From: Linus Torvalds Date: Fri, 20 Feb 2026 23:05:26 +0000 (-0800) Subject: Merge tag 'trace-v7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux... X-Git-Tag: v7.0-rc1~32 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=68010e7b3daf0c2cf91eccb329703e82d1ef5aff;p=thirdparty%2Fkernel%2Flinux.git Merge tag 'trace-v7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix possible dereference of uninitialized pointer When validating the persistent ring buffer on boot up, if the first validation fails, a reference to "head_page" is performed in the error path, but it skips over the initialization of that variable. Move the initialization before the first validation check. - Fix use of event length in validation of persistent ring buffer On boot up, the persistent ring buffer is checked to see if it is valid by several methods. One being to walk all the events in the memory location to make sure they are all valid. The length of the event is used to move to the next event. This length is determined by the data in the buffer. If that length is corrupted, it could possibly make the next event to check located at a bad memory location. Validate the length field of the event when doing the event walk. - Fix function graph on archs that do not support use of ftrace_ops When an architecture defines HAVE_DYNAMIC_FTRACE_WITH_ARGS, it means that its function graph tracer uses the ftrace_ops of the function tracer to call its callbacks. This allows a single registered callback to be called directly instead of checking the callback's meta data's hash entries against the function being traced. For architectures that do not support this feature, it must always call the loop function that tests each registered callback (even if there's only one). The loop function tests each callback's meta data against its hash of functions and will call its callback if the function being traced is in its hash map. The issue was that there was no check against this and the direct function was being called even if the architecture didn't support it. This meant that if function tracing was enabled at the same time as a callback was registered with the function graph tracer, its callback would be called for every function that the function tracer also traced, even if the callback's meta data only wanted to be called back for a small subset of functions. Prevent the direct calling for those architectures that do not support it. - Fix references to trace_event_file for hist files The hist files used event_file_data() to get a reference to the associated trace_event_file the histogram was attached to. This would return a pointer even if the trace_event_file is about to be freed (via RCU). Instead it should use the event_file_file() helper that returns NULL if the trace_event_file is marked to be freed so that no new references are added to it. - Wake up hist poll readers when an event is being freed When polling on a hist file, the task is only awoken when a hist trigger is triggered. This means that if an event is being freed while there's a task waiting on its hist file, it will need to wait until the hist trigger occurs to wake it up and allow the freeing to happen. Note, the event will not be completely freed until all references are removed, and a hist poller keeps a reference. But it should still be woken when the event is being freed. * tag 'trace-v7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: Wake up poll waiters for hist files when removing an event tracing: Fix checking of freed trace_event_file for hist files fgraph: Do not call handlers direct when not using ftrace_ops tracing: ring-buffer: Fix to check event length before using ring-buffer: Fix possible dereference of uninitialized pointer --- 68010e7b3daf0c2cf91eccb329703e82d1ef5aff