From: Christoph Müllner Date: Mon, 23 Nov 2020 13:15:06 +0000 (+0100) Subject: boot/arm-trusted-firmware: Forward stack protection configuration X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=7b3fcbcdaa8cb6a99208399d1402c837685d7639;p=buildroot.git boot/arm-trusted-firmware: Forward stack protection configuration TF-A supports stack smashing protection (-fstack-protector-*). However, that feature is currently silently disabled because ENABLE_STACK_PROTECTOR is not set during build time. As documented in the TF-A user guide, the flag ENABLE_STACK_PROTECTOR is required to enable stack protection support. When enabled the symbols for the stack protector (e.g. __stack_chk_guard) are built. This needs to be done because TF-A does not link against an external library that provides that symbols (e.g. libc). So in case we see that BR2_SSP_* is enabled, let's enable the corresponding ENABLE_STACK_PROTECTOR build flag for TF-A as documented in the TF-A user guide. This patch also fixes a the following linker errors with older TF-A versions if BR2_SSP_* is enabled (i.e. -fstack-protector-* is used as compiler flag) and ENABLE_STACK_PROTECTOR is not set, which are caused by the missing stack protector symbols: [...] params_setup.c:(.text.params_early_setup+0xc): undefined reference to `__stack_chk_guard' aarch64-none-linux-gnu-ld: params_setup.c:(.text.params_early_setup+0x14): undefined reference to `__stack_chk_guard' aarch64-none-linux-gnu-ld: params_setup.c:(.text.params_early_setup+0x104): undefined reference to `__stack_chk_guard' aarch64-none-linux-gnu-ld: params_setup.c:(.text.params_early_setup+0x118): undefined reference to `__stack_chk_fail' aarch64-none-linux-gnu-ld: ./build/px30/release/bl31/pmu.o: in function `rockchip_soc_sys_pwr_dm_suspend': pmu.c:(.text.rockchip_soc_sys_pwr_dm_suspend+0xc): undefined reference to `__stack_chk_guard' [...] TF-A releases after Nov 2019, that include 7af195e29a4, will circumvent these issue by explicitliy and silently disabling the stack protector by appending '-fno-stack-protector' to the compiler flags in case ENABLE_STACK_PROTECTOR is not set. Tested on a Rockchip PX30 based system (TF-A v2.2 and upstream/master). Signed-off-by: Christoph Müllner Reviewed-by: Baruch Siach Signed-off-by: Arnout Vandecappelle (Essensium/Mind) --- diff --git a/boot/arm-trusted-firmware/arm-trusted-firmware.mk b/boot/arm-trusted-firmware/arm-trusted-firmware.mk index a3553e36cf..0597cecf71 100644 --- a/boot/arm-trusted-firmware/arm-trusted-firmware.mk +++ b/boot/arm-trusted-firmware/arm-trusted-firmware.mk @@ -100,6 +100,14 @@ ARM_TRUSTED_FIRMWARE_MAKE_OPTS += MV_DDR_PATH=$(MV_DDR_MARVELL_DIR) ARM_TRUSTED_FIRMWARE_DEPENDENCIES += mv-ddr-marvell endif +ifeq ($(BR2_SSP_REGULAR),y) +ARM_TRUSTED_FIRMWARE_MAKE_OPTS += ENABLE_STACK_PROTECTOR=default +else ifeq ($(BR2_SSP_STRONG),y) +ARM_TRUSTED_FIRMWARE_MAKE_OPTS += ENABLE_STACK_PROTECTOR=strong +else ifeq ($(BR2_SSP_ALL),y) +ARM_TRUSTED_FIRMWARE_MAKE_OPTS += ENABLE_STACK_PROTECTOR=all +endif + ARM_TRUSTED_FIRMWARE_MAKE_TARGETS = all ifeq ($(BR2_TARGET_ARM_TRUSTED_FIRMWARE_FIP),y)