Add support for stack-protector

Add support for stack protector for UBOOT, SPL, and TPL
as well as new pytest for stackprotector

Signed-off-by: Joel Peshkin <joel.peshkin@broadcom.com>

Adjust UEFI build flags.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
This commit is contained in:
Joel Peshkin 2021-04-11 11:21:58 +02:00 committed by Tom Rini
parent 1598c83ece
commit 4e9bce1243
14 changed files with 105 additions and 2 deletions

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@ -1062,6 +1062,13 @@ F: include/sqfs.h
F: cmd/sqfs.c
F: test/py/tests/test_fs/test_squashfs/
STACKPROTECTOR
M: Joel Peshkin <joel.peshkin@broadcom.com>
S: Maintained
F: common/stackprot.c
F: cmd/stackprot_test.c
F: test/py/tests/test_stackprotector.py
TARGET_BCMNS3
M: Bharat Gooty <bharat.gooty@broadcom.com>
M: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>

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@ -676,7 +676,12 @@ else
KBUILD_CFLAGS += -O2
endif
ifeq ($(CONFIG_STACKPROTECTOR),y)
KBUILD_CFLAGS += $(call cc-option,-fstack-protector-strong)
CFLAGS_EFI += $(call cc-option,-fno-stack-protector)
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+

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@ -11,7 +11,8 @@ CONFIG_STANDALONE_LOAD_ADDR = 0xc100000
endif
endif
CFLAGS_NON_EFI := -fno-pic -ffixed-r9 -ffunction-sections -fdata-sections
CFLAGS_NON_EFI := -fno-pic -ffixed-r9 -ffunction-sections -fdata-sections \
-fstack-protector-strong
CFLAGS_EFI := -fpic -fshort-wchar
LDFLAGS_FINAL += --gc-sections

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@ -27,6 +27,7 @@ obj-$(CONFIG_SPL_BUILD) += spl.o
obj-y += fdt_fixup.o
# For building EFI apps
CFLAGS_NON_EFI := -fstack-protector-strong
CFLAGS_$(EFI_CRT0) := $(CFLAGS_EFI)
CFLAGS_REMOVE_$(EFI_CRT0) := $(CFLAGS_NON_EFI)

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@ -42,7 +42,7 @@ OBJCOPYFLAGS_EFI := -j .text -j .sdata -j .data -j .dynamic -j .dynsym \
# Compiler flags to be added when building UEFI applications
CFLAGS_EFI := -fpic -fshort-wchar
# Compiler flags to be removed when building UEFI applications
CFLAGS_NON_EFI := -mregparm=3
CFLAGS_NON_EFI := -mregparm=3 -fstack-protector-strong
ifeq ($(CONFIG_EFI_STUB_64BIT),)
CFLAGS_EFI += $(call cc-option, -mno-red-zone)

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@ -2325,6 +2325,15 @@ config CMD_AVB
avb read_part_hex - read data from partition and output to stdout
avb write_part - write data to partition
avb verify - run full verification chain
config CMD_STACKPROTECTOR_TEST
bool "Test command for stack protector"
depends on STACKPROTECTOR
help
Enable stackprot_test command
The stackprot_test command will force a stack overrun to test
the stack smashing detection mechanisms.
endmenu
config CMD_UBI

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@ -144,6 +144,7 @@ obj-$(CONFIG_CMD_SPI) += spi.o
obj-$(CONFIG_CMD_STRINGS) += strings.o
obj-$(CONFIG_CMD_SMC) += smccc.o
obj-$(CONFIG_CMD_SYSBOOT) += sysboot.o pxe_utils.o
obj-$(CONFIG_CMD_STACKPROTECTOR_TEST) += stackprot_test.o
obj-$(CONFIG_CMD_TERMINAL) += terminal.o
obj-$(CONFIG_CMD_TIME) += time.o
obj-$(CONFIG_CMD_TIMER) += timer.o

19
cmd/stackprot_test.c Normal file
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@ -0,0 +1,19 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2021 Broadcom
*/
#include <common.h>
#include <command.h>
static int do_test_stackprot_fail(struct cmd_tbl *cmdtp, int flag, int argc,
char *const argv[])
{
char a[128];
memset(a, 0xa5, 512);
return 0;
}
U_BOOT_CMD(stackprot_test, 1, 1, do_test_stackprot_fail,
"test stack protector fail", "");

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@ -618,6 +618,23 @@ 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 compiler's stack-protector
canary logic
config SPL_STACKPROTECTOR
bool "Stack Protector buffer overflow detection for SPL"
depends on STACKPROTECTOR && SPL
default n
config TPL_STACKPROTECTOR
bool "Stack Protector buffer overflow detection for TPL"
depends on STACKPROTECTOR && TPL
default n
endmenu
menu "Update support"

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@ -137,6 +137,7 @@ 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
obj-$(CONFIG_SCP03) += scp03.o
obj-$(CONFIG_QFW) += qfw.o

20
common/stackprot.c Normal file
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@ -0,0 +1,20 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2021 Broadcom
*/
#include <common.h>
#include <asm/global_data.h>
DECLARE_GLOBAL_DATA_PTR;
unsigned long __stack_chk_guard = (unsigned long)(0xfeedf00ddeadbeef & ~0UL);
void __stack_chk_fail(void)
{
void *ra;
ra = __builtin_extract_return_addr(__builtin_return_address(0));
panic("Stack smashing detected in function:\n%p relocated from %p",
ra, ra - gd->reloc_off);
}

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@ -25,6 +25,7 @@ CONFIG_LOG_SYSLOG=y
CONFIG_LOG_ERROR_RETURN=y
CONFIG_DISPLAY_BOARDINFO_LATE=y
CONFIG_MISC_INIT_F=y
CONFIG_STACKPROTECTOR=y
CONFIG_ANDROID_AB=y
CONFIG_CMD_CPU=y
CONFIG_CMD_LICENSE=y
@ -97,6 +98,7 @@ CONFIG_CMD_CRAMFS=y
CONFIG_CMD_EXT4_WRITE=y
CONFIG_CMD_SQUASHFS=y
CONFIG_CMD_MTDPARTS=y
CONFIG_CMD_STACKPROTECTOR_TEST=y
CONFIG_MAC_PARTITION=y
CONFIG_AMIGA_PARTITION=y
CONFIG_OF_CONTROL=y

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@ -67,6 +67,12 @@ 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)

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@ -0,0 +1,14 @@
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2021 Broadcom
import pytest
import signal
@pytest.mark.buildconfigspec('cmd_stackprotector_test')
def test_stackprotector(u_boot_console):
"""Test that the stackprotector function works."""
u_boot_console.run_command('stackprot_test',wait_for_prompt=False)
expected_response = 'Stack smashing detected'
u_boot_console.wait_for(expected_response)
u_boot_console.restart_uboot()