Bug 188591
| Summary: | Function ioat_dma_self_test() does not set error code when the call to dma_mapping_error() fails | ||
|---|---|---|---|
| Product: | Drivers | Reporter: | bianpan (bianpan2010) |
| Component: | Infiniband/RDMA | Assignee: | drivers_infiniband-rdma |
| Status: | RESOLVED CODE_FIX | ||
| Severity: | normal | ||
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | linux-4.9-rc6 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: | The patch fixes the bug | ||
Created attachment 256377 [details]
The patch fixes the bug
The patch has been merged into the lastest version. So I will close the bug.
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Function dma_mapping_error() returns a NULL pointer on failure. In function ioat_dma_self_test() defined in file drivers/dma/ioat/init.c, variable err takes the error code. However, the value of err is 0 (indicates success) even when the calls to dma_mapping_error() fail at line 341 or 346. Though this error may occur rarely, it is better to assgin "-ENOMEM" to err before the jump instructions at lines 343 and 348. Codes related to these two bugs are summarised as follows. ioat_dma_self_test @@ drivers/dma/ioat/init.c 302 static int ioat_dma_self_test(struct ioatdma_device *ioat_dma) 303 { ... 313 int err = 0; ... 332 dma_chan = container_of(dma->channels.next, struct dma_chan, 333 device_node); 334 if (dma->device_alloc_chan_resources(dma_chan) < 1) { 335 dev_err(dev, "selftest cannot allocate chan resource\n"); 336 err = -ENODEV; 337 goto out; 338 } 339 340 dma_src = dma_map_single(dev, src, IOAT_TEST_SIZE, DMA_TO_DEVICE); 341 if (dma_mapping_error(dev, dma_src)) { 342 dev_err(dev, "mapping src buffer failed\n"); 343 goto free_resources; // insert "err = -ENOMEM" before this jump instruction? 344 } 345 dma_dest = dma_map_single(dev, dest, IOAT_TEST_SIZE, DMA_FROM_DEVICE); 346 if (dma_mapping_error(dev, dma_dest)) { 347 dev_err(dev, "mapping dest buffer failed\n"); 348 goto unmap_src; // insert "err = -ENOMEM" before this jump instruction? 349 } ... 387 unmap_dma: 388 dma_unmap_single(dev, dma_dest, IOAT_TEST_SIZE, DMA_FROM_DEVICE); 389 unmap_src: 390 dma_unmap_single(dev, dma_src, IOAT_TEST_SIZE, DMA_TO_DEVICE); 391 free_resources: 392 dma->device_free_chan_resources(dma_chan); 393 out: 394 kfree(src); 395 kfree(dest); 396 return err; 397 } Thanks very much!