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authorLinus Torvalds <torvalds@linux-foundation.org>2026-09-13 12:27:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-09-13 12:27:00 -0700
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Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted
Pull tracing fixes from Steven Rostedt: - Don't destroy user event fields when removal fails User event fields are destroyed before the event is removed from visibility. But that can fail leaving the still visible event with no fields. Move the destroying of the fields to after the event is successfully removed from visibility. - Initialize function graph state is fork before calling copy_exec_state() For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, ftrace_graph_exit_task() will free the tasks ret_stack pointer. Since that pointer is still using the parent's ret_stack, it mistakenly frees the parent's pointer too. Call ftrace_graph_init() on the task first which will NULL out the new tasks's ret_stack and if the copy fails, it will not free anything. - Remove FGRAPH_MAX_INDEX The macro FGRAPH_MAX_INDEX was added but never used. Remove it. - Save ent_size in function graph printing of nested functions The function graph tracer needs to look at the next event to see if the next event is the return of the current function entry. If it is, it prints a single line: ktime_get(); Otherwise it prints it like a nested function: tick_nohz_irq_exit() { ktime_get(); kcpustat_irq_exit(); } In order to look at the next event, it must save the current event so that it has the information to print from it. It saves the event in the iterator descriptor called "ent". What it doesn't save is the ent_size of the event which is now used to know if the function graph arguments are to be printed. The peek doesn't save the size so the size used happens to be that of the size of the last event that was seen. Save the entry event size in the iterator descriptor so that the correct size is used. - Fix several errors with freeing data in the histogram code The histogram code had a lot of leaked or or incorrect accounting when failures happen. Correct them. - Fix histogram regression of .percent and .graph modifiers Up until 6.3 histogram values could have "percent" or "graph" modifiers that changed how they were printed. But a change that added restricting histograms values from being strings, stack traces and other modifiers inadvertently prevented them from using the percent and graph modifiers, which were legal use cases for values. Put back the percent and graph modifiers. - Fix various typos in the comments - Set the trace_clock before initializing a histogram with clock argument The histogram API allows the user to specific which trace clock to use via a "clock=" string. The histogram is set up first before the clock is checked. If the passed in clock is not valid, it exits without fully fixing up the histogram leaving it on the list and a use-after-free can trigger. Update the clock argument first and if it fails then exit gracefully before the histogram trigger is placed on any lists. - Restore :mod: trailer after parsing in ftrace_set_clr_event The function ftrace_set_clr_event() modifies the parse string and needs to put it back to what was passed in. It searches for ":mod:" via a strsep() but fails to put back the first ':' in the string. Add back the ':' in the passed in string. - Take trace_array reference when opening a tracer options file The options files are dynamically created and some tracers add their own options. When a tracer adds their own list of options, the trace_array holding them has an array to hold the list of options for each tracer. This array increases in size via a krealloc(), and the new entry gets a newly allocated array to hold the options of the new tracer being added. The element in each entry of the tracer's option array holds a pointer back to the trace_array, a pointer to the tracer it is associated to, a pointer to the flags of the option. The issue is that these arrays are freed when the trace_array is freed when its instance it represents is removed from the instances directory. There's a race that an open of one of these options files can happen when the instance is being removed. Add a new helper function to be called by the open function of the options file to iterate all existing trace_arrays under a lock and find the one that has the given option element in one of it's tracer arrays. If found, then update the associated trace_array's reference counter to keep it from being freed. If not found, have the open call return -ENODEV. - Disable interrupts when acquiring the lock in rb_wake_up_waiters() The function rb_wake_up_waiters() assumes it will be called in interrupt context and does not disable irqs when taking cpu_buffer->reader_lock, which can be called in hard interrupt context. The issue is in PREEMPT_RT, this function is called in thread context leaving this lock open to a deadlock. Take the lock with interrupts disabled. - Use rcu_assign_pointer() for tmp_ops filter hash The tmp_ops used in update_ftrace_direct_mod() assigns its filter_hash field directly, but that field is annotated as __rcu and sparse complains. Assign it with rcu_assign_pointer() - Fix use-after-free in enable_trigger_private_data_free() The trace_event_call is accessed through the event_trigger_data's trace_event_file pointer to put the trace_event_call on freeing. The issue is that the trace_event_file data may have been freed already causing a use-after-free. Add a field to the event_trigger_data that points directly to the trace_event_call so that it can decrement its reference directly without needing to go through the trace_event_file. - Fix accounting of buffer data remote headers trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the number of pages is needed for the asked for size as it doesn't take into account the meta data on each page. Add a helper function to do the calculation properly and use that in these functions. - Catch nr_page_va overflow in ring_buffer_desc sizing The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. - Do not resize the subbuf order if any per_cpu buffer is disabled The mmapping of ring buffers disables resizing the subbuffers, but it is done per-cpu whereas the subbuf size change is done for all the per_cpu buffers under the buffer->mutex. It could change the size of some while the mapping is happening on others. Have the resize of the subbuf order check all the per_cpu buffers under the lock to see if any of them is disabled before starting and causing an inconsistency between buffers that are being mapped. * tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits) ring-buffer: Check resize_disabled before publishing the new subbuf order tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing tracing/remotes: Account for ring buffer page header in size calculation tracing: Don't dereference trace_event_file in deferred trigger free ftrace: Use rcu_assign_pointer() for tmp_ops filter hash ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters() tracing: Take trace_array reference when opening a tracer options file tracing: Fix ring_buffer_read_page_size() kernel-doc tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event() tracing: Fix memory corruption from a "STACKTRACE" histogram key tracing: Fix memory corruption from the histogram stacktrace modifier tracing: Undo the registration when enabling the histogram trigger fails tracing: Take the reference before publishing the named histogram trigger tracing: Set the trace clock before registering the histogram trigger tracing: Fix typo "preceeded" in comment tracing: Fix typo "availabe" in comment tracing: Let histogram values keep the percent and graph modifiers tracing: Keep the entry count when the histogram stats allocation fails tracing: Free histogram the field rejected for a bad modifier tracing: Free histogram the var ref when its initialization fails ...
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+==============
+AMDGPU DebugFS
+==============
+
+The amdgpu driver provides a number of debugfs files to aid in debugging
+issues in the driver. These are usually found in
+/sys/kernel/debug/dri/<num>.
+
+DebugFS Files
+=============
+
+amdgpu_benchmark
+----------------
+
+Run benchmarks using the DMA engine the driver uses for GPU memory paging.
+Write a number to the file to run the test. The results are written to the
+kernel log. VRAM is on device memory (dGPUs) or carve out (APUs) and GTT
+(Graphics Translation Tables) is system memory that is accessible by the GPU.
+The following tests are available:
+
+- 1: simple test, VRAM to GTT and GTT to VRAM
+- 2: simple test, VRAM to VRAM
+- 3: GTT to VRAM, buffer size sweep, powers of 2
+- 4: VRAM to GTT, buffer size sweep, powers of 2
+- 5: VRAM to VRAM, buffer size sweep, powers of 2
+- 6: GTT to VRAM, buffer size sweep, common display sizes
+- 7: VRAM to GTT, buffer size sweep, common display sizes
+- 8: VRAM to VRAM, buffer size sweep, common display sizes
+
+amdgpu_test_ib
+--------------
+
+Read this file to run simple IB (Indirect Buffer) tests on all kernel managed
+rings. IBs are command buffers usually generated by userspace applications
+which are submitted to the kernel for execution on an particular GPU engine.
+This just runs the simple IB tests included in the kernel. These tests
+are engine specific and verify that IB submission works.
+
+amdgpu_discovery
+----------------
+
+Provides raw access to the IP discovery binary provided by the GPU. Read this
+file to access the raw binary. This is useful for verifying the contents of
+the IP discovery table. It is chip specific.
+
+amdgpu_vbios
+------------
+
+Provides raw access to the ROM binary image from the GPU. Read this file to
+access the raw binary. This is useful for verifying the contents of the
+video BIOS ROM. It is board specific.
+
+amdgpu_evict_gtt
+----------------
+
+Evict all buffers from the GTT memory pool. Read this file to evict all
+buffers from this pool.
+
+amdgpu_evict_vram
+-----------------
+
+Evict all buffers from the VRAM memory pool. Read this file to evict all
+buffers from this pool.
+
+amdgpu_gpu_recover
+------------------
+
+Trigger a GPU reset. Read this file to trigger reset the entire GPU.
+All work currently running on the GPU will be lost.
+
+amdgpu_ring_<name>
+------------------
+
+Provides read access to the kernel managed ring buffers for each ring <name>.
+These are useful for debugging problems on a particular ring. The ring buffer
+is how the CPU sends commands to the GPU. The CPU writes commands into the
+buffer and then asks the GPU engine to process it. This is the raw binary
+contents of the ring buffer. Use a tool like UMR to decode the rings into human
+readable form.
+
+amdgpu_mqd_<name>
+-----------------
+
+Provides read access to the kernel managed MQD (Memory Queue Descriptor) for
+ring <name> managed by the kernel driver. MQDs define the features of the ring
+and are used to store the ring's state when it is not connected to hardware.
+The driver writes the requested ring features and metadata (GPU addresses of
+the ring itself and associated buffers) to the MQD and the firmware uses the MQD
+to populate the hardware when the ring is mapped to a hardware slot. Only
+available on engines which use MQDs. This provides access to the raw MQD
+binary.
+
+amdgpu_error_<name>
+-------------------
+
+Provides an interface to set an error code on the dma fences associated with
+ring <name>. The error code specified is propagated to all fences associated
+with the ring. Use this to inject a fence error into a ring.
+
+amdgpu_pm_info
+--------------
+
+Provides human readable information about the power management features
+and state of the GPU. This includes current GFX clock, Memory clock,
+voltages, average SoC power, temperature, GFX load, Memory load, SMU
+feature mask, VCN power state, clock and power gating features.
+
+amdgpu_firmware_info
+--------------------
+
+Lists the firmware versions for all firmwares used by the GPU. Only
+entries with a non-0 version are valid. If the version is 0, the firmware
+is not valid for the GPU.
+
+amdgpu_fence_info
+-----------------
+
+Shows the last signalled and emitted fence sequence numbers for each
+kernel driver managed ring. Fences are associated with submissions
+to the engine. Emitted fences have been submitted to the ring
+and signalled fences have been signalled by the GPU. Rings with a
+larger emitted fence value have outstanding work that is still being
+processed by the engine that owns that ring. When the emitted and
+signalled fence values are equal, the ring is idle.
+
+amdgpu_gem_info
+---------------
+
+Lists all of the PIDs using the GPU and the GPU buffers that they have
+allocated. This lists the buffer size, pool (VRAM, GTT, etc.), and buffer
+attributes (CPU access required, CPU cache attributes, etc.).
+
+amdgpu_vm_info
+--------------
+
+Lists all of the PIDs using the GPU and the GPU buffers that they have
+allocated as well as the status of those buffers relative to that process'
+GPU virtual address space (e.g., evicted, idle, invalidated, etc.).
+
+amdgpu_sa_info
+--------------
+
+Prints out all of the suballocations (sa) by the suballocation manager in the
+kernel driver. Prints the GPU address, size, and fence info associated
+with each suballocation. The suballocations are used internally within
+the kernel driver for various things.
+
+amdgpu_<pool>_mm
+----------------
+
+Prints TTM information about the memory pool <pool>.
+
+amdgpu_vram
+-----------
+
+Provides direct access to VRAM. Used by tools like UMR to inspect
+objects in VRAM.
+
+amdgpu_iomem
+------------
+
+Provides direct access to GTT memory. Used by tools like UMR to inspect
+GTT memory.
+
+amdgpu_regs_*
+-------------
+
+Provides direct access to various register apertures on the GPU. Used
+by tools like UMR to access GPU registers.
+
+amdgpu_regs2
+------------
+
+Provides an IOCTL interface used by UMR for interacting with GPU registers.
+
+
+amdgpu_sensors
+--------------
+
+Provides an interface to query GPU power metrics (temperature, average
+power, etc.). Used by tools like UMR to query GPU power metrics.
+
+
+amdgpu_gca_config
+-----------------
+
+Provides an interface to query GPU details (Graphics/Compute Array config,
+PCI config, GPU family, etc.). Used by tools like UMR to query GPU details.
+
+amdgpu_wave
+-----------
+
+Used to query GFX/compute wave information from the hardware. Used by tools
+like UMR to query GFX/compute wave information.
+
+amdgpu_gpr
+----------
+
+Used to query GFX/compute GPR (General Purpose Register) information from the
+hardware. Used by tools like UMR to query GPRs when debugging shaders.
+
+amdgpu_gprwave
+--------------
+
+Provides an IOCTL interface used by UMR for interacting with shader waves.
+
+amdgpu_fw_attestation
+---------------------
+
+Provides an interface for reading back firmware attestation records.