From a31d793dbabd9251b5f46fb885a307b042bc79fe Mon Sep 17 00:00:00 2001 From: Sami Tolvanen Date: Fri, 11 Dec 2020 10:46:32 -0800 Subject: [PATCH] arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS DYNAMIC_FTRACE_WITH_REGS uses -fpatchable-function-entry, which makes running recordmcount unnecessary as there are no mcount calls in object files, and __mcount_loc doesn't need to be generated. While there's normally no harm in running recordmcount even when it's not strictly needed, this won't work with LTO as we have LLVM bitcode instead of ELF objects. This change selects FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY, which disables recordmcount when patchable function entries are used instead. Signed-off-by: Sami Tolvanen Acked-by: Will Deacon Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20201211184633.3213045-16-samitolvanen@google.com --- arch/arm64/Kconfig | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 05e17351e4f33..d644d975eddbf 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -162,6 +162,8 @@ config ARM64 select HAVE_DYNAMIC_FTRACE select HAVE_DYNAMIC_FTRACE_WITH_REGS \ if $(cc-option,-fpatchable-function-entry=2) + select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ + if DYNAMIC_FTRACE_WITH_REGS select HAVE_EFFICIENT_UNALIGNED_ACCESS select HAVE_FAST_GUP select HAVE_FTRACE_MCOUNT_RECORD -- 2.39.5