On Mon, 2017-10-02 at 13:00 +0200, Arnd Bergmann wrote:
> On Mon, Oct 2, 2017 at 12:13 PM, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
> > 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.
>
> I see. Should we maybe open-code the ib_uverbs_init_udata_buf_or_null()
> call in this function?
>
> diff --git a/drivers/infiniband/core/uverbs_std_types.c
> b/drivers/infiniband/core/uverbs_std_types.c
> index b095bce7f238..039802ae7332 100644
> --- a/drivers/infiniband/core/uverbs_std_types.c
> +++ b/drivers/infiniband/core/uverbs_std_types.c
> @@ -227,27 +227,26 @@ static void create_udata(struct uverbs_attr_bundle *ctx,
> * to use uverbs_attr_bundle instead of ib_udata.
> * Assume attr == 0 is input and attr == 1 is output.
> */
> - void __user *inbuf;
> - size_t inbuf_len = 0;
> - void __user *outbuf;
> - size_t outbuf_len = 0;
> const struct uverbs_attr *uhw_in =
> uverbs_attr_get(ctx, UVERBS_UHW_IN);
> const struct uverbs_attr *uhw_out =
> uverbs_attr_get(ctx, UVERBS_UHW_OUT);
>
> if (!IS_ERR(uhw_in)) {
> - inbuf = uhw_in->ptr_attr.ptr;
> - inbuf_len = uhw_in->ptr_attr.len;
> + udata->inbuf = uhw_in->ptr_attr.ptr;
> + udata->inbuf_len = uhw_in->ptr_attr.len;
> + } else {
> + udata->inbuf = NULL;
> + udata->inbuf_len = 0;
> }
>
> if (!IS_ERR(uhw_out)) {
> - outbuf = uhw_out->ptr_attr.ptr;
> - outbuf_len = uhw_out->ptr_attr.len;
> + udata->outbuf = uhw_out->ptr_attr.ptr;
> + udata->outbuf_len = uhw_out->ptr_attr.len;
> + } else {
> + udata->outbuf = NULL;
> + udata->outbuf_len = 0;
> }
> -
> - ib_uverbs_init_udata_buf_or_null(udata, inbuf, outbuf, inbuf_len,
> - outbuf_len);
> }
>
> static int uverbs_create_cq_handler(struct ib_device *ib_dev,
>
> Arnd
> --
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Arnd, can you send this as a proper patch with attribution and a Signed-
off-by: please.
--
Doug Ledford <dledford@xxxxxxxxxx>
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