On 1/10/21 4:39 PM, Joel Peshkin wrote:
Cc: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com Cc: Jagan Teki jagan@amarulasolutions.com Cc: Kever Yang kever.yang@rock-chips.com Cc: Heinrich Schuchardt xypron.glpk@gmx.de Cc: AKASHI Takahiro takahiro.akashi@linaro.org Cc: Usama Arif usama.arif@arm.com Cc: Sam Protsenko joe.skb7@gmail.com Cc: Masahiro Yamada masahiroy@kernel.org Cc: Philippe Reynes philippe.reynes@softathome.com Cc: Eugeniu Rosca roscaeugeniu@gmail.com Cc: Jan Kiszka jan.kiszka@siemens.com
Signed-off-by: Joel Peshkin joel.peshkin@broadcom.com
Makefile | 4 ++++ common/Kconfig | 15 +++++++++++++++ common/Makefile | 2 ++ common/stackprot.c | 17 +++++++++++++++++ scripts/Makefile.spl | 6 ++++++ 5 files changed, 44 insertions(+) create mode 100644 common/stackprot.c
diff --git a/Makefile b/Makefile index 3ee4cc00dd..6e7a81ec7d 100644 --- a/Makefile +++ b/Makefile @@ -677,7 +677,11 @@ else KBUILD_CFLAGS += -O2 endif
+ifeq ($(CONFIG_STACKPROTECTOR),y) +KBUILD_CFLAGS += $(call cc-option,-fstack-protector-strong) +else KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector) +endif KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks)
# disable stringop warnings in gcc 8+ diff --git a/common/Kconfig b/common/Kconfig index 2bce8c9ba1..e30c3c4ab8 100644 --- a/common/Kconfig +++ b/common/Kconfig @@ -595,6 +595,21 @@ config TPL_HASH and the algorithms it supports are defined in common/hash.c. See also CMD_HASH for command-line access.
+config STACKPROTECTOR
- bool "Stack Protector buffer overflow detection"
- default n
- help
Enable stack smash detection through gcc built-in stack-protectorcanary logic+config SPL_STACKPROTECTOR
- bool "Stack Protector buffer overflow detection for SPL"
- default n
+config TPL_STACKPROTECTOR
- bool "Stack Protector buffer overflow detection for SPL"
%s/SPL/TPL/
default n
endmenu
menu "Update support"
diff --git a/common/Makefile b/common/Makefile index bcf352d016..fe71e18317 100644 --- a/common/Makefile +++ b/common/Makefile @@ -138,3 +138,5 @@ obj-$(CONFIG_CMD_LOADB) += xyzModem.o obj-$(CONFIG_$(SPL_TPL_)YMODEM_SUPPORT) += xyzModem.o
obj-$(CONFIG_AVB_VERIFY) += avb_verify.o +obj-$(CONFIG_$(SPL_TPL_)STACKPROTECTOR) += stackprot.o
diff --git a/common/stackprot.c b/common/stackprot.c new file mode 100644 index 0000000000..7c95b8544f --- /dev/null +++ b/common/stackprot.c @@ -0,0 +1,17 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*
- Copyright 2021 Broadcom
- */
+#include <common.h>
+DECLARE_GLOBAL_DATA_PTR;
+unsigned long __stack_chk_guard = 0xfeedf00ddeadbeef;
+void __stack_chk_fail(void)
The standalone EFI binaries are compiled with -fstack-protector-strong when selecting CONFIG_STACKPROTECTOR.
Do we need a function __stack_chk_fail) in lib/efi_selftest/efi_freestanding.c and lib/efi_loader/efi_freestanding.c too?
Could you, please, provide unit tests demonstrating that the stack protection is actually working SPL, main U-Boot, and the EFI binaries.
Best regards
Heinrich
+{
- panic("Stack smashing detected in function: %p relocated from %p",
__builtin_return_address(0),__builtin_return_address(0) - gd->reloc_off);+} diff --git a/scripts/Makefile.spl b/scripts/Makefile.spl index 9f1f7445d7..1505e4e851 100644 --- a/scripts/Makefile.spl +++ b/scripts/Makefile.spl @@ -63,6 +63,12 @@ include $(srctree)/scripts/Makefile.lib KBUILD_CFLAGS += -ffunction-sections -fdata-sections LDFLAGS_FINAL += --gc-sections
+ifeq ($(CONFIG_$(SPL_TPL_)STACKPROTECTOR),y) +KBUILD_CFLAGS += -fstack-protector-strong +else +KBUILD_CFLAGS += -fno-stack-protector +endif
- # FIX ME cpp_flags := $(KBUILD_CPPFLAGS) $(PLATFORM_CPPFLAGS) $(UBOOTINCLUDE) \ $(NOSTDINC_FLAGS)