Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754398Ab1FGNGx (ORCPT ); Tue, 7 Jun 2011 09:06:53 -0400 Received: from e23smtp09.au.ibm.com ([202.81.31.142]:37632 "EHLO e23smtp09.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754345Ab1FGNGv (ORCPT ); Tue, 7 Jun 2011 09:06:51 -0400 From: Srikar Dronamraju To: Peter Zijlstra , Ingo Molnar Cc: Steven Rostedt , Srikar Dronamraju , Linux-mm , Arnaldo Carvalho de Melo , Linus Torvalds , Jonathan Corbet , Hugh Dickins , Christoph Hellwig , Masami Hiramatsu , Thomas Gleixner , Andi Kleen , Oleg Nesterov , LKML , Jim Keniston , Roland McGrath , Ananth N Mavinakayanahalli , Andrew Morton Date: Tue, 07 Jun 2011 18:29:56 +0530 Message-Id: <20110607125956.28590.17518.sendpatchset@localhost6.localdomain6> In-Reply-To: <20110607125804.28590.92092.sendpatchset@localhost6.localdomain6> References: <20110607125804.28590.92092.sendpatchset@localhost6.localdomain6> Subject: [PATCH v4 3.0-rc2-tip 9/22] 9: uprobes: task specific information. Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5450 Lines: 188 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 | 9 ++++++--- include/linux/uprobes.h | 25 +++++++++++++++++++++++++ kernel/fork.c | 4 ++++ kernel/uprobes.c | 38 ++++++++++++++++++++++++++++++++++++++ 4 files changed, 73 insertions(+), 3 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index a837b20..9af9c99 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1304,9 +1304,9 @@ struct task_struct { unsigned long stack_canary; #endif - /* + /* * pointers to (original) parent process, youngest child, younger sibling, - * older sibling, respectively. (p->father can be replaced with + * older sibling, respectively. (p->father can be replaced with * p->real_parent->pid) */ struct task_struct *real_parent; /* real parent process */ @@ -1561,6 +1561,9 @@ struct task_struct { #ifdef CONFIG_HAVE_HW_BREAKPOINT atomic_t ptrace_bp_refcnt; #endif +#ifdef CONFIG_UPROBES + struct uprobe_task *utask; +#endif }; /* Future-safe accessor for struct task_struct's cpus_allowed. */ @@ -2127,7 +2130,7 @@ static inline int dequeue_signal_lock(struct task_struct *tsk, sigset_t *mask, s spin_unlock_irqrestore(&tsk->sighand->siglock, flags); return ret; -} +} extern void block_all_signals(int (*notifier)(void *priv), void *priv, sigset_t *mask); diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index fc2f9d2..821e000 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 */ #endif /* CONFIG_ARCH_SUPPORTS_UPROBES */ /* Post-execution fixups. Some architectures may define others. */ @@ -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(); @@ -111,6 +134,7 @@ 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 free_uprobe_utask(struct task_struct *tsk); struct vm_area_struct; extern int mmap_uprobe(struct vm_area_struct *vma); @@ -133,5 +157,6 @@ static inline int mmap_uprobe(struct vm_area_struct *vma) { return 0; } +static inline void free_uprobe_utask(struct task_struct *tsk) {} #endif /* CONFIG_UPROBES */ #endif /* _LINUX_UPROBES_H */ diff --git a/kernel/fork.c b/kernel/fork.c index f6c7cb1..bf5999b 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -196,6 +196,7 @@ void __put_task_struct(struct task_struct *tsk) delayacct_tsk_free(tsk); put_signal_struct(tsk->signal); + free_uprobe_utask(tsk); if (!profile_handoff_task(tsk)) free_task(tsk); } @@ -1268,6 +1269,9 @@ 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 93a53c0..2bb2bd7 100644 --- a/kernel/uprobes.c +++ b/kernel/uprobes.c @@ -1022,3 +1022,41 @@ mmap_out: down_write(&mm->mmap_sem); return ret; } + +/* + * Called with no locks held. + * Called in context of a exiting or a exec-ing thread. + */ +void free_uprobe_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/