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* [bug report] tracing: Rewrite filter logic to be simpler and faster
@ 2018-03-27  7:30 Dan Carpenter
  2018-03-27 13:59 ` Steven Rostedt
  2018-03-27 14:25 ` Dan Carpenter
  0 siblings, 2 replies; 3+ messages in thread
From: Dan Carpenter @ 2018-03-27  7:30 UTC (permalink / raw)
  To: kernel-janitors

Hello Steven Rostedt (VMware),

The patch 80765597bc58: "tracing: Rewrite filter logic to be simpler
and faster" from Mar 9, 2018, leads to the following static checker
warning:

    kernel/trace/trace_events_filter.c:1794 apply_event_filter()
    error: uninitialized symbol 'filter'.

    kernel/trace/trace_events_filter.c:2052 ftrace_profile_set_filter()
    error: uninitialized symbol 'filter'.

kernel/trace/trace_events_filter.c
  1686  /**
  1687   * create_filter - create a filter for a trace_event_call
  1688   * @call: trace_event_call to create a filter for
  1689   * @filter_str: filter string
  1690   * @set_str: remember @filter_str and enable detailed error in filter
  1691   * @filterp: out param for created filter (always updated on return)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
filterp is supposed to get updated.

  1692   *
  1693   * Creates a filter for @call with @filter_str.  If @set_str is %true,
  1694   * @filter_str is copied and recorded in the new filter.
  1695   *
  1696   * On success, returns 0 and *@filterp points to the new filter.  On
  1697   * failure, returns -errno and *@filterp may point to %NULL or to a new
  1698   * filter.  In the latter case, the returned filter contains error
  1699   * information if @set_str is %true and the caller is responsible for
  1700   * freeing it.
  1701   */
  1702  static int create_filter(struct trace_event_call *call,
  1703                           char *filter_string, bool set_str,
  1704                           struct event_filter **filterp)
  1705  {
  1706          struct filter_parse_error *pe = NULL;
  1707          struct event_filter *filter = NULL;
  1708          int err;
  1709  
  1710          err = create_filter_start(filter_string, set_str, &pe, &filter);
  1711          if (err)
  1712                  return err;
                        ^^^^^^^^^^^
But it's not on this new error path.

  1713  
  1714          err = process_preds(call, filter_string, filter, pe);
  1715          if (err && set_str)
  1716                  append_filter_err(pe, filter);
  1717  
  1718          *filterp = filter;
  1719          return err;
  1720  }


regards,
dan carpenter

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [bug report] tracing: Rewrite filter logic to be simpler and faster
  2018-03-27  7:30 [bug report] tracing: Rewrite filter logic to be simpler and faster Dan Carpenter
@ 2018-03-27 13:59 ` Steven Rostedt
  2018-03-27 14:25 ` Dan Carpenter
  1 sibling, 0 replies; 3+ messages in thread
From: Steven Rostedt @ 2018-03-27 13:59 UTC (permalink / raw)
  To: kernel-janitors

On Tue, 27 Mar 2018 10:30:36 +0300
Dan Carpenter <dan.carpenter@oracle.com> wrote:

> Hello Steven Rostedt (VMware),
> 
> The patch 80765597bc58: "tracing: Rewrite filter logic to be simpler
> and faster" from Mar 9, 2018, leads to the following static checker
> warning:
> 
>     kernel/trace/trace_events_filter.c:1794 apply_event_filter()
>     error: uninitialized symbol 'filter'.
> 
>     kernel/trace/trace_events_filter.c:2052 ftrace_profile_set_filter()
>     error: uninitialized symbol 'filter'.
> 
> kernel/trace/trace_events_filter.c
>   1686  /**
>   1687   * create_filter - create a filter for a trace_event_call
>   1688   * @call: trace_event_call to create a filter for
>   1689   * @filter_str: filter string
>   1690   * @set_str: remember @filter_str and enable detailed error in filter
>   1691   * @filterp: out param for created filter (always updated on return)
>             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> filterp is supposed to get updated.

Wow, your static analyzer reads comments?

> 
>   1692   *
>   1693   * Creates a filter for @call with @filter_str.  If @set_str is %true,
>   1694   * @filter_str is copied and recorded in the new filter.
>   1695   *
>   1696   * On success, returns 0 and *@filterp points to the new filter.  On
>   1697   * failure, returns -errno and *@filterp may point to %NULL or to a new
>   1698   * filter.  In the latter case, the returned filter contains error
>   1699   * information if @set_str is %true and the caller is responsible for
>   1700   * freeing it.
>   1701   */
>   1702  static int create_filter(struct trace_event_call *call,
>   1703                           char *filter_string, bool set_str,
>   1704                           struct event_filter **filterp)
>   1705  {
>   1706          struct filter_parse_error *pe = NULL;
>   1707          struct event_filter *filter = NULL;
>   1708          int err;
>   1709  
>   1710          err = create_filter_start(filter_string, set_str, &pe, &filter);
>   1711          if (err)
>   1712                  return err;
>                         ^^^^^^^^^^^
> But it's not on this new error path.

Yep, I should investigate this.

Thanks,

-- Steve

> 
>   1713  
>   1714          err = process_preds(call, filter_string, filter, pe);
>   1715          if (err && set_str)
>   1716                  append_filter_err(pe, filter);
>   1717  
>   1718          *filterp = filter;
>   1719          return err;
>   1720  }
> 
> 
> regards,
> dan carpenter


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [bug report] tracing: Rewrite filter logic to be simpler and faster
  2018-03-27  7:30 [bug report] tracing: Rewrite filter logic to be simpler and faster Dan Carpenter
  2018-03-27 13:59 ` Steven Rostedt
@ 2018-03-27 14:25 ` Dan Carpenter
  1 sibling, 0 replies; 3+ messages in thread
From: Dan Carpenter @ 2018-03-27 14:25 UTC (permalink / raw)
  To: kernel-janitors

On Tue, Mar 27, 2018 at 09:59:16AM -0400, Steven Rostedt wrote:
> On Tue, 27 Mar 2018 10:30:36 +0300
> Dan Carpenter <dan.carpenter@oracle.com> wrote:
> 
> > Hello Steven Rostedt (VMware),
> > 
> > The patch 80765597bc58: "tracing: Rewrite filter logic to be simpler
> > and faster" from Mar 9, 2018, leads to the following static checker
> > warning:
> > 
> >     kernel/trace/trace_events_filter.c:1794 apply_event_filter()
> >     error: uninitialized symbol 'filter'.
> > 
> >     kernel/trace/trace_events_filter.c:2052 ftrace_profile_set_filter()
> >     error: uninitialized symbol 'filter'.
> > 
> > kernel/trace/trace_events_filter.c
> >   1686  /**
> >   1687   * create_filter - create a filter for a trace_event_call
> >   1688   * @call: trace_event_call to create a filter for
> >   1689   * @filter_str: filter string
> >   1690   * @set_str: remember @filter_str and enable detailed error in filter
> >   1691   * @filterp: out param for created filter (always updated on return)
> >             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > filterp is supposed to get updated.
> 
> Wow, your static analyzer reads comments?
>

At first I complained to Tejun by mistake and he was like, "read the
comments"...

regards,
dan carpenter


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2018-03-27 14:25 UTC | newest]

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2018-03-27  7:30 [bug report] tracing: Rewrite filter logic to be simpler and faster Dan Carpenter
2018-03-27 13:59 ` Steven Rostedt
2018-03-27 14:25 ` Dan Carpenter

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