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From 6ad35e463cbd086b4d4e7bb5aca1da6b73e614c8 Mon Sep 17 00:00:00 2001
From: Mike Frysinger <vapier@gentoo.org>
Date: Tue, 20 Jul 2021 21:08:31 +0200
Subject: [PATCH 1/6] Gentoo: gold/ld: add support for poisoned system
directories
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
This is based on the old CodeSourcery patch written by Joseph Myers to add
support to the link for detecting & rejecting bad -L paths when using a
cross-compiler. The differences here:
* The command line flags are always available.
* We can turn on & off the warning via the command line.
* The configure option controls the default warning behavior.
* Add support for gold.
It is not currently upstream, nor has it been submitted at all. There are
no plans to do so currently either.
BUG=chromium:488360
TEST=`cbuildbot chromiumos-sdk` passes # tests arm/amd64/mipsel/x86
TEST=`cbuildbot panther_moblab-full whirlwind-release` pass
TEST=`cbuildbot {x32,arm64}-generic-full` has no new failures
TEST=x86_64-cros-linux-gnu-ld throws warnings when using -L/lib (gold & bfd)
Reviewed-on: https://chromium-review.googlesource.com/272083
(cherry picked from commit f92dbf35c00ab13cee36f6be8ae5ca46454d9000)
Ported to binutils 2.37 by Andreas K. Hüttel <dilfridge@gentoo.org>
Ported to binutils 2.39 by WANG Xuerui <xen0n@gentoo.org>
---
gold/options.cc | 33 +++++++++++++++++++++++++++++++++
gold/options.h | 7 +++++++
ld/config.in | 3 +++
ld/configure | 20 ++++++++++++++++++--
ld/configure.ac | 10 ++++++++++
ld/ld.h | 7 +++++++
ld/ld.texi | 18 ++++++++++++++++++
ld/ldfile.c | 20 ++++++++++++++++++++
ld/ldlex.h | 3 +++
ld/ldmain.c | 7 +++++++
ld/lexsup.c | 24 ++++++++++++++++++++++++
11 files changed, 150 insertions(+), 2 deletions(-)
diff --git a/gold/options.cc b/gold/options.cc
index 04be98a3e39..64439f8af7a 100644
--- a/gold/options.cc
+++ b/gold/options.cc
@@ -1355,6 +1355,39 @@ General_options::finalize()
// in the path, as appropriate.
this->add_sysroot();
+ // Now check if library_path is poisoned.
+ if (this->warn_poison_system_directories())
+ {
+ std::vector<std::string> bad_paths;
+
+ bad_paths.push_back("/lib");
+ // TODO: This check is disabled for now due to a bunch of packages that
+ // use libtool and relink with -L/usr/lib paths (albeit after the right
+ // sysroot path). Once those are fixed we can enable.
+ // We also need to adjust it so it only rejects one or two levels deep.
+ // Gcc's internal paths also live below /usr/lib.
+ // http://crbug.com/488360
+ // bad_paths.push_back("/usr/lib");
+ bad_paths.push_back("/usr/local/lib");
+ bad_paths.push_back("/usr/X11R6/lib");
+
+ for (std::vector<std::string>::const_iterator b = bad_paths.begin();
+ b != bad_paths.end();
+ ++b)
+ for (Dir_list::iterator p = this->library_path_.value.begin();
+ p != this->library_path_.value.end();
+ ++p)
+ if (!p->name().compare(0, b->size(), *b))
+ {
+ if (this->error_poison_system_directories())
+ gold_fatal(_("library search path \"%s\" is unsafe for "
+ "cross-compilation"), p->name().c_str());
+ else
+ gold_warning(_("library search path \"%s\" is unsafe for "
+ "cross-compilation"), p->name().c_str());
+ }
+ }
+
// Now that we've normalized the options, check for contradictory ones.
if (this->shared() && this->is_static())
gold_fatal(_("-shared and -static are incompatible"));
diff --git a/gold/options.h b/gold/options.h
index 9509a445e8e..a3d76b294cd 100644
--- a/gold/options.h
+++ b/gold/options.h
@@ -1394,6 +1394,13 @@ class General_options
DEFINE_bool(warn_multiple_gp, options::TWO_DASHES, '\0', false,
N_("Ignored"), NULL);
+ DEFINE_bool(warn_poison_system_directories, options::TWO_DASHES, '\0', false,
+ N_("Warn for -L options using system directories"),
+ N_("Do not warn for -L options using system directories"));
+ DEFINE_bool(error_poison_system_directories, options::TWO_DASHES, '\0', false,
+ N_("Give an error for -L options using system directories"),
+ NULL);
+
DEFINE_bool(warn_search_mismatch, options::TWO_DASHES, '\0', true,
N_("Warn when skipping an incompatible library"),
N_("Don't warn when skipping an incompatible library"));
diff --git a/ld/config.in b/ld/config.in
index 0ccd79d59cd..5e39814bce0 100644
--- a/ld/config.in
+++ b/ld/config.in
@@ -55,6 +55,9 @@
language is requested. */
#undef ENABLE_NLS
+/* Define to warn for use of native system library directories */
+#undef ENABLE_POISON_SYSTEM_DIRECTORIES
+
/* Additional extension a shared object might have. */
#undef EXTRA_SHLIB_EXTENSION
diff --git a/ld/configure b/ld/configure
index 1c2b64870b1..46b5789c77e 100755
--- a/ld/configure
+++ b/ld/configure
@@ -836,6 +836,7 @@ with_lib_path
enable_targets
enable_64_bit_bfd
with_sysroot
+enable_poison_system_directories
enable_gold
enable_got
enable_compressed_debug_sections
@@ -1514,6 +1515,8 @@ Optional Features:
--enable-checking enable run-time checks
--enable-targets alternative target configurations
--enable-64-bit-bfd 64-bit support (on hosts with narrower word sizes)
+ --enable-poison-system-directories
+ warn for use of native system library directories
--enable-gold[=ARG] build gold [ARG={default,yes,no}]
--enable-got=<type> GOT handling scheme (target, single, negative,
multigot)
@@ -11491,7 +11494,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 11494 "configure"
+#line 11497 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -11597,7 +11600,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 11600 "configure"
+#line 11603 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -15349,6 +15352,19 @@ fi
+# Check whether --enable-poison-system-directories was given.
+if test "${enable_poison_system_directories+set}" = set; then :
+ enableval=$enable_poison_system_directories;
+else
+ enable_poison_system_directories=no
+fi
+
+if test "x${enable_poison_system_directories}" = "xyes"; then
+
+$as_echo "#define ENABLE_POISON_SYSTEM_DIRECTORIES 1" >>confdefs.h
+
+fi
+
# Check whether --enable-gold was given.
if test "${enable_gold+set}" = set; then :
enableval=$enable_gold; case "${enableval}" in
diff --git a/ld/configure.ac b/ld/configure.ac
index eb55904c090..0844c2364c5 100644
--- a/ld/configure.ac
+++ b/ld/configure.ac
@@ -102,6 +102,16 @@ AC_SUBST(use_sysroot)
AC_SUBST(TARGET_SYSTEM_ROOT)
AC_SUBST(TARGET_SYSTEM_ROOT_DEFINE)
+AC_ARG_ENABLE([poison-system-directories],
+ AS_HELP_STRING([--enable-poison-system-directories],
+ [warn for use of native system library directories]),,
+ [enable_poison_system_directories=no])
+if test "x${enable_poison_system_directories}" = "xyes"; then
+ AC_DEFINE([ENABLE_POISON_SYSTEM_DIRECTORIES],
+ [1],
+ [Define to warn for use of native system library directories])
+fi
+
dnl Use --enable-gold to decide if this linker should be the default.
dnl "install_as_default" is set to false if gold is the default linker.
dnl "installed_linker" is the installed BFD linker name.
diff --git a/ld/ld.h b/ld/ld.h
index f3086bf30de..90cf1ca51e5 100644
--- a/ld/ld.h
+++ b/ld/ld.h
@@ -162,6 +162,13 @@ typedef struct
in the linker script. */
bool force_group_allocation;
+ /* If true warn for uses of system directories when cross linking. */
+ bool warn_poison_system_directories;
+
+ /* If true (default false) give an error for uses of system
+ directories when cross linking instead of a warning. */
+ bool error_poison_system_directories;
+
/* Big or little endian as set on command line. */
enum endian_enum endian;
diff --git a/ld/ld.texi b/ld/ld.texi
index eabbec8faa9..45f4858526c 100644
--- a/ld/ld.texi
+++ b/ld/ld.texi
@@ -2947,6 +2947,24 @@ creation of the metadata note, if one had been enabled by an earlier
occurrence of the --package-metdata option.
If the linker has been built with libjansson, then the JSON string
will be validated.
+
+@kindex --warn-poison-system-directories
+@item --warn-poison-system-directories
+Warn for @option{-L} options using system directories such as
+@file{/usr/lib} when cross linking. This option is intended for use
+in environments that want to detect and reject incorrect link settings.
+
+@kindex --no-warn-poison-system-directories
+@item --no-warn-poison-system-directories
+Do not warn for @option{-L} options using system directories such as
+@file{/usr/lib} when cross linking. This option is intended for use
+in chroot environments when such directories contain the correct
+libraries for the target system rather than the host.
+
+@kindex --error-poison-system-directories
+@item --error-poison-system-directories
+Give an error instead of a warning for @option{-L} options using
+system directories when cross linking.
@end table
@c man end
diff --git a/ld/ldfile.c b/ld/ldfile.c
index 731ae5f7aed..6b67e29041b 100644
--- a/ld/ldfile.c
+++ b/ld/ldfile.c
@@ -117,6 +117,26 @@ ldfile_add_library_path (const char *name, bool cmdline)
new_dirs->name = concat (ld_sysroot, name + strlen ("$SYSROOT"), (const char *) NULL);
else
new_dirs->name = xstrdup (name);
+
+ if (command_line.warn_poison_system_directories
+ && (!strncmp (name, "/lib", 4)
+ /* TODO: This check is disabled for now due to a bunch of packages that
+ * use libtool and relink with -L/usr/lib paths (albeit after the right
+ * sysroot path). Once those are fixed we can enable.
+ * We also need to adjust it so it only rejects one or two levels deep.
+ * Gcc's internal paths also live below /usr/lib.
+ * http://crbug.com/488360 */
+ /* || !strncmp (name, "/usr/lib", 8) */
+ || !strncmp (name, "/usr/local/lib", 14)
+ || !strncmp (name, "/usr/X11R6/lib", 14)))
+ {
+ if (command_line.error_poison_system_directories)
+ einfo (_("%X%P: error: library search path \"%s\" is unsafe for "
+ "cross-compilation\n"), name);
+ else
+ einfo (_("%P: warning: library search path \"%s\" is unsafe for "
+ "cross-compilation\n"), name);
+ }
}
/* Try to open a BFD for a lang_input_statement. */
diff --git a/ld/ldlex.h b/ld/ldlex.h
index 57ade1f754b..b35a6122e09 100644
--- a/ld/ldlex.h
+++ b/ld/ldlex.h
@@ -149,6 +149,9 @@ enum option_values
OPTION_PRINT_OUTPUT_FORMAT,
OPTION_PRINT_SYSROOT,
OPTION_IGNORE_UNRESOLVED_SYMBOL,
+ OPTION_WARN_POISON_SYSTEM_DIRECTORIES,
+ OPTION_NO_WARN_POISON_SYSTEM_DIRECTORIES,
+ OPTION_ERROR_POISON_SYSTEM_DIRECTORIES,
OPTION_PUSH_STATE,
OPTION_POP_STATE,
OPTION_DISABLE_MULTIPLE_DEFS_ABS,
diff --git a/ld/ldmain.c b/ld/ldmain.c
index ea72b14a301..706ec9ce26e 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -321,6 +321,13 @@ main (int argc, char **argv)
command_line.warn_mismatch = true;
command_line.warn_search_mismatch = true;
command_line.check_section_addresses = -1;
+ command_line.warn_poison_system_directories =
+#ifdef ENABLE_POISON_SYSTEM_DIRECTORIES
+ true;
+#else
+ false;
+#endif
+ command_line.error_poison_system_directories = false;
/* We initialize DEMANGLING based on the environment variable
COLLECT_NO_DEMANGLE. The gcc collect2 program will demangle the
diff --git a/ld/lexsup.c b/ld/lexsup.c
index 9225f71b3ce..db5b170bc7c 100644
--- a/ld/lexsup.c
+++ b/ld/lexsup.c
@@ -579,6 +579,18 @@ static const struct ld_option ld_options[] =
OPTION_IGNORE_UNRESOLVED_SYMBOL},
'\0', N_("SYMBOL"),
N_("Unresolved SYMBOL will not cause an error or warning"), TWO_DASHES },
+ { {"warn-poison-system-directories", no_argument, NULL,
+ OPTION_WARN_POISON_SYSTEM_DIRECTORIES},
+ '\0', NULL, N_("Warn for -L options using system directories"),
+ TWO_DASHES },
+ { {"no-warn-poison-system-directories", no_argument, NULL,
+ OPTION_NO_WARN_POISON_SYSTEM_DIRECTORIES},
+ '\0', NULL, N_("Do not warn for -L options using system directories"),
+ TWO_DASHES },
+ { {"error-poison-system-directories", no_argument, NULL,
+ OPTION_ERROR_POISON_SYSTEM_DIRECTORIES},
+ '\0', NULL, N_("Give an error for -L options using system directories"),
+ TWO_DASHES },
{ {"push-state", no_argument, NULL, OPTION_PUSH_STATE},
'\0', NULL, N_("Push state of flags governing input file handling"),
TWO_DASHES },
@@ -1679,6 +1691,18 @@ parse_args (unsigned argc, char **argv)
}
break;
+ case OPTION_WARN_POISON_SYSTEM_DIRECTORIES:
+ command_line.warn_poison_system_directories = true;
+ break;
+
+ case OPTION_NO_WARN_POISON_SYSTEM_DIRECTORIES:
+ command_line.warn_poison_system_directories = false;
+ break;
+
+ case OPTION_ERROR_POISON_SYSTEM_DIRECTORIES:
+ command_line.error_poison_system_directories = true;
+ break;
+
case OPTION_PUSH_STATE:
input_flags.pushed = xmemdup (&input_flags,
sizeof (input_flags),
--
2.35.1
|