diff options
| -rw-r--r-- | include/linux/uprobes.h | 2 | ||||
| -rw-r--r-- | kernel/events/uprobes.c | 38 |
2 files changed, 3 insertions, 37 deletions
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index efe4b3308c74..03ae547c1c31 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -99,8 +99,8 @@ struct xol_area { struct uprobes_state { struct xol_area *xol_area; - atomic_t count; }; + extern int __weak set_swbp(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr); extern int __weak set_orig_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr, bool verify); extern bool __weak is_swbp_insn(uprobe_opcode_t *insn); diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 0cefde276641..6f1664d217dc 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -678,18 +678,7 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, uprobe->flags |= UPROBE_COPY_INSN; } - /* - * Ideally, should be updating the probe count after the breakpoint - * has been successfully inserted. However a thread could hit the - * breakpoint we just inserted even before the probe count is - * incremented. If this is the first breakpoint placed, breakpoint - * notifier might ignore uprobes and pass the trap to the thread. - * Hence increment before and decrement on failure. - */ - atomic_inc(&mm->uprobes_state.count); ret = set_swbp(&uprobe->arch, mm, vaddr); - if (ret) - atomic_dec(&mm->uprobes_state.count); return ret; } @@ -697,8 +686,7 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, static void remove_breakpoint(struct uprobe *uprobe, struct mm_struct *mm, unsigned long vaddr) { - if (!set_orig_insn(&uprobe->arch, mm, vaddr, true)) - atomic_dec(&mm->uprobes_state.count); + set_orig_insn(&uprobe->arch, mm, vaddr, true); } /* @@ -1051,13 +1039,6 @@ int uprobe_mmap(struct vm_area_struct *vma) if (!is_swbp_at_addr(vma->vm_mm, vaddr)) continue; - - /* - * Unable to insert a breakpoint, but - * breakpoint lies underneath. Increment the - * probe count. - */ - atomic_inc(&vma->vm_mm->uprobes_state.count); } if (!ret) @@ -1068,9 +1049,6 @@ int uprobe_mmap(struct vm_area_struct *vma) mutex_unlock(uprobes_mmap_hash(inode)); - if (ret) - atomic_sub(count, &vma->vm_mm->uprobes_state.count); - return ret; } @@ -1089,9 +1067,6 @@ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned lon if (!atomic_read(&vma->vm_mm->mm_users)) /* called by mmput() ? */ return; - if (!atomic_read(&vma->vm_mm->uprobes_state.count)) - return; - inode = vma->vm_file->f_mapping->host; if (!inode) return; @@ -1100,13 +1075,6 @@ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned lon build_probe_list(inode, vma, start, end, &tmp_list); list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) { - unsigned long vaddr = offset_to_vaddr(vma, uprobe->offset); - /* - * An unregister could have removed the probe before - * unmap. So check before we decrement the count. - */ - if (is_swbp_at_addr(vma->vm_mm, vaddr) == 1) - atomic_dec(&vma->vm_mm->uprobes_state.count); put_uprobe(uprobe); } mutex_unlock(uprobes_mmap_hash(inode)); @@ -1217,7 +1185,6 @@ void uprobe_clear_state(struct mm_struct *mm) void uprobe_reset_state(struct mm_struct *mm) { mm->uprobes_state.xol_area = NULL; - atomic_set(&mm->uprobes_state.count, 0); } /* @@ -1585,8 +1552,7 @@ int uprobe_pre_sstep_notifier(struct pt_regs *regs) { struct uprobe_task *utask; - if (!current->mm || !atomic_read(¤t->mm->uprobes_state.count)) - /* task is currently not uprobed */ + if (!current->mm) return 0; utask = current->utask; |