From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758585AbdCVBge (ORCPT ); Tue, 21 Mar 2017 21:36:34 -0400 Received: from mail.kernel.org ([198.145.29.136]:32878 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757457AbdCVBg1 (ORCPT ); Tue, 21 Mar 2017 21:36:27 -0400 Message-Id: <20170322013502.448616656@goodmis.org> User-Agent: quilt/0.63-1 Date: Tue, 21 Mar 2017 21:35:02 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Thomas Gleixner , Peter Zijlstra , Masami Hiramatsu , "H. Peter Anvin" , Andy Lutomirski , Josh Poimboeuf , Linus Torvalds Subject: [PATCH 0/6] [GIT PULL] ftrace/x86: Ftrace cleanup and add support for -mfentry on x86_32 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Ingo, Thomas or H.Peter, I believe this is all set to go now. I updated those patches that Linus commented on and I don't believe there are any more issues. I ran this through several tests (although some of my tests are failing due to bugs introduced by others in 4.11-rc2). You can take this as a patch series, or you can pull from my tree defined below. It's based on 4.11-rc2 as I noticed that tip/x86/core is rather outdated, and Linus is fine with basing off of his tagged releases. ] With the issues of gcc screwing around with the mcount stack frame causing function graph tracer to panic on x86_32, and with Linus saying that we should start deprecating mcount (at least on x86), I figured that x86_32 needs to support fentry. First, I renamed mcount_64.S to ftrace_64.S. As we want to get away from mcount, having the ftrace code in a file called mcount seems rather backwards. Next I moved the ftrace code out of entry_32.S. It's not in entry_64.S and it does not belong in entry_32.S. I noticed that the x86_32 code has the same issue as the x86_64 did in the past with respect to a stack frame. I fixed that just for the main ftrace_caller. The ftrace_regs_caller is rather special, and so is function graph tracing. I realized the ftrace_regs_caller code was complex due to me aggressively saving flags, even though I could still do push, lea and mov without changing them. That made the logic a little nicer. Finally I added the fentry code. I tested this with an older compiler (for mcount) with and without FRAME_POINTER set. I also did it with a new compiler (with fentry), with and without FRAME_POINTER. I tested function tracing, stack tracing, function_graph tracing, and kprobes (as that uses the ftrace_regs_caller). Please pull (or take the patch series) from: git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git tip/x86/ftrace Head SHA1: e086b1da846b8e53f4de11e38d02d05b1ec5db58 Steven Rostedt (VMware) (6): ftrace/x86_64: Rename mcount_64.S to ftrace_64.S ftrace/x86_32: Move the ftrace specific code out of entry_32.S ftrace/x86_32: Add stack frame pointer to ftrace_caller ftrace/x86_32: Clean up ftrace_regs_caller ftrace/x86_32: Add -mfentry support to x86_32 with DYNAMIC_FTRACE set ftrace/x86: Use Makefile logic instead of #ifdef for compiling ftrace_*.o ---- Changes since v3: * Changed comment about regs being skipped (Josh Poimboeuf) * Change subject line to fix typo (Josh Poimboeuf) arch/x86/Kconfig | 2 +- arch/x86/entry/entry_32.S | 169 ------------------ arch/x86/kernel/Makefile | 5 +- arch/x86/kernel/ftrace_32.S | 246 +++++++++++++++++++++++++++ arch/x86/kernel/{mcount_64.S => ftrace_64.S} | 4 - 5 files changed, 250 insertions(+), 176 deletions(-) create mode 100644 arch/x86/kernel/ftrace_32.S rename arch/x86/kernel/{mcount_64.S => ftrace_64.S} (99%) Diff against v3: diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S index 4d52e0d49e26..de50c9084d16 100644 --- a/arch/x86/kernel/ftrace_32.S +++ b/arch/x86/kernel/ftrace_32.S @@ -167,7 +167,7 @@ GLOBAL(ftrace_regs_call) popl %gs /* use lea to not affect flags */ - lea 3*4(%esp), %esp /* Skip orig_ax, ip and flags */ + lea 3*4(%esp), %esp /* Skip orig_ax, ip and cs */ jmp .Lftrace_ret #else /* ! CONFIG_DYNAMIC_FTRACE */