From patchwork Thu May 23 09:50:22 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 10957181 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0D45015A6 for ; Thu, 23 May 2019 09:50:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E702028397 for ; Thu, 23 May 2019 09:50:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DAA98283A2; Thu, 23 May 2019 09:50:29 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4A2E828446 for ; Thu, 23 May 2019 09:50:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730034AbfEWJu3 (ORCPT ); Thu, 23 May 2019 05:50:29 -0400 Received: from new1-smtp.messagingengine.com ([66.111.4.221]:47325 "EHLO new1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729972AbfEWJu2 (ORCPT ); Thu, 23 May 2019 05:50:28 -0400 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailnew.nyi.internal (Postfix) with ESMTP id 8A7FA350B8; Thu, 23 May 2019 05:50:25 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Thu, 23 May 2019 05:50:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=vPXYb+ dQPu1PmLAsppSBBCsxX99YN2sLe8ibkLaPLj4=; b=WmhWP7S8StsnpVd7A31Sp4 aZOvHNr0ephz4kN8DlHv66HX4Mz2dRSJ/WEt4ncDqYKLLtibH6pNcrbXWFIXXb9+ phWa5qd39aDDuyYizw0XUBBbcu2QVbakK6p73FO6B0Vjqfi9FEIFlx7N44/kOIyP Bp4k0o1Xp9fZBzf3lzPkAowGNnOtAAlectWM2ofw6guJxy6YBTx01Cui+9/9ayMq strX8+Da3XSzIY6JSk4/2p/uEYP/WT4Rtw4f+TJSK6AwrdPrWMfRLgOWo5Hz+J/r WITwkWjd0NhcPNfeGhjDe7slVAIdGsw6sKLEQfq/jvMAQUta7FWbMzKb29hoxuVQ == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduuddruddugedgvdduucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefuvffhfffkgggtgfesthekredttd dtlfenucfhrhhomhepoehgrhgvghhkhheslhhinhhugihfohhunhgurghtihhonhdrohhr gheqnecukfhppeekfedrkeeirdekledruddtjeenucfrrghrrghmpehmrghilhhfrhhomh epghhrvghgsehkrhhorghhrdgtohhmnecuvehluhhsthgvrhfuihiivgepud X-ME-Proxy: Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) by mail.messagingengine.com (Postfix) with ESMTPA id 51BB480061; Thu, 23 May 2019 05:50:24 -0400 (EDT) Subject: FAILED: patch "[PATCH] x86_64: Allow breakpoints to emulate call instructions" failed to apply to 4.4-stable tree To: peterz@infradead.org, bigeasy@linutronix.de, bp@alien8.de, hpa@zytor.com, jgross@suse.com, jikos@kernel.org, joe.lawrence@redhat.com, jpoimboe@redhat.com, jroedel@suse.de, konrad.wilk@oracle.com, linux-kselftest@vger.kernel.org, luto@kernel.org, mbenes@suse.cz, mhiramat@kernel.org, mingo@redhat.com, nayna@linux.ibm.com, ndesaulniers@google.com, nstange@suse.de, pmladek@suse.com, rostedt@goodmis.org, shuah@kernel.org, tglx@linutronix.de, tim.c.chen@linux.intel.com, x86@kernel.org, yamada.masahiro@socionext.com, zohar@linux.ibm.com Cc: From: Date: Thu, 23 May 2019 11:50:22 +0200 Message-ID: <1558605022149172@kroah.com> MIME-Version: 1.0 Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 4b33dadf37666c0860b88f9e52a16d07bf6d0b03 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 1 May 2019 15:11:17 +0200 Subject: [PATCH] x86_64: Allow breakpoints to emulate call instructions In order to allow breakpoints to emulate call instructions, they need to push the return address onto the stack. The x86_64 int3 handler adds a small gap to allow the stack to grow some. Use this gap to add the return address to be able to emulate a call instruction at the breakpoint location. These helper functions are added: int3_emulate_jmp(): changes the location of the regs->ip to return there. (The next two are only for x86_64) int3_emulate_push(): to push the address onto the gap in the stack int3_emulate_call(): push the return address and change regs->ip Cc: Andy Lutomirski Cc: Nicolai Stange Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: the arch/x86 maintainers Cc: Josh Poimboeuf Cc: Jiri Kosina Cc: Miroslav Benes Cc: Petr Mladek Cc: Joe Lawrence Cc: Shuah Khan Cc: Konrad Rzeszutek Wilk Cc: Tim Chen Cc: Sebastian Andrzej Siewior Cc: Mimi Zohar Cc: Juergen Gross Cc: Nick Desaulniers Cc: Nayna Jain Cc: Masahiro Yamada Cc: Joerg Roedel Cc: "open list:KERNEL SELFTEST FRAMEWORK" Cc: stable@vger.kernel.org Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching") Tested-by: Nicolai Stange Reviewed-by: Nicolai Stange Reviewed-by: Masami Hiramatsu Signed-off-by: Peter Zijlstra (Intel) [ Modified to only work for x86_64 and added comment to int3_emulate_push() ] Signed-off-by: Steven Rostedt (VMware) diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h index e85ff65c43c3..05861cc08787 100644 --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -39,4 +39,32 @@ extern int poke_int3_handler(struct pt_regs *regs); extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler); extern int after_bootmem; +static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip) +{ + regs->ip = ip; +} + +#define INT3_INSN_SIZE 1 +#define CALL_INSN_SIZE 5 + +#ifdef CONFIG_X86_64 +static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val) +{ + /* + * The int3 handler in entry_64.S adds a gap between the + * stack where the break point happened, and the saving of + * pt_regs. We can extend the original stack because of + * this gap. See the idtentry macro's create_gap option. + */ + regs->sp -= sizeof(unsigned long); + *(unsigned long *)regs->sp = val; +} + +static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func) +{ + int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE); + int3_emulate_jmp(regs, func); +} +#endif + #endif /* _ASM_X86_TEXT_PATCHING_H */