From patchwork Fri Oct 18 16:10:20 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 176896 Delivered-To: patch@linaro.org Received: by 2002:a92:7e96:0:0:0:0:0 with SMTP id q22csp1065761ill; Fri, 18 Oct 2019 09:11:08 -0700 (PDT) X-Google-Smtp-Source: APXvYqxoF0E18/PkW+A2R1SEqlckPqZ2Au6U/xL/I4SbQqKUb6yGhFYWZeiCQUdaGvIyWEogNlku X-Received: by 2002:a50:f390:: with SMTP id g16mr10463829edm.41.1571415068385; Fri, 18 Oct 2019 09:11:08 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1571415068; cv=none; d=google.com; s=arc-20160816; b=o0OWNpOPMYFfQHoB5AzIFfuPQ56zMdGAeNwIANEDSVJ9AiNkxwWo0UOj015scfJpYd hOOTqaA74KN4glJ+1AbIW1l3c0OSmDnaDW1RUpNRN+Nf6BAIJjbHLQMtsKo81kRpip1b cvqji6cOZ5imuDEhbDUCATEKzxaWRsNKfw8nRA7uCwhvFntP5N0tTgxye8T6u3YpFVvg NIqOM75gEE/26aFdTDSlIjrk6UV6Ny26syqkzjni5cebLdBET5dxXe/XbwzdQoG+jA12 Yd3pDme02qPFMv0ChSbGAM68gPsVhrx9sNN2V1i73LFuorRRLjfY0CePSbgLQs+Dym/Q 0hAw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:cc:to:from:subject:references :mime-version:message-id:in-reply-to:date:dkim-signature; bh=soVi6argGh8CkyJ/tZS/XQoN8aAv6F/7ncnrrIAGrbI=; b=bBTsb7Eh9LZBzCPMcEhdTpVYk4Yp+odlP3OV2vzpFta81qjwNF/icgycAD6tP6fv+t tgNI+6IduCznIPK8wRoCVY6HLd5ZZsC1WYTd8ur9bWog9yWGNFxH1jBKBQ2rdS76OFB3 UvFbJv2vdIsRVhHr4cga4p5tHtxY7I/wYZOguIqj12oNw0foMfQamGMC2IXWyZmqFZ/R gWqdB6x4HreD2BdIrjPWu8aWZXGLzWMBFtqwIdtPw+tugYOvncD/5t4JDl+ZrLLIIQ+I VRBqFXUxr6naZrFpbDacb3gTWxovT/LXv+EKS2+Ghu/iOb2bBU0icJ7tbmhbarHenMx+ 2tOA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=RTWmB+YR; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id jx7si3783714ejb.84.2019.10.18.09.11.08; Fri, 18 Oct 2019 09:11:08 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=RTWmB+YR; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2442957AbfJRQLF (ORCPT + 26 others); Fri, 18 Oct 2019 12:11:05 -0400 Received: from mail-vs1-f73.google.com ([209.85.217.73]:47476 "EHLO mail-vs1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2442937AbfJRQLD (ORCPT ); Fri, 18 Oct 2019 12:11:03 -0400 Received: by mail-vs1-f73.google.com with SMTP id r26so1566823vsq.14 for ; Fri, 18 Oct 2019 09:11:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=soVi6argGh8CkyJ/tZS/XQoN8aAv6F/7ncnrrIAGrbI=; b=RTWmB+YRhbyTrupTegTePDqh83wahNiLo24V/vkd3XNh2/VjRfOzsP8l9UA07iBYVh cNCOrmz1KApedjuZfTuf+oEAy7uJ9vOjlPpxsg7OkJReg5LlWaNnJSadKKQxT6uV8oo9 DYHGRvWBz3/GUdtlA0wIAJuRmYFSW5vXFhnZ39LEFxcVI9DqpO8eIN9kDWvp9NjS8BGy xN5pkbK5dusYfEE++LF7k5cNY+Cu1x/v4ps1Ft2zcALY7q2NKOD2KsdADykKFGjX/ek9 pgnN2RfC3QCLk3Iaa8HyaKxHiBf6citZAP2zBGFrT6GXMyCWAMsRsDGnPTlW+RbabIhg vExA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=soVi6argGh8CkyJ/tZS/XQoN8aAv6F/7ncnrrIAGrbI=; b=fzmkheGA7ta/bA4L4nyFJeMhCP2jGDqdw084+96IHN+nSqSEXsMYU3RNJvvwdnUv16 YU3DUp0AwYOTc5XBxKc4oIiA+iABk7+OefUgsclHzMJGwleUqwMrq+P1tPOC34IiK4nQ vvCbl1FMLrLJKcB01ltUwOXVJN9g5RJDtMFh6CxUB53jomqN6mA/bD0Jqd5HYOEtWf9/ gpgXaTjvZCSoGybGkprdvtCXZKEjBxPN659CWOSrK6BtKxgnHojA6xQvP0GL4oBLfSpX VKC6Co4ejXesMN07lvoK+4aNBfbqhLHOSVgTLDZa7aiWrMcARHHA16um8goaZF7SvOjd h2Fg== X-Gm-Message-State: APjAAAUNuJgVIxOyO4TA8OtUi8mB5xybtq0n0G1ShRQYW4wzH/3wWsqG wswO1q1QaHDXMOZlhO7VX//aElekpvMjz8M9S6A= X-Received: by 2002:a67:e34b:: with SMTP id s11mr5965401vsm.195.1571415062790; Fri, 18 Oct 2019 09:11:02 -0700 (PDT) Date: Fri, 18 Oct 2019 09:10:20 -0700 In-Reply-To: <20191018161033.261971-1-samitolvanen@google.com> Message-Id: <20191018161033.261971-6-samitolvanen@google.com> Mime-Version: 1.0 References: <20191018161033.261971-1-samitolvanen@google.com> X-Mailer: git-send-email 2.23.0.866.gb869b98d4c-goog Subject: [PATCH 05/18] arm64: kbuild: reserve reg x18 from general allocation by the compiler From: Sami Tolvanen To: Will Deacon , Catalin Marinas , Steven Rostedt , Ard Biesheuvel Cc: Dave Martin , Kees Cook , Laura Abbott , Mark Rutland , Nick Desaulniers , clang-built-linux@googlegroups.com, kernel-hardening@lists.openwall.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Sami Tolvanen Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ard Biesheuvel Before we can start using register x18 for a special purpose (as permitted by the AAPCS64 ABI), we need to tell the compiler that it is off limits for general allocation. So tag it as 'fixed', and remove the mention from the LL/SC compiler flag override. Link: https://patchwork.kernel.org/patch/9836881/ Signed-off-by: Ard Biesheuvel Signed-off-by: Sami Tolvanen --- arch/arm64/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.23.0.866.gb869b98d4c-goog Reviewed-by: Nick Desaulniers diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 2c0238ce0551..1c7b276bc7c5 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -55,7 +55,7 @@ endif KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) $(brokengasinst) \ $(compat_vdso) $(cc_has_k_constraint) -KBUILD_CFLAGS += -fno-asynchronous-unwind-tables +KBUILD_CFLAGS += -fno-asynchronous-unwind-tables -ffixed-x18 KBUILD_CFLAGS += $(call cc-disable-warning, psabi) KBUILD_AFLAGS += $(lseinstr) $(brokengasinst) $(compat_vdso)