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

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

[Vincent Mihalkovic via Libc-alpha]

[-- Attachment #1: Type: text/plain, Size: 343 bytes --]

Hi,

I have seen that the development branch is open for glibc 2.33.
In reaction to previous e-mail communication with Florian Weimer:

> "I guest we could add --argv0 now (well, after the 2.32 release), and if
> it's incompatible with some applications, we can perhaps tweak it later."
>
I'm sending my argv0 patch again.

vincent mihalkovic

[-- Attachment #2: changelog.txt --]
[-- Type: text/plain, Size: 240 bytes --]

2020-07-22  Vincent Mihalkovic  <vmihalko@redhat.com>

	* elf/Makefile: added argv0 test case, Modified.
	* elf/rtld.c: added --argv0 option, Modified.
	* elf/argv0test.c: test case, New file.
	* elf/tst-rtld-argv0.sh: test case, New file.

[-- Attachment #3: argv0.patch --]
[-- Type: application/x-patch, Size: 4788 bytes --]

Re: [PATCH] ld.so: add an --argv0 option

[Adhemerval Zanella via Libc-alpha]

On 12/08/2020 08:06, Vincent Mihalkovic via Libc-alpha wrote:
> Hi,
> 
> I have seen that the development branch is open for glibc 2.33.
> In reaction to previous e-mail communication with Florian Weimer:
> 
>> "I guest we could add --argv0 now (well, after the 2.32 release), and if
>> it's incompatible with some applications, we can perhaps tweak it later."
>>
> I'm sending my argv0 patch again.
> 
> vincent mihalkovic
> 

No need to send ChangeLog.txt anymore.  As a side note I would like ask you send
the patch as inline instead of attachments.

> diff --git a/elf/Makefile b/elf/Makefile
> index 0b78721848..f38904d831 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 \

Ok.

> @@ -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 +1797,11 @@ $(objpfx)tst-tls-ie-dlmopen.out: \
>    $(objpfx)tst-tls-ie-mod6.so
>  
>  $(objpfx)tst-tls-surplus: $(libdl)
> +
> +ARGV0 = test-argv0
> +$(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)' '$(ARGV0)' > $@; \
> +    $(evaluate-test)

Ok.

> diff --git a/elf/argv0test.c b/elf/argv0test.c
> new file mode 100644
> index 0000000000..4c79bebf23
> --- /dev/null
> +++ b/elf/argv0test.c
> @@ -0,0 +1,13 @@
> +#include <stdio.h>   // for printf
> +#include <string.h>  // for strcmp
> +
> +
> +int main( int argc, char *argv[] ) {
> +	int result = strcmp( argv[0], "test-argv0");
> + 
> +	printf ("argv[0] = %s, strcmp( argv[0], \"test-argv0\" ) = %d, %s\n", \
> +					argv[0], result, !result ? "ok" : "wrong");
> +
> +	return result;
> +
> +}
> diff --git a/elf/rtld.c b/elf/rtld.c

Please use libsupport even for such simple tests. Also use glibc code style [1].

> index 5b882163fa..cafa4f9bd3 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;

Ok.

> @@ -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 +1395,11 @@ 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;
> +	  }

Use the glibc code style and conventions [1]. In this case just drop the brackets.

>      }
>    else
>      {
> diff --git a/elf/tst-rtld-argv0.sh b/elf/tst-rtld-argv0.sh
> new file mode 100755
> index 0000000000..5f873b6c5c
> --- /dev/null
> +++ b/elf/tst-rtld-argv0.sh
> @@ -0,0 +1,37 @@
> +#!/bin/sh
> +# Test --argv0 argument ld.so.
> +# Copyright (C) 2019-2020 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

Ok.

[1] https://sourceware.org/glibc/wiki/Style_and_Conventions

[PATCH v2] ld.so: add an --argv0 option

[vmihalko--- via Libc-alpha]

From: Vincent Mihalkovic <vmihalko@redhat.com>

---
 elf/Makefile          | 13 +++++++++++--
 elf/argv0test.c       | 18 ++++++++++++++++++
 elf/rtld.c            | 17 ++++++++++++++++-
 elf/tst-rtld-argv0.sh | 37 +++++++++++++++++++++++++++++++++++++
 4 files changed, 82 insertions(+), 3 deletions(-)
 create mode 100644 elf/argv0test.c
 create mode 100755 elf/tst-rtld-argv0.sh

diff --git a/elf/Makefile b/elf/Makefile
index 0b787218..f38904d8 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 +1797,11 @@ $(objpfx)tst-tls-ie-dlmopen.out: \
   $(objpfx)tst-tls-ie-mod6.so
 
 $(objpfx)tst-tls-surplus: $(libdl)
+
+ARGV0 = test-argv0
+$(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)' '$(ARGV0)' > $@; \
+    $(evaluate-test)
diff --git a/elf/argv0test.c b/elf/argv0test.c
new file mode 100644
index 00000000..137ced8d
--- /dev/null
+++ b/elf/argv0test.c
@@ -0,0 +1,18 @@
+#include <stdio.h>   // for printf
+#include <string.h>  // for strcmp
+
+static int
+do_test (int argc, char **argv)
+{
+	int result = strcmp (argv[0], "test-argv0");
+
+	printf ("argv[0] = %s, strcmp (argv[0], \"test-argv0\") = %d, %s\n",
+					argv[0], result, !result ? "ok" : "wrong");
+
+	return result;
+
+}
+
+
+#define TEST_FUNCTION_ARGV do_test
+#include <support/test-driver.c>
diff --git a/elf/rtld.c b/elf/rtld.c
index 5b882163..e66e033c 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..5f873b6c
--- /dev/null
+++ b/elf/tst-rtld-argv0.sh
@@ -0,0 +1,37 @@
+#!/bin/sh
+# Test --argv0 argument ld.so.
+# Copyright (C) 2019-2020 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

Re: [PATCH v2] ld.so: add an --argv0 option

[Adhemerval Zanella via Libc-alpha]

On 26/08/2020 08:53, vmihalko--- via Libc-alpha wrote:
> From: Vincent Mihalkovic <vmihalko@redhat.com>

The testcase still misses some pieces (copyright headers, indentation, libsupport
usage).

> 
> ---
>  elf/Makefile          | 13 +++++++++++--
>  elf/argv0test.c       | 18 ++++++++++++++++++
>  elf/rtld.c            | 17 ++++++++++++++++-
>  elf/tst-rtld-argv0.sh | 37 +++++++++++++++++++++++++++++++++++++
>  4 files changed, 82 insertions(+), 3 deletions(-)
>  create mode 100644 elf/argv0test.c
>  create mode 100755 elf/tst-rtld-argv0.sh
> 
> diff --git a/elf/Makefile b/elf/Makefile
> index 0b787218..f38904d8 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 +1797,11 @@ $(objpfx)tst-tls-ie-dlmopen.out: \
>    $(objpfx)tst-tls-ie-mod6.so
>  
>  $(objpfx)tst-tls-surplus: $(libdl)
> +
> +ARGV0 = test-argv0
> +$(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)' '$(ARGV0)' > $@; \
> +    $(evaluate-test)
> diff --git a/elf/argv0test.c b/elf/argv0test.c
> new file mode 100644
> index 00000000..137ced8d
> --- /dev/null
> +++ b/elf/argv0test.c
> @@ -0,0 +1,18 @@

It misses the GPL copyright header.

> +#include <stdio.h>   // for printf
> +#include <string.h>  // for strcmp

Afaik the style prefer C-style comments over C++ one, even though they are
added on C99.

> +
> +static int
> +do_test (int argc, char **argv)
> +{
> +	int result = strcmp (argv[0], "test-argv0");
> +
> +	printf ("argv[0] = %s, strcmp (argv[0], \"test-argv0\") = %d, %s\n",
> +					argv[0], result, !result ? "ok" : "wrong");
> +
> +	return result;
> +
> +}
> +
> +
> +#define TEST_FUNCTION_ARGV do_test
> +#include <support/test-driver.c>

The indentation it still off, it should be use double space not four space.
Also a simple implementation using libsupport would be:

  #include <support/check.h>

  static int
  do_test (int argc, char **argv)
  {
     TEST_COMPARE_BLOB (argv[0], strlen (argv[0]),
			"test-argv0", strlen ("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..e66e033c 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..5f873b6c
> --- /dev/null
> +++ b/elf/tst-rtld-argv0.sh
> @@ -0,0 +1,37 @@
> +#!/bin/sh
> +# Test --argv0 argument ld.so.
> +# Copyright (C) 2019-2020 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
> 

[PATCH v3] ld.so: add an --argv0 option

[vincent via Libc-alpha]

From: Vincent Mihalkovic <vmihalko@redhat.com>

I hope everything is fine now, thanks for the feedback and help with
the patch. I was writing the test case against this documentation:
https://sourceware.org/glibc/wiki/Testing/Testsuite and could't find
any documentation for libsupport, that's why I didn't use it.

---
 elf/Makefile          | 13 +++++++++++--
 elf/argv0test.c       | 32 ++++++++++++++++++++++++++++++++
 elf/rtld.c            | 17 ++++++++++++++++-
 elf/tst-rtld-argv0.sh | 37 +++++++++++++++++++++++++++++++++++++
 4 files changed, 96 insertions(+), 3 deletions(-)
 create mode 100644 elf/argv0test.c
 create mode 100755 elf/tst-rtld-argv0.sh

diff --git a/elf/Makefile b/elf/Makefile
index 0b787218..f38904d8 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 +1797,11 @@ $(objpfx)tst-tls-ie-dlmopen.out: \
   $(objpfx)tst-tls-ie-mod6.so
 
 $(objpfx)tst-tls-surplus: $(libdl)
+
+ARGV0 = test-argv0
+$(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)' '$(ARGV0)' > $@; \
+    $(evaluate-test)
diff --git a/elf/argv0test.c b/elf/argv0test.c
new file mode 100644
index 00000000..6c6c7e9a
--- /dev/null
+++ b/elf/argv0test.c
@@ -0,0 +1,32 @@
+/* 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_BLOB (argv[0], strlen (argv[0]),
+                       "test-argv0", strlen ("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..e66e033c 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

Re: [PATCH v3] ld.so: add an --argv0 option

[Adhemerval Zanella via Libc-alpha]

On 31/08/2020 10:22, vincent via Libc-alpha wrote:
> From: Vincent Mihalkovic <vmihalko@redhat.com>
> 
> I hope everything is fine now, thanks for the feedback and help with
> the patch. I was writing the test case against this documentation:
> https://sourceware.org/glibc/wiki/Testing/Testsuite and could't find
> any documentation for libsupport, that's why I didn't use it.

On the 'Writing a test case' bullet it has a minimal example where it does
use libsupport and it also points the documentation at support/README-testing.c.
Maybe we can outline it is what we refer as libsupport on patch review.

LGTM with the elf/argv0test.c indentation fixed.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> 
> ---
>  elf/Makefile          | 13 +++++++++++--
>  elf/argv0test.c       | 32 ++++++++++++++++++++++++++++++++
>  elf/rtld.c            | 17 ++++++++++++++++-
>  elf/tst-rtld-argv0.sh | 37 +++++++++++++++++++++++++++++++++++++
>  4 files changed, 96 insertions(+), 3 deletions(-)
>  create mode 100644 elf/argv0test.c
>  create mode 100755 elf/tst-rtld-argv0.sh
> 
> diff --git a/elf/Makefile b/elf/Makefile
> index 0b787218..f38904d8 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 \

Ok.

> @@ -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 \

Ok.

> @@ -1796,3 +1797,11 @@ $(objpfx)tst-tls-ie-dlmopen.out: \
>    $(objpfx)tst-tls-ie-mod6.so
>  
>  $(objpfx)tst-tls-surplus: $(libdl)
> +
> +ARGV0 = test-argv0
> +$(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)' '$(ARGV0)' > $@; \
> +    $(evaluate-test)

Ok.

> diff --git a/elf/argv0test.c b/elf/argv0test.c
> new file mode 100644
> index 00000000..6c6c7e9a
> --- /dev/null
> +++ b/elf/argv0test.c
> @@ -0,0 +1,32 @@
> +/* 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_BLOB (argv[0], strlen (argv[0]),
> +                       "test-argv0", strlen ("test-argv0"));
> +return 0;
> +}
> +
> +#define TEST_FUNCTION_ARGV do_test
> +#include <support/test-driver.c>

Indentation seems off, use double space and align the 'return'.

> diff --git a/elf/rtld.c b/elf/rtld.c
> index 5b882163..e66e033c 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;

Ok.

> @@ -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
>      {

Ok.

> 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
> 

Ok.

[PATCH v4] ld.so: add an --argv0 option

[vincent via Libc-alpha]

From: Vincent Mihalkovic <vmihalko@redhat.com>

Indentation fixed. 

Thank's for your time and help.

Vincent Mihalkovic
---
 elf/Makefile          | 13 +++++++++++--
 elf/argv0test.c       | 32 ++++++++++++++++++++++++++++++++
 elf/rtld.c            | 17 ++++++++++++++++-
 elf/tst-rtld-argv0.sh | 37 +++++++++++++++++++++++++++++++++++++
 4 files changed, 96 insertions(+), 3 deletions(-)
 create mode 100644 elf/argv0test.c
 create mode 100755 elf/tst-rtld-argv0.sh

diff --git a/elf/Makefile b/elf/Makefile
index 0b787218..f38904d8 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 +1797,11 @@ $(objpfx)tst-tls-ie-dlmopen.out: \
   $(objpfx)tst-tls-ie-mod6.so
 
 $(objpfx)tst-tls-surplus: $(libdl)
+
+ARGV0 = test-argv0
+$(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)' '$(ARGV0)' > $@; \
+    $(evaluate-test)
diff --git a/elf/argv0test.c b/elf/argv0test.c
new file mode 100644
index 00000000..fcb99581
--- /dev/null
+++ b/elf/argv0test.c
@@ -0,0 +1,32 @@
+/* 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_BLOB (argv[0], strlen (argv[0]),
+                     "test-argv0", strlen ("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..e66e033c 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

Re: [PATCH v4] ld.so: add an --argv0 option

[Andreas Schwab]

On Sep 14 2020, vincent via Libc-alpha wrote:

> @@ -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;

Indentation is still off here.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

[PATCH v5] ld.so: add an --argv0 option

[vincent via Libc-alpha]

From: Vincent Mihalkovic <vmihalko@redhat.com>

---
 elf/Makefile          | 13 +++++++++++--
 elf/argv0test.c       | 32 ++++++++++++++++++++++++++++++++
 elf/rtld.c            | 17 ++++++++++++++++-
 elf/tst-rtld-argv0.sh | 37 +++++++++++++++++++++++++++++++++++++
 4 files changed, 96 insertions(+), 3 deletions(-)
 create mode 100644 elf/argv0test.c
 create mode 100755 elf/tst-rtld-argv0.sh

diff --git a/elf/Makefile b/elf/Makefile
index 0b787218..f38904d8 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 +1797,11 @@ $(objpfx)tst-tls-ie-dlmopen.out: \
   $(objpfx)tst-tls-ie-mod6.so
 
 $(objpfx)tst-tls-surplus: $(libdl)
+
+ARGV0 = test-argv0
+$(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)' '$(ARGV0)' > $@; \
+    $(evaluate-test)
diff --git a/elf/argv0test.c b/elf/argv0test.c
new file mode 100644
index 00000000..fcb99581
--- /dev/null
+++ b/elf/argv0test.c
@@ -0,0 +1,32 @@
+/* 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_BLOB (argv[0], strlen (argv[0]),
+                     "test-argv0", strlen ("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

[PATCH v5] ld.so: add an --argv0 option

[vincent via Libc-alpha]

From: Vincent Mihalkovic <vmihalko@redhat.com>

Hi,

is there any problem with this patch?  

vincent mihalkovic
---
 elf/Makefile          | 13 +++++++++++--
 elf/argv0test.c       | 32 ++++++++++++++++++++++++++++++++
 elf/rtld.c            | 17 ++++++++++++++++-
 elf/tst-rtld-argv0.sh | 37 +++++++++++++++++++++++++++++++++++++
 4 files changed, 96 insertions(+), 3 deletions(-)
 create mode 100644 elf/argv0test.c
 create mode 100755 elf/tst-rtld-argv0.sh

diff --git a/elf/Makefile b/elf/Makefile
index 0b787218..f38904d8 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 +1797,11 @@ $(objpfx)tst-tls-ie-dlmopen.out: \
   $(objpfx)tst-tls-ie-mod6.so
 
 $(objpfx)tst-tls-surplus: $(libdl)
+
+ARGV0 = test-argv0
+$(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)' '$(ARGV0)' > $@; \
+    $(evaluate-test)
diff --git a/elf/argv0test.c b/elf/argv0test.c
new file mode 100644
index 00000000..fcb99581
--- /dev/null
+++ b/elf/argv0test.c
@@ -0,0 +1,32 @@
+/* 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_BLOB (argv[0], strlen (argv[0]),
+                     "test-argv0", strlen ("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

Re: [PATCH v5] ld.so: add an --argv0 option

[Florian Weimer via Libc-alpha]

* vincent via Libc-alpha:

> is there any problem with this patch?

I think adding a NEWS entry would make sense.

> +ARGV0 = test-argv0
> +$(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)' '$(ARGV0)' > $@; \
> +    $(evaluate-test)

Here I do not think the ARGV0 variable adds much clarity.

> +#include <string.h>
> +#include <support/check.h>
> +
> +static int
> +do_test (int argc, char **argv)
> +{
> +  TEST_COMPARE_BLOB (argv[0], strlen (argv[0]),
> +                     "test-argv0", strlen ("test-argv0"));
> +  return 0;
> +}

You can use TEST_COMPARE_STRING, which will do the strlen for you.

The patch itself looks okay to me.

Thanks,
Florian
-- 
Red Hat GmbH, https://de.redhat.com/ , Registered seat: Grasbrunn,
Commercial register: Amtsgericht Muenchen, HRB 153243,
Managing Directors: Charles Cachera, Brian Klemm, Laurie Krebs, Michael O'Neill

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

[vincent via Libc-alpha]

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

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

[vincent via Libc-alpha]

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

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
-- 
2.25.4

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

[Florian Weimer via Libc-alpha]

* 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
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