diff mbox series

[v6] ld.so: add an --argv0 option

Message ID 20200929082122.530578-1-vmihalko@redhat.com
State New
Headers show
Series [v6] ld.so: add an --argv0 option | expand

Commit Message

Bae, Chang Seok via Libc-alpha Sept. 29, 2020, 8:21 a.m. UTC
From: Vincent Mihalkovic <vmihalko@redhat.com>

Hi,

I'm resending this patch due to small grammar corrections in NEWS.

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

Comments

Florian Weimer Sept. 29, 2020, 10:37 a.m. UTC | #1
* vincent via Libc-alpha:

> I'm resending this patch due to small grammar corrections in NEWS.

I have pushed this for you, after adding the reference to bug 16124.
(The NEWS entry will likely see further updates due to other ld.so
changes.)

Thank you for your contribution to glibc.

Florian
diff mbox series

Patch

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 provides 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