From: Willy Tarreau <w@1wt.eu>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: linux-kernel@vger.kernel.org, Willy Tarreau <w@1wt.eu>
Subject: [PATCH v2 18/22] tools/nolibc: add auxiliary vector retrieval for mips
Date: Tue, 10 Jan 2023 08:24:30 +0100 [thread overview]
Message-ID: <20230110072434.3863-19-w@1wt.eu> (raw)
In-Reply-To: <20230110072434.3863-1-w@1wt.eu>
In the _start block we now iterate over envp to find the auxiliary
vector after the NULL. The pointer is saved into an _auxv variable
that is marked as weak so that it's accessible from multiple units.
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
tools/include/nolibc/arch-mips.h | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/tools/include/nolibc/arch-mips.h b/tools/include/nolibc/arch-mips.h
index 7d22f7bc38b3..bf83432d23ed 100644
--- a/tools/include/nolibc/arch-mips.h
+++ b/tools/include/nolibc/arch-mips.h
@@ -177,6 +177,7 @@ struct sys_stat_struct {
})
char **environ __attribute__((weak));
+const unsigned long *_auxv __attribute__((weak));
/* startup code, note that it's called __start on MIPS */
void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __start(void)
@@ -196,6 +197,16 @@ void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) __start(void)
"lui $a3, %hi(environ)\n" // load environ into a3 (hi)
"addiu $a3, %lo(environ)\n" // load environ into a3 (lo)
"sw $a2,($a3)\n" // store envp(a2) into environ
+
+ "move $t0, $a2\n" // iterate t0 over envp, look for NULL
+ "0:" // do {
+ "lw $a3, ($t0)\n" // a3=*(t0);
+ "bne $a3, $0, 0b\n" // } while (a3);
+ "addiu $t0, $t0, 4\n" // delayed slot: t0+=4;
+ "lui $a3, %hi(_auxv)\n" // load _auxv into a3 (hi)
+ "addiu $a3, %lo(_auxv)\n" // load _auxv into a3 (lo)
+ "sw $t0, ($a3)\n" // store t0 into _auxv
+
"li $t0, -8\n"
"and $sp, $sp, $t0\n" // sp must be 8-byte aligned
"addiu $sp,$sp,-16\n" // the callee expects to save a0..a3 there!
--
2.17.5
next prev parent reply other threads:[~2023-01-10 7:26 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 ` [PATCH v2 12/22] tools/nolibc: export environ as a weak symbol on s390 Willy Tarreau
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 ` Willy Tarreau [this message]
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
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