coreboot-kgpe-d16/toolchain.inc
Julius Werner 8d8799a33a arm, arm64, mips: Add rough static stack size checks with -Wstack-usage
We've seen an increasing need to reduce stack sizes more and more for
space reasons, and it's always guesswork because no one has a good idea
how little is too litte. We now have boards with 3K and 2K stacks, and
old pieces of common code often allocate large temporary buffers that
would lead to very dangerous and hard to detect bugs when someone
eventually tries to use them on one of those.

This patch tries improve this situation at least a bit by declaring 2K
as the minimum stack size all of coreboot code should work with. It
checks all function frames with -Wstack-usage=1536 to make sure we don't
allocate more than 1.5K in a single buffer. This is of course not a
perfect test, but it should catch the most common situation of declaring
a single, large buffer in some close-to-leaf function (with the
assumption that 0.5K is hopefully enough for all the "normal" functions
above that).

Change one example where we were a bit overzealous and put a 1K buffer
into BSS back to stack allocation, since it actually conforms to this
new assumption and frees up another kilobyte of that highly sought-after
verstage space. Not touching x86 with any of this since it's lack of
__PRE_RAM__ BSS often requires it to allocate way more on the stack than
would usually be considered sane.

BRANCH=veyron
BUG=None
TEST=Compiled Cosmos, Daisy, Falco, Blaze, Pit, Storm, Urara and Pinky,
made sure they still build as well as before and don't show any stack
usage warnings.

Change-Id: Idc53d33bd8487bbef49d3ecd751914b0308006ec
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 8e5931066575e256dfc2295c3dab7f0e1b65417f
Original-Change-Id: I30bd9c2c77e0e0623df89b9e5bb43ed29506be98
Original-Signed-off-by: Julius Werner <jwerner@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/236978
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/9729
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
2015-07-29 20:25:59 +02:00

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6.1 KiB
PHP

##
## This file is part of the coreboot project.
##
## Copyright (C) 2014 Google Inc
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; version 2 of the License.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc.
##
# ccache integration
ifeq ($(CONFIG_CCACHE),y)
CCACHE:=$(word 1,$(wildcard $(addsuffix /ccache,$(subst :, ,$(PATH)))))
ifeq ($(CCACHE),)
$(error ccache selected, but not found in PATH)
endif
export CCACHE_COMPILERCHECK=content
export CCACHE_BASEDIR=$(top)
$(foreach arch,$(ARCH_SUPPORTED), \
$(eval CC_$(arch):=$(CCACHE) $(CC_$(arch))))
HOSTCC:=$(CCACHE) $(HOSTCC)
HOSTCXX:=$(CCACHE) $(HOSTCXX)
ROMCC=$(CCACHE) $(ROMCC_BIN)
endif
# scan-build integration
ifneq ($(CCC_ANALYZER_OUTPUT_FORMAT),)
ifeq ($(CCC_ANALYZER_ANALYSIS),)
export CCC_ANALYZER_ANALYSIS := -analyzer-opt-analyze-headers
endif
$(foreach arch,$(ARCH_SUPPORTED), \
$(eval CC_$(arch):=CCC_CC="$(CC_$(arch))" $(CC) ))
HOSTCC:=CCC_CC="$(HOSTCC)" $(CC)
HOSTCXX:=CCC_CXX="$(HOSTCXX)" $(CXX)
ROMCC=CCC_CC="$(ROMCC_BIN)" $(CC)
endif
COREBOOT_STANDARD_STAGES := bootblock libverstage verstage romstage ramstage
MAP-libverstage := verstage
ARCHDIR-i386 := x86
ARCHDIR-x86_32 := x86
ARCHDIR-x86_64 := x86
ARCHDIR-arm := arm
ARCHDIR-arm64 := arm64
ARCHDIR-riscv := riscv
ARCHDIR-mips := mips
CFLAGS_arm += -ffunction-sections -fdata-sections
CFLAGS_arm64 += -ffunction-sections -fdata-sections -mgeneral-regs-only
CFLAGS_mips += -mips32r2 -G 0 -ffunction-sections -fdata-sections
CFLAGS_mips += -mno-abicalls -fno-pic
CFLAGS_x86_32 += -ffunction-sections -fdata-sections
CFLAGS_riscv += -ffunction-sections -fdata-sections
CFLAGS_x86_64 += -mcmodel=large -mno-red-zone
# Some boards only provide 2K stacks, so storing lots of data there leads to
# problems. Since C rules don't allow us to statically determine the maximum
# stack use, we use 1.5K as heuristic, assuming that we typically have lots
# of tiny stack frames and the odd large one.
#
# Store larger buffers in BSS, use MAYBE_STATIC to share code with __PRE_RAM__
# on x86.
# Since GCCs detection of dynamic array bounds unfortunately seems to be
# very basic, you'll sometimes have to use a static upper bound for the
# size and an assert() to make sure it's honored (see gpio_base3_value()
# for an example).
# (If you absolutely need a larger stack frame and are 100% sure it cannot
# cause problems, you can whitelist it with #pragma diagnostic.)
CFLAGS_arm += -Wstack-usage=1536
CFLAGS_arm64 += -Wstack-usage=1536
CFLAGS_mips += -Wstack-usage=1536
CFLAGS_riscv += -Wstack-usage=1536
toolchain_to_dir = \
$(foreach arch,$(ARCH_SUPPORTED),\
$(eval CPPFLAGS_$(arch) += \
-Isrc/arch/$(ARCHDIR-$(arch))/include))
# set_stage_toolchain: Decides the toolchain to be used by every stage
# E.g.: If bootblock is x86_32, it sets ARCH-BOOTBLOCK-y = x86_32, whereas
# ARCH-BOOTBLOCK-n = armv7. Then, ARCH-BOOTBLOCK-y can be used anywhere to
# decide the compiler toolchain for bootblock stage
# This step is essential for initializing the toolchain for coreboot standard
# stages i.e. bootblock, romstage and ramstage, since it acts as the second
# parameter to create_class_compiler below in init_standard_toolchain
map_stage = $(strip $(if $(MAP-$(1)),$(MAP-$(1)),$(1)))
set_stage_toolchain= \
$(foreach arch,$(ARCH_SUPPORTED),$(eval ARCH-$(1)-$($(shell echo CONFIG_ARCH_$(call map_stage,$(1))_$(arch) | tr '[:lower:]' '[:upper:]')) := $(arch)))
# create_class_compiler: Used to create compiler tool set for
# special classes
# @1: special class
# @2: compiler set to be used
# e.g.: smm special class uses i386 as compiler set
define create_class_compiler
$(if $(2),,$(error building $(1) without the required toolchain))
CC_$(1) := $(CC_$(2))
LD_$(1) := $(LD_$(2))
NM_$(1) := $(NM_$(2))
AR_$(1) := $(AR_$(2))
OBJCOPY_$(1) := $(OBJCOPY_$(2))
OBJDUMP_$(1) := $(OBJDUMP_$(2))
STRIP_$(1) := $(STRIP_$(2))
READELF_$(1) := $(READELF_$(2))
CFLAGS_$(1) = $$(CFLAGS_common) $$(CFLAGS_$(2))
CPPFLAGS_$(1) = $$(CPPFLAGS_common) $$(CPPFLAGS_$(2))
COMPILER_RT_$(1) := $$(COMPILER_RT_$(2))
COMPILER_RT_FLAGS_$(1) := $$(COMPILER_RT_FLAGS_$(2))
endef
# define_class: Allows defining any program as dynamic class and compiler tool
# set for the same based on the architecture for which the program is to be
# compiled
# @1: program (class name)
# @2: architecture for which the program needs to be compiled
# IMP: Ensure that define_class is called before any .c or .S files are added to
# the class of the program. Check subdirs-y for order of subdirectory inclusions
define define_class
classes-y += $(1)
$(eval $(call create_class_compiler,$(1),$(2)))
endef
# initialize standard toolchain (CC,AS and others) for give stage
# @1 : stage for which the toolchain is to be initialized
init_standard_toolchain = \
$(eval $(call set_stage_toolchain,$(1))) \
$(eval $(call create_class_compiler,$(1),$(ARCH-$(1)-y)))
init_stages = \
$(foreach stage,$(COREBOOT_STANDARD_STAGES),$(eval $(call init_standard_toolchain,$(stage))))
$(eval $(call toolchain_to_dir))
$(call init_stages)
# Test for coreboot toolchain (except when explicitely not requested)
ifneq ($(NOCOMPILE),1)
# only run if we're doing a build (not for tests, kconfig, ...), using gcc
# rationale: gcc versions by Linux distributions tend to be quite messed up
COMPILERFAIL:=0
ifeq ($(CONFIG_COMPILER_GCC),y)
ifneq ($(CONFIG_ANY_TOOLCHAIN),y)
$(foreach arch,$(sort $(foreach stage,$(COREBOOT_STANDARD_STAGES),$(ARCH-$(stage)-y))), \
$(if $(shell $(CC_$(arch)) -v 2>&1 |grep -q "gcc version .*coreboot toolchain" || echo not-coreboot), \
$(eval COMPILERFAIL:=1)$(warning Please use the coreboot toolchain for '$(arch)' (or prove that your toolchain works))))
endif
endif
endif
ifeq ($(COMPILERFAIL),1)
$(error consider building our compilers: make crossgcc)
endif