From nobody Thu May 14 07:28:36 2026 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 C92F31AB51E; Wed, 20 Nov 2024 14:08:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732111725; cv=none; b=mT9r0WCyBImKKT5REnX/EP7dfyobpDtNBG9vAfcYiyqBsLWftJNIVi9If9ltPg2TWeV8sfGiTZ9tLzHXs9JEKEp6b3o2kBiN77A/aDVowISubATcPWLCSNSRSxD5svUzmudbzKkBh5gWDI/kzzME++PocMDRr1390cBUwJvPy7I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732111725; c=relaxed/simple; bh=0rtD2vJdBwhaemkw4RhjcLdbZDRuId21Y8WhxOGrsfg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=C91jfsL3zn6m/o+5wgH6HFmjiG8N1UbEiMl95h+gMbjxzJyNjWZDYZHo155yPBPoZMRVuIiLeCiL97UllyEqT2ToT3Rd4iNplhkaz6WWufQDh2E2YwPmU9BUbT87cERy8RHqAdyriXODmv/mAchmnnuznXEGIBzzRlz2JQCUpBA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=e/GIiMW3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="e/GIiMW3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6D411C4CECD; Wed, 20 Nov 2024 14:08:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1732111725; bh=0rtD2vJdBwhaemkw4RhjcLdbZDRuId21Y8WhxOGrsfg=; h=From:To:Cc:Subject:Date:From; b=e/GIiMW3YK9CtbqIkAF38GLeYiPscyNrsYQYm90iYs2U8fsWF19Q3DqiqwBIElMyJ jJs9aA9N1vFPVPu5j1ApXmaXJu9XXtO0LZCbOxX7J/LM8yGRjVJZl5l0kmFT1dBSJM fDWbsy8T7880tGHEqhRFEn+QVYbC4e1zj5WPRXtEafNdSQkWIR5Ng1im/jwnaxr3rh MrIz6c5KV4432vNAyGl79U8c0vwNLDgJ5PY8n23SxdYOkigi0VFDAhpK6goFkT53Hk Rpk3BXAYiwcgkR5gwMAHEdNd2/PY6q+8Dhk8uTGvdNF5yyV50RFURmXRnX67C+kz3X 6blfReAhZ3s/w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Linus Walleij , kernel test robot , Nathan Chancellor , Russell King , Sasha Levin , linux@armlinux.org.uk, arnd@arndb.de, samitolvanen@google.com, linux-arm-kernel@lists.infradead.org, llvm@lists.linux.dev Subject: [PATCH AUTOSEL 4.19] ARM: 9434/1: cfi: Fix compilation corner case Date: Wed, 20 Nov 2024 09:08:38 -0500 Message-ID: <20241120140842.1769864-1-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 4.19.324 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Linus Walleij [ Upstream commit 4aea16b7cfb76bd3361858ceee6893ef5c9b5570 ] When enabling expert mode CONFIG_EXPERT and using that power user mode to disable the branch prediction hardening !CONFIG_HARDEN_BRANCH_PREDICTOR, the assembly linker in CLANG notices that some assembly in proc-v7.S does not have corresponding C call sites, i.e. the prototypes in proc-v7-bugs.c are enclosed in ifdef CONFIG_HARDEN_BRANCH_PREDICTOR so this assembly: SYM_TYPED_FUNC_START(cpu_v7_smc_switch_mm) SYM_TYPED_FUNC_START(cpu_v7_hvc_switch_mm) Results in: ld.lld: error: undefined symbol: __kcfi_typeid_cpu_v7_smc_switch_mm >>> referenced by proc-v7.S:94 (.../arch/arm/mm/proc-v7.S:94) >>> arch/arm/mm/proc-v7.o:(.text+0x108) in archive vmlinux.a ld.lld: error: undefined symbol: __kcfi_typeid_cpu_v7_hvc_switch_mm >>> referenced by proc-v7.S:105 (.../arch/arm/mm/proc-v7.S:105) >>> arch/arm/mm/proc-v7.o:(.text+0x124) in archive vmlinux.a Fix this by adding an additional requirement that CONFIG_HARDEN_BRANCH_PREDICTOR has to be enabled to compile these assembly calls. Closes: https://lore.kernel.org/oe-kbuild-all/202411041456.ZsoEiD7T-lkp@int= el.com/ Reported-by: kernel test robot Reviewed-by: Nathan Chancellor Signed-off-by: Linus Walleij Signed-off-by: Russell King (Oracle) Signed-off-by: Sasha Levin --- arch/arm/mm/proc-v7.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S index e351d682c2e36..8bde80b31a861 100644 --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -94,7 +94,7 @@ ENTRY(cpu_v7_dcache_clean_area) ret lr ENDPROC(cpu_v7_dcache_clean_area) =20 -#ifdef CONFIG_ARM_PSCI +#if defined(CONFIG_ARM_PSCI) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR) .arch_extension sec ENTRY(cpu_v7_smc_switch_mm) stmfd sp!, {r0 - r3} --=20 2.43.0