From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id 9E6278D003E for ; Mon, 14 Mar 2011 09:43:03 -0400 (EDT) Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [202.81.31.245]) by e23smtp09.au.ibm.com (8.14.4/8.13.1) with ESMTP id p2EDgbAL003008 for ; Tue, 15 Mar 2011 00:42:37 +1100 Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p2EDgbVC2199636 for ; Tue, 15 Mar 2011 00:42:37 +1100 Received: from d23av03.au.ibm.com (loopback [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p2EDgaVc031510 for ; Tue, 15 Mar 2011 00:42:37 +1100 From: Srikar Dronamraju Date: Mon, 14 Mar 2011 19:06:54 +0530 Message-Id: <20110314133654.27435.10282.sendpatchset@localhost6.localdomain6> In-Reply-To: <20110314133403.27435.7901.sendpatchset@localhost6.localdomain6> References: <20110314133403.27435.7901.sendpatchset@localhost6.localdomain6> Subject: [PATCH v2 2.6.38-rc8-tip 15/20] 15: x86: uprobes exception notifier for x86. Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra , Ingo Molnar Cc: Steven Rostedt , Srikar Dronamraju , Linux-mm , Arnaldo Carvalho de Melo , Linus Torvalds , Ananth N Mavinakayanahalli , Christoph Hellwig , Andi Kleen , Masami Hiramatsu , Oleg Nesterov , LKML , Jim Keniston , Roland McGrath , SystemTap , Andrew Morton , "Paul E. McKenney" Provides a uprobes exception notifier for x86. This uprobes_exception notifier gets called in interrupt context and routes int3 and singlestep exception when a uprobed process encounters a INT3 or a singlestep exception. Signed-off-by: Ananth N Mavinakayanahalli Signed-off-by: Srikar Dronamraju --- arch/x86/include/asm/uprobes.h | 3 +++ arch/x86/kernel/signal.c | 14 ++++++++++++++ arch/x86/kernel/uprobes.c | 29 +++++++++++++++++++++++++++++ 3 files changed, 46 insertions(+), 0 deletions(-) diff --git a/arch/x86/include/asm/uprobes.h b/arch/x86/include/asm/uprobes.h index 0e1b23f..f49cf49 100644 --- a/arch/x86/include/asm/uprobes.h +++ b/arch/x86/include/asm/uprobes.h @@ -22,6 +22,7 @@ * Srikar Dronamraju * Jim Keniston */ +#include typedef u8 uprobe_opcode_t; #define MAX_UINSN_BYTES 16 @@ -52,4 +53,6 @@ extern int pre_xol(struct uprobe *uprobe, struct pt_regs *regs); extern int post_xol(struct uprobe *uprobe, struct pt_regs *regs); extern void arch_uprobe_enable_sstep(struct pt_regs *regs); extern void arch_uprobe_disable_sstep(struct pt_regs *regs); +extern int uprobes_exception_notify(struct notifier_block *self, + unsigned long val, void *data); #endif /* _ASM_UPROBES_H */ diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 4fd173c..0b06b94 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include @@ -848,6 +849,19 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) if (thread_info_flags & _TIF_SIGPENDING) do_signal(regs); + if (thread_info_flags & _TIF_UPROBE) { + clear_thread_flag(TIF_UPROBE); +#ifdef CONFIG_X86_32 + /* + * On x86_32, do_notify_resume() gets called with + * interrupts disabled. Hence enable interrupts if they + * are still disabled. + */ + local_irq_enable(); +#endif + uprobe_notify_resume(regs); + } + if (thread_info_flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); tracehook_notify_resume(regs); diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 5667e90..b55469c 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -569,3 +569,32 @@ void arch_uprobe_disable_sstep(struct pt_regs *regs) clear_thread_flag(TIF_FORCED_TF); regs->flags &= ~X86_EFLAGS_TF; } + +/* + * Wrapper routine for handling exceptions. + */ +int uprobes_exception_notify(struct notifier_block *self, + unsigned long val, void *data) +{ + struct die_args *args = data; + struct pt_regs *regs = args->regs; + int ret = NOTIFY_DONE; + + /* We are only interested in userspace traps */ + if (regs && !user_mode_vm(regs)) + return NOTIFY_DONE; + + switch (val) { + case DIE_INT3: + /* Run your handler here */ + if (uprobe_bkpt_notifier(regs)) + ret = NOTIFY_STOP; + break; + case DIE_DEBUG: + if (uprobe_post_notifier(regs)) + ret = NOTIFY_STOP; + default: + break; + } + return ret; +} -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org