Driver core fixes for 4.17-rc3

Here are some small driver core and firmware fixes for 4.17-rc3
 
 There's a kobject WARN() removal to make syzkaller a lot happier about
 some "normal" error paths that it keeps hitting, which should reduce the
 number of false-positives we have been getting recently.
 
 There's also some fimware test and documentation fixes, and the
 coredump() function signature change that needed to happen after -rc1
 before drivers started to take advantage of it.
 
 All of these have been in linux-next with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg Kroah-Hartman:
 "Here are some small driver core and firmware fixes for 4.17-rc3

  There's a kobject WARN() removal to make syzkaller a lot happier about
  some "normal" error paths that it keeps hitting, which should reduce
  the number of false-positives we have been getting recently.

  There's also some fimware test and documentation fixes, and the
  coredump() function signature change that needed to happen after -rc1
  before drivers started to take advantage of it.

  All of these have been in linux-next with no reported issues"

* tag 'driver-core-4.17-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  firmware: some documentation fixes
  selftests:firmware: fixes a call to a wrong function name
  kobject: don't use WARN for registration failures
  firmware: Fix firmware documentation for recent file renames
  test_firmware: fix setting old custom fw path back on exit, second try
  test_firmware: Install all scripts
  drivers: change struct device_driver::coredump() return type to void

Documentation/driver-api/firmware/request_firmware.rst

@@ -17,17 +17,17 @@ an error is returned.
 
 request_firmware
 ----------------
-.. kernel-doc:: drivers/base/firmware_class.c
+.. kernel-doc:: drivers/base/firmware_loader/main.c
    :functions: request_firmware
 
 request_firmware_direct
 -----------------------
-.. kernel-doc:: drivers/base/firmware_class.c
+.. kernel-doc:: drivers/base/firmware_loader/main.c
    :functions: request_firmware_direct
 
 request_firmware_into_buf
 -------------------------
-.. kernel-doc:: drivers/base/firmware_class.c
+.. kernel-doc:: drivers/base/firmware_loader/main.c
    :functions: request_firmware_into_buf
 
 Asynchronous firmware requests
@@ -41,7 +41,7 @@ in atomic contexts.
 
 request_firmware_nowait
 -----------------------
-.. kernel-doc:: drivers/base/firmware_class.c
+.. kernel-doc:: drivers/base/firmware_loader/main.c
    :functions: request_firmware_nowait
 
 Special optimizations on reboot
@@ -50,12 +50,12 @@ Special optimizations on reboot
 Some devices have an optimization in place to enable the firmware to be
 retained during system reboot. When such optimizations are used the driver
 author must ensure the firmware is still available on resume from suspend,
-this can be done with firmware_request_cache() insted of requesting for the
+this can be done with firmware_request_cache() instead of requesting for the
-firmare to be loaded.
+firmware to be loaded.
 
 firmware_request_cache()
------------------------
+------------------------
-.. kernel-doc:: drivers/base/firmware_class.c
+.. kernel-doc:: drivers/base/firmware_loader/main.c
    :functions: firmware_request_cache
 
 request firmware API expected driver use

Documentation/driver-api/infrastructure.rst

@@ -28,7 +28,7 @@ Device Drivers Base
 .. kernel-doc:: drivers/base/node.c
    :internal:
 
-.. kernel-doc:: drivers/base/firmware_class.c
+.. kernel-doc:: drivers/base/firmware_loader/main.c
    :export:
 
 .. kernel-doc:: drivers/base/transport_class.c

Documentation/power/suspend-and-cpuhotplug.txt

@@ -168,7 +168,7 @@ update on the CPUs, as discussed below:
 
 [Please bear in mind that the kernel requests the microcode images from
 userspace, using the request_firmware() function defined in
-drivers/base/firmware_class.c]
+drivers/base/firmware_loader/main.c]
 
 
 a. When all the CPUs are identical:

drivers/base/firmware_loader/fallback.c

@@ -537,8 +537,8 @@ exit:
 }
 
 /**
- * fw_load_sysfs_fallback - load a firmware via the syfs fallback mechanism
+ * fw_load_sysfs_fallback - load a firmware via the sysfs fallback mechanism
- * @fw_sysfs: firmware syfs information for the firmware to load
+ * @fw_sysfs: firmware sysfs information for the firmware to load
  * @opt_flags: flags of options, FW_OPT_*
  * @timeout: timeout to wait for the load
  *

drivers/base/firmware_loader/fallback.h

@@ -6,7 +6,7 @@
 #include <linux/device.h>
 
 /**
- * struct firmware_fallback_config - firmware fallback configuratioon settings
+ * struct firmware_fallback_config - firmware fallback configuration settings
  *
  * Helps describe and fine tune the fallback mechanism.
  *

include/linux/device.h

@@ -256,7 +256,9 @@ enum probe_type {
  *		automatically.
  * @pm:		Power management operations of the device which matched
  *		this driver.
- * @coredump:	Called through sysfs to initiate a device coredump.
+ * @coredump:	Called when sysfs entry is written to. The device driver
+ *		is expected to call the dev_coredump API resulting in a
+ *		uevent.
  * @p:		Driver core's private data, no one other than the driver
  *		core can touch this.
  *
@@ -288,7 +290,7 @@ struct device_driver {
 	const struct attribute_group **groups;
 
 	const struct dev_pm_ops *pm;
-	int (*coredump) (struct device *dev);
+	void (*coredump) (struct device *dev);
 
 	struct driver_private *p;
 };

lib/kobject.c

@@ -233,13 +233,12 @@ static int kobject_add_internal(struct kobject *kobj)
 
 		/* be noisy on error issues */
 		if (error == -EEXIST)
-			WARN(1,
+			pr_err("%s failed for %s with -EEXIST, don't try to register things with the same name in the same directory.\n",
-			     "%s failed for %s with -EEXIST, don't try to register things with the same name in the same directory.\n",
+			       __func__, kobject_name(kobj));
-			     __func__, kobject_name(kobj));
 		else
-			WARN(1, "%s failed for %s (error: %d parent: %s)\n",
+			pr_err("%s failed for %s (error: %d parent: %s)\n",
-			     __func__, kobject_name(kobj), error,
+			       __func__, kobject_name(kobj), error,
-			     parent ? kobject_name(parent) : "'none'");
+			       parent ? kobject_name(parent) : "'none'");
 	} else
 		kobj->state_in_sysfs = 1;
 

tools/testing/selftests/firmware/Makefile

@@ -4,6 +4,7 @@
 all:
 
 TEST_PROGS := fw_run_tests.sh
+TEST_FILES := fw_fallback.sh fw_filesystem.sh fw_lib.sh
 
 include ../lib.mk
 

tools/testing/selftests/firmware/fw_lib.sh

@@ -154,11 +154,13 @@ test_finish()
 	if [ "$HAS_FW_LOADER_USER_HELPER" = "yes" ]; then
 		echo "$OLD_TIMEOUT" >/sys/class/firmware/timeout
 	fi
-	if [ "$OLD_FWPATH" = "" ]; then
-		OLD_FWPATH=" "
-	fi
 	if [ "$TEST_REQS_FW_SET_CUSTOM_PATH" = "yes" ]; then
-		echo -n "$OLD_FWPATH" >/sys/module/firmware_class/parameters/path
+		if [ "$OLD_FWPATH" = "" ]; then
+			# A zero-length write won't work; write a null byte
+			printf '\000' >/sys/module/firmware_class/parameters/path
+		else
+			echo -n "$OLD_FWPATH" >/sys/module/firmware_class/parameters/path
+		fi
 	fi
 	if [ -f $FW ]; then
 		rm -f "$FW"

tools/testing/selftests/firmware/fw_run_tests.sh

@@ -66,5 +66,5 @@ if [ -f $FW_FORCE_SYSFS_FALLBACK ]; then
 	run_test_config_0003
 else
 	echo "Running basic kernel configuration, working with your config"
-	run_test
+	run_tests
 fi