Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756463Ab1CNNlq (ORCPT ); Mon, 14 Mar 2011 09:41:46 -0400 Received: from e28smtp02.in.ibm.com ([122.248.162.2]:56561 "EHLO e28smtp02.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755798Ab1CNNlo (ORCPT ); Mon, 14 Mar 2011 09:41:44 -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 , Masami Hiramatsu , Oleg Nesterov , Andrew Morton , SystemTap , Jim Keniston , Roland McGrath , Ananth N Mavinakayanahalli , LKML , "Paul E. McKenney" Date: Mon, 14 Mar 2011 19:06:00 +0530 Message-Id: <20110314133600.27435.25623.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 10/20] 10: uprobes: task specific information. Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4867 Lines: 168 Uprobes needs to maintain some task specific information include if a task is currently uprobed, the currently handing uprobe, any arch specific information (for example to handle rip relative instructions), the per-task slot where the original instruction is copied to before single-stepping. Provides routines to create/manage and free the task specific information. Signed-off-by: Srikar Dronamraju --- include/linux/sched.h | 3 +++ include/linux/uprobes.h | 25 +++++++++++++++++++++++++ kernel/fork.c | 4 ++++ kernel/uprobes.c | 38 ++++++++++++++++++++++++++++++++++++++ 4 files changed, 70 insertions(+), 0 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index c15936f..d7c9cd0 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1527,6 +1527,9 @@ struct task_struct { unsigned long memsw_bytes; /* uncharged mem+swap usage */ } memcg_batch; #endif +#ifdef CONFIG_UPROBES + struct uprobe_task *utask; +#endif }; /* Future-safe accessor for struct task_struct's cpus_allowed. */ diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index 1f54aae..d5be840 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -26,12 +26,14 @@ #include #ifdef CONFIG_ARCH_SUPPORTS_UPROBES #include +struct uprobe_task_arch_info; /* arch specific task info */ #else /* * ARCH_SUPPORTS_UPROBES is not defined. */ typedef u8 uprobe_opcode_t; struct uprobe_arch_info {}; /* arch specific info*/ +struct uprobe_task_arch_info {}; /* arch specific task info */ /* Post-execution fixups. Some architectures may define others. */ #endif /* CONFIG_ARCH_SUPPORTS_UPROBES */ @@ -77,6 +79,27 @@ struct uprobe { int copy; }; +enum uprobe_task_state { + UTASK_RUNNING, + UTASK_BP_HIT, + UTASK_SSTEP +}; + +/* + * uprobe_utask -- not a user-visible struct. + * Corresponds to a thread in a probed process. + * Guarded by uproc->mutex. + */ +struct uprobe_task { + unsigned long xol_vaddr; + unsigned long vaddr; + + enum uprobe_task_state state; + struct uprobe_task_arch_info tskinfo; + + struct uprobe *active_uprobe; +}; + /* * Most architectures can use the default versions of @read_opcode(), * @set_bkpt(), @set_orig_insn(), and @is_bkpt_insn(); @@ -100,6 +123,7 @@ extern int register_uprobe(struct inode *inode, loff_t offset, struct uprobe_consumer *consumer); extern void unregister_uprobe(struct inode *inode, loff_t offset, struct uprobe_consumer *consumer); +extern void uprobe_free_utask(struct task_struct *tsk); struct vm_area_struct; extern void uprobe_mmap(struct vm_area_struct *vma); @@ -118,6 +142,7 @@ static inline void uprobe_dup_mmap(struct mm_struct *old_mm, struct mm_struct *mm) { } +static inline void uprobe_free_utask(struct task_struct *tsk) {} static inline void uprobe_mmap(struct vm_area_struct *vma) { } #endif /* CONFIG_UPROBES */ #endif /* _LINUX_UPROBES_H */ diff --git a/kernel/fork.c b/kernel/fork.c index b6d6877..de3d10a 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -191,6 +191,7 @@ void __put_task_struct(struct task_struct *tsk) delayacct_tsk_free(tsk); put_signal_struct(tsk->signal); + uprobe_free_utask(tsk); if (!profile_handoff_task(tsk)) free_task(tsk); } @@ -1214,6 +1215,9 @@ static struct task_struct *copy_process(unsigned long clone_flags, INIT_LIST_HEAD(&p->pi_state_list); p->pi_state_cache = NULL; #endif +#ifdef CONFIG_UPROBES + p->utask = NULL; +#endif /* * sigaltstack should be cleared when sharing the same VM */ diff --git a/kernel/uprobes.c b/kernel/uprobes.c index 8ed5b77..f3540ff 100644 --- a/kernel/uprobes.c +++ b/kernel/uprobes.c @@ -806,3 +806,41 @@ mmap_out: up_read(&mm->mmap_sem); down_write(&mm->mmap_sem); } + +/* + * Called with no locks held. + * Called in context of a exiting or a exec-ing thread. + */ +void uprobe_free_utask(struct task_struct *tsk) +{ + struct uprobe_task *utask = tsk->utask; + + if (!utask) + return; + + if (utask->active_uprobe) + put_uprobe(utask->active_uprobe); + kfree(utask); + tsk->utask = NULL; +} + +/* + * Allocate a uprobe_task object for the task. + * Called when the thread hits a breakpoint for the first time. + * + * Returns: + * - pointer to new uprobe_task on success + * - negative errno otherwise + */ +static struct uprobe_task *add_utask(void) +{ + struct uprobe_task *utask; + + utask = kzalloc(sizeof *utask, GFP_KERNEL); + if (unlikely(utask == NULL)) + return ERR_PTR(-ENOMEM); + + utask->active_uprobe = NULL; + current->utask = utask; + return utask; +} -- 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/