diff options
Diffstat (limited to 'kernel/events/uprobes.c')
| -rw-r--r-- | kernel/events/uprobes.c | 44 |
1 files changed, 21 insertions, 23 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index c3b65d1c844..33912086d54 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -579,6 +579,11 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file, return ret; } +static inline bool consumer_filter(struct uprobe_consumer *uc) +{ + return true; /* TODO: !uc->filter || uc->filter(...) */ +} + static bool filter_chain(struct uprobe *uprobe) { struct uprobe_consumer *uc; @@ -586,8 +591,7 @@ static bool filter_chain(struct uprobe *uprobe) down_read(&uprobe->consumer_rwsem); for (uc = uprobe->consumers; uc; uc = uc->next) { - /* TODO: ret = uc->filter(...) */ - ret = true; + ret = consumer_filter(uc); if (ret) break; } @@ -603,15 +607,6 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, bool first_uprobe; int ret; - /* - * If probe is being deleted, unregister thread could be done with - * the vma-rmap-walk through. Adding a probe now can be fatal since - * nobody will be able to cleanup. But in this case filter_chain() - * must return false, all consumers have gone away. - */ - if (!filter_chain(uprobe)) - return 0; - ret = prepare_uprobe(uprobe, vma->vm_file, mm, vaddr); if (ret) return ret; @@ -636,12 +631,6 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, static int remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr) { - if (!test_bit(MMF_HAS_UPROBES, &mm->flags)) - return 0; - - if (filter_chain(uprobe)) - return 0; - set_bit(MMF_RECALC_UPROBES, &mm->flags); return set_orig_insn(&uprobe->arch, mm, vaddr); } @@ -781,10 +770,14 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register) vaddr_to_offset(vma, info->vaddr) != uprobe->offset) goto unlock; - if (is_register) - err = install_breakpoint(uprobe, mm, vma, info->vaddr); - else - err |= remove_breakpoint(uprobe, mm, info->vaddr); + if (is_register) { + /* consult only the "caller", new consumer. */ + if (consumer_filter(uprobe->consumers)) + err = install_breakpoint(uprobe, mm, vma, info->vaddr); + } else if (test_bit(MMF_HAS_UPROBES, &mm->flags)) { + if (!filter_chain(uprobe)) + err |= remove_breakpoint(uprobe, mm, info->vaddr); + } unlock: up_write(&mm->mmap_sem); @@ -968,9 +961,14 @@ int uprobe_mmap(struct vm_area_struct *vma) mutex_lock(uprobes_mmap_hash(inode)); build_probe_list(inode, vma, vma->vm_start, vma->vm_end, &tmp_list); - + /* + * We can race with uprobe_unregister(), this uprobe can be already + * removed. But in this case filter_chain() must return false, all + * consumers have gone away. + */ list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) { - if (!fatal_signal_pending(current)) { + if (!fatal_signal_pending(current) && + filter_chain(uprobe)) { unsigned long vaddr = offset_to_vaddr(vma, uprobe->offset); install_breakpoint(uprobe, vma->vm_mm, vma, vaddr); } |