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* [bug report] IB/uverbs: clean up INIT_UDATA_BUF_OR_NULL usage
@ 2017-10-02 10:13 Dan Carpenter
  2017-10-02 11:00 ` Arnd Bergmann
  0 siblings, 1 reply; 4+ messages in thread
From: Dan Carpenter @ 2017-10-02 10:13 UTC (permalink / raw)
  To: arnd-r2nGTMty4D4; +Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA

Hello Arnd Bergmann,

The patch 12f727721eee: "IB/uverbs: clean up INIT_UDATA_BUF_OR_NULL
usage" from Sep 6, 2017, leads to the following static checker
warning:

	drivers/infiniband/core/uverbs_std_types.c:249 create_udata()
	error: uninitialized symbol 'inbuf'.

drivers/infiniband/core/uverbs_std_types.c
   222  static void create_udata(struct uverbs_attr_bundle *ctx,
   223                           struct ib_udata *udata)
   224  {
   225          /*
   226           * This is for ease of conversion. The purpose is to convert all drivers
   227           * to use uverbs_attr_bundle instead of ib_udata.
   228           * Assume attr == 0 is input and attr == 1 is output.
   229           */
   230          void __user *inbuf;
   231          size_t inbuf_len = 0;
   232          void __user *outbuf;
   233          size_t outbuf_len = 0;
   234          const struct uverbs_attr *uhw_in =
   235                  uverbs_attr_get(ctx, UVERBS_UHW_IN);
   236          const struct uverbs_attr *uhw_out =
   237                  uverbs_attr_get(ctx, UVERBS_UHW_OUT);
   238  
   239          if (!IS_ERR(uhw_in)) {
   240                  inbuf = uhw_in->ptr_attr.ptr;
   241                  inbuf_len = uhw_in->ptr_attr.len;
   242          }
   243  
   244          if (!IS_ERR(uhw_out)) {
   245                  outbuf = uhw_out->ptr_attr.ptr;
   246                  outbuf_len = uhw_out->ptr_attr.len;
   247          }
   248  
   249          ib_uverbs_init_udata_buf_or_null(udata, inbuf, outbuf, inbuf_len,
   250                                           outbuf_len);

In the original code, this was a macro so smatch understood that we
don't use inbuf and outbuf if they aren't initialized.  Now it's a
function and smatch generates a warning if you pass uninitialized
variables to a function.

It's not a bug, but it's really ugly.

   251  }

regards,
dan carpenter
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^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2017-11-10 22:12 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-10-02 10:13 [bug report] IB/uverbs: clean up INIT_UDATA_BUF_OR_NULL usage Dan Carpenter
2017-10-02 11:00 ` Arnd Bergmann
     [not found]   ` <CAK8P3a1t6zyQXtfov6HguOb9V7E4i54pK8+y8BjPqGqvsc9mpQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-11-10 17:58     ` Doug Ledford
     [not found]       ` <1510336682.3735.3.camel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2017-11-10 22:12         ` Arnd Bergmann

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