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  <adhemerval.zanella@linaro.org>
This commit is contained in:
Florian Weimer 2020-10-08 10:57:10 +02:00
parent 2bf9e641fd
commit 9590a71adc
4 changed files with 65 additions and 26 deletions

View File

@ -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

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@ -19,7 +19,9 @@
#ifndef _DL_MAIN
#define _DL_MAIN
#include <ldsodefs.h>
#include <limits.h>
#include <stdlib.h>
/* 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 */

51
elf/dl-usage.c Normal file
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@ -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
<https://www.gnu.org/licenses/>. */
#include <dl-cache.h>
#include <dl-main.h>
#include <ldsodefs.h>
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");
}

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@ -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;