From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751171AbdJCRq3 (ORCPT ); Tue, 3 Oct 2017 13:46:29 -0400 Received: from terminus.zytor.com ([65.50.211.136]:35963 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750767AbdJCRq1 (ORCPT ); Tue, 3 Oct 2017 13:46:27 -0400 Date: Tue, 3 Oct 2017 10:42:42 -0700 From: tip-bot for Josh Poimboeuf Message-ID: Cc: jpoimboe@redhat.com, davem@davemloft.net, torvalds@linux-foundation.org, anil.s.keshavamurthy@intel.com, mingo@kernel.org, mhiramat@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, ananth@linux.vnet.ibm.com, richard@sigma-star.at, peterz@infradead.org Reply-To: peterz@infradead.org, richard@sigma-star.at, tglx@linutronix.de, ananth@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, hpa@zytor.com, anil.s.keshavamurthy@intel.com, mhiramat@kernel.org, mingo@kernel.org, torvalds@linux-foundation.org, davem@davemloft.net, jpoimboe@redhat.com In-Reply-To: <7aef2f8ecd75c2f505ef9b80490412262cf4a44c.1507038547.git.jpoimboe@redhat.com> References: <7aef2f8ecd75c2f505ef9b80490412262cf4a44c.1507038547.git.jpoimboe@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] kprobes/x86: Set up frame pointer in kprobe trampoline Git-Commit-ID: ee213fc72fd67d0988525af501534f4cb924d1e9 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: ee213fc72fd67d0988525af501534f4cb924d1e9 Gitweb: https://git.kernel.org/tip/ee213fc72fd67d0988525af501534f4cb924d1e9 Author: Josh Poimboeuf AuthorDate: Tue, 3 Oct 2017 08:51:43 -0500 Committer: Ingo Molnar CommitDate: Tue, 3 Oct 2017 19:11:27 +0200 kprobes/x86: Set up frame pointer in kprobe trampoline Richard Weinberger saw an unwinder warning when running bcc's opensnoop: WARNING: kernel stack frame pointer at ffff99ef4076bea0 in opensnoop:2008 has bad value 0000000000000008 unwind stack type:0 next_sp: (null) mask:0x2 graph_idx:0 ... ffff99ef4076be88: ffff99ef4076bea0 (0xffff99ef4076bea0) ffff99ef4076be90: ffffffffac442721 (optimized_callback +0x81/0x90) ... A lockdep stack trace was initiated from inside a kprobe handler, when the unwinder noticed a bad frame pointer on the stack. The bad frame pointer is related to the fact that the kprobe optprobe trampoline doesn't save the frame pointer before calling into optimized_callback(). Reported-and-tested-by: Richard Weinberger Signed-off-by: Josh Poimboeuf Acked-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Anil S Keshavamurthy Cc: David S . Miller Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/7aef2f8ecd75c2f505ef9b80490412262cf4a44c.1507038547.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/kprobes/common.h | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kprobes/common.h b/arch/x86/kernel/kprobes/common.h index db2182d..3fc0f9a 100644 --- a/arch/x86/kernel/kprobes/common.h +++ b/arch/x86/kernel/kprobes/common.h @@ -3,6 +3,15 @@ /* Kprobes and Optprobes common header */ +#include + +#ifdef CONFIG_FRAME_POINTER +# define SAVE_RBP_STRING " push %" _ASM_BP "\n" \ + " mov %" _ASM_SP ", %" _ASM_BP "\n" +#else +# define SAVE_RBP_STRING " push %" _ASM_BP "\n" +#endif + #ifdef CONFIG_X86_64 #define SAVE_REGS_STRING \ /* Skip cs, ip, orig_ax. */ \ @@ -17,7 +26,7 @@ " pushq %r10\n" \ " pushq %r11\n" \ " pushq %rbx\n" \ - " pushq %rbp\n" \ + SAVE_RBP_STRING \ " pushq %r12\n" \ " pushq %r13\n" \ " pushq %r14\n" \ @@ -48,7 +57,7 @@ " pushl %es\n" \ " pushl %ds\n" \ " pushl %eax\n" \ - " pushl %ebp\n" \ + SAVE_RBP_STRING \ " pushl %edi\n" \ " pushl %esi\n" \ " pushl %edx\n" \