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From:   "Paul E. McKenney" <paulmck@kernel.org>
To:     linux-kernel@vger.kernel.org
Cc:     gwml@vger.gnuweeb.org, kernel-team@meta.com, w@lwt.eu,
        =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>,
        Willy Tarreau <w@1wt.eu>,
        "Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH v2 nolibc 21/53] tools/nolibc: arm: add stackprotector support
Date:   Mon, 12 Jun 2023 13:44:42 -0700
Message-Id: <20230612204514.292087-21-paulmck@kernel.org>
In-Reply-To: <8b757cc0-3719-4e63-a755-9710384137bc@paulmck-laptop>
References: <8b757cc0-3719-4e63-a755-9710384137bc@paulmck-laptop>
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From: Thomas Weißschuh <linux@weissschuh.net>

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 tools/include/nolibc/arch-arm.h         | 7 ++++++-
 tools/testing/selftests/nolibc/Makefile | 1 +
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/include/nolibc/arch-arm.h b/tools/include/nolibc/arch-arm.h
index 2eab1aef321b..202e64f537dc 100644
--- a/tools/include/nolibc/arch-arm.h
+++ b/tools/include/nolibc/arch-arm.h
@@ -199,10 +199,15 @@ struct sys_stat_struct {
 char **environ __attribute__((weak));
 const unsigned long *_auxv __attribute__((weak));
 
+#define __ARCH_SUPPORTS_STACK_PROTECTOR
+
 /* startup code */
-void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void)
+void __attribute__((weak,noreturn,optimize("omit-frame-pointer"),no_stack_protector)) _start(void)
 {
 	__asm__ volatile (
+#ifdef NOLIBC_STACKPROTECTOR
+		"bl __stack_chk_init\n"       /* initialize stack protector                          */
+#endif
 		"pop {%r0}\n"                 /* argc was in the stack                               */
 		"mov %r1, %sp\n"              /* argv = sp                                           */
 
diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index fa0075479a26..7585035cbb0d 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -83,6 +83,7 @@ CFLAGS_STKP_i386 = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_STKP_x86_64 = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_STKP_x86 = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_STKP_arm64 = $(CFLAGS_STACKPROTECTOR)
+CFLAGS_STKP_arm = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_s390 = -m64
 CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables -std=c89 \
 		$(call cc-option,-fno-stack-protector) \
-- 
2.40.1