Hi Douglas, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on scsi/for-next] [also build test WARNING on linus/master v5.5-rc6] [cannot apply to mkp-scsi/for-next next-20200110] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Douglas-Gilbert/sg-add-v4-interface/20200113-080059 base: https://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git for-next If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp@xxxxxxxxx> New smatch warnings: drivers/scsi/sg.c:504 sg_open() error: potential null dereference 'sfp'. (sg_add_sfp returns null) Old smatch warnings: drivers/scsi/sg.c:3238 sg_find_srp_by_id() warn: statement has no effect 3 vim +/sfp +504 drivers/scsi/sg.c 433 434 /* 435 * Corresponds to the open() system call on sg devices. Implements O_EXCL on 436 * a per device basis using 'open_cnt'. If O_EXCL and O_NONBLOCK and there is 437 * already a sg handle open on this device then it fails with an errno of 438 * EBUSY. Without the O_NONBLOCK flag then this thread enters an interruptible 439 * wait until the other handle(s) are closed. 440 */ 441 static int 442 sg_open(struct inode *inode, struct file *filp) 443 { 444 bool o_excl, non_block; 445 int min_dev = iminor(inode); 446 int op_flags = filp->f_flags; 447 int res; 448 __maybe_unused int o_count; 449 struct sg_device *sdp; 450 struct sg_fd *sfp; 451 452 nonseekable_open(inode, filp); 453 o_excl = !!(op_flags & O_EXCL); 454 non_block = !!(op_flags & O_NONBLOCK); 455 if (o_excl && ((op_flags & O_ACCMODE) == O_RDONLY)) 456 return -EPERM;/* not permitted, need write access for O_EXCL */ 457 sdp = sg_get_dev(min_dev); /* increments sdp->d_ref */ 458 if (IS_ERR(sdp)) 459 return PTR_ERR(sdp); 460 461 /* Prevent the device driver from vanishing while we sleep */ 462 res = scsi_device_get(sdp->device); 463 if (res) 464 goto sg_put; 465 res = scsi_autopm_get_device(sdp->device); 466 if (res) 467 goto sdp_put; 468 res = sg_allow_if_err_recovery(sdp, non_block); 469 if (res) 470 goto error_out; 471 472 mutex_lock(&sdp->open_rel_lock); 473 if (op_flags & O_NONBLOCK) { 474 if (o_excl) { 475 if (atomic_read(&sdp->open_cnt) > 0) { 476 res = -EBUSY; 477 goto error_mutex_locked; 478 } 479 } else { 480 if (SG_HAVE_EXCLUDE(sdp)) { 481 res = -EBUSY; 482 goto error_mutex_locked; 483 } 484 } 485 } else { 486 res = sg_wait_open_event(sdp, o_excl); 487 if (res) /* -ERESTARTSYS or -ENODEV */ 488 goto error_mutex_locked; 489 } 490 491 /* N.B. at this point we are holding the open_rel_lock */ 492 if (o_excl) 493 set_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm); 494 495 o_count = atomic_inc_return(&sdp->open_cnt); 496 sfp = sg_add_sfp(sdp); /* increments sdp->d_ref */ 497 if (IS_ERR(sfp)) { 498 atomic_dec(&sdp->open_cnt); 499 res = PTR_ERR(sfp); 500 goto out_undo; 501 } 502 503 filp->private_data = sfp; > 504 sfp->tid = (current ? current->pid : -1); 505 mutex_unlock(&sdp->open_rel_lock); 506 SG_LOG(3, sfp, "%s: minor=%d, op_flags=0x%x; %s count after=%d%s\n", 507 __func__, min_dev, op_flags, "device open", o_count, 508 ((op_flags & O_NONBLOCK) ? " O_NONBLOCK" : "")); 509 510 res = 0; 511 sg_put: 512 kref_put(&sdp->d_ref, sg_device_destroy); 513 /* if success, sdp->d_ref is incremented twice, decremented once */ 514 return res; 515 516 out_undo: 517 if (o_excl) { /* undo if error */ 518 clear_bit(SG_FDEV_EXCLUDE, sdp->fdev_bm); 519 wake_up_interruptible(&sdp->open_wait); 520 } 521 error_mutex_locked: 522 mutex_unlock(&sdp->open_rel_lock); 523 error_out: 524 scsi_autopm_put_device(sdp->device); 525 sdp_put: 526 scsi_device_put(sdp->device); 527 goto sg_put; 528 } 529 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx Intel Corporation
