From 782f46cbce5328da9380f166bd31cd17a04a7b10 Mon Sep 17 00:00:00 2001 From: Naveen N Rao Date: Wed, 30 Oct 2024 12:38:43 +0530 Subject: 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 Signed-off-by: Hari Bathini Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20241030070850.1361304-11-hbathini@linux.ibm.com --- arch/powerpc/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/Kconfig') diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 6aaca48955a3..bb99ec9da63c 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -243,7 +243,7 @@ config PPC select HAVE_FUNCTION_DESCRIPTORS if PPC64_ELF_ABI_V1 select HAVE_FUNCTION_ERROR_INJECTION select HAVE_FUNCTION_GRAPH_TRACER - select HAVE_FUNCTION_TRACER if PPC64 || (PPC32 && CC_IS_GCC) + select HAVE_FUNCTION_TRACER if !COMPILE_TEST && (PPC64 || (PPC32 && CC_IS_GCC)) select HAVE_GCC_PLUGINS if GCC_VERSION >= 50200 # plugin support on gcc <= 5.1 is buggy on PPC select HAVE_GENERIC_VDSO select HAVE_HARDLOCKUP_DETECTOR_ARCH if PPC_BOOK3S_64 && SMP -- cgit v1.2.3-70-g09d2