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, 187 insertions, 0 deletions

diff --git a/include/rdma/restrack.h b/include/rdma/restrack.h
new file mode 100644
index 000000000..47fec3083
--- /dev/null
+++ b/include/rdma/restrack.h
@@ -0,0 +1,187 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/*
+ * Copyright (c) 2017-2018 Mellanox Technologies. All rights reserved.
+ */
+
+#ifndef _RDMA_RESTRACK_H_
+#define _RDMA_RESTRACK_H_
+
+#include <linux/typecheck.h>
+#include <linux/sched.h>
+#include <linux/kref.h>
+#include <linux/completion.h>
+#include <linux/sched/task.h>
+#include <uapi/rdma/rdma_netlink.h>
+#include <linux/xarray.h>
+
+/* Mark entry as containing driver specific details, it is used to provide QP subtype for now */
+#define RESTRACK_DD XA_MARK_1
+
+struct ib_device;
+struct sk_buff;
+
+/**
+ * enum rdma_restrack_type - HW objects to track
+ */
+enum rdma_restrack_type {
+	/**
+	 * @RDMA_RESTRACK_PD: Protection domain (PD)
+	 */
+	RDMA_RESTRACK_PD,
+	/**
+	 * @RDMA_RESTRACK_CQ: Completion queue (CQ)
+	 */
+	RDMA_RESTRACK_CQ,
+	/**
+	 * @RDMA_RESTRACK_QP: Queue pair (QP)
+	 */
+	RDMA_RESTRACK_QP,
+	/**
+	 * @RDMA_RESTRACK_CM_ID: Connection Manager ID (CM_ID)
+	 */
+	RDMA_RESTRACK_CM_ID,
+	/**
+	 * @RDMA_RESTRACK_MR: Memory Region (MR)
+	 */
+	RDMA_RESTRACK_MR,
+	/**
+	 * @RDMA_RESTRACK_CTX: Verbs contexts (CTX)
+	 */
+	RDMA_RESTRACK_CTX,
+	/**
+	 * @RDMA_RESTRACK_COUNTER: Statistic Counter
+	 */
+	RDMA_RESTRACK_COUNTER,
+	/**
+	 * @RDMA_RESTRACK_SRQ: Shared receive queue (SRQ)
+	 */
+	RDMA_RESTRACK_SRQ,
+	/**
+	 * @RDMA_RESTRACK_DMAH: DMA handle
+	 */
+	RDMA_RESTRACK_DMAH,
+	/**
+	 * @RDMA_RESTRACK_COMP_CNTR: Completion Counter
+	 */
+	RDMA_RESTRACK_COMP_CNTR,
+	/**
+	 * @RDMA_RESTRACK_MAX: Last entry, used for array dclarations
+	 */
+	RDMA_RESTRACK_MAX
+};
+
+/**
+ * struct rdma_restrack_entry - metadata per-entry
+ */
+struct rdma_restrack_entry {
+	/**
+	 * @valid: validity indicator
+	 *
+	 * The entries are filled during rdma_restrack_add,
+	 * can be attempted to be free during rdma_restrack_del.
+	 *
+	 * As an example for that, see mlx5 QPs with type MLX5_IB_QPT_HW_GSI
+	 */
+	bool			valid;
+	/**
+	 * @no_track: don't add this entry to restrack DB
+	 *
+	 * This field is used to mark an entry that doesn't need to be added to
+	 * internal restrack DB and presented later to the users at the nldev
+	 * query stage.
+	 */
+	u8			no_track : 1;
+	/**
+	 * @kref: Protect destroy of the resource
+	 */
+	struct kref		kref;
+	/**
+	 * @comp: Signal that all consumers of resource are completed their work
+	 */
+	struct completion	comp;
+	/**
+	 * @task: owner of resource tracking entity
+	 *
+	 * There are two types of entities: created by user and created
+	 * by kernel.
+	 *
+	 * This is relevant for the entities created by users.
+	 * For the entities created by kernel, this pointer will be NULL.
+	 */
+	struct task_struct	*task;
+	/**
+	 * @kern_name: name of owner for the kernel created entities.
+	 */
+	const char		*kern_name;
+	/**
+	 * @type: various objects in restrack database
+	 */
+	enum rdma_restrack_type	type;
+	/**
+	 * @user: user resource
+	 */
+	bool			user;
+	/**
+	 * @id: ID to expose to users
+	 */
+	u32 id;
+};
+
+u32 rdma_restrack_count(struct ib_device *dev, enum rdma_restrack_type type,
+			bool show_details);
+/**
+ * rdma_is_kernel_res() - check the owner of resource
+ * @res:  resource entry
+ */
+static inline bool rdma_is_kernel_res(const struct rdma_restrack_entry *res)
+{
+	return !res->user;
+}
+
+/**
+ * rdma_restrack_get() - grab to protect resource from release
+ * @res:  resource entry
+ */
+int __must_check rdma_restrack_get(struct rdma_restrack_entry *res);
+
+/**
+ * rdma_restrack_put() - release resource
+ * @res:  resource entry
+ */
+int rdma_restrack_put(struct rdma_restrack_entry *res);
+
+/*
+ * Helper functions for rdma drivers when filling out
+ * nldev driver attributes.
+ */
+int rdma_nl_put_driver_u32(struct sk_buff *msg, const char *name, u32 value);
+int rdma_nl_put_driver_u32_hex(struct sk_buff *msg, const char *name,
+			       u32 value);
+int rdma_nl_put_driver_u64(struct sk_buff *msg, const char *name, u64 value);
+int rdma_nl_put_driver_u64_hex(struct sk_buff *msg, const char *name,
+			       u64 value);
+int rdma_nl_put_driver_string(struct sk_buff *msg, const char *name,
+			      const char *str);
+int rdma_nl_stat_hwcounter_entry(struct sk_buff *msg, const char *name,
+				 u64 value);
+
+struct rdma_restrack_entry *rdma_restrack_get_byid(struct ib_device *dev,
+						   enum rdma_restrack_type type,
+						   u32 id);
+
+/**
+ * rdma_restrack_no_track() - don't add resource to the DB
+ * @res: resource entry
+ *
+ * Every user of this API should be cross examined.
+ * Probably you don't need to use this function.
+ */
+static inline void rdma_restrack_no_track(struct rdma_restrack_entry *res)
+{
+	res->no_track = true;
+}
+static inline bool rdma_restrack_is_tracked(struct rdma_restrack_entry *res)
+{
+	return !res->no_track;
+}
+#endif /* _RDMA_RESTRACK_H_ */