Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

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

1 files changed, 276 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/debugfs-intel-iommu b/Documentation/ABI/testing/debugfs-intel-iommu
new file mode 100644
index 000000000..2ab846450
--- /dev/null
+++ b/Documentation/ABI/testing/debugfs-intel-iommu
@@ -0,0 +1,276 @@
+What:		/sys/kernel/debug/iommu/intel/iommu_regset
+Date:		December 2023
+Contact:	Jingqi Liu <Jingqi.liu@intel.com>
+Description:
+		This file dumps all the register contents for each IOMMU device.
+
+		Example in Kabylake:
+
+		::
+
+		 $ sudo cat /sys/kernel/debug/iommu/intel/iommu_regset
+
+		 IOMMU: dmar0 Register Base Address: 26be37000
+
+		 Name                    Offset          Contents
+		 VER                     0x00            0x0000000000000010
+		 GCMD                    0x18            0x0000000000000000
+		 GSTS                    0x1c            0x00000000c7000000
+		 FSTS                    0x34            0x0000000000000000
+		 FECTL                   0x38            0x0000000000000000
+
+		 [...]
+
+		 IOMMU: dmar1 Register Base Address: fed90000
+
+		 Name                    Offset          Contents
+		 VER                     0x00            0x0000000000000010
+		 GCMD                    0x18            0x0000000000000000
+		 GSTS                    0x1c            0x00000000c7000000
+		 FSTS                    0x34            0x0000000000000000
+		 FECTL                   0x38            0x0000000000000000
+
+		 [...]
+
+		 IOMMU: dmar2 Register Base Address: fed91000
+
+		 Name                    Offset          Contents
+		 VER                     0x00            0x0000000000000010
+		 GCMD                    0x18            0x0000000000000000
+		 GSTS                    0x1c            0x00000000c7000000
+		 FSTS                    0x34            0x0000000000000000
+		 FECTL                   0x38            0x0000000000000000
+
+		 [...]
+
+What:		/sys/kernel/debug/iommu/intel/ir_translation_struct
+Date:		December 2023
+Contact:	Jingqi Liu <Jingqi.liu@intel.com>
+Description:
+		This file dumps the table entries for Interrupt
+		remapping and Interrupt posting.
+
+		Example in Kabylake:
+
+		::
+
+		 $ sudo cat /sys/kernel/debug/iommu/intel/ir_translation_struct
+
+		 Remapped Interrupt supported on IOMMU: dmar0
+		 IR table address:100900000
+
+		 Entry SrcID   DstID    Vct IRTE_high           IRTE_low
+		 0     00:0a.0 00000080 24  0000000000040050    000000800024000d
+		 1     00:0a.0 00000001 ef  0000000000040050    0000000100ef000d
+
+		 Remapped Interrupt supported on IOMMU: dmar1
+		 IR table address:100300000
+		 Entry SrcID   DstID    Vct IRTE_high           IRTE_low
+		 0     00:02.0 00000002 26  0000000000040010    000000020026000d
+
+		 [...]
+
+		 ****
+
+		 Posted Interrupt supported on IOMMU: dmar0
+		 IR table address:100900000
+		 Entry SrcID   PDA_high PDA_low  Vct IRTE_high          IRTE_low
+
+What:		/sys/kernel/debug/iommu/intel/dmar_translation_struct
+Date:		December 2023
+Contact:	Jingqi Liu <Jingqi.liu@intel.com>
+Description:
+		This file dumps Intel IOMMU DMA remapping tables, such
+		as root table, context table, PASID directory and PASID
+		table entries in debugfs. For legacy mode, it doesn't
+		support PASID, and hence PASID field is defaulted to
+		'-1' and other PASID related fields are invalid.
+
+		Example in Kabylake:
+
+		::
+
+		 $ sudo cat /sys/kernel/debug/iommu/intel/dmar_translation_struct
+
+		 IOMMU dmar1: Root Table Address: 0x103027000
+		 B.D.F   Root_entry
+		 00:02.0 0x0000000000000000:0x000000010303e001
+
+		 Context_entry
+		 0x0000000000000102:0x000000010303f005
+
+		 PASID   PASID_table_entry
+		 -1      0x0000000000000000:0x0000000000000000:0x0000000000000000
+
+		 IOMMU dmar0: Root Table Address: 0x103028000
+		 B.D.F   Root_entry
+		 00:0a.0 0x0000000000000000:0x00000001038a7001
+
+		 Context_entry
+		 0x0000000000000000:0x0000000103220e7d
+
+		 PASID   PASID_table_entry
+		 0       0x0000000000000000:0x0000000000800002:0x00000001038a5089
+
+		 [...]
+
+What:		/sys/kernel/debug/iommu/intel/invalidation_queue
+Date:		December 2023
+Contact:	Jingqi Liu <Jingqi.liu@intel.com>
+Description:
+		This file exports invalidation queue internals of each
+		IOMMU device.
+
+		Example in Kabylake:
+
+		::
+
+		 $ sudo cat /sys/kernel/debug/iommu/intel/invalidation_queue
+
+		 Invalidation queue on IOMMU: dmar0
+		 Base: 0x10022e000      Head: 20        Tail: 20
+		 Index          qw0                    qw1                     qw2
+		     0   0000000000000014        0000000000000000        0000000000000000
+		     1   0000000200000025        0000000100059c04        0000000000000000
+		     2   0000000000000014        0000000000000000        0000000000000000
+
+				qw3                  status
+			 0000000000000000        0000000000000000
+			 0000000000000000        0000000000000000
+			 0000000000000000        0000000000000000
+
+		 [...]
+
+		 Invalidation queue on IOMMU: dmar1
+		 Base: 0x10026e000      Head: 32        Tail: 32
+		 Index           qw0                     qw1                   status
+		     0   0000000000000004        0000000000000000         0000000000000000
+		     1   0000000200000025        0000000100059804         0000000000000000
+		     2   0000000000000011        0000000000000000         0000000000000000
+
+		 [...]
+
+What:		/sys/kernel/debug/iommu/intel/dmar_perf_latency
+Date:		December 2023
+Contact:	Jingqi Liu <Jingqi.liu@intel.com>
+Description:
+		This file is used to control and show counts of
+		execution time ranges for various types per DMAR.
+
+		Firstly, write a value to
+		/sys/kernel/debug/iommu/intel/dmar_perf_latency
+		to enable sampling.
+
+		The possible values are as follows:
+
+		* 0 - disable sampling all latency data
+
+		* 1 - enable sampling IOTLB invalidation latency data
+
+		* 2 - enable sampling devTLB invalidation latency data
+
+		* 3 - enable sampling intr entry cache invalidation latency data
+
+		Next, read /sys/kernel/debug/iommu/intel/dmar_perf_latency gives
+		a snapshot of sampling result of all enabled monitors.
+
+		Examples in Kabylake:
+
+		::
+
+		 1) Disable sampling all latency data:
+
+		 $ sudo echo 0 > /sys/kernel/debug/iommu/intel/dmar_perf_latency
+
+		 2) Enable sampling IOTLB invalidation latency data
+
+		 $ sudo echo 1 > /sys/kernel/debug/iommu/intel/dmar_perf_latency
+
+		 $ sudo cat /sys/kernel/debug/iommu/intel/dmar_perf_latency
+
+		 IOMMU: dmar0 Register Base Address: 26be37000
+				 <0.1us   0.1us-1us    1us-10us  10us-100us   100us-1ms
+		 inv_iotlb           0           0           0           0           0
+
+				 1ms-10ms      >=10ms     min(us)     max(us) average(us)
+		 inv_iotlb           0           0           0           0           0
+
+		 [...]
+
+		 IOMMU: dmar2 Register Base Address: fed91000
+				 <0.1us   0.1us-1us    1us-10us  10us-100us   100us-1ms
+		 inv_iotlb           0           0          18           0           0
+
+				 1ms-10ms      >=10ms     min(us)     max(us) average(us)
+		 inv_iotlb           0           0           2           2           2
+
+		 3) Enable sampling devTLB invalidation latency data
+
+		 $ sudo echo 2 > /sys/kernel/debug/iommu/intel/dmar_perf_latency
+
+		 $ sudo cat /sys/kernel/debug/iommu/intel/dmar_perf_latency
+
+		 IOMMU: dmar0 Register Base Address: 26be37000
+				 <0.1us   0.1us-1us    1us-10us  10us-100us   100us-1ms
+		 inv_devtlb           0           0           0           0           0
+
+				 >=10ms     min(us)     max(us) average(us)
+		 inv_devtlb           0           0           0           0
+
+		 [...]
+
+What:		/sys/kernel/debug/iommu/intel/<bdf>/domain_translation_struct
+Date:		December 2023
+Contact:	Jingqi Liu <Jingqi.liu@intel.com>
+Description:
+		This file dumps a specified page table of Intel IOMMU
+		in legacy mode or scalable mode.
+
+		For a device that only supports legacy mode, dump its
+		page table by the debugfs file in the debugfs device
+		directory. e.g.
+		/sys/kernel/debug/iommu/intel/0000:00:02.0/domain_translation_struct.
+
+		For a device that supports scalable mode, dump the
+		page table of specified pasid by the debugfs file in
+		the debugfs pasid directory. e.g.
+		/sys/kernel/debug/iommu/intel/0000:00:02.0/1/domain_translation_struct.
+
+		Examples in Kabylake:
+
+		::
+
+		 1) Dump the page table of device "0000:00:02.0" that only supports legacy mode.
+
+		 $ sudo cat /sys/kernel/debug/iommu/intel/0000:00:02.0/domain_translation_struct
+
+		 Device 0000:00:02.0 @0x1017f8000
+		 IOVA_PFN                PML5E                   PML4E
+		 0x000000008d800 |       0x0000000000000000      0x00000001017f9003
+		 0x000000008d801 |       0x0000000000000000      0x00000001017f9003
+		 0x000000008d802 |       0x0000000000000000      0x00000001017f9003
+
+		 PDPE                    PDE                     PTE
+		 0x00000001017fa003      0x00000001017fb003      0x000000008d800003
+		 0x00000001017fa003      0x00000001017fb003      0x000000008d801003
+		 0x00000001017fa003      0x00000001017fb003      0x000000008d802003
+
+		 [...]
+
+		 2) Dump the page table of device "0000:00:0a.0" with PASID "1" that
+		 supports scalable mode.
+
+		 $ sudo cat /sys/kernel/debug/iommu/intel/0000:00:0a.0/1/domain_translation_struct
+
+		 Device 0000:00:0a.0 with pasid 1 @0x10c112000
+		 IOVA_PFN                PML5E                   PML4E
+		 0x0000000000000 |       0x0000000000000000      0x000000010df93003
+		 0x0000000000001 |       0x0000000000000000      0x000000010df93003
+		 0x0000000000002 |       0x0000000000000000      0x000000010df93003
+
+		 PDPE                    PDE                     PTE
+		 0x0000000106ae6003      0x0000000104b38003      0x0000000147c00803
+		 0x0000000106ae6003      0x0000000104b38003      0x0000000147c01803
+		 0x0000000106ae6003      0x0000000104b38003      0x0000000147c02803
+
+		 [...]