diff options
| -rw-r--r-- | elf/Makefile | 5 | ||||
| -rw-r--r-- | elf/dl-object.c | 17 | ||||
| -rw-r--r-- | elf/rtld.c | 6 | ||||
| -rw-r--r-- | elf/setup-vdso.h | 2 | ||||
| -rw-r--r-- | elf/tst-audit22.c | 124 | ||||
| -rw-r--r-- | elf/tst-auditmod22.c | 51 | ||||
| -rw-r--r-- | include/dlfcn.h | 2 |
7 files changed, 199 insertions, 8 deletions
diff --git a/elf/Makefile b/elf/Makefile index 7fcb9c9b2c..f427e2d6a3 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -232,6 +232,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \ tst-dl-is_dso tst-ro-dynamic \ tst-audit18 \ tst-audit19b \ + tst-audit22 \ tst-rtld-run-static \ # reldep9 tests-internal += loadtest unload unload2 circleload1 \ @@ -382,6 +383,7 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \ tst-auditmod19a \ tst-auditmod19b \ tst-audit19bmod \ + tst-auditmod22 \ # Most modules build with _ISOMAC defined, but those filtered out # depend on internal headers. @@ -1594,6 +1596,9 @@ $(objpfx)tst-audit19b.out: $(objpfx)tst-auditmod19b.so $(objpfx)tst-audit19b: $(objpfx)tst-audit19bmod.so tst-audit19b-ARGS = -- $(host-test-program-cmd) +$(objpfx)tst-audit22.out: $(objpfx)tst-auditmod22.so +tst-audit22-ARGS = -- $(host-test-program-cmd) + # tst-sonamemove links against an older implementation of the library. LDFLAGS-tst-sonamemove-linkmod1.so = \ -Wl,--version-script=tst-sonamemove-linkmod1.map \ diff --git a/elf/dl-object.c b/elf/dl-object.c index 1875599eb2..dee49a32d4 100644 --- a/elf/dl-object.c +++ b/elf/dl-object.c @@ -59,16 +59,19 @@ _dl_new_object (char *realname, const char *libname, int type, { #ifdef SHARED unsigned int naudit; - if (__glibc_unlikely ((mode & __RTLD_OPENEXEC) != 0)) + if (__glibc_unlikely ((mode & (__RTLD_OPENEXEC | __RTLD_VDSO)) != 0)) { - assert (type == lt_executable); - assert (nsid == LM_ID_BASE); + if (mode & __RTLD_OPENEXEC) + { + assert (type == lt_executable); + assert (nsid == LM_ID_BASE); - /* Ignore the specified libname for the main executable. It is - only known with an explicit loader invocation. */ - libname = ""; + /* Ignore the specified libname for the main executable. It is + only known with an explicit loader invocation. */ + libname = ""; + } - /* We create the map for the executable before we know whether + /* We create the map for the executable and vDSO before we know whether we have auditing libraries and if yes, how many. Assume the worst. */ naudit = DL_NNS; diff --git a/elf/rtld.c b/elf/rtld.c index b215ce6909..e78001c2a4 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -1912,6 +1912,12 @@ dl_main (const ElfW(Phdr) *phdr, assert (i == npreloads); } +#ifdef NEED_DL_SYSINFO_DSO + /* Now that the audit modules are opened, call la_objopen for the vDSO. */ + if (GLRO(dl_sysinfo_map) != NULL) + _dl_audit_objopen (GLRO(dl_sysinfo_map), LM_ID_BASE); +#endif + /* Load all the libraries specified by DT_NEEDED entries. If LD_PRELOAD specified some libraries to load, these are inserted before the actual dependencies in the executable's searchlist for symbol resolution. */ diff --git a/elf/setup-vdso.h b/elf/setup-vdso.h index 3f20578046..2b013d974a 100644 --- a/elf/setup-vdso.h +++ b/elf/setup-vdso.h @@ -30,7 +30,7 @@ setup_vdso (struct link_map *main_map __attribute__ ((unused)), We just want our data structures to describe it as if we had just mapped and relocated it normally. */ struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL, - 0, LM_ID_BASE); + __RTLD_VDSO, LM_ID_BASE); if (__glibc_likely (l != NULL)) { l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso) diff --git a/elf/tst-audit22.c b/elf/tst-audit22.c new file mode 100644 index 0000000000..18fd22a760 --- /dev/null +++ b/elf/tst-audit22.c @@ -0,0 +1,124 @@ +/* Check DTAUDIT and vDSO interaction. + Copyright (C) 2021 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 + <https://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include <getopt.h> +#include <limits.h> +#include <inttypes.h> +#include <string.h> +#include <stdlib.h> +#include <support/capture_subprocess.h> +#include <support/check.h> +#include <support/xstdio.h> +#include <support/support.h> +#include <sys/auxv.h> + +static int restart; +#define CMDLINE_OPTIONS \ + { "restart", no_argument, &restart, 1 }, + +static uintptr_t vdso_addr; + +static int +handle_restart (void) +{ + fprintf (stderr, "vdso: %p\n", (void*) vdso_addr); + return 0; +} + +static uintptr_t +parse_address (const char *str) +{ + void *r; + TEST_COMPARE (sscanf (str, "%p\n", &r), 1); + return (uintptr_t) r; +} + +static inline bool +startswith (const char *str, const char *pre) +{ + size_t lenpre = strlen (pre); + size_t lenstr = strlen (str); + return lenstr >= lenpre && memcmp (pre, str, lenpre) == 0; +} + +static int +do_test (int argc, char *argv[]) +{ + vdso_addr = getauxval (AT_SYSINFO_EHDR); + if (vdso_addr == 0) + FAIL_UNSUPPORTED ("getauxval (AT_SYSINFO_EHDR) returned 0"); + + /* We must have either: + - One our fource parameters left if called initially: + + path to ld.so optional + + "--library-path" optional + + the library path optional + + the application name */ + if (restart) + return handle_restart (); + + char *spargv[9]; + int i = 0; + for (; i < argc - 1; i++) + spargv[i] = argv[i + 1]; + spargv[i++] = (char *) "--direct"; + spargv[i++] = (char *) "--restart"; + spargv[i] = NULL; + + setenv ("LD_AUDIT", "tst-auditmod22.so", 0); + struct support_capture_subprocess result + = support_capture_subprogram (spargv[0], spargv); + support_capture_subprocess_check (&result, "tst-audit22", 0, sc_allow_stderr); + + /* The respawned process should always print the vDSO address (otherwise it + will fails as unsupported). However, on some architectures the audit + module might see the vDSO with l_addr being 0, meaning a fixed mapping + (linux-gate.so). In this case we don't check its value against + AT_SYSINFO_EHDR one. */ + uintptr_t vdso_process = 0; + bool vdso_audit_found = false; + uintptr_t vdso_audit = 0; + + FILE *out = fmemopen (result.err.buffer, result.err.length, "r"); + TEST_VERIFY (out != NULL); + char *buffer = NULL; + size_t buffer_length = 0; + while (xgetline (&buffer, &buffer_length, out)) + { + if (startswith (buffer, "vdso: ")) + vdso_process = parse_address (buffer + strlen ("vdso: ")); + else if (startswith (buffer, "vdso found: ")) + { + vdso_audit = parse_address (buffer + strlen ("vdso found: ")); + vdso_audit_found = true; + } + } + + TEST_COMPARE (vdso_audit_found, true); + if (vdso_audit != 0) + TEST_COMPARE (vdso_process, vdso_audit); + + free (buffer); + xfclose (out); + + return 0; +} + +#define TEST_FUNCTION_ARGV do_test +#include <support/test-driver.c> diff --git a/elf/tst-auditmod22.c b/elf/tst-auditmod22.c new file mode 100644 index 0000000000..8e05ce8cbb --- /dev/null +++ b/elf/tst-auditmod22.c @@ -0,0 +1,51 @@ +/* Check DTAUDIT and vDSO interaction. + Copyright (C) 2021 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 + <https://www.gnu.org/licenses/>. */ + +#include <link.h> +#include <inttypes.h> +#include <stdbool.h> +#include <string.h> +#include <stdio.h> +#include <sys/auxv.h> + +static inline bool +startswith (const char *str, const char *pre) +{ + size_t lenpre = strlen (pre); + size_t lenstr = strlen (str); + return lenstr < lenpre ? false : memcmp (pre, str, lenpre) == 0; +} + +unsigned int +la_version (unsigned int version) +{ + return LAV_CURRENT; +} + +unsigned int +la_objopen (struct link_map *map, Lmid_t lmid, uintptr_t *cookie) +{ + /* The linux-gate.so is placed at a fixed address, thus l_addr being 0, + and it might be the value reported as the AT_SYSINFO_EHDR. */ + if (map->l_addr == 0 && startswith (map->l_name, "linux-gate.so")) + fprintf (stderr, "vdso found: %p\n", NULL); + else if (map->l_addr == getauxval (AT_SYSINFO_EHDR)) + fprintf (stderr, "vdso found: %p\n", (void*) map->l_addr); + + return 0; +} diff --git a/include/dlfcn.h b/include/dlfcn.h index a4c283728f..e73294b0af 100644 --- a/include/dlfcn.h +++ b/include/dlfcn.h @@ -12,6 +12,8 @@ #define __RTLD_AUDIT 0x08000000 #define __RTLD_SECURE 0x04000000 /* Apply additional security checks. */ #define __RTLD_NOIFUNC 0x02000000 /* Suppress calling ifunc functions. */ +#define __RTLD_VDSO 0x01000000 /* Tell _dl_new_object the object is + system-loaded. */ #define __LM_ID_CALLER -2 |