diff options
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/uprobes.c | 19 |
1 files changed, 7 insertions, 12 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 40ced98..5d38b40 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -41,6 +41,11 @@ #define MAX_UPROBE_XOL_SLOTS UINSNS_PER_PAGE static struct rb_root uprobes_tree = RB_ROOT; +/* + * allows us to skip the uprobe_mmap if there are no uprobe events active + * at this time. Probably a fine grained per inode count is better? + */ +#define no_uprobe_events() RB_EMPTY_ROOT(&uprobes_tree) static DEFINE_SPINLOCK(uprobes_treelock); /* serialize rbtree access */ @@ -74,13 +79,6 @@ static struct mutex uprobes_mmap_mutex[UPROBES_HASH_SZ]; static struct percpu_rw_semaphore dup_mmap_sem; -/* - * uprobe_events allows us to skip the uprobe_mmap if there are no uprobe - * events active at this time. Probably a fine grained per inode count is - * better? - */ -static atomic_t uprobe_events = ATOMIC_INIT(0); - /* Have a copy of original instruction */ #define UPROBE_COPY_INSN 0 /* Can skip singlestep */ @@ -460,8 +458,6 @@ static struct uprobe *alloc_uprobe(struct inode *inode, loff_t offset) kfree(uprobe); uprobe = cur_uprobe; iput(inode); - } else { - atomic_inc(&uprobe_events); } return uprobe; @@ -685,7 +681,6 @@ static void delete_uprobe(struct uprobe *uprobe) spin_unlock(&uprobes_treelock); iput(uprobe->inode); put_uprobe(uprobe); - atomic_dec(&uprobe_events); } struct map_info { @@ -975,7 +970,7 @@ int uprobe_mmap(struct vm_area_struct *vma) struct uprobe *uprobe, *u; struct inode *inode; - if (!atomic_read(&uprobe_events) || !valid_vma(vma, true)) + if (no_uprobe_events() || !valid_vma(vma, true)) return 0; inode = vma->vm_file->f_mapping->host; @@ -1021,7 +1016,7 @@ vma_has_uprobes(struct vm_area_struct *vma, unsigned long start, unsigned long e */ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end) { - if (!atomic_read(&uprobe_events) || !valid_vma(vma, false)) + if (no_uprobe_events() || !valid_vma(vma, false)) return; if (!atomic_read(&vma->vm_mm->mm_users)) /* called by mmput() ? */ |