Messages in this thread | | | From | Oded Gabbay <> | Date | Mon, 11 Oct 2021 16:59:09 +0300 | Subject | Re: [kbuild] [ogabbay:habanalabs-next 17/19] drivers/misc/habanalabs/common/command_submission.c:2421 hl_cs_poll_fences() error: we previously assumed 'fence' could be null (see line 2402) |
| |
On Mon, Oct 11, 2021 at 2:48 PM Dan Carpenter <dan.carpenter@oracle.com> wrote: > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/ogabbay/linux.git habanalabs-next > head: 41548e6097f0e2673e99c18aa74c9bbba341c9ba > commit: 2819e6243c5cdf6619cdaddaf117076a043d7bb2 [17/19] habanalabs: fix NULL pointer dereference > config: x86_64-randconfig-m001-20211011 (attached as .config) > compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp@intel.com> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com> > > smatch warnings: > drivers/misc/habanalabs/common/command_submission.c:2421 hl_cs_poll_fences() error: we previously assumed 'fence' could be null (see line 2402) > > vim +/fence +2421 drivers/misc/habanalabs/common/command_submission.c > > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2346 static int hl_cs_poll_fences(struct multi_cs_data *mcs_data) > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2347 { > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2348 struct hl_fence **fence_ptr = mcs_data->fence_arr; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2349 struct hl_device *hdev = mcs_data->ctx->hdev; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2350 int i, rc, arr_len = mcs_data->arr_len; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2351 u64 *seq_arr = mcs_data->seq_arr; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2352 ktime_t max_ktime, first_cs_time; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2353 enum hl_cs_wait_status status; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2354 > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2355 memset(fence_ptr, 0, arr_len * sizeof(*fence_ptr)); > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2356 > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2357 /* get all fences under the same lock */ > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2358 rc = hl_ctx_get_fences(mcs_data->ctx, seq_arr, fence_ptr, arr_len); > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2359 if (rc) > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2360 return rc; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2361 > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2362 /* > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2363 * set to maximum time to verify timestamp is valid: if at the end > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2364 * this value is maintained- no timestamp was updated > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2365 */ > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2366 max_ktime = ktime_set(KTIME_SEC_MAX, 0); > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2367 first_cs_time = max_ktime; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2368 > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2369 for (i = 0; i < arr_len; i++, fence_ptr++) { > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2370 struct hl_fence *fence = *fence_ptr; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2371 > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2372 /* > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2373 * function won't sleep as it is called with timeout 0 (i.e. > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2374 * poll the fence) > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2375 */ > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2376 rc = hl_wait_for_fence(mcs_data->ctx, seq_arr[i], fence, > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2377 &status, 0, NULL); > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2378 if (rc) { > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2379 dev_err(hdev->dev, > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2380 "wait_for_fence error :%d for CS seq %llu\n", > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2381 rc, seq_arr[i]); > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2382 break; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2383 } > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2384 > 2819e6243c5cdf drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-06 2385 /* > 2819e6243c5cdf drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-06 2386 * It is possible to get an old sequence numbers from user > 2819e6243c5cdf drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-06 2387 * which related to already completed CSs and their fences > 2819e6243c5cdf drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-06 2388 * already gone. In this case, no need to consider its QID for > 2819e6243c5cdf drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-06 2389 * mcs completion. > 2819e6243c5cdf drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-06 2390 */ > 2819e6243c5cdf drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-06 2391 if (fence) > ^^^^^ > 2819e6243c5cdf drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-06 2392 mcs_data->stream_master_qid_map |= > 2819e6243c5cdf drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-06 2393 fence->stream_master_qid_map; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2394 > f0d5ad46a0eba1 drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-03 2395 /* > f0d5ad46a0eba1 drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-03 2396 * Using mcs_handling_done to avoid possibility of mcs_data > f0d5ad46a0eba1 drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-03 2397 * returns to user indicating CS completed before it finished > f0d5ad46a0eba1 drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-03 2398 * all of its mcs handling, to avoid race the next time the > f0d5ad46a0eba1 drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-03 2399 * user waits for mcs. > f0d5ad46a0eba1 drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-03 2400 */ > 2819e6243c5cdf drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-06 2401 if (status == CS_WAIT_STATUS_BUSY || > 2819e6243c5cdf drivers/misc/habanalabs/common/command_submission.c Dani Liberman 2021-10-06 @2402 (fence && !fence->mcs_handling_done)) > ^^^^^ > Checks for NULL > > > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2403 continue; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2404 > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2405 mcs_data->completion_bitmap |= BIT(i); > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2406 > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2407 /* > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2408 * best effort to extract timestamp. few notes: > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2409 * - if even single fence is gone we cannot extract timestamp > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2410 * (as fence not exist anymore) > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2411 * - for all completed CSs we take the earliest timestamp. > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2412 * for this we have to validate that: > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2413 * 1. given timestamp was indeed set > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2414 * 2. the timestamp is earliest of all timestamps so far > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2415 */ > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2416 > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2417 if (status == CS_WAIT_STATUS_GONE) { > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2418 mcs_data->update_ts = false; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2419 mcs_data->gone_cs = true; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2420 } else if (mcs_data->update_ts && > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 @2421 (ktime_compare(fence->timestamp, > ^^^^^^^ > Unchecked dereferences. Hi Dan, Thanks for the report. I believe this is a false positive, because if the fence is NULL, then status *must* be CS_WAIT_STATUS_GONE. I agree the code is not well written here and you can only understand the above if you go and look in the code of hl_wait_for_fence(). Therefore, we will refactor the code here to make it more readable and depend only on the status field instead of checking if the fence pointer is NULL.
Oded
> > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2422 ktime_set(0, 0)) > 0) && > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2423 (ktime_compare(fence->timestamp, first_cs_time) < 0)) { > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2424 first_cs_time = fence->timestamp; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2425 } > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2426 } > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2427 > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2428 hl_fences_put(mcs_data->fence_arr, arr_len); > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2429 > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2430 if (mcs_data->update_ts && > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2431 (ktime_compare(first_cs_time, max_ktime) != 0)) > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2432 mcs_data->timestamp = ktime_to_ns(first_cs_time); > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2433 > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2434 return rc; > 215f0c1775d550 drivers/misc/habanalabs/common/command_submission.c Ohad Sharabi 2021-06-14 2435 } > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org > > _______________________________________________ > kbuild mailing list -- kbuild@lists.01.org > To unsubscribe send an email to kbuild-leave@lists.01.org >
| |