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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