[PATCH v6] ld.so: add an --argv0 option
vmihalko@redhat.com
vmihalko@redhat.com
Thu Sep 24 12:43:09 GMT 2020
From: Vincent Mihalkovic <vmihalko@redhat.com>
> I think adding a NEWS entry would make sense.
NEWS entry added.
> Here I do not think the ARGV0 variable adds much clarity.
I removed the ARGV0 variable.
> You can use TEST_COMPARE_STRING, which will do the strlen for you.
There was TEST_COMPARE_BLOB because Adhemerval Zanella suggest it
in https://sourceware.org/pipermail/libc-alpha/2020-August/117278.html.
I've changed it to TEST_COMPARE_STRING.
Thank you for your advice,
vincent mihalkovic
---
NEWS | 3 +++
elf/Makefile | 12 ++++++++++--
elf/argv0test.c | 31 +++++++++++++++++++++++++++++++
elf/rtld.c | 17 ++++++++++++++++-
elf/tst-rtld-argv0.sh | 37 +++++++++++++++++++++++++++++++++++++
5 files changed, 97 insertions(+), 3 deletions(-)
create mode 100644 elf/argv0test.c
create mode 100755 elf/tst-rtld-argv0.sh
diff --git a/NEWS b/NEWS
index fc8dd154..099fc3c8 100644
--- a/NEWS
+++ b/NEWS
@@ -9,6 +9,9 @@ Version 2.33
Major new features:
+* The dynamic linker accepts the --argv0 argument and provide opportunity
+ to change argv[0] string.
+
* The mallinfo2 function is added to report statistics as per mallinfo,
but with larger field widths to accurately report values that are
larger than fit in an integer.
diff --git a/elf/Makefile b/elf/Makefile
index 0b787218..c587e9f0 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -210,7 +210,8 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \
tst-filterobj tst-filterobj-dlopen tst-auxobj tst-auxobj-dlopen \
tst-audit14 tst-audit15 tst-audit16 \
tst-single_threaded tst-single_threaded-pthread \
- tst-tls-ie tst-tls-ie-dlmopen
+ tst-tls-ie tst-tls-ie-dlmopen \
+ argv0test
# reldep9
tests-internal += loadtest unload unload2 circleload1 \
neededtest neededtest2 neededtest3 neededtest4 \
@@ -414,7 +415,7 @@ endif
ifeq (yes,$(build-shared))
ifeq ($(run-built-tests),yes)
tests-special += $(objpfx)tst-pathopt.out $(objpfx)tst-rtld-load-self.out \
- $(objpfx)tst-rtld-preload.out
+ $(objpfx)tst-rtld-preload.out $(objpfx)argv0test.out
endif
tests-special += $(objpfx)check-textrel.out $(objpfx)check-execstack.out \
$(objpfx)check-wx-segment.out \
@@ -1796,3 +1797,10 @@ $(objpfx)tst-tls-ie-dlmopen.out: \
$(objpfx)tst-tls-ie-mod6.so
$(objpfx)tst-tls-surplus: $(libdl)
+
+$(objpfx)argv0test.out: tst-rtld-argv0.sh $(objpfx)ld.so \
+ $(objpfx)argv0test
+ $(SHELL) $< $(objpfx)ld.so $(objpfx)argv0test \
+ '$(test-wrapper-env)' '$(run_program_env)' \
+ '$(rpath-link)' 'test-argv0' > $@; \
+ $(evaluate-test)
diff --git a/elf/argv0test.c b/elf/argv0test.c
new file mode 100644
index 00000000..c22ba5ea
--- /dev/null
+++ b/elf/argv0test.c
@@ -0,0 +1,31 @@
+/* Test for --argv0 option ld.so.
+
+ Copyright (C) 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 <string.h>
+#include <support/check.h>
+
+static int
+do_test (int argc, char **argv)
+{
+ TEST_COMPARE_STRING (argv[0], "test-argv0");
+ return 0;
+}
+
+#define TEST_FUNCTION_ARGV do_test
+#include <support/test-driver.c>
diff --git a/elf/rtld.c b/elf/rtld.c
index 5b882163..9918fda0 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -1202,6 +1202,8 @@ dl_main (const ElfW(Phdr) *phdr,
installing it. */
rtld_is_main = true;
+ char *argv0 = NULL;
+
/* Note the place where the dynamic linker actually came from. */
GL(dl_rtld_map).l_name = rtld_progname;
@@ -1259,6 +1261,14 @@ dl_main (const ElfW(Phdr) *phdr,
else if (! strcmp (_dl_argv[1], "--preload") && _dl_argc > 2)
{
preloadarg = _dl_argv[2];
+ _dl_skip_args += 2;
+ _dl_argc -= 2;
+ _dl_argv += 2;
+ }
+ else if (! strcmp (_dl_argv[1], "--argv0") && _dl_argc > 2)
+ {
+ argv0 = _dl_argv[2];
+
_dl_skip_args += 2;
_dl_argc -= 2;
_dl_argv += 2;
@@ -1292,7 +1302,8 @@ of this helper program; chances are you did not intend to run this program.\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");
+ --preload LIST preload objects named in LIST\n\
+ --argv0 STRING set argv[0] to STRING before running\n");
++_dl_skip_args;
--_dl_argc;
@@ -1384,6 +1395,10 @@ of this helper program; chances are you did not intend to run this program.\n\
break;
}
#endif
+
+ /* Set the argv[0] string now that we've processed the executable. */
+ if (argv0 != NULL)
+ _dl_argv[0] = argv0;
}
else
{
diff --git a/elf/tst-rtld-argv0.sh b/elf/tst-rtld-argv0.sh
new file mode 100755
index 00000000..14d97fb3
--- /dev/null
+++ b/elf/tst-rtld-argv0.sh
@@ -0,0 +1,37 @@
+#!/bin/sh
+# Test for --argv0 option ld.so.
+# Copyright (C) 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/>.
+
+set -e
+
+rtld=$1
+test_program=$2
+test_wrapper_env=$3
+run_program_env=$4
+library_path=$5
+argv0=$6
+
+echo "# [${test_wrapper_env}] [${run_program_env}] [$rtld] [--library-path]" \
+ "[$library_path] [--argv0] [$argv0] [$test_program]"
+${test_wrapper_env} \
+${run_program_env} \
+$rtld --library-path "$library_path" \
+ --argv0 "$argv0" $test_program 2>&1 && rc=0 || rc=$?
+echo "# exit status $rc"
+
+exit $rc
--
2.25.4
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