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, 400 insertions, 0 deletions

diff --git a/include/net/9p/client.h b/include/net/9p/client.h
new file mode 100644
index 000000000..55c6cb54b
--- /dev/null
+++ b/include/net/9p/client.h
@@ -0,0 +1,400 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * 9P Client Definitions
+ *
+ *  Copyright (C) 2008 by Eric Van Hensbergen <ericvh@gmail.com>
+ *  Copyright (C) 2007 by Latchesar Ionkov <lucho@ionkov.net>
+ */
+
+#ifndef NET_9P_CLIENT_H
+#define NET_9P_CLIENT_H
+
+#include <linux/utsname.h>
+#include <linux/idr.h>
+#include <linux/tracepoint-defs.h>
+
+/* Number of requests per row */
+#define P9_ROW_MAXTAG 255
+
+/* DEFAULT MSIZE = 32 pages worth of payload + P9_HDRSZ +
+ * room for write (16 extra) or read (11 extra) operands.
+ */
+
+#define DEFAULT_MSIZE ((128 * 1024) + P9_IOHDRSZ)
+
+/** enum p9_proto_versions - 9P protocol versions
+ * @p9_proto_legacy: 9P Legacy mode, pre-9P2000.u
+ * @p9_proto_2000u: 9P2000.u extension
+ * @p9_proto_2000L: 9P2000.L extension
+ */
+
+enum p9_proto_versions {
+	p9_proto_legacy,
+	p9_proto_2000u,
+	p9_proto_2000L,
+};
+
+
+/**
+ * enum p9_trans_status - different states of underlying transports
+ * @Connected: transport is connected and healthy
+ * @Disconnected: transport has been disconnected
+ * @Hung: transport is connected by wedged
+ *
+ * This enumeration details the various states a transport
+ * instatiation can be in.
+ */
+
+enum p9_trans_status {
+	Connected,
+	BeginDisconnect,
+	Disconnected,
+	Hung,
+};
+
+/**
+ * enum p9_req_status_t - status of a request
+ * @REQ_STATUS_ALLOC: request has been allocated but not sent
+ * @REQ_STATUS_UNSENT: request waiting to be sent
+ * @REQ_STATUS_SENT: request sent to server
+ * @REQ_STATUS_RCVD: response received from server
+ * @REQ_STATUS_FLSHD: request has been flushed
+ * @REQ_STATUS_ERROR: request encountered an error on the client side
+ */
+
+enum p9_req_status_t {
+	REQ_STATUS_ALLOC,
+	REQ_STATUS_UNSENT,
+	REQ_STATUS_SENT,
+	REQ_STATUS_RCVD,
+	REQ_STATUS_FLSHD,
+	REQ_STATUS_ERROR,
+};
+
+/**
+ * struct p9_req_t - request slots
+ * @status: status of this request slot
+ * @t_err: transport error
+ * @wq: wait_queue for the client to block on for this request
+ * @tc: the request fcall structure
+ * @rc: the response fcall structure
+ * @req_list: link for higher level objects to chain requests
+ */
+struct p9_req_t {
+	int status;
+	int t_err;
+	refcount_t refcount;
+	wait_queue_head_t wq;
+	struct p9_fcall tc;
+	struct p9_fcall rc;
+	struct list_head req_list;
+};
+
+/**
+ * struct p9_client - per client instance state
+ * @lock: protect @fids and @reqs
+ * @msize: maximum data size negotiated by protocol
+ * @proto_version: 9P protocol version to use
+ * @trans_mod: module API instantiated with this client
+ * @status: connection state
+ * @trans: tranport instance state and API
+ * @fids: All active FID handles
+ * @reqs: All active requests.
+ * @name: node name used as client id
+ *
+ * The client structure is used to keep track of various per-client
+ * state that has been instantiated.
+ */
+struct p9_client {
+	spinlock_t lock;
+	unsigned int msize;
+	unsigned char proto_version;
+	struct p9_trans_module *trans_mod;
+	enum p9_trans_status status;
+	void *trans;
+	struct kmem_cache *fcall_cache;
+
+	union {
+		struct {
+			int rfd;
+			int wfd;
+		} fd;
+		struct {
+			u16 port;
+			bool privport;
+
+		} tcp;
+	} trans_opts;
+
+	struct idr fids;
+	struct idr reqs;
+
+	char name[__NEW_UTS_LEN + 1];
+};
+
+/**
+ * struct p9_fd_opts - holds client options during parsing
+ * @msize: maximum data size negotiated by protocol
+ * @prot-Oversion: 9P protocol version to use
+ * @trans_mod: module API instantiated with this client
+ *
+ * These parsed options get transferred into client in
+ * apply_client_options()
+ */
+struct p9_client_opts {
+	unsigned int msize;
+	unsigned char proto_version;
+	struct p9_trans_module *trans_mod;
+};
+
+/**
+ * struct p9_fd_opts - per-transport options for fd transport
+ * @rfd: file descriptor for reading (trans=fd)
+ * @wfd: file descriptor for writing (trans=fd)
+ * @port: port to connect to (trans=tcp)
+ * @privport: port is privileged
+ */
+struct p9_fd_opts {
+	int rfd;
+	int wfd;
+	u16 port;
+	bool privport;
+};
+
+/**
+ * struct p9_rdma_opts - Collection of mount options for rdma transport
+ * @port: port of connection
+ * @privport: Whether a privileged port may be used
+ * @sq_depth: The requested depth of the SQ. This really doesn't need
+ * to be any deeper than the number of threads used in the client
+ * @rq_depth: The depth of the RQ. Should be greater than or equal to SQ depth
+ * @timeout: Time to wait in msecs for CM events
+ */
+struct p9_rdma_opts {
+	short port;
+	bool privport;
+	int sq_depth;
+	int rq_depth;
+	long timeout;
+};
+
+/**
+ * struct p9_session_opts - holds parsed options for v9fs_session_info
+ * @flags: session options of type &p9_session_flags
+ * @nodev: set to 1 to disable device mapping
+ * @debug: debug level
+ * @afid: authentication handle
+ * @cache: cache mode of type &p9_cache_bits
+ * @cachetag: the tag of the cache associated with this session
+ * @uname: string user name to mount hierarchy as
+ * @aname: mount specifier for remote hierarchy
+ * @dfltuid: default numeric userid to mount hierarchy as
+ * @dfltgid: default numeric groupid to mount hierarchy as
+ * @uid: if %V9FS_ACCESS_SINGLE, the numeric uid which mounted the hierarchy
+ * @session_lock_timeout: retry interval for blocking locks
+ * @ndentry_timeout_ms: Negative dentry lookup cache retention time in ms
+ *
+ * This strucure holds options which are parsed and will be transferred
+ * to the v9fs_session_info structure when mounted, and therefore largely
+ * duplicates struct v9fs_session_info.
+ */
+struct p9_session_opts {
+	unsigned int flags;
+	unsigned char nodev;
+	unsigned short debug;
+	unsigned int afid;
+	unsigned int cache;
+	unsigned int ndentry_timeout_ms;
+#ifdef CONFIG_9P_FSCACHE
+	char *cachetag;
+#endif
+	char *uname;
+	char *aname;
+	kuid_t dfltuid;
+	kgid_t dfltgid;
+	kuid_t uid;
+	long session_lock_timeout;
+};
+
+/* Used by mount API to store parsed mount options */
+struct v9fs_context {
+	struct p9_client_opts	client_opts;
+	struct p9_fd_opts	fd_opts;
+	struct p9_rdma_opts	rdma_opts;
+	struct p9_session_opts	session_opts;
+};
+
+/**
+ * struct p9_fid - file system entity handle
+ * @clnt: back pointer to instantiating &p9_client
+ * @fid: numeric identifier for this handle
+ * @mode: current mode of this fid (enum?)
+ * @qid: the &p9_qid server identifier this handle points to
+ * @iounit: the server reported maximum transaction size for this file
+ * @uid: the numeric uid of the local user who owns this handle
+ * @rdir: readdir accounting structure (allocated on demand)
+ * @dlist: per-dentry fid tracking
+ *
+ * TODO: This needs lots of explanation.
+ */
+enum fid_source {
+	FID_FROM_OTHER,
+	FID_FROM_INODE,
+	FID_FROM_DENTRY,
+};
+
+struct p9_fid {
+	struct p9_client *clnt;
+	u32 fid;
+	refcount_t count;
+	int mode;
+	struct p9_qid qid;
+	u32 iounit;
+	kuid_t uid;
+
+	void *rdir;
+
+	struct hlist_node dlist;	/* list of all fids attached to a dentry */
+	struct hlist_node ilist;
+};
+
+/**
+ * struct p9_dirent - directory entry structure
+ * @qid: The p9 server qid for this dirent
+ * @d_off: offset to the next dirent
+ * @d_type: type of file
+ * @d_name: file name
+ */
+
+struct p9_dirent {
+	struct p9_qid qid;
+	u64 d_off;
+	unsigned char d_type;
+	char d_name[256];
+};
+
+struct iov_iter;
+
+int p9_show_client_options(struct seq_file *m, struct p9_client *clnt);
+int p9_client_statfs(struct p9_fid *fid, struct p9_rstatfs *sb);
+int p9_client_rename(struct p9_fid *fid, struct p9_fid *newdirfid,
+		     const char *name);
+int p9_client_renameat(struct p9_fid *olddirfid, const char *old_name,
+		       struct p9_fid *newdirfid, const char *new_name);
+struct p9_client *p9_client_create(struct fs_context *fc);
+void p9_client_destroy(struct p9_client *clnt);
+void p9_client_disconnect(struct p9_client *clnt);
+void p9_client_begin_disconnect(struct p9_client *clnt);
+struct p9_fid *p9_client_attach(struct p9_client *clnt, struct p9_fid *afid,
+				const char *uname, kuid_t n_uname, const char *aname);
+struct p9_fid *p9_client_walk(struct p9_fid *oldfid, uint16_t nwname,
+		const unsigned char * const *wnames, int clone);
+int p9_client_open(struct p9_fid *fid, int mode);
+int p9_client_fcreate(struct p9_fid *fid, const char *name, u32 perm, int mode,
+							char *extension);
+int p9_client_link(struct p9_fid *fid, struct p9_fid *oldfid, const char *newname);
+int p9_client_symlink(struct p9_fid *fid, const char *name, const char *symname,
+		kgid_t gid, struct p9_qid *qid);
+int p9_client_create_dotl(struct p9_fid *ofid, const char *name, u32 flags, u32 mode,
+		kgid_t gid, struct p9_qid *qid);
+int p9_client_clunk(struct p9_fid *fid);
+int p9_client_fsync(struct p9_fid *fid, int datasync);
+int p9_client_remove(struct p9_fid *fid);
+int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags);
+int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err);
+int p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to,
+		int *err);
+int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err);
+struct netfs_io_subrequest;
+void p9_client_write_subreq(struct netfs_io_subrequest *subreq);
+int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset);
+int p9dirent_read(struct p9_client *clnt, char *buf, int len,
+		  struct p9_dirent *dirent);
+struct p9_wstat *p9_client_stat(struct p9_fid *fid);
+int p9_client_wstat(struct p9_fid *fid, struct p9_wstat *wst);
+int p9_client_setattr(struct p9_fid *fid, struct p9_iattr_dotl *attr);
+
+struct p9_stat_dotl *p9_client_getattr_dotl(struct p9_fid *fid,
+							u64 request_mask);
+
+int p9_client_mknod_dotl(struct p9_fid *oldfid, const char *name, int mode,
+			dev_t rdev, kgid_t gid, struct p9_qid *qid);
+int p9_client_mkdir_dotl(struct p9_fid *fid, const char *name, int mode,
+				kgid_t gid, struct p9_qid *qid);
+int p9_client_lock_dotl(struct p9_fid *fid, struct p9_flock *flock, u8 *status);
+int p9_client_getlock_dotl(struct p9_fid *fid, struct p9_getlock *fl);
+void p9_fcall_fini(struct p9_fcall *fc);
+struct p9_req_t *p9_tag_lookup(struct p9_client *c, u16 tag);
+
+static inline void p9_req_get(struct p9_req_t *r)
+{
+	refcount_inc(&r->refcount);
+}
+
+static inline int p9_req_try_get(struct p9_req_t *r)
+{
+	return refcount_inc_not_zero(&r->refcount);
+}
+
+int p9_req_put(struct p9_client *c, struct p9_req_t *r);
+
+/* We cannot have the real tracepoints in header files,
+ * use a wrapper function */
+DECLARE_TRACEPOINT(9p_fid_ref);
+void do_trace_9p_fid_get(struct p9_fid *fid);
+void do_trace_9p_fid_put(struct p9_fid *fid);
+
+/* fid reference counting helpers:
+ *  - fids used for any length of time should always be referenced through
+ *    p9_fid_get(), and released with p9_fid_put()
+ *  - v9fs_fid_lookup() or similar will automatically call get for you
+ *    and also require a put
+ *  - the *_fid_add() helpers will stash the fid in the inode,
+ *    at which point it is the responsibility of evict_inode()
+ *    to call the put
+ *  - the last put will automatically send a clunk to the server
+ */
+static inline struct p9_fid *p9_fid_get(struct p9_fid *fid)
+{
+	if (tracepoint_enabled(9p_fid_ref))
+		do_trace_9p_fid_get(fid);
+
+	refcount_inc(&fid->count);
+
+	return fid;
+}
+
+static inline int p9_fid_put(struct p9_fid *fid)
+{
+	if (!fid || IS_ERR(fid))
+		return 0;
+
+	if (tracepoint_enabled(9p_fid_ref))
+		do_trace_9p_fid_put(fid);
+
+	if (!refcount_dec_and_test(&fid->count))
+		return 0;
+
+	return p9_client_clunk(fid);
+}
+
+void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status);
+
+int p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type,
+		    int16_t *tag, int rewind);
+int p9stat_read(struct p9_client *clnt, char *buf, int len,
+		struct p9_wstat *st);
+void p9stat_free(struct p9_wstat *stbuf);
+
+int p9_is_proto_dotu(struct p9_client *clnt);
+int p9_is_proto_dotl(struct p9_client *clnt);
+struct p9_fid *p9_client_xattrwalk(struct p9_fid *file_fid,
+				   const char *attr_name, u64 *attr_size);
+int p9_client_xattrcreate(struct p9_fid *fid, const char *name,
+			  u64 attr_size, int flags);
+int p9_client_readlink(struct p9_fid *fid, char **target);
+
+int p9_client_init(void);
+void p9_client_exit(void);
+
+#endif /* NET_9P_CLIENT_H */