Commit 0b984652 authored Oct 30, 2024 by Naveen N Rao Committed by Michael Ellerman Oct 31, 2024

powerpc/trace: Account for -fpatchable-function-entry support by toolchain

So far, we have relied on the fact that gcc supports both
-mprofile-kernel, as well as -fpatchable-function-entry, and clang
supports neither. Our Makefile only checks for CONFIG_MPROFILE_KERNEL to
decide which files to build. Clang has a feature request out [*] to
implement -fpatchable-function-entry, and is unlikely to support
-mprofile-kernel.

Update our Makefile checks so that we pick up the correct files to build
once clang picks up support for -fpatchable-function-entry.

[*] https://github.com/llvm/llvm-project/issues/57031



Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241030070850.1361304-2-hbathini@linux.ibm.com

parent 62f8f307

arch/powerpc/kernel/trace/Makefile

+7 −4

Original line number	Diff line number	Diff line
		@@ -9,12 +9,15 @@ CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)
		CFLAGS_REMOVE_ftrace_64_pg.o = $(CC_FLAGS_FTRACE)
		endif

		obj32-$(CONFIG_FUNCTION_TRACER) += ftrace.o ftrace_entry.o
		ifdef CONFIG_MPROFILE_KERNEL
		obj64-$(CONFIG_FUNCTION_TRACER) += ftrace.o ftrace_entry.o
		ifdef CONFIG_FUNCTION_TRACER
		obj32-y += ftrace.o ftrace_entry.o
		ifeq ($(CONFIG_MPROFILE_KERNEL)$(CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY),)
		obj64-y += ftrace_64_pg.o ftrace_64_pg_entry.o
		else
		obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_64_pg.o ftrace_64_pg_entry.o
		obj64-y += ftrace.o ftrace_entry.o
		endif
		endif

		obj-$(CONFIG_TRACING) += trace_clock.o

		obj-$(CONFIG_PPC64) += $(obj64-y)