From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755602Ab1KJTFJ (ORCPT ); Thu, 10 Nov 2011 14:05:09 -0500 Received: from e23smtp07.au.ibm.com ([202.81.31.140]:37863 "EHLO e23smtp07.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755562Ab1KJTFE (ORCPT ); Thu, 10 Nov 2011 14:05:04 -0500 From: Srikar Dronamraju To: Peter Zijlstra , Linus Torvalds Cc: Oleg Nesterov , Andrew Morton , LKML , Linux-mm , Ingo Molnar , Andi Kleen , Christoph Hellwig , Steven Rostedt , Roland McGrath , Thomas Gleixner , Masami Hiramatsu , Arnaldo Carvalho de Melo , Anton Arapov , Ananth N Mavinakayanahalli , Jim Keniston , Stephen Wilson Date: Fri, 11 Nov 2011 00:10:01 +0530 Message-Id: <20111110184001.11361.52020.sendpatchset@srdronam.in.ibm.com> In-Reply-To: <20111110183725.11361.57827.sendpatchset@srdronam.in.ibm.com> References: <20111110183725.11361.57827.sendpatchset@srdronam.in.ibm.com> Subject: [PATCH v6 3.2-rc1 13/28] x86: define a x86 specific exception notifier. Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Uprobes uses notifier mechanism to get in control when an application encounters a breakpoint or a singlestep exception. Signed-off-by: Ananth N Mavinakayanahalli Signed-off-by: Srikar Dronamraju --- Changelog (since v5) - No more do a i386 specific enable interrupts. (Its now part of another patchset posted separately) arch/x86/include/asm/uprobes.h | 4 ++++ arch/x86/kernel/signal.c | 6 ++++++ arch/x86/kernel/uprobes.c | 29 +++++++++++++++++++++++++++++ 3 files changed, 39 insertions(+), 0 deletions(-) diff --git a/arch/x86/include/asm/uprobes.h b/arch/x86/include/asm/uprobes.h index 509c023..19a5949 100644 --- a/arch/x86/include/asm/uprobes.h +++ b/arch/x86/include/asm/uprobes.h @@ -23,6 +23,8 @@ * Jim Keniston */ +#include + typedef u8 uprobe_opcode_t; #define MAX_UINSN_BYTES 16 #define UPROBES_XOL_SLOT_BYTES 128 /* to keep it cache aligned */ @@ -40,4 +42,6 @@ struct uprobe_arch_info {}; struct uprobe; extern int analyze_insn(struct mm_struct *mm, struct uprobe *uprobe); extern void set_instruction_pointer(struct pt_regs *regs, unsigned long vaddr); +extern int uprobe_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 54ddaeb..4fdf470 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include @@ -820,6 +821,11 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) mce_notify_process(); #endif /* CONFIG_X86_64 && CONFIG_X86_MCE */ + if (thread_info_flags & _TIF_UPROBE) { + clear_thread_flag(TIF_UPROBE); + uprobe_notify_resume(regs); + } + /* deal with pending signal delivery */ if (thread_info_flags & _TIF_SIGPENDING) do_signal(regs); diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 67b926f..2ee5ddc 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -407,3 +407,32 @@ void set_instruction_pointer(struct pt_regs *regs, unsigned long vaddr) { regs->ip = vaddr; } + +/* + * Wrapper routine for handling exceptions. + */ +int uprobe_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; +}