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
  ...

1 files changed, 168 insertions, 0 deletions

diff --git a/include/uapi/xen/privcmd.h b/include/uapi/xen/privcmd.h
new file mode 100644
index 000000000..8e2c8fd44
--- /dev/null
+++ b/include/uapi/xen/privcmd.h
@@ -0,0 +1,168 @@
+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR MIT) */
+/******************************************************************************
+ * privcmd.h
+ *
+ * Interface to /proc/xen/privcmd.
+ *
+ * Copyright (c) 2003-2005, K A Fraser
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef __LINUX_PUBLIC_PRIVCMD_H__
+#define __LINUX_PUBLIC_PRIVCMD_H__
+
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <xen/interface/xen.h>
+
+struct privcmd_hypercall {
+	__u64 op;
+	__u64 arg[5];
+};
+
+struct privcmd_mmap_entry {
+	__u64 va;
+	/*
+	 * This should be a GFN. It's not possible to change the name because
+	 * it's exposed to the user-space.
+	 */
+	__u64 mfn;
+	__u64 npages;
+};
+
+struct privcmd_mmap {
+	int num;
+	domid_t dom; /* target domain */
+	struct privcmd_mmap_entry __user *entry;
+};
+
+struct privcmd_mmapbatch {
+	int num;     /* number of pages to populate */
+	domid_t dom; /* target domain */
+	__u64 addr;  /* virtual address */
+	xen_pfn_t __user *arr; /* array of mfns - or'd with
+				  PRIVCMD_MMAPBATCH_*_ERROR on err */
+};
+
+#define PRIVCMD_MMAPBATCH_MFN_ERROR     0xf0000000U
+#define PRIVCMD_MMAPBATCH_PAGED_ERROR   0x80000000U
+
+struct privcmd_mmapbatch_v2 {
+	unsigned int num; /* number of pages to populate */
+	domid_t dom;      /* target domain */
+	__u64 addr;       /* virtual address */
+	const xen_pfn_t __user *arr; /* array of mfns */
+	int __user *err;  /* array of error codes */
+};
+
+struct privcmd_dm_op_buf {
+	void __user *uptr;
+	size_t size;
+};
+
+struct privcmd_dm_op {
+	domid_t dom;
+	__u16 num;
+	const struct privcmd_dm_op_buf __user *ubufs;
+};
+
+struct privcmd_mmap_resource {
+	domid_t dom;
+	__u32 type;
+	__u32 id;
+	__u32 idx;
+	__u64 num;
+	__u64 addr;
+};
+
+/* For privcmd_irqfd::flags */
+#define PRIVCMD_IRQFD_FLAG_DEASSIGN (1 << 0)
+
+struct privcmd_irqfd {
+	__u64 dm_op;
+	__u32 size; /* Size of structure pointed by dm_op */
+	__u32 fd;
+	__u32 flags;
+	domid_t dom;
+	__u8 pad[2];
+};
+
+/* For privcmd_ioeventfd::flags */
+#define PRIVCMD_IOEVENTFD_FLAG_DEASSIGN (1 << 0)
+
+struct privcmd_ioeventfd {
+	__u64 ioreq;
+	__u64 ports;
+	__u64 addr;
+	__u32 addr_len;
+	__u32 event_fd;
+	__u32 vcpus;
+	__u32 vq;
+	__u32 flags;
+	domid_t dom;
+	__u8 pad[2];
+};
+
+struct privcmd_pcidev_get_gsi {
+	__u32 sbdf;
+	__u32 gsi;
+};
+
+/*
+ * @cmd: IOCTL_PRIVCMD_HYPERCALL
+ * @arg: &privcmd_hypercall_t
+ * Return: Value returned from execution of the specified hypercall.
+ *
+ * @cmd: IOCTL_PRIVCMD_MMAPBATCH_V2
+ * @arg: &struct privcmd_mmapbatch_v2
+ * Return: 0 on success (i.e., arg->err contains valid error codes for
+ * each frame).  On an error other than a failed frame remap, -1 is
+ * returned and errno is set to EINVAL, EFAULT etc.  As an exception,
+ * if the operation was otherwise successful but any frame failed with
+ * -ENOENT, then -1 is returned and errno is set to ENOENT.
+ */
+#define IOCTL_PRIVCMD_HYPERCALL					\
+	_IOC(_IOC_NONE, 'P', 0, sizeof(struct privcmd_hypercall))
+#define IOCTL_PRIVCMD_MMAP					\
+	_IOC(_IOC_NONE, 'P', 2, sizeof(struct privcmd_mmap))
+#define IOCTL_PRIVCMD_MMAPBATCH					\
+	_IOC(_IOC_NONE, 'P', 3, sizeof(struct privcmd_mmapbatch))
+#define IOCTL_PRIVCMD_MMAPBATCH_V2				\
+	_IOC(_IOC_NONE, 'P', 4, sizeof(struct privcmd_mmapbatch_v2))
+#define IOCTL_PRIVCMD_DM_OP					\
+	_IOC(_IOC_NONE, 'P', 5, sizeof(struct privcmd_dm_op))
+#define IOCTL_PRIVCMD_RESTRICT					\
+	_IOC(_IOC_NONE, 'P', 6, sizeof(domid_t))
+#define IOCTL_PRIVCMD_MMAP_RESOURCE				\
+	_IOC(_IOC_NONE, 'P', 7, sizeof(struct privcmd_mmap_resource))
+#define IOCTL_PRIVCMD_IRQFD					\
+	_IOW('P', 8, struct privcmd_irqfd)
+#define IOCTL_PRIVCMD_IOEVENTFD					\
+	_IOW('P', 9, struct privcmd_ioeventfd)
+#define IOCTL_PRIVCMD_PCIDEV_GET_GSI				\
+	_IOC(_IOC_NONE, 'P', 10, sizeof(struct privcmd_pcidev_get_gsi))
+
+#endif /* __LINUX_PUBLIC_PRIVCMD_H__ */