linux-stable/arch/powerpc/Makefile.postlink
Naveen N Rao 782f46cbce powerpc/ftrace: Add a postlink script to validate function tracer
Function tracer on powerpc can only work with vmlinux having a .text
size of up to ~64MB due to powerpc branch instruction having a limited
relative branch range of 32MB. Today, this is only detected on kernel
boot when ftrace is init'ed. Add a post-link script to check the size of
.text so that we can detect this at build time, and break the build if
necessary.

We add a dependency on !COMPILE_TEST for CONFIG_HAVE_FUNCTION_TRACER so
that allyesconfig and other test builds can continue to work without
enabling ftrace.

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241030070850.1361304-11-hbathini@linux.ibm.com
2024-10-31 11:00:54 +11:00

54 lines
1.4 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
# ===========================================================================
# Post-link powerpc pass
# ===========================================================================
#
# 1. Check that vmlinux relocations look sane
PHONY := __archpost
__archpost:
-include include/config/auto.conf
include $(srctree)/scripts/Kbuild.include
quiet_cmd_head_check = CHKHEAD $@
cmd_head_check = $(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/head_check.sh "$(NM)" "$@"
quiet_cmd_relocs_check = CHKREL $@
ifdef CONFIG_PPC_BOOK3S_64
cmd_relocs_check = \
$(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/relocs_check.sh "$(OBJDUMP)" "$(NM)" "$@" ; \
$(BASH) $(srctree)/arch/powerpc/tools/unrel_branch_check.sh "$(OBJDUMP)" "$(NM)" "$@"
else
cmd_relocs_check = \
$(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/relocs_check.sh "$(OBJDUMP)" "$(NM)" "$@"
endif
quiet_cmd_ftrace_check = CHKFTRC $@
cmd_ftrace_check = $(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/ftrace_check.sh "$(NM)" "$@"
# `@true` prevents complaint when there is nothing to be done
vmlinux: FORCE
@true
ifdef CONFIG_PPC64
$(call cmd,head_check)
endif
ifdef CONFIG_RELOCATABLE
$(call if_changed,relocs_check)
endif
ifdef CONFIG_FUNCTION_TRACER
ifndef CONFIG_PPC64_ELF_ABI_V1
$(call cmd,ftrace_check)
endif
endif
clean:
rm -f .tmp_symbols.txt
PHONY += FORCE clean
FORCE:
.PHONY: $(PHONY)