linux/scripts/Makefile
Steven Rostedt (Google) 4ed308c445 ftrace: Have architectures opt-in for mcount build time sorting
First S390 complained that the sorting of the mcount sections at build
time caused the kernel to crash on their architecture. Now PowerPC is
complaining about it too. And also ARM64 appears to be having issues.

It may be necessary to also update the relocation table for the values
in the mcount table. Not only do we have to sort the table, but also
update the relocations that may be applied to the items in the table.

If the system is not relocatable, then it is fine to sort, but if it is,
some architectures may have issues (although x86 does not as it shifts all
addresses the same).

Add a HAVE_BUILDTIME_MCOUNT_SORT that an architecture can set to say it is
safe to do the sorting at build time.

Also update the config to compile in build time sorting in the sorttable
code in scripts/ to depend on CONFIG_BUILDTIME_MCOUNT_SORT.

Link: https://lore.kernel.org/all/944D10DA-8200-4BA9-8D0A-3BED9AA99F82@linux.ibm.com/
Link: https://lkml.kernel.org/r/20220127153821.3bc1ac6e@gandalf.local.home

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Yinan Liu <yinan@linux.alibaba.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Tested-by: Sachin Sant <sachinp@linux.ibm.com>
Fixes: 72b3942a17 ("scripts: ftrace - move the sort-processing in ftrace_init")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-01-27 19:15:44 -05:00

44 lines
1.4 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
###
# scripts contains sources for various helper programs used throughout
# the kernel for the build process.
hostprogs-always-$(CONFIG_BUILD_BIN2C) += bin2c
hostprogs-always-$(CONFIG_KALLSYMS) += kallsyms
hostprogs-always-$(BUILD_C_RECORDMCOUNT) += recordmcount
hostprogs-always-$(CONFIG_BUILDTIME_TABLE_SORT) += sorttable
hostprogs-always-$(CONFIG_ASN1) += asn1_compiler
hostprogs-always-$(CONFIG_MODULE_SIG_FORMAT) += sign-file
hostprogs-always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE) += insert-sys-cert
HOSTCFLAGS_sorttable.o = -I$(srctree)/tools/include
HOSTLDLIBS_sorttable = -lpthread
HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include
HOSTCFLAGS_sign-file.o = $(shell pkg-config --cflags libcrypto 2> /dev/null)
HOSTLDLIBS_sign-file = $(shell pkg-config --libs libcrypto 2> /dev/null || echo -lcrypto)
ifdef CONFIG_UNWINDER_ORC
ifeq ($(ARCH),x86_64)
ARCH := x86
endif
HOSTCFLAGS_sorttable.o += -I$(srctree)/tools/arch/x86/include
HOSTCFLAGS_sorttable.o += -DUNWINDER_ORC_ENABLED
endif
ifdef CONFIG_BUILDTIME_MCOUNT_SORT
HOSTCFLAGS_sorttable.o += -DMCOUNT_SORT_ENABLED
endif
# The following programs are only built on demand
hostprogs += unifdef
# The module linker script is preprocessed on demand
targets += module.lds
subdir-$(CONFIG_GCC_PLUGINS) += gcc-plugins
subdir-$(CONFIG_MODVERSIONS) += genksyms
subdir-$(CONFIG_SECURITY_SELINUX) += selinux
# Let clean descend into subdirs
subdir- += basic dtc gdb kconfig mod