The following commit has been merged into the perf/core branch of tip: Commit-ID: bb18c5de1c288050ef8bd4af4ca16896ad4cd3fc Gitweb: https://git.kernel.org/tip/bb18c5de1c288050ef8bd4af4ca16896ad4cd3fc Author: Oleg Nesterov <oleg@xxxxxxxxxx> AuthorDate: Thu, 01 Aug 2024 15:27:39 +02:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Fri, 02 Aug 2024 11:30:32 +02:00 uprobes: change uprobe_register() to use uprobe_unregister() instead of __uprobe_unregister() If register_for_each_vma() fails uprobe_register() can safely drop uprobe->register_rwsem and use uprobe_unregister(). There is no worry about the races with another register/unregister, consumer_add() was already called so this case doesn't differ from _unregister() right after the successful _register(). Yes this means the extra up_write() + down_write(), but this is the slow and unlikely case anyway. Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Reviewed-by: Jiri Olsa <jolsa@xxxxxxxxxx> Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx> Acked-by: "Masami Hiramatsu (Google)" <mhiramat@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240801132739.GA8809@xxxxxxxxxx --- kernel/events/uprobes.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index b33f139..eacf287 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1174,16 +1174,18 @@ struct uprobe *uprobe_register(struct inode *inode, if (likely(uprobe_is_active(uprobe))) { consumer_add(uprobe, uc); ret = register_for_each_vma(uprobe, uc); - if (ret) - __uprobe_unregister(uprobe, uc); } up_write(&uprobe->register_rwsem); put_uprobe(uprobe); - if (unlikely(ret == -EAGAIN)) - goto retry; + if (ret) { + if (unlikely(ret == -EAGAIN)) + goto retry; + uprobe_unregister(uprobe, uc); + return ERR_PTR(ret); + } - return ret ? ERR_PTR(ret) : uprobe; + return uprobe; } EXPORT_SYMBOL_GPL(uprobe_register);