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From:   Willy Tarreau <w@1wt.eu>
To:     "Paul E. McKenney" <paulmck@kernel.org>
Cc:     linux@weissschuh.net, linux-kernel@vger.kernel.org,
        Willy Tarreau <w@1wt.eu>
Subject: [PATCH 8/8] tools/nolibc: x86_64: add stackprotector support
Date:   Sat, 25 Mar 2023 16:45:16 +0100
Message-Id: <20230325154516.7995-9-w@1wt.eu>
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From: Thomas Weißschuh <linux@weissschuh.net>

Enable the new stackprotector support for x86_64.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
 tools/include/nolibc/arch-x86_64.h      | 5 +++++
 tools/testing/selftests/nolibc/Makefile | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/tools/include/nolibc/arch-x86_64.h b/tools/include/nolibc/arch-x86_64.h
index 17f6751208e7..f7f2a11d4c3b 100644
--- a/tools/include/nolibc/arch-x86_64.h
+++ b/tools/include/nolibc/arch-x86_64.h
@@ -181,6 +181,8 @@ struct sys_stat_struct {
 char **environ __attribute__((weak));
 const unsigned long *_auxv __attribute__((weak));
 
+#define __ARCH_SUPPORTS_STACK_PROTECTOR
+
 /* startup code */
 /*
  * x86-64 System V ABI mandates:
@@ -191,6 +193,9 @@ const unsigned long *_auxv __attribute__((weak));
 void __attribute__((weak,noreturn,optimize("omit-frame-pointer"))) _start(void)
 {
 	__asm__ volatile (
+#ifdef NOLIBC_STACKPROTECTOR
+		"call __stack_chk_init\n"   // initialize stack protector
+#endif
 		"pop %rdi\n"                // argc   (first arg, %rdi)
 		"mov %rsp, %rsi\n"          // argv[] (second arg, %rsi)
 		"lea 8(%rsi,%rdi,8),%rdx\n" // then a NULL then envp (third arg, %rdx)
diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index ab99786c1e94..bbce57420465 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -80,6 +80,8 @@ CFLAGS_STACKPROTECTOR = -DNOLIBC_STACKPROTECTOR \
 			$(call cc-option,-mstack-protector-guard=global) \
 			$(call cc-option,-fstack-protector-all)
 CFLAGS_STKP_i386 = $(CFLAGS_STACKPROTECTOR)
+CFLAGS_STKP_x86_64 = $(CFLAGS_STACKPROTECTOR)
+CFLAGS_STKP_x86 = $(CFLAGS_STACKPROTECTOR)
 CFLAGS_s390 = -m64
 CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables \
 		$(call cc-option,-fno-stack-protector) \
-- 
2.17.5