From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- Documentation/ABI/testing/sysfs-class-devlink | 130 ++++++++++++++++++++++++++ 1 file changed, 130 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-devlink (limited to 'Documentation/ABI/testing/sysfs-class-devlink') diff --git a/Documentation/ABI/testing/sysfs-class-devlink b/Documentation/ABI/testing/sysfs-class-devlink new file mode 100644 index 000000000..8a21ce515 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-devlink @@ -0,0 +1,130 @@ +What: /sys/class/devlink/.../ +Date: May 2020 +Contact: Saravana Kannan +Description: + Provide a place in sysfs for the device link objects in the + kernel at any given time. The name of a device link directory, + denoted as ... above, is of the form -- + where is the supplier bus:device name and + is the consumer bus:device name. + +What: /sys/class/devlink/.../auto_remove_on +Date: May 2020 +Contact: Saravana Kannan +Description: + This file indicates if the device link will ever be + automatically removed by the driver core when the consumer and + supplier devices themselves are still present. + + This will be one of the following strings: + + - 'consumer unbind' + - 'supplier unbind' + - 'never' + + 'consumer unbind' means the device link will be removed when + the consumer's driver is unbound from the consumer device. + + 'supplier unbind' means the device link will be removed when + the supplier's driver is unbound from the supplier device. + + 'never' means the device link will not be automatically removed + when as long as the supplier and consumer devices themselves + are still present. + +What: /sys/class/devlink/.../consumer +Date: May 2020 +Contact: Saravana Kannan +Description: + This file is a symlink to the consumer device's sysfs directory. + +What: /sys/class/devlink/.../runtime_pm +Date: May 2020 +Contact: Saravana Kannan +Description: + This file indicates if the device link has any impact on the + runtime power management behavior of the consumer and supplier + devices. For example: Making sure the supplier doesn't enter + runtime suspend while the consumer is active. + + This will be one of the following strings: + + === ======================================== + '0' Does not affect runtime power management + '1' Affects runtime power management + === ======================================== + +What: /sys/class/devlink/.../status +Date: May 2020 +Contact: Saravana Kannan +Description: + This file indicates the status of the device link. The status + of a device link is affected by whether the supplier and + consumer devices have been bound to their corresponding + drivers. The status of a device link also affects the binding + and unbinding of the supplier and consumer devices with their + drivers and also affects whether the software state of the + supplier device is synced with the hardware state of the + supplier device after boot up. + See also: sysfs-devices-state_synced. + + This will be one of the following strings: + + - 'not tracked' + - 'dormant' + - 'available' + - 'consumer probing' + - 'active' + - 'supplier unbinding' + - 'unknown' + + 'not tracked' means this device link does not track the status + and has no impact on the binding, unbinding and syncing the + hardware and software device state. + + 'dormant' means the supplier and the consumer devices have not + bound to their driver. + + 'available' means the supplier has bound to its driver and is + available to supply resources to the consumer device. + + 'consumer probing' means the consumer device is currently + trying to bind to its driver. + + 'active' means the supplier and consumer devices have both + bound successfully to their drivers. + + 'supplier unbinding' means the supplier devices is currently in + the process of unbinding from its driver. + + 'unknown' means the state of the device link is not any of the + above. If this is ever the value, there's a bug in the kernel. + +What: /sys/class/devlink/.../supplier +Date: May 2020 +Contact: Saravana Kannan +Description: + This file is a symlink to the supplier device's sysfs directory. + +What: /sys/class/devlink/.../sync_state_only +Date: May 2020 +Contact: Saravana Kannan +Description: + This file indicates if the device link is limited to only + affecting the syncing of the hardware and software state of the + supplier device. + + This will be one of the following strings: + + === ================================ + '0' + '1' Affects runtime power management + === ================================ + + '0' means the device link can affect other device behaviors + like binding/unbinding, suspend/resume, runtime power + management, etc. + + '1' means the device link will only affect the syncing of + hardware and software state of the supplier device after boot + up and doesn't not affect other behaviors of the devices. -- cgit v1.3.1