@ -0,0 +1,24 @@ +/* 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; if not, see + . */ + +#include "tst-filterobj-lib.h" + +/* We never want to see the output of the filter object */ +const char *get_text (void) +{ + return "Hello from filter object (FAIL)"; +} diff --git a/elf/tst-filterobj-lib.c b/elf/tst-filterobj-lib.c new file mode 100644 index 0000000..07e2348 --- /dev/null +++ b/elf/tst-filterobj-lib.c @@ -0,0 +1,24 @@ +/* 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; if not, see + . */ + +#include "tst-filterobj-lib.h" + +/* This is the real implementation that wants to be called */ +const char *get_text (void) +{ + return "Hello from filtee (PASS)"; +} diff --git a/elf/tst-filterobj-lib.h b/elf/tst-filterobj-lib.h new file mode 100644 index 0000000..bed9bf8 --- /dev/null +++ b/elf/tst-filterobj-lib.h @@ -0,0 +1,18 @@ +/* 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; if not, see + . */ + +const char *get_text (void); diff --git a/elf/tst-filterobj.c b/elf/tst-filterobj.c new file mode 100644 index 0000000..d38eb9b --- /dev/null +++ b/elf/tst-filterobj.c @@ -0,0 +1,36 @@ +/* Test that symbols from filter objects are resolved to the filtee. + + 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; if not, see + . */ + +#include +#include "support/check.h" +#include "tst-filterobj-lib.h" + +static int do_test (void) +{ + const char* text = get_text (); + + printf ("%s\n", text); + + /* Verify the text matches what we expect from the filtee */ + TEST_COMPARE_STRING (text, "Hello from filtee (PASS)"); + + return 0; +} + +#include "support/test-driver.c"