Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756426Ab2HUPOt (ORCPT ); Tue, 21 Aug 2012 11:14:49 -0400 Received: from terminus.zytor.com ([198.137.202.10]:59483 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754898Ab2HUPOq (ORCPT ); Tue, 21 Aug 2012 11:14:46 -0400 Date: Tue, 21 Aug 2012 08:14:24 -0700 From: tip-bot for Masami Hiramatsu Message-ID: Cc: fche@redhat.com, mingo@redhat.com, linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, ananth@in.ibm.com, fweisbec@gmail.com, masami.hiramatsu.pt@hitachi.com, rostedt@goodmis.org, akpm@linux-foundation.org, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@redhat.com, fche@redhat.com, ananth@in.ibm.com, fweisbec@gmail.com, masami.hiramatsu.pt@hitachi.com, akpm@linux-foundation.org, rostedt@goodmis.org, tglx@linutronix.de In-Reply-To: <20120605102838.27845.26317.stgit@localhost.localdomain> References: <20120605102838.27845.26317.stgit@localhost.localdomain> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] kprobes/x86: ftrace based optimization for x86 Git-Commit-ID: e52538965119319447c0800c534da73142c27be2 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 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Tue, 21 Aug 2012 08:14:30 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4510 Lines: 136 Commit-ID: e52538965119319447c0800c534da73142c27be2 Gitweb: http://git.kernel.org/tip/e52538965119319447c0800c534da73142c27be2 Author: Masami Hiramatsu AuthorDate: Tue, 5 Jun 2012 19:28:38 +0900 Committer: Steven Rostedt CommitDate: Tue, 31 Jul 2012 10:29:59 -0400 kprobes/x86: ftrace based optimization for x86 Add function tracer based kprobe optimization support handlers on x86. This allows kprobes to use function tracer for probing on mcount call. Link: http://lkml.kernel.org/r/20120605102838.27845.26317.stgit@localhost.localdomain Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Ananth N Mavinakayanahalli Cc: "Frank Ch. Eigler" Cc: Andrew Morton Cc: Frederic Weisbecker Signed-off-by: Masami Hiramatsu [ Updated to new port of ftrace save regs functions ] Signed-off-by: Steven Rostedt --- arch/x86/include/asm/kprobes.h | 1 + arch/x86/kernel/kprobes.c | 48 ++++++++++++++++++++++++++++++++++++++++ include/linux/kprobes.h | 2 +- kernel/kprobes.c | 2 +- 4 files changed, 51 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/kprobes.h b/arch/x86/include/asm/kprobes.h index 5478825..d3ddd17 100644 --- a/arch/x86/include/asm/kprobes.h +++ b/arch/x86/include/asm/kprobes.h @@ -27,6 +27,7 @@ #include #define __ARCH_WANT_KPROBES_INSN_SLOT +#define ARCH_SUPPORTS_KPROBES_ON_FTRACE struct pt_regs; struct kprobe; diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c index e2f751e..47ae102 100644 --- a/arch/x86/kernel/kprobes.c +++ b/arch/x86/kernel/kprobes.c @@ -1052,6 +1052,54 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) return 0; } +#ifdef KPROBES_CAN_USE_FTRACE +/* Ftrace callback handler for kprobes */ +void __kprobes kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *ops, struct pt_regs *regs) +{ + struct kprobe *p; + struct kprobe_ctlblk *kcb; + unsigned long flags; + + /* Disable irq for emulating a breakpoint and avoiding preempt */ + local_irq_save(flags); + + p = get_kprobe((kprobe_opcode_t *)ip); + if (unlikely(!p) || kprobe_disabled(p)) + goto end; + + kcb = get_kprobe_ctlblk(); + if (kprobe_running()) { + kprobes_inc_nmissed_count(p); + } else { + regs->ip += sizeof(kprobe_opcode_t); + + __this_cpu_write(current_kprobe, p); + kcb->kprobe_status = KPROBE_HIT_ACTIVE; + if (p->pre_handler) + p->pre_handler(p, regs); + + if (unlikely(p->post_handler)) { + /* Emulate singlestep as if there is a 5byte nop */ + regs->ip = ip + MCOUNT_INSN_SIZE; + kcb->kprobe_status = KPROBE_HIT_SSDONE; + p->post_handler(p, regs, 0); + } + __this_cpu_write(current_kprobe, NULL); + regs->ip = ip; /* Recover for next callback */ + } +end: + local_irq_restore(flags); +} + +int __kprobes arch_prepare_kprobe_ftrace(struct kprobe *p) +{ + p->ainsn.insn = NULL; + p->ainsn.boostable = -1; + return 0; +} +#endif + int __init arch_init_kprobes(void) { return arch_init_optprobes(); diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h index aa0d05e..23755ba 100644 --- a/include/linux/kprobes.h +++ b/include/linux/kprobes.h @@ -318,7 +318,7 @@ extern int proc_kprobes_optimization_handler(struct ctl_table *table, #endif /* CONFIG_OPTPROBES */ #ifdef KPROBES_CAN_USE_FTRACE extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, - struct pt_regs *regs); + struct ftrace_ops *ops, struct pt_regs *regs); extern int arch_prepare_kprobe_ftrace(struct kprobe *p); #endif diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 69c16ef..35b4315 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -921,7 +921,7 @@ static __kprobes struct kprobe *alloc_aggr_kprobe(struct kprobe *p) #ifdef KPROBES_CAN_USE_FTRACE static struct ftrace_ops kprobe_ftrace_ops __read_mostly = { - .regs_func = kprobe_ftrace_handler, + .func = kprobe_ftrace_handler, .flags = FTRACE_OPS_FL_SAVE_REGS, }; static int kprobe_ftrace_enabled; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/