[PATCH 8/8] tools/nolibc: x86_64: add stackprotector support

Willy Tarreau
2023-03-25T15:46:13Z

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