From: Willy Tarreau <w@1wt.eu>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: linux-kernel@vger.kernel.org, Sven Schnelle <svens@linux.ibm.com>,
Willy Tarreau <w@1wt.eu>
Subject: [PATCH v2 12/22] tools/nolibc: export environ as a weak symbol on s390
Date: Tue, 10 Jan 2023 08:24:24 +0100 [thread overview]
Message-ID: <20230110072434.3863-13-w@1wt.eu> (raw)
In-Reply-To: <20230110072434.3863-1-w@1wt.eu>
From: Sven Schnelle <svens@linux.ibm.com>
The environ is retrieved from the _start code and is easy to store at
this moment. Let's declare the variable weak and store the value into
it. By not being static it will be visible to all units. By being weak,
if some programs already declared it, they will continue to be able to
use it. This was tested on s390 both with environ inherited from
_start and extracted from envp.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
tools/include/nolibc/arch-s390.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h
index b58f64d47b82..039b454e79f0 100644
--- a/tools/include/nolibc/arch-s390.h
+++ b/tools/include/nolibc/arch-s390.h
@@ -159,6 +159,8 @@ struct sys_stat_struct {
_arg1; \
})
+char **environ __attribute__((weak));
+
/* startup code */
void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void)
{
@@ -174,6 +176,8 @@ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void)
"la %r4,8(%r4)\n" /* advance pointer */
"jnz 0b\n" /* no -> test next pointer */
/* yes -> r4 now contains start of envp */
+ "larl %r1,environ\n"
+ "stg %r4,0(%r1)\n"
"aghi %r15,-160\n" /* allocate new stackframe */
"xc 0(8,%r15),0(%r15)\n" /* clear backchain */
--
2.17.5
next prev parent reply other threads:[~2023-01-10 7:30 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-10 7:24 [PATCH v2 00/22] nolibc: usability improvements (errno, environ, auxv) Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 01/22] tools/nolibc: make compiler and assembler agree on the section around _start Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 02/22] tools/nolibc: enable support for thumb1 mode for ARM Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 03/22] tools/nolibc: support thumb mode with frame pointers on ARM Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 04/22] tools/nolibc: remove local definitions of O_* flags for open/fcntl Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 05/22] tools/nolibc: make errno a weak symbol instead of a static one Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 06/22] tools/nolibc: export environ as a weak symbol on x86_64 Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 07/22] tools/nolibc: export environ as a weak symbol on i386 Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 08/22] tools/nolibc: export environ as a weak symbol on arm64 Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 09/22] tools/nolibc: export environ as a weak symbol on arm Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 10/22] tools/nolibc: export environ as a weak symbol on mips Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 11/22] tools/nolibc: export environ as a weak symbol on riscv Willy Tarreau
2023-01-10 7:24 ` Willy Tarreau [this message]
2023-01-10 7:24 ` [PATCH v2 13/22] tools/nolibc: add auxiliary vector retrieval for i386 Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 14/22] tools/nolibc: add auxiliary vector retrieval for x86_64 Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 15/22] tools/nolibc: add auxiliary vector retrieval for arm64 Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 16/22] tools/nolibc: add auxiliary vector retrieval for arm Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 17/22] tools/nolibc: add auxiliary vector retrieval for riscv Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 18/22] tools/nolibc: add auxiliary vector retrieval for mips Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 19/22] tools/nolibc: add auxiliary vector retrieval for s390 Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 20/22] nolibc/stdlib: Implement `getauxval(3)` function Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 21/22] nolibc/sys: Implement `getpagesize(2)` function Willy Tarreau
2023-01-10 7:24 ` [PATCH v2 22/22] selftests/nolibc: Add `getpagesize(2)` selftest Willy Tarreau
2023-01-10 22:21 ` [PATCH v2 00/22] nolibc: usability improvements (errno, environ, auxv) Paul E. McKenney
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230110072434.3863-13-w@1wt.eu \
--to=w@1wt.eu \
--cc=linux-kernel@vger.kernel.org \
--cc=paulmck@kernel.org \
--cc=svens@linux.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox