diff --git a/usr.bin/ldd/ldd.1 b/usr.bin/ldd/ldd.1 index 2a90d5ac537d..d263eabcf4ff 100644 --- a/usr.bin/ldd/ldd.1 +++ b/usr.bin/ldd/ldd.1 @@ -1,89 +1,73 @@ .\" $FreeBSD$ .\" -.Dd October 23, 2018 +.Dd August 28, 2021 .Dt LDD 1 .Os .Sh NAME .Nm ldd .Nd list dynamic object dependencies .Sh SYNOPSIS .Nm .Op Fl a -.Op Fl v .Op Fl f Ar format .Ar program ... .Sh DESCRIPTION The .Nm utility displays all shared objects that are needed to run the given program or to load the given shared object. Contrary to .Xr nm 1 , the list includes .Dq indirect dependencies that are the result of needed shared objects which themselves depend on yet other shared objects. .Pp Zero, one or two .Fl f options may be given. The argument is a format string passed to .Xr rtld 1 and allows customization of .Nm Ns 's output. If one is given, it sets .Ev LD_TRACE_LOADED_OBJECTS_FMT1 . If two are given, they set .Ev LD_TRACE_LOADED_OBJECTS_FMT1 and .Ev LD_TRACE_LOADED_OBJECTS_FMT2 , respectively. See .Xr rtld 1 for details, including a list of recognized conversion characters. .Pp The .Fl a option displays the list of all objects that are needed by each loaded object. -This option does not work with -.Xr a.out 5 -binaries. -.Pp -The -.Fl v -option displays a verbose listing of the dynamic linking headers -encoded in the executable. -See the source code and include -files for the definitive meaning of all the fields. .Sh IMPLEMENTATION NOTES .Nm lists the dependencies of an executable by setting .Xr rtld 1 environment variables and running the executable in a child process. If the executable is corrupt or invalid, .Nm may therefore fail without providing any diagnostic error messages. .Sh EXAMPLES The following is an example of a shell pipeline which uses the .Fl f option. It will print a report of all ELF binaries in the current directory, which link against libc.so.6: .Dl "find . -type f | xargs -n1 file -F ' ' | grep 'ELF.*dynamically' | cut -f1 -d' ' | xargs ldd -f '%A %o\en' | grep libc.so.6" .Sh SEE ALSO .Xr ld 1 , .Xr nm 1 , .Xr readelf 1 , .Xr rtld 1 .Sh HISTORY A .Nm utility first appeared in SunOS 4.0, it appeared in its current form in .Fx 1.1 . -.Pp -The -.Fl v -support is based on code written by -.An John Polstra Aq Mt jdp@polstra.com diff --git a/usr.bin/ldd/ldd.c b/usr.bin/ldd/ldd.c index f948b7312863..3353345d549d 100644 --- a/usr.bin/ldd/ldd.c +++ b/usr.bin/ldd/ldd.c @@ -1,472 +1,464 @@ /*- * SPDX-License-Identifier: BSD-4-Clause * * Copyright (c) 1993 Paul Kranenburg * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Paul Kranenburg. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * 32-bit ELF data structures can only be used if the system header[s] declare * them. There is no official macro for determining whether they are declared, * so check for the existence of one of the 32-macros defined in elf(5). */ #ifdef ELF32_R_TYPE #define ELF32_SUPPORTED #endif #define LDD_SETENV(name, value, overwrite) do { \ setenv("LD_" name, value, overwrite); \ setenv("LD_32_" name, value, overwrite); \ } while (0) #define LDD_UNSETENV(name) do { \ unsetenv("LD_" name); \ unsetenv("LD_32_" name); \ } while (0) static int is_executable(const char *fname, int fd, int *is_shlib, int *type); static void usage(void); #define TYPE_UNKNOWN 0 #define TYPE_ELF 1 /* Architecture default */ #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) #define TYPE_ELF32 2 /* Explicit 32 bits on architectures >32 bits */ #define _PATH_LDD32 "/usr/bin/ldd32" static int -execldd32(char *file, char *fmt1, char *fmt2, int aflag, int vflag) +execldd32(char *file, char *fmt1, char *fmt2, int aflag) { char *argv[9]; int i, rval, status; LDD_UNSETENV("TRACE_LOADED_OBJECTS"); rval = 0; i = 0; argv[i++] = strdup(_PATH_LDD32); if (aflag) argv[i++] = strdup("-a"); - if (vflag) - argv[i++] = strdup("-v"); if (fmt1 != NULL) { argv[i++] = strdup("-f"); argv[i++] = strdup(fmt1); } if (fmt2 != NULL) { argv[i++] = strdup("-f"); argv[i++] = strdup(fmt2); } argv[i++] = strdup(file); argv[i++] = NULL; switch (fork()) { case -1: err(1, "fork"); break; case 0: execv(_PATH_LDD32, argv); warn("%s", _PATH_LDD32); _exit(127); break; default: if (wait(&status) < 0) rval = 1; else if (WIFSIGNALED(status)) rval = 1; else if (WIFEXITED(status) && WEXITSTATUS(status) != 0) rval = 1; break; } while (i--) free(argv[i]); LDD_SETENV("TRACE_LOADED_OBJECTS", "yes", 1); return (rval); } #endif int main(int argc, char *argv[]) { char *fmt1, *fmt2; - int rval, c, aflag, vflag; + int rval, c, aflag; - aflag = vflag = 0; + aflag = 0; fmt1 = fmt2 = NULL; - while ((c = getopt(argc, argv, "af:v")) != -1) { + while ((c = getopt(argc, argv, "af:")) != -1) { switch (c) { case 'a': aflag++; break; case 'f': if (fmt1 != NULL) { if (fmt2 != NULL) errx(1, "too many formats"); fmt2 = optarg; } else fmt1 = optarg; break; - case 'v': - vflag++; - break; default: usage(); /* NOTREACHED */ } } argc -= optind; argv += optind; - if (vflag && fmt1 != NULL) - errx(1, "-v may not be used with -f"); - if (argc <= 0) { usage(); /* NOTREACHED */ } rval = 0; for (; argc > 0; argc--, argv++) { int fd, status, is_shlib, rv, type; if ((fd = open(*argv, O_RDONLY, 0)) < 0) { warn("%s", *argv); rval |= 1; continue; } rv = is_executable(*argv, fd, &is_shlib, &type); close(fd); if (rv == 0) { rval |= 1; continue; } switch (type) { case TYPE_ELF: break; #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) case TYPE_ELF32: - rval |= execldd32(*argv, fmt1, fmt2, aflag, vflag); + rval |= execldd32(*argv, fmt1, fmt2, aflag); continue; #endif case TYPE_UNKNOWN: default: /* * This shouldn't happen unless is_executable() * is broken. */ errx(EDOOFUS, "unknown executable type"); } /* ld.so magic */ LDD_SETENV("TRACE_LOADED_OBJECTS", "yes", 1); if (fmt1 != NULL) LDD_SETENV("TRACE_LOADED_OBJECTS_FMT1", fmt1, 1); if (fmt2 != NULL) LDD_SETENV("TRACE_LOADED_OBJECTS_FMT2", fmt2, 1); LDD_SETENV("TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1); if (aflag) LDD_SETENV("TRACE_LOADED_OBJECTS_ALL", "1", 1); else if (fmt1 == NULL && fmt2 == NULL) /* Default formats */ printf("%s:\n", *argv); fflush(stdout); switch (fork()) { case -1: err(1, "fork"); break; default: if (wait(&status) < 0) { warn("wait"); rval |= 1; } else if (WIFSIGNALED(status)) { fprintf(stderr, "%s: signal %d\n", *argv, WTERMSIG(status)); rval |= 1; } else if (WIFEXITED(status) && WEXITSTATUS(status) != 0) { fprintf(stderr, "%s: exit status %d\n", *argv, WEXITSTATUS(status)); rval |= 1; } break; case 0: if (is_shlib == 0) { execl(*argv, *argv, (char *)NULL); warn("%s", *argv); } else { dlopen(*argv, RTLD_TRACE); warnx("%s: %s", *argv, dlerror()); } _exit(1); } } return rval; } static void usage(void) { - fprintf(stderr, "usage: ldd [-a] [-v] [-f format] program ...\n"); + fprintf(stderr, "usage: ldd [-a] [-f format] program ...\n"); exit(1); } static bool has_freebsd_abi_tag(const char *fname, Elf *elf, GElf_Ehdr *ehdr, off_t offset, size_t len) { Elf_Data dst, src; const Elf_Note *note; char *buf; const char *name; void *copy; size_t namesz, descsz; bool has_abi_tag; buf = elf_rawfile(elf, NULL); if (buf == NULL) { warnx("%s: %s", fname, elf_errmsg(0)); return (false); } memset(&src, 0, sizeof(src)); src.d_buf = buf + offset; src.d_size = len; src.d_type = ELF_T_NOTE; src.d_version = EV_CURRENT; memset(&dst, 0, sizeof(dst)); dst.d_buf = copy = malloc(len); dst.d_size = len; dst.d_type = ELF_T_NOTE; dst.d_version = EV_CURRENT; if (gelf_xlatetom(elf, &dst, &src, ehdr->e_ident[EI_DATA]) == NULL) { warnx("%s: failed to parse notes: %s", fname, elf_errmsg(0)); free(copy); return (false); } buf = copy; has_abi_tag = false; for (;;) { if (len < sizeof(*note)) break; note = (const void *)buf; buf += sizeof(*note); len -= sizeof(*note); namesz = roundup2(note->n_namesz, sizeof(uint32_t)); descsz = roundup2(note->n_descsz, sizeof(uint32_t)); if (len < namesz + descsz) break; name = buf; if (note->n_namesz == sizeof(ELF_NOTE_FREEBSD) && strncmp(name, ELF_NOTE_FREEBSD, note->n_namesz) == 0 && note->n_type == NT_FREEBSD_ABI_TAG && note->n_descsz == sizeof(uint32_t)) { has_abi_tag = true; break; } buf += namesz + descsz; len -= namesz + descsz; } free(copy); return (has_abi_tag); } static bool is_pie(const char *fname, Elf *elf, GElf_Ehdr *ehdr, off_t offset, size_t len) { Elf_Data dst, src; char *buf; void *copy; const GElf_Dyn *dyn; size_t dynsize; u_int count, i; bool pie; buf = elf_rawfile(elf, NULL); if (buf == NULL) { warnx("%s: %s", fname, elf_errmsg(0)); return (false); } dynsize = gelf_fsize(elf, ELF_T_DYN, 1, EV_CURRENT); if (dynsize == 0) { warnx("%s: %s", fname, elf_errmsg(0)); return (false); } count = len / dynsize; memset(&src, 0, sizeof(src)); src.d_buf = buf + offset; src.d_size = len; src.d_type = ELF_T_DYN; src.d_version = EV_CURRENT; memset(&dst, 0, sizeof(dst)); dst.d_buf = copy = malloc(count * sizeof(*dyn)); dst.d_size = count * sizeof(*dyn); dst.d_type = ELF_T_DYN; dst.d_version = EV_CURRENT; if (gelf_xlatetom(elf, &dst, &src, ehdr->e_ident[EI_DATA]) == NULL) { warnx("%s: failed to parse .dynamic: %s", fname, elf_errmsg(0)); free(copy); return (false); } dyn = copy; pie = false; for (i = 0; i < count; i++) { if (dyn[i].d_tag != DT_FLAGS_1) continue; pie = (dyn[i].d_un.d_val & DF_1_PIE) != 0; break; } free(copy); return (pie); } static int is_executable(const char *fname, int fd, int *is_shlib, int *type) { Elf *elf; GElf_Ehdr ehdr; GElf_Phdr phdr; bool dynamic, freebsd, pie; int i; *is_shlib = 0; *type = TYPE_UNKNOWN; dynamic = false; freebsd = false; pie = false; if (elf_version(EV_CURRENT) == EV_NONE) { warnx("unsupported libelf"); return (0); } elf = elf_begin(fd, ELF_C_READ, NULL); if (elf == NULL) { warnx("%s: %s", fname, elf_errmsg(0)); return (0); } if (elf_kind(elf) != ELF_K_ELF) { elf_end(elf); warnx("%s: not a dynamic ELF executable", fname); return (0); } if (gelf_getehdr(elf, &ehdr) == NULL) { warnx("%s: %s", fname, elf_errmsg(0)); elf_end(elf); return (0); } *type = TYPE_ELF; #if __ELF_WORD_SIZE > 32 && defined(ELF32_SUPPORTED) if (gelf_getclass(elf) == ELFCLASS32) { *type = TYPE_ELF32; } #endif freebsd = ehdr.e_ident[EI_OSABI] == ELFOSABI_FREEBSD; for (i = 0; i < ehdr.e_phnum; i++) { if (gelf_getphdr(elf, i, &phdr) == NULL) { warnx("%s: %s", fname, elf_errmsg(0)); elf_end(elf); return (0); } switch (phdr.p_type) { case PT_NOTE: if (ehdr.e_ident[EI_OSABI] == ELFOSABI_NONE && !freebsd) freebsd = has_freebsd_abi_tag(fname, elf, &ehdr, phdr.p_offset, phdr.p_filesz); break; case PT_DYNAMIC: dynamic = true; if (ehdr.e_type == ET_DYN) pie = is_pie(fname, elf, &ehdr, phdr.p_offset, phdr.p_filesz); break; } } if (!dynamic) { elf_end(elf); warnx("%s: not a dynamic ELF executable", fname); return (0); } if (ehdr.e_type == ET_DYN && !pie) { *is_shlib = 1; if (!freebsd) { elf_end(elf); warnx("%s: not a FreeBSD ELF shared object", fname); return (0); } } elf_end(elf); return (1); }