Hi, Thanks for the report. > -----Original Message----- > From: linux-acpi-owner@xxxxxxxxxxxxxxx [mailto:linux-acpi- > owner@xxxxxxxxxxxxxxx] On Behalf Of Dan Carpenter > Sent: Wednesday, December 23, 2015 3:49 AM > To: Zheng, Lv <lv.zheng@xxxxxxxxx> > Cc: linux-acpi@xxxxxxxxxxxxxxx > Subject: re: ACPI / debugger: Add IO interface to access debugger > functionalities > > Hello Lv Zheng, > > The patch 8cfb0cdf07e2: "ACPI / debugger: Add IO interface to access > debugger functionalities" from Dec 3, 2015, leads to the following > static checker warning: > > drivers/acpi/acpi_dbg.c:533 acpi_aml_open() > error: double unlock 'mutex:&acpi_aml_io.lock' > > drivers/acpi/acpi_dbg.c > 498 } else { > 499 /* > 500 * No writer is allowed unless the debugger thread is > 501 * ready. > 502 */ > 503 if (!(acpi_aml_io.flags & ACPI_AML_OPENED)) { > 504 ret = -ENODEV; > 505 goto err_lock; > > Holding lock. > > 506 } > 507 } > 508 if (acpi_aml_active_reader == file) { > 509 pr_debug("Opening debugger interface.\n"); > 510 mutex_unlock(&acpi_aml_io.lock); > 511 > 512 pr_debug("Initializing debugger thread.\n"); > 513 status = acpi_initialize_debugger(); > 514 if (ACPI_FAILURE(status)) { > 515 pr_err("Failed to initialize debugger.\n"); > 516 ret = -EINVAL; > 517 goto err_lock; > > Not holding lock. > > 518 } > 520 pr_debug("Debugger thread initialized.\n"); > 521 > 522 mutex_lock(&acpi_aml_io.lock); [Lv Zheng] Here the lock is held again. I also noticed that the above line should be put under the locking environment: > 519 acpi_aml_io.flags |= ACPI_AML_OPENED; Thanks for the report. I'll submit a fix for this. Best regards -Lv > 523 acpi_aml_io.out_crc.head = acpi_aml_io.out_crc.tail = 0; > 524 acpi_aml_io.in_crc.head = acpi_aml_io.in_crc.tail = 0; > 525 pr_debug("Debugger interface opened.\n"); > 526 } > 527 acpi_aml_io.users++; > 528 err_lock: > 529 if (IS_ERR_VALUE(ret)) { > 530 if (acpi_aml_active_reader == file) > 531 acpi_aml_active_reader = NULL; > 532 } > 533 mutex_unlock(&acpi_aml_io.lock); > > Double onlock. > > 534 return ret; > 535 } > > regards, > dan carpenter > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
