Re: [PATCH v7 1/3] arm64: replace -pg with CC_FLAGS_FTRACE in Makefiles
From: Mark Rutland <mark.rutland@arm.com>
Date: 2019-01-18 17:25:04
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Hi Torsten, On Fri, Jan 18, 2019 at 05:39:04PM +0100, Torsten Duwe wrote:
Ftrace instrumentation might also be introduced by -fpatchable-function-entry, not only -pg. Ensure the Makefiles are flexible to filter out the respective flags in "notrace" directories.
I think this is a cleanup regardless of whether we use -fpatchable-function-entry. Can we please give this a more complete description, e.g. | Currently arm64 makefiles assume that ftrace will use '-pg', and remove | this flag specifically, rather than the contents of $(CC_FLAGS_FTRACE). | | In preparation for arm64 supporting ftrace built on other compiler | options, let's have the arm64 makefiles remove the $(CC_FLAGS_FTRACE) | flags, whatever these may be, rather than assuming '-pg'. | | There should be no functional change as a result of this patch.
Signed-off-by: Torsten Duwe <redacted> --- arch/arm64/kernel/Makefile | 6 +++--- drivers/firmware/efi/libstub/Makefile | 3 ++-
This misses arch/arm64/lib/Makefile and mm/kasan/makefile. Could we please split this into three patches, addressing: * arm64 * efistub * kasan ... since those have distinct maintainers. All those patches can be part of this series, but having them as separate patches is a bit nicer for review.
quoted hunk ↗ jump to hunk
2 files changed, 5 insertions(+), 4 deletions(-)--- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile@@ -7,9 +7,9 @@ CPPFLAGS_vmlinux.lds := -DTEXT_OFFSET=$( AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET) CFLAGS_armv8_deprecated.o := -I$(src) -CFLAGS_REMOVE_ftrace.o = -pg -CFLAGS_REMOVE_insn.o = -pg -CFLAGS_REMOVE_return_address.o = -pg +CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_insn.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_return_address.o = $(CC_FLAGS_FTRACE) # Object file lists. obj-y := debug-monitors.o entry.o irq.o fpsimd.o \ --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile@@ -16,7 +16,8 @@ cflags-$(CONFIG_X86) += -m$(BITS) -D__K # arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly # disable the stackleak plugin -cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS)) -fpie \ +cflags-$(CONFIG_ARM64) := $(filter-out $(CC_FLAGS_FTRACE)\ + ,$(KBUILD_CFLAGS)) -fpie \ $(DISABLE_STACKLEAK_PLUGIN)
Why do we need to swtich to using filter-out. AFAICT, subst works just fine. To keepthis legible, it would be nicer to split it like: cflags-$(CONFIG_ARM64) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ -fpie $(DISABLE_STACKLEAK_PLUGIN)
cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \ -fno-builtin -fpic \
Please clean up this instance too, at least for consistency. Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel