From 9590a71adcf134c77f2d0f5711b0d6ab1b4193e6 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Thu, 8 Oct 2020 10:57:10 +0200 Subject: [PATCH] elf: Move ld.so error/help output to _dl_usage Also add a comment to elf/Makefile, explaining why we cannot use config.status for autoconf template processing. Reviewed-by: Adhemerval Zanella --- elf/Makefile | 9 ++++++++- elf/dl-main.h | 5 +++++ elf/dl-usage.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ elf/rtld.c | 26 +------------------------- 4 files changed, 65 insertions(+), 26 deletions(-) create mode 100644 elf/dl-usage.c diff --git a/elf/Makefile b/elf/Makefile index 6a76beb..8cdc44f 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -59,7 +59,7 @@ elide-routines.os = $(all-dl-routines) dl-support enbl-secure dl-origin \ # ld.so uses those routines, plus some special stuff for being the program # interpreter and operating independent of libc. rtld-routines = rtld $(all-dl-routines) dl-sysdep dl-environ dl-minimal \ - dl-error-minimal dl-conflict dl-hwcaps + dl-error-minimal dl-conflict dl-hwcaps dl-usage all-rtld-routines = $(rtld-routines) $(sysdep-rtld-routines) CFLAGS-dl-runtime.c += -fexceptions -fasynchronous-unwind-tables @@ -618,6 +618,12 @@ ldso_install: $(inst_rtlddir)/$(rtld-installed-name) endif +# Workarounds for ${exec_prefix} expansion in configure variables. +# config.status cannot be used directly for processing ldd.bash.in or +# expanding variables such as sysconfdir because the expansion +# contains the literal string ${exec_prefix}, which is not valid in C +# headers or installed shell scripts. + ldd-rewrite = -e 's%@RTLD@%$(rtlddir)/$(rtld-installed-name)%g' \ -e 's%@VERSION@%$(version)%g' \ -e 's|@PKGVERSION@|$(PKGVERSION)|g' \ @@ -655,6 +661,7 @@ libof-ldconfig = ldconfig CFLAGS-dl-cache.c += $(SYSCONF-FLAGS) CFLAGS-cache.c += $(SYSCONF-FLAGS) CFLAGS-rtld.c += $(SYSCONF-FLAGS) +CFLAGS-dl-usage.c += $(SYSCONF-FLAGS) cpp-srcs-left := $(all-rtld-routines:=.os) lib := rtld diff --git a/elf/dl-main.h b/elf/dl-main.h index bcc9bcf..b01f433 100644 --- a/elf/dl-main.h +++ b/elf/dl-main.h @@ -19,7 +19,9 @@ #ifndef _DL_MAIN #define _DL_MAIN +#include #include +#include /* Length limits for names and paths, to protect the dynamic linker, particularly when __libc_enable_secure is active. */ @@ -95,4 +97,7 @@ call_init_paths (const struct dl_main_state *state) _dl_init_paths (state->library_path); } +/* Print ld.so usage information and exit. */ +_Noreturn void _dl_usage (void) attribute_hidden; + #endif /* _DL_MAIN */ diff --git a/elf/dl-usage.c b/elf/dl-usage.c new file mode 100644 index 0000000..f3d89d2 --- /dev/null +++ b/elf/dl-usage.c @@ -0,0 +1,51 @@ +/* Print usage information and help for ld.so. + Copyright (C) 1995-2020 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 +#include + +void +_dl_usage (void) +{ + _dl_fatal_printf ("\ +Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\ +You have invoked `ld.so', the helper program for shared library executables.\n\ +This program usually lives in the file `/lib/ld.so', and special directives\n\ +in executable files using ELF shared libraries tell the system's program\n\ +loader to load the helper program from this file. This helper program loads\n\ +the shared libraries needed by the program executable, prepares the program\n\ +to run, and runs it. You may invoke this helper program directly from the\n\ +command line to load and run an ELF executable file; this is like executing\n\ +that file itself, but always uses this helper program from the file you\n\ +specified, instead of the helper program file specified in the executable\n\ +file you run. This is mostly of use for maintainers to test new versions\n\ +of this helper program; chances are you did not intend to run this program.\n\ +\n\ + --list list all dependencies and how they are resolved\n\ + --verify verify that given object really is a dynamically linked\n\ + object we can handle\n\ + --inhibit-cache Do not use " LD_SO_CACHE "\n\ + --library-path PATH use given PATH instead of content of the environment\n\ + variable LD_LIBRARY_PATH\n\ + --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\ + in LIST\n\ + --audit LIST use objects named in LIST as auditors\n\ + --preload LIST preload objects named in LIST\n\ + --argv0 STRING set argv[0] to STRING before running\n"); +} diff --git a/elf/rtld.c b/elf/rtld.c index 8e35c3a..ee5bf17 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -1246,31 +1246,7 @@ dl_main (const ElfW(Phdr) *phdr, /* If we have no further argument the program was called incorrectly. Grant the user some education. */ if (_dl_argc < 2) - _dl_fatal_printf ("\ -Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\ -You have invoked `ld.so', the helper program for shared library executables.\n\ -This program usually lives in the file `/lib/ld.so', and special directives\n\ -in executable files using ELF shared libraries tell the system's program\n\ -loader to load the helper program from this file. This helper program loads\n\ -the shared libraries needed by the program executable, prepares the program\n\ -to run, and runs it. You may invoke this helper program directly from the\n\ -command line to load and run an ELF executable file; this is like executing\n\ -that file itself, but always uses this helper program from the file you\n\ -specified, instead of the helper program file specified in the executable\n\ -file you run. This is mostly of use for maintainers to test new versions\n\ -of this helper program; chances are you did not intend to run this program.\n\ -\n\ - --list list all dependencies and how they are resolved\n\ - --verify verify that given object really is a dynamically linked\n\ - object we can handle\n\ - --inhibit-cache Do not use " LD_SO_CACHE "\n\ - --library-path PATH use given PATH instead of content of the environment\n\ - variable LD_LIBRARY_PATH\n\ - --inhibit-rpath LIST ignore RUNPATH and RPATH information in object names\n\ - in LIST\n\ - --audit LIST use objects named in LIST as auditors\n\ - --preload LIST preload objects named in LIST\n\ - --argv0 STRING set argv[0] to STRING before running\n"); + _dl_usage (); ++_dl_skip_args; --_dl_argc; -- 2.7.4