kernel/linux.git/drivers/base/core.c, branch v5.4.239

drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functions

2022-01-16T08:15:38+00:00

commit aa838896d87af561a33ecefea1caa4c15a68bc47 upstream. Convert the various sprintf fmaily calls in sysfs device show functions to sysfs_emit and sysfs_emit_at for PAGE_SIZE buffer safety. Done with: $ spatch -sp-file sysfs_emit_dev.cocci --in-place --max-width=80 . And cocci script: $ cat sysfs_emit_dev.cocci @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - sprintf(buf, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - snprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - scnprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; expression chr; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - strcpy(buf, chr); + sysfs_emit(buf, chr); ...> } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - sprintf(buf, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - snprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - scnprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... - len += scnprintf(buf + len, PAGE_SIZE - len, + len += sysfs_emit_at(buf, len, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; expression chr; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { ... - strcpy(buf, chr); - return strlen(buf); + return sysfs_emit(buf, chr); } Signed-off-by: Joe Perches Link: https://lore.kernel.org/r/3d033c33056d88bbe34d4ddb62afd05ee166ab9a.1600285923.git.joe@perches.com Cc: Lee Jones Signed-off-by: Greg Kroah-Hartman

PCI/MSI: Protect msi_desc::masked for multi-MSI

2021-08-18T06:57:03+00:00

commit 77e89afc25f30abd56e76a809ee2884d7c1b63ce upstream. Multi-MSI uses a single MSI descriptor and there is a single mask register when the device supports per vector masking. To avoid reading back the mask register the value is cached in the MSI descriptor and updates are done by clearing and setting bits in the cache and writing it to the device. But nothing protects msi_desc::masked and the mask register from being modified concurrently on two different CPUs for two different Linux interrupts which belong to the same multi-MSI descriptor. Add a lock to struct device and protect any operation on the mask and the mask register with it. This makes the update of msi_desc::masked unconditional, but there is no place which requires a modification of the hardware register without updating the masked cache. msi_mask_irq() is now an empty wrapper which will be cleaned up in follow up changes. The problem goes way back to the initial support of multi-MSI, but picking the commit which introduced the mask cache is a valid cut off point (2.6.30). Fixes: f2440d9acbe8 ("PCI MSI: Refactor interrupt masking code") Signed-off-by: Thomas Gleixner Tested-by: Marc Zyngier Reviewed-by: Marc Zyngier Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210729222542.726833414@linutronix.de Signed-off-by: Greg Kroah-Hartman

driver core: Extend device_is_dependent()

2021-01-27T10:47:51+00:00

commit 3d1cf435e201d1fd63e4346b141881aed086effd upstream. If the device passed as the target (second argument) to device_is_dependent() is not completely registered (that is, it has been initialized, but not added yet), but the parent pointer of it is set, it may be missing from the list of the parent's children and device_for_each_child() called by device_is_dependent() cannot be relied on to catch that dependency. For this reason, modify device_is_dependent() to check the ancestors of the target device by following its parent pointer in addition to the device_for_each_child() walk. Fixes: 9ed9895370ae ("driver core: Functional dependencies tracking support") Reported-by: Stephan Gerhold Tested-by: Stephan Gerhold Reviewed-by: Saravana Kannan Signed-off-by: Rafael J. Wysocki Link: https://lore.kernel.org/r/17705994.d592GUb2YH@kreacher Cc: stable Signed-off-by: Greg Kroah-Hartman

Revert "device property: Keep secondary firmware node secondary by type"

2021-01-12T19:16:23+00:00

commit 47f4469970d8861bc06d2d4d45ac8200ff07c693 upstream. While commit d5dcce0c414f ("device property: Keep secondary firmware node secondary by type") describes everything correct in its commit message, the change it made does the opposite and original commit c15e1bdda436 ("device property: Fix the secondary firmware node handling in set_primary_fwnode()") was fully correct. Revert the former one here and improve documentation in the next patch. Fixes: d5dcce0c414f ("device property: Keep secondary firmware node secondary by type") Signed-off-by: Bard Liao Reviewed-by: Andy Shevchenko Reviewed-by: Heikki Krogerus Cc: 5.10+ # 5.10+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM: runtime: Drop runtime PM references to supplier on link removal

2020-11-10T11:37:34+00:00

commit e0e398e204634db8fb71bd89cf2f6e3e5bd09b51 upstream. While removing a device link, drop the supplier device's runtime PM usage counter as many times as needed to drop all of the runtime PM references to it from the consumer in addition to dropping the consumer's link count. Fixes: baa8809f6097 ("PM / runtime: Optimize the use of device links") Signed-off-by: Rafael J. Wysocki Cc: 5.1+ # 5.1+ Tested-by: Xiang Chen Reviewed-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

device property: Don't clear secondary pointer for shared primary firmware node

2020-11-05T10:43:37+00:00

commit 99aed9227073fb34ce2880cbc7063e04185a65e1 upstream. It appears that firmware nodes can be shared between devices. In such case when a (child) device is about to be deleted, its firmware node may be shared and ACPI_COMPANION_SET(..., NULL) call for it breaks the secondary link of the shared primary firmware node. In order to prevent that, check, if the device has a parent and parent's firmware node is shared with its child, and avoid crashing the link. Fixes: c15e1bdda436 ("device property: Fix the secondary firmware node handling in set_primary_fwnode()") Reported-by: Ferry Toth Signed-off-by: Andy Shevchenko Reviewed-by: Heikki Krogerus Tested-by: Ferry Toth Cc: 5.9+ # 5.9+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

device property: Keep secondary firmware node secondary by type

2020-11-05T10:43:37+00:00

commit d5dcce0c414fcbfe4c2037b66ac69ea5f9b3f75c upstream. Behind primary and secondary we understand the type of the nodes which might define their ordering. However, if primary node gone, we can't maintain the ordering by definition of the linked list. Thus, by ordering secondary node becomes first in the list. But in this case the meaning of it is still secondary (or auxiliary). The type of the node is maintained by the secondary pointer in it: secondary pointer Meaning NULL or valid primary node ERR_PTR(-ENODEV) secondary node So, if by some reason we do the following sequence of calls set_primary_fwnode(dev, NULL); set_primary_fwnode(dev, primary); we should preserve secondary node. This concept is supported by the description of set_primary_fwnode() along with implementation of set_secondary_fwnode(). Hence, fix the commit c15e1bdda436 to follow this as well. Fixes: c15e1bdda436 ("device property: Fix the secondary firmware node handling in set_primary_fwnode()") Cc: Ferry Toth Signed-off-by: Andy Shevchenko Reviewed-by: Heikki Krogerus Tested-by: Ferry Toth Cc: 5.9+ # 5.9+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

device property: Fix the secondary firmware node handling in set_primary_fwnode()

2020-09-03T09:27:05+00:00

commit c15e1bdda4365a5f17cdadf22bf1c1df13884a9e upstream. When the primary firmware node pointer is removed from a device (set to NULL) the secondary firmware node pointer, when it exists, is made the primary node for the device. However, the secondary firmware node pointer of the original primary firmware node is never cleared (set to NULL). To avoid situation where the secondary firmware node pointer is pointing to a non-existing object, clearing it properly when the primary node is removed from a device in set_primary_fwnode(). Fixes: 97badf873ab6 ("device property: Make it possible to use secondary firmware nodes") Cc: All applicable Signed-off-by: Heikki Krogerus Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: Avoid cpufreq_suspend() deadlock on system shutdown

2019-10-10T09:11:17+00:00

It is incorrect to set the cpufreq syscore shutdown callback pointer to cpufreq_suspend(), because that function cannot be run in the syscore stage of system shutdown for two reasons: (a) it may attempt to carry out actions depending on devices that have already been shut down at that point and (b) the RCU synchronization carried out by it may not be able to make progress then. The latter issue has been present since commit 45975c7d21a1 ("rcu: Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds"), but the former one has been there since commit 90de2a4aa9f3 ("cpufreq: suspend cpufreq governors on shutdown") regardless. Fix that by dropping cpufreq_syscore_ops altogether and making device_shutdown() call cpufreq_suspend() directly before shutting down devices, which is along the lines of what system-wide power management does. Fixes: 45975c7d21a1 ("rcu: Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds") Fixes: 90de2a4aa9f3 ("cpufreq: suspend cpufreq governors on shutdown") Reported-by: Ville Syrjälä Tested-by: Ville Syrjälä Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Cc: 4.0+ # 4.0+

Merge tag 'driver-core-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2019-09-18T17:04:39+00:00

Pull driver core updates from Greg Kroah-Hartman: "Here is the big driver core update for 5.4-rc1. There was a bit of a churn in here, with a number of core and OF platform patches being added to the tree, and then after much discussion and review and a day-long in-person meeting, they were decided to be reverted and a new set of patches is currently being reviewed on the mailing list. Other than that churn, there are two "persistent" branches in here that other trees will be pulling in as well during the merge window. One branch to add support for drivers to have the driver core automatically add sysfs attribute files when a driver is bound to a device so that the driver doesn't have to manually do it (and then clean it up, as it always gets it wrong). There's another branch in here for generic lookup helpers for the driver core that lots of busses are starting to use. That's the majority of the non-driver-core changes in this patch series. There's also some on-going debugfs file creation cleanup that has been slowly happening over the past few releases, with the goal to hopefully get that done sometime next year. All of these have been in linux-next for a while now with no reported issues" [ Note that the above-mentioned generic lookup helpers branch was already brought in by the LED merge (commit 4feaab05dc1e) that had shared it. Also note that that common branch introduced an i2c bug due to a bad conversion, which got fixed here. - Linus ] * tag 'driver-core-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (49 commits) coccinelle: platform_get_irq: Fix parse error driver-core: add include guard to linux/container.h sysfs: add BIN_ATTR_WO() macro driver core: platform: Export platform_get_irq_optional() hwmon: pwm-fan: Use platform_get_irq_optional() driver core: platform: Introduce platform_get_irq_optional() Revert "driver core: Add support for linking devices during device addition" Revert "driver core: Add edit_links() callback for drivers" Revert "of/platform: Add functional dependency link from DT bindings" Revert "driver core: Add sync_state driver/bus callback" Revert "of/platform: Pause/resume sync state during init and of_platform_populate()" Revert "of/platform: Create device links for all child-supplier depencencies" Revert "of/platform: Don't create device links for default busses" Revert "of/platform: Fix fn definitons for of_link_is_valid() and of_link_property()" Revert "of/platform: Fix device_links_supplier_sync_state_resume() warning" Revert "of/platform: Disable generic device linking code for PowerPC" devcoredump: fix typo in comment devcoredump: use memory_read_from_buffer of/platform: Disable generic device linking code for PowerPC device.h: Fix warnings for mismatched parameter names in comments ...