From patchwork Thu Feb 13 15:21:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 231411 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 99EF9C3B18B for ; Thu, 13 Feb 2020 15:48:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7304A20661 for ; Thu, 13 Feb 2020 15:48:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581608905; bh=dVJglPzkGQNWLRZbvnUE/tGiFH6lQqO/45Lkw0Kd2MA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Qp4+YfaDI9arZ1Fc4JkTI4R2REKT4qO+2TjYPcLDn8z49eDW0XjbAlFlAAobdc2he xq0A7//iOe1Bexz/0cfOwYve2heB2LcCn4KptVSih2WJ8k4BY70RXeVtPev02LSgMx Vihn47xD3gE5wcLfIw5FXAT8o/FwQBaxT/up+HR8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727874AbgBMPsY (ORCPT ); Thu, 13 Feb 2020 10:48:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:47872 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729295AbgBMP04 (ORCPT ); Thu, 13 Feb 2020 10:26:56 -0500 Received: from localhost (unknown [104.132.1.104]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EFA0B206DB; Thu, 13 Feb 2020 15:26:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581607615; bh=dVJglPzkGQNWLRZbvnUE/tGiFH6lQqO/45Lkw0Kd2MA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eI/shsGzg4Pn+ydIjDTWZSfig+al9DF8B8yJgI8IBFXpJNILRE55fvJd+RC+EmZCY drKSf2ZrTRM7gia74hc7JwOfHPZfrVeipKYC5V4a7oORy1wBNmiXj5KFQtAa53WgXR YZicYS2KYT3Mh0eNBhDe2Llb0UBRpbdPhpUKIOxA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Peter Zijlstra (Intel)" , Josh Poimboeuf , Linus Torvalds , Thomas Gleixner , Ingo Molnar , Dmitry Safonov Subject: [PATCH 4.19 51/52] x86/stackframe: Move ENCODE_FRAME_POINTER to asm/frame.h Date: Thu, 13 Feb 2020 07:21:32 -0800 Message-Id: <20200213151830.764945877@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200213151810.331796857@linuxfoundation.org> References: <20200213151810.331796857@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Peter Zijlstra commit a9b3c6998d4a7d53a787cf4d0fd4a4c11239e517 upstream. In preparation for wider use, move the ENCODE_FRAME_POINTER macros to a common header and provide inline asm versions. These macros are used to encode a pt_regs frame for the unwinder; see unwind_frame.c:decode_frame_pointer(). Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar Signed-off-by: Dmitry Safonov Signed-off-by: Greg Kroah-Hartman --- arch/x86/entry/calling.h | 15 ------------- arch/x86/entry/entry_32.S | 16 -------------- arch/x86/include/asm/frame.h | 49 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 49 insertions(+), 31 deletions(-) --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -172,21 +172,6 @@ For 32-bit we have the following convent .endif .endm -/* - * This is a sneaky trick to help the unwinder find pt_regs on the stack. The - * frame pointer is replaced with an encoded pointer to pt_regs. The encoding - * is just setting the LSB, which makes it an invalid stack address and is also - * a signal to the unwinder that it's a pt_regs pointer in disguise. - * - * NOTE: This macro must be used *after* PUSH_AND_CLEAR_REGS because it corrupts - * the original rbp. - */ -.macro ENCODE_FRAME_POINTER ptregs_offset=0 -#ifdef CONFIG_FRAME_POINTER - leaq 1+\ptregs_offset(%rsp), %rbp -#endif -.endm - #ifdef CONFIG_PAGE_TABLE_ISOLATION /* --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -245,22 +245,6 @@ .Lend_\@: .endm -/* - * This is a sneaky trick to help the unwinder find pt_regs on the stack. The - * frame pointer is replaced with an encoded pointer to pt_regs. The encoding - * is just clearing the MSB, which makes it an invalid stack address and is also - * a signal to the unwinder that it's a pt_regs pointer in disguise. - * - * NOTE: This macro must be used *after* SAVE_ALL because it corrupts the - * original rbp. - */ -.macro ENCODE_FRAME_POINTER -#ifdef CONFIG_FRAME_POINTER - mov %esp, %ebp - andl $0x7fffffff, %ebp -#endif -.endm - .macro RESTORE_INT_REGS popl %ebx popl %ecx --- a/arch/x86/include/asm/frame.h +++ b/arch/x86/include/asm/frame.h @@ -22,6 +22,35 @@ pop %_ASM_BP .endm +#ifdef CONFIG_X86_64 +/* + * This is a sneaky trick to help the unwinder find pt_regs on the stack. The + * frame pointer is replaced with an encoded pointer to pt_regs. The encoding + * is just setting the LSB, which makes it an invalid stack address and is also + * a signal to the unwinder that it's a pt_regs pointer in disguise. + * + * NOTE: This macro must be used *after* PUSH_AND_CLEAR_REGS because it corrupts + * the original rbp. + */ +.macro ENCODE_FRAME_POINTER ptregs_offset=0 + leaq 1+\ptregs_offset(%rsp), %rbp +.endm +#else /* !CONFIG_X86_64 */ +/* + * This is a sneaky trick to help the unwinder find pt_regs on the stack. The + * frame pointer is replaced with an encoded pointer to pt_regs. The encoding + * is just clearing the MSB, which makes it an invalid stack address and is also + * a signal to the unwinder that it's a pt_regs pointer in disguise. + * + * NOTE: This macro must be used *after* SAVE_ALL because it corrupts the + * original ebp. + */ +.macro ENCODE_FRAME_POINTER + mov %esp, %ebp + andl $0x7fffffff, %ebp +.endm +#endif /* CONFIG_X86_64 */ + #else /* !__ASSEMBLY__ */ #define FRAME_BEGIN \ @@ -30,12 +59,32 @@ #define FRAME_END "pop %" _ASM_BP "\n" +#ifdef CONFIG_X86_64 +#define ENCODE_FRAME_POINTER \ + "lea 1(%rsp), %rbp\n\t" +#else /* !CONFIG_X86_64 */ +#define ENCODE_FRAME_POINTER \ + "movl %esp, %ebp\n\t" \ + "andl $0x7fffffff, %ebp\n\t" +#endif /* CONFIG_X86_64 */ + #endif /* __ASSEMBLY__ */ #define FRAME_OFFSET __ASM_SEL(4, 8) #else /* !CONFIG_FRAME_POINTER */ +#ifdef __ASSEMBLY__ + +.macro ENCODE_FRAME_POINTER ptregs_offset=0 +.endm + +#else /* !__ASSEMBLY */ + +#define ENCODE_FRAME_POINTER + +#endif + #define FRAME_BEGIN #define FRAME_END #define FRAME_OFFSET 0