From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 07A4A1FBA for ; Fri, 9 Jun 2023 03:47:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3242C433D2; Fri, 9 Jun 2023 03:47:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686282429; bh=dcV7Up3dX/0Q6e4I77beL4sZLmsZvEFx4770r6J9KUU=; h=From:To:Cc:Subject:Date:From; b=PObKMaXAZoJwykEDSZBjQbZ/5BCacQ425AuvusabUPgLPKEkIprk96+NisnK9mMPC Ff8pG83QF33pKHWihIoqUe+oWjnLhibSgg+y9sLLStI4KPKRHl/8xIFxEp3zdBuhqD SFwGMCaSt/diOS/4GJqlJ8uEt+vsluVSTLy9EsEtNuE6LH+24MrFWtc7j00o8esIUB KgGVwA/wgGedge64ouZM0ZIZxoPl5nrgPaarceZfgbzzmexJe8dzjKX+q7iu64oe/c +yqpKjiobcWY3pdE16RhxfSXAZc4b0Xa2iZEdhiE3byz8fhHd1KVrH+DYQaINli8ez fkiSV/QdFZmIw== From: Naveen N Rao To: Cc: llvm@lists.linux.dev, Nathan Chancellor , Nick Desaulniers , Christophe Leroy Subject: [PATCH] powerpc/ftrace: Disable ftrace on ppc32 if using clang Date: Fri, 9 Jun 2023 09:15:01 +0530 Message-Id: <20230609034501.407971-1-naveen@kernel.org> X-Mailer: git-send-email 2.40.1 Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Ftrace on ppc32 expects a three instruction sequence at the beginning of each function when specifying -pg: mflr r0 stw r0,4(r1) bl _mcount This is the case with all supported versions of gcc. Clang however emits a branch to _mcount after the function prologue, similar to the pre -mprofile-kernel ABI on ppc64. This is not supported. Disable ftrace on ppc32 if using clang for now. This can be re-enabled later if clang picks up support for -fpatchable-function-entry on ppc32. Signed-off-by: Naveen N Rao --- arch/powerpc/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index bff5820b7cda14..d85e3cf4016d90 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -236,7 +236,7 @@ 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 + select HAVE_FUNCTION_TRACER if 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 base-commit: bd517a8442b6c6646a136421cd4c1b95bf4ce32b -- 2.40.1