Messages in this thread | | | Date | Mon, 30 Jun 2014 20:49:22 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH 4/4] tracing/uprobes: Fix the usage of uprobe_buffer_enable() in probe_event_enable() |
| |
(2014/06/28 2:01), Oleg Nesterov wrote: > The usage of uprobe_buffer_enable() added by dcad1a20 is very wrong, > > 1. uprobe_buffer_enable() and uprobe_buffer_disable() are not balanced, > _enable() should be called only if !enabled. > > 2. If uprobe_buffer_enable() fails probe_event_enable() should clear > tp.flags and free event_file_link. > > 3. If uprobe_register() fails it should do uprobe_buffer_disable().
Looks good to me ;)
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Thanks,
> > Signed-off-by: Oleg Nesterov <oleg@redhat.com> > --- > kernel/trace/trace_uprobe.c | 31 +++++++++++++++++++------------ > 1 files changed, 19 insertions(+), 12 deletions(-) > > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c > index c4cf0ab..3c9b97e 100644 > --- a/kernel/trace/trace_uprobe.c > +++ b/kernel/trace/trace_uprobe.c > @@ -911,26 +911,33 @@ probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file, > tu->tp.flags |= TP_FLAG_PROFILE; > } > > - ret = uprobe_buffer_enable(); > - if (ret < 0) > - return ret; > - > WARN_ON(!uprobe_filter_is_empty(&tu->filter)); > > if (enabled) > return 0; > > + ret = uprobe_buffer_enable(); > + if (ret) > + goto err_flags; > + > tu->consumer.filter = filter; > ret = uprobe_register(tu->inode, tu->offset, &tu->consumer); > - if (ret) { > - if (file) { > - list_del(&link->list); > - kfree(link); > - tu->tp.flags &= ~TP_FLAG_TRACE; > - } else > - tu->tp.flags &= ~TP_FLAG_PROFILE; > - } > + if (ret) > + goto err_buffer; > > + return 0; > + > + err_buffer: > + uprobe_buffer_disable(); > + > + err_flags: > + if (file) { > + list_del(&link->list); > + kfree(link); > + tu->tp.flags &= ~TP_FLAG_TRACE; > + } else { > + tu->tp.flags &= ~TP_FLAG_PROFILE; > + } > return ret; > } > >
-- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com
| |