From 1b08e907211cdc744f54871736005d9f3e7f182c Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 14 Sep 2012 18:52:10 +0200 Subject: uprobes: Kill UTASK_BP_HIT state Kill UTASK_BP_HIT state, it buys nothing but complicates the code. It is only used in uprobe_notify_resume() to decide who should be called, we can check utask->active_uprobe != NULL instead. And this allows us to simplify handle_swbp(), no need to clear utask->state. Likewise we could kill UTASK_SSTEP, but UTASK_BP_HIT is worse and imho should die. The problem is, it creates the special case when task->utask is NULL, we can't distinguish RUNNING and BP_HIT. With this patch utask == NULL always means RUNNING. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju --- include/linux/uprobes.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index e6f0331e3d45..18d839da6517 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -59,7 +59,6 @@ struct uprobe_consumer { #ifdef CONFIG_UPROBES enum uprobe_task_state { UTASK_RUNNING, - UTASK_BP_HIT, UTASK_SSTEP, UTASK_SSTEP_ACK, UTASK_SSTEP_TRAPPED, -- cgit v1.2.3 From cb9a19fe4aa51afa34786bd383e6614fa0083d58 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Sun, 30 Sep 2012 20:11:45 +0200 Subject: uprobes: Introduce prepare_uprobe() Preparation. Extract the copy_insn/arch_uprobe_analyze_insn code from install_breakpoint() into the new helper, prepare_uprobe(). And move uprobe->flags defines from uprobes.h to uprobes.c, nobody else can use them anyway. Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju --- include/linux/uprobes.h | 10 --------- kernel/events/uprobes.c | 60 +++++++++++++++++++++++++++++++++---------------- 2 files changed, 41 insertions(+), 29 deletions(-) (limited to 'include/linux') diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index 18d839da6517..24594571c5a3 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -35,16 +35,6 @@ struct inode; # include #endif -/* flags that denote/change uprobes behaviour */ - -/* Have a copy of original instruction */ -#define UPROBE_COPY_INSN 0x1 - -/* Dont run handlers when first register/ last unregister in progress*/ -#define UPROBE_RUN_HANDLER 0x2 -/* Can skip singlestep */ -#define UPROBE_SKIP_SSTEP 0x4 - struct uprobe_consumer { int (*handler)(struct uprobe_consumer *self, struct pt_regs *regs); /* diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index c718fef28617..4f315fa94c52 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -78,6 +78,13 @@ static struct mutex uprobes_mmap_mutex[UPROBES_HASH_SZ]; */ static atomic_t uprobe_events = ATOMIC_INIT(0); +/* Have a copy of original instruction */ +#define UPROBE_COPY_INSN 0x1 +/* Dont run handlers when first register/ last unregister in progress*/ +#define UPROBE_RUN_HANDLER 0x2 +/* Can skip singlestep */ +#define UPROBE_SKIP_SSTEP 0x4 + struct uprobe { struct rb_node rb_node; /* node in the rb tree */ atomic_t ref; @@ -563,6 +570,37 @@ static int copy_insn(struct uprobe *uprobe, struct file *filp) return __copy_insn(mapping, filp, uprobe->arch.insn, bytes, uprobe->offset); } +static int prepare_uprobe(struct uprobe *uprobe, struct file *file, + struct mm_struct *mm, unsigned long vaddr) +{ + int ret = 0; + + if (uprobe->flags & UPROBE_COPY_INSN) + return ret; + + ret = copy_insn(uprobe, file); + if (ret) + goto out; + + ret = -ENOTSUPP; + if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn)) + goto out; + + ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, vaddr); + if (ret) + goto out; + + /* write_opcode() assumes we don't cross page boundary */ + BUG_ON((uprobe->offset & ~PAGE_MASK) + + UPROBE_SWBP_INSN_SIZE > PAGE_SIZE); + + smp_wmb(); /* pairs with rmb() in find_active_uprobe() */ + uprobe->flags |= UPROBE_COPY_INSN; + + out: + return ret; +} + static int install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, struct vm_area_struct *vma, unsigned long vaddr) @@ -580,25 +618,9 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, if (!uprobe->consumers) return 0; - if (!(uprobe->flags & UPROBE_COPY_INSN)) { - ret = copy_insn(uprobe, vma->vm_file); - if (ret) - return ret; - - if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn)) - return -ENOTSUPP; - - ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, vaddr); - if (ret) - return ret; - - /* write_opcode() assumes we don't cross page boundary */ - BUG_ON((uprobe->offset & ~PAGE_MASK) + - UPROBE_SWBP_INSN_SIZE > PAGE_SIZE); - - smp_wmb(); /* pairs with rmb() in find_active_uprobe() */ - uprobe->flags |= UPROBE_COPY_INSN; - } + ret = prepare_uprobe(uprobe, vma->vm_file, mm, vaddr); + if (ret) + return ret; /* * set MMF_HAS_UPROBES in advance for uprobe_pre_sstep_notifier(), -- cgit v1.2.3