Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757610Ab1DAOp2 (ORCPT ); Fri, 1 Apr 2011 10:45:28 -0400 Received: from e28smtp08.in.ibm.com ([122.248.162.8]:37657 "EHLO e28smtp08.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757317Ab1DAOpV (ORCPT ); Fri, 1 Apr 2011 10:45:21 -0400 From: Srikar Dronamraju To: Peter Zijlstra , Ingo Molnar Cc: Steven Rostedt , Srikar Dronamraju , Linux-mm , Arnaldo Carvalho de Melo , Linus Torvalds , Andi Kleen , Christoph Hellwig , Jonathan Corbet , Thomas Gleixner , Masami Hiramatsu , Oleg Nesterov , Andrew Morton , SystemTap , Jim Keniston , Roland McGrath , Ananth N Mavinakayanahalli , LKML Date: Fri, 01 Apr 2011 20:05:37 +0530 Message-Id: <20110401143537.15455.82130.sendpatchset@localhost6.localdomain6> In-Reply-To: <20110401143223.15455.19844.sendpatchset@localhost6.localdomain6> References: <20110401143223.15455.19844.sendpatchset@localhost6.localdomain6> Subject: [PATCH v3 2.6.39-rc1-tip 16/26] 16: x86: uprobes exception notifier for x86. Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3446 Lines: 106 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 0c9c8b6..bb5c03c 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 @@ -49,4 +50,6 @@ 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 bf98841..e0ce207 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -583,3 +583,32 @@ 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 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/