diff options
| -rw-r--r-- | NEWS | 4 | ||||
| -rw-r--r-- | elf/Makefile | 3 | ||||
| -rw-r--r-- | elf/rtld.c | 50 | ||||
| -rw-r--r-- | elf/tst-rtld-run-static.c | 62 | ||||
| -rw-r--r-- | sysdeps/generic/dl-execve.h | 25 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/dl-execve.h | 25 |
6 files changed, 161 insertions, 8 deletions
@@ -184,6 +184,10 @@ Major new features: than or equal to a given integer. This function is a GNU extension, although Solaris also provides a similar function. +* When invoked explicitly, the dynamic linker now uses the kernel to + execute programs that do not have any dynamic dependency (that is, + they are statically linked). This feature is Linux-specific. + Deprecated and removed features, and other changes affecting compatibility: * The function pthread_mutex_consistent_np has been deprecated; programs diff --git a/elf/Makefile b/elf/Makefile index 4723c15..ef36008 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -231,6 +231,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \ tst-tls20 tst-tls21 tst-dlmopen-dlerror tst-dlmopen-gethostbyname \ tst-dl-is_dso tst-ro-dynamic \ tst-audit18 \ + tst-rtld-run-static \ # reldep9 tests-internal += loadtest unload unload2 circleload1 \ neededtest neededtest2 neededtest3 neededtest4 \ @@ -1977,3 +1978,5 @@ $(objpfx)tst-ro-dynamic-mod.so: $(objpfx)tst-ro-dynamic-mod.os \ $(LINK.o) -nostdlib -nostartfiles -shared -o $@ \ -Wl,--script=tst-ro-dynamic-mod.map \ $(objpfx)tst-ro-dynamic-mod.os + +$(objpfx)tst-rtld-run-static.out: $(objpfx)/ldconfig @@ -50,6 +50,7 @@ #include <gnu/lib-names.h> #include <dl-tunables.h> #include <get-dynamic-info.h> +#include <dl-execve.h> #include <assert.h> @@ -1106,6 +1107,45 @@ load_audit_modules (struct link_map *main_map, struct audit_list *audit_list) } } +/* Check if the executable is not actualy dynamically linked, and + invoke it directly in that case. */ +static void +rtld_chain_load (struct link_map *main_map, char *argv0) +{ + /* The dynamic loader run against itself. */ + const char *rtld_soname + = ((const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB]) + + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val); + if (main_map->l_info[DT_SONAME] != NULL + && strcmp (rtld_soname, + ((const char *) D_PTR (main_map, l_info[DT_STRTAB]) + + main_map->l_info[DT_SONAME]->d_un.d_val)) == 0) + _dl_fatal_printf ("%s: loader cannot load itself\n", rtld_soname); + + /* With DT_NEEDED dependencies, the executable is dynamically + linked. */ + if (__glibc_unlikely (main_map->l_info[DT_NEEDED] != NULL)) + return; + + /* If the executable has program interpreter, it is dynamically + linked. */ + for (size_t i = 0; i < main_map->l_phnum; ++i) + if (main_map->l_phdr[i].p_type == PT_INTERP) + return; + + const char *pathname = _dl_argv[0]; + if (argv0 != NULL) + _dl_argv[0] = argv0; + int errcode = __rtld_execve (pathname, _dl_argv, _environ); + const char *errname = strerrorname_np (errcode); + if (errname != NULL) + _dl_fatal_printf("%s: cannot execute %s: %s\n", + rtld_soname, pathname, errname); + else + _dl_fatal_printf("%s: cannot execute %s: %d\n", + rtld_soname, pathname, errno); +} + static void dl_main (const ElfW(Phdr) *phdr, ElfW(Word) phnum, @@ -1374,14 +1414,8 @@ dl_main (const ElfW(Phdr) *phdr, /* Now the map for the main executable is available. */ main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded; - if (__glibc_likely (state.mode == rtld_mode_normal) - && GL(dl_rtld_map).l_info[DT_SONAME] != NULL - && main_map->l_info[DT_SONAME] != NULL - && strcmp ((const char *) D_PTR (&GL(dl_rtld_map), l_info[DT_STRTAB]) - + GL(dl_rtld_map).l_info[DT_SONAME]->d_un.d_val, - (const char *) D_PTR (main_map, l_info[DT_STRTAB]) - + main_map->l_info[DT_SONAME]->d_un.d_val) == 0) - _dl_fatal_printf ("loader cannot load itself\n"); + if (__glibc_likely (state.mode == rtld_mode_normal)) + rtld_chain_load (main_map, argv0); phdr = main_map->l_phdr; phnum = main_map->l_phnum; diff --git a/elf/tst-rtld-run-static.c b/elf/tst-rtld-run-static.c new file mode 100644 index 0000000..7281093 --- /dev/null +++ b/elf/tst-rtld-run-static.c @@ -0,0 +1,62 @@ +/* Test running statically linked programs using ld.so. + 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 <support/check.h> +#include <support/support.h> +#include <support/capture_subprocess.h> +#include <string.h> +#include <stdlib.h> + +static int +do_test (void) +{ + char *ldconfig_path = xasprintf ("%s/elf/ldconfig", support_objdir_root); + + { + char *argv[] = { (char *) "ld.so", ldconfig_path, (char *) "--help", NULL }; + struct support_capture_subprocess cap + = support_capture_subprogram (support_objdir_elf_ldso, argv); + support_capture_subprocess_check (&cap, "no --argv0", 0, sc_allow_stdout); + puts ("info: output without --argv0:"); + puts (cap.out.buffer); + TEST_VERIFY (strstr (cap.out.buffer, "Usage: ldconfig [OPTION...]\n") + == cap.out.buffer); + support_capture_subprocess_free (&cap); + } + + { + char *argv[] = + { + (char *) "ld.so", (char *) "--argv0", (char *) "ldconfig-argv0", + ldconfig_path, (char *) "--help", NULL + }; + struct support_capture_subprocess cap + = support_capture_subprogram (support_objdir_elf_ldso, argv); + support_capture_subprocess_check (&cap, "with --argv0", 0, sc_allow_stdout); + puts ("info: output with --argv0:"); + puts (cap.out.buffer); + TEST_VERIFY (strstr (cap.out.buffer, "Usage: ldconfig-argv0 [OPTION...]\n") + == cap.out.buffer); + support_capture_subprocess_free (&cap); + } + + free (ldconfig_path); + return 0; +} + +#include <support/test-driver.c> diff --git a/sysdeps/generic/dl-execve.h b/sysdeps/generic/dl-execve.h new file mode 100644 index 0000000..5fd097d --- /dev/null +++ b/sysdeps/generic/dl-execve.h @@ -0,0 +1,25 @@ +/* execve for the dynamic linker. Generic stub version. + 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> + +static int +__rtld_execve (const char *path, char *const *argv, char *const *envp) +{ + return ENOSYS; +} diff --git a/sysdeps/unix/sysv/linux/dl-execve.h b/sysdeps/unix/sysv/linux/dl-execve.h new file mode 100644 index 0000000..ead3e1c --- /dev/null +++ b/sysdeps/unix/sysv/linux/dl-execve.h @@ -0,0 +1,25 @@ +/* execve for the dynamic linker. Linux version. + 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> + +static inline int +__rtld_execve (const char *path, char *const *argv, char *const *envp) +{ + return -INTERNAL_SYSCALL_CALL (execve, path, argv, envp); +} |