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, 348 insertions, 0 deletions

diff --git a/net/sunrpc/stats.c b/net/sunrpc/stats.c
new file mode 100644
index 000000000..d08711bee
--- /dev/null
+++ b/net/sunrpc/stats.c
@@ -0,0 +1,348 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/net/sunrpc/stats.c
+ *
+ * procfs-based user access to generic RPC statistics. The stats files
+ * reside in /proc/net/rpc.
+ *
+ * The read routines assume that the buffer passed in is just big enough.
+ * If you implement an RPC service that has its own stats routine which
+ * appends the generic RPC stats, make sure you don't exceed the PAGE_SIZE
+ * limit.
+ *
+ * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/sunrpc/metrics.h>
+#include <linux/rcupdate.h>
+
+#include <trace/events/sunrpc.h>
+
+#include "netns.h"
+
+#define RPCDBG_FACILITY	RPCDBG_MISC
+
+/*
+ * Get RPC client stats
+ */
+static int rpc_proc_show(struct seq_file *seq, void *v) {
+	const struct rpc_stat	*statp = seq->private;
+	const struct rpc_program *prog = statp->program;
+	unsigned int i, j;
+
+	seq_printf(seq,
+		"net %u %u %u %u\n",
+			statp->netcnt,
+			statp->netudpcnt,
+			statp->nettcpcnt,
+			statp->nettcpconn);
+	seq_printf(seq,
+		"rpc %u %u %u\n",
+			statp->rpccnt,
+			statp->rpcretrans,
+			statp->rpcauthrefresh);
+
+	for (i = 0; i < prog->nrvers; i++) {
+		const struct rpc_version *vers = prog->version[i];
+		if (!vers)
+			continue;
+		seq_printf(seq, "proc%u %u",
+					vers->number, vers->nrprocs);
+		for (j = 0; j < vers->nrprocs; j++)
+			seq_printf(seq, " %u", vers->counts[j]);
+		seq_putc(seq, '\n');
+	}
+	return 0;
+}
+
+static int rpc_proc_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, rpc_proc_show, pde_data(inode));
+}
+
+static const struct proc_ops rpc_proc_ops = {
+	.proc_open	= rpc_proc_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= single_release,
+};
+
+/*
+ * Get RPC server stats
+ */
+void svc_seq_show(struct seq_file *seq, const struct svc_stat *statp)
+{
+	const struct svc_program *prog = statp->program;
+	const struct svc_version *vers;
+	unsigned int i, j, k;
+	unsigned long count;
+
+	seq_printf(seq,
+		"net %u %u %u %u\n",
+			statp->netcnt,
+			statp->netudpcnt,
+			statp->nettcpcnt,
+			statp->nettcpconn);
+	seq_printf(seq,
+		"rpc %u %u %u %u %u\n",
+			statp->rpccnt,
+			statp->rpcbadfmt+statp->rpcbadauth+statp->rpcbadclnt,
+			statp->rpcbadfmt,
+			statp->rpcbadauth,
+			statp->rpcbadclnt);
+
+	for (i = 0; i < prog->pg_nvers; i++) {
+		vers = prog->pg_vers[i];
+		if (!vers)
+			continue;
+		seq_printf(seq, "proc%d %u", i, vers->vs_nproc);
+		for (j = 0; j < vers->vs_nproc; j++) {
+			count = 0;
+			for_each_possible_cpu(k)
+				count += per_cpu(statp->vs_count[i][j], k);
+			seq_printf(seq, " %lu", count);
+		}
+		seq_putc(seq, '\n');
+	}
+}
+EXPORT_SYMBOL_GPL(svc_seq_show);
+
+/**
+ * rpc_alloc_iostats - allocate an rpc_iostats structure
+ * @clnt: RPC program, version, and xprt
+ *
+ */
+struct rpc_iostats *rpc_alloc_iostats(struct rpc_clnt *clnt)
+{
+	struct rpc_iostats *stats;
+	int i;
+
+	stats = kzalloc_objs(*stats, clnt->cl_maxproc);
+	if (stats) {
+		for (i = 0; i < clnt->cl_maxproc; i++)
+			spin_lock_init(&stats[i].om_lock);
+	}
+	return stats;
+}
+EXPORT_SYMBOL_GPL(rpc_alloc_iostats);
+
+/**
+ * rpc_free_iostats - release an rpc_iostats structure
+ * @stats: doomed rpc_iostats structure
+ *
+ */
+void rpc_free_iostats(struct rpc_iostats *stats)
+{
+	kfree(stats);
+}
+EXPORT_SYMBOL_GPL(rpc_free_iostats);
+
+/**
+ * rpc_count_iostats_metrics - tally up per-task stats
+ * @task: completed rpc_task
+ * @op_metrics: stat structure for OP that will accumulate stats from @task
+ */
+void rpc_count_iostats_metrics(const struct rpc_task *task,
+			       struct rpc_iostats *op_metrics)
+{
+	struct rpc_rqst *req = task->tk_rqstp;
+	ktime_t backlog, execute, now;
+
+	if (!op_metrics || !req)
+		return;
+
+	now = ktime_get();
+	spin_lock(&op_metrics->om_lock);
+
+	op_metrics->om_ops++;
+	/* kernel API: om_ops must never become larger than om_ntrans */
+	op_metrics->om_ntrans += max(req->rq_ntrans, 1);
+	op_metrics->om_timeouts += task->tk_timeouts;
+
+	op_metrics->om_bytes_sent += req->rq_xmit_bytes_sent;
+	op_metrics->om_bytes_recv += req->rq_reply_bytes_recvd;
+
+	backlog = 0;
+	if (ktime_to_ns(req->rq_xtime)) {
+		backlog = ktime_sub(req->rq_xtime, task->tk_start);
+		op_metrics->om_queue = ktime_add(op_metrics->om_queue, backlog);
+	}
+
+	op_metrics->om_rtt = ktime_add(op_metrics->om_rtt, req->rq_rtt);
+
+	execute = ktime_sub(now, task->tk_start);
+	op_metrics->om_execute = ktime_add(op_metrics->om_execute, execute);
+	if (task->tk_status < 0)
+		op_metrics->om_error_status++;
+
+	spin_unlock(&op_metrics->om_lock);
+
+	trace_rpc_stats_latency(req->rq_task, backlog, req->rq_rtt, execute);
+}
+EXPORT_SYMBOL_GPL(rpc_count_iostats_metrics);
+
+/**
+ * rpc_count_iostats - tally up per-task stats
+ * @task: completed rpc_task
+ * @stats: array of stat structures
+ *
+ * Uses the statidx from @task
+ */
+void rpc_count_iostats(const struct rpc_task *task, struct rpc_iostats *stats)
+{
+	rpc_count_iostats_metrics(task,
+				  &stats[task->tk_msg.rpc_proc->p_statidx]);
+}
+EXPORT_SYMBOL_GPL(rpc_count_iostats);
+
+static void _print_name(struct seq_file *seq, unsigned int op,
+			const struct rpc_procinfo *procs)
+{
+	if (procs[op].p_name)
+		seq_printf(seq, "\t%12s: ", procs[op].p_name);
+	else if (op == 0)
+		seq_printf(seq, "\t        NULL: ");
+	else
+		seq_printf(seq, "\t%12u: ", op);
+}
+
+static void _add_rpc_iostats(struct rpc_iostats *a, struct rpc_iostats *b)
+{
+	a->om_ops += b->om_ops;
+	a->om_ntrans += b->om_ntrans;
+	a->om_timeouts += b->om_timeouts;
+	a->om_bytes_sent += b->om_bytes_sent;
+	a->om_bytes_recv += b->om_bytes_recv;
+	a->om_queue = ktime_add(a->om_queue, b->om_queue);
+	a->om_rtt = ktime_add(a->om_rtt, b->om_rtt);
+	a->om_execute = ktime_add(a->om_execute, b->om_execute);
+	a->om_error_status += b->om_error_status;
+}
+
+static void _print_rpc_iostats(struct seq_file *seq, struct rpc_iostats *stats,
+			       int op, const struct rpc_procinfo *procs)
+{
+	_print_name(seq, op, procs);
+	seq_printf(seq, "%lu %lu %lu %llu %llu %llu %llu %llu %lu\n",
+		   stats->om_ops,
+		   stats->om_ntrans,
+		   stats->om_timeouts,
+		   stats->om_bytes_sent,
+		   stats->om_bytes_recv,
+		   ktime_to_ms(stats->om_queue),
+		   ktime_to_ms(stats->om_rtt),
+		   ktime_to_ms(stats->om_execute),
+		   stats->om_error_status);
+}
+
+static int do_print_stats(struct rpc_clnt *clnt, struct rpc_xprt *xprt, void *seqv)
+{
+	struct seq_file *seq = seqv;
+
+	xprt->ops->print_stats(xprt, seq);
+	return 0;
+}
+
+void rpc_clnt_show_stats(struct seq_file *seq, struct rpc_clnt *clnt)
+{
+	unsigned int op, maxproc = clnt->cl_maxproc;
+
+	if (!clnt->cl_metrics)
+		return;
+
+	seq_printf(seq, "\tRPC iostats version: %s  ", RPC_IOSTATS_VERS);
+	seq_printf(seq, "p/v: %u/%u (%s)\n",
+			clnt->cl_prog, clnt->cl_vers, clnt->cl_program->name);
+
+	rpc_clnt_iterate_for_each_xprt(clnt, do_print_stats, seq);
+
+	seq_printf(seq, "\tper-op statistics\n");
+	for (op = 0; op < maxproc; op++) {
+		struct rpc_iostats stats = {};
+		struct rpc_clnt *next = clnt;
+		do {
+			_add_rpc_iostats(&stats, &next->cl_metrics[op]);
+			if (next == next->cl_parent)
+				break;
+			next = next->cl_parent;
+		} while (next);
+		_print_rpc_iostats(seq, &stats, op, clnt->cl_procinfo);
+	}
+}
+EXPORT_SYMBOL_GPL(rpc_clnt_show_stats);
+
+/*
+ * Register/unregister RPC proc files
+ */
+static inline struct proc_dir_entry *
+do_register(struct net *net, const char *name, void *data,
+	    const struct proc_ops *proc_ops)
+{
+	struct sunrpc_net *sn;
+
+	dprintk("RPC:       registering /proc/net/rpc/%s\n", name);
+	sn = net_generic(net, sunrpc_net_id);
+	return proc_create_data(name, 0, sn->proc_net_rpc, proc_ops, data);
+}
+
+struct proc_dir_entry *
+rpc_proc_register(struct net *net, struct rpc_stat *statp)
+{
+	return do_register(net, statp->program->name, statp, &rpc_proc_ops);
+}
+EXPORT_SYMBOL_GPL(rpc_proc_register);
+
+void
+rpc_proc_unregister(struct net *net, const char *name)
+{
+	struct sunrpc_net *sn;
+
+	sn = net_generic(net, sunrpc_net_id);
+	remove_proc_entry(name, sn->proc_net_rpc);
+}
+EXPORT_SYMBOL_GPL(rpc_proc_unregister);
+
+struct proc_dir_entry *
+svc_proc_register(struct net *net, struct svc_stat *statp, const struct proc_ops *proc_ops)
+{
+	return do_register(net, statp->program->pg_name, net, proc_ops);
+}
+EXPORT_SYMBOL_GPL(svc_proc_register);
+
+void
+svc_proc_unregister(struct net *net, const char *name)
+{
+	struct sunrpc_net *sn;
+
+	sn = net_generic(net, sunrpc_net_id);
+	remove_proc_entry(name, sn->proc_net_rpc);
+}
+EXPORT_SYMBOL_GPL(svc_proc_unregister);
+
+int rpc_proc_init(struct net *net)
+{
+	struct sunrpc_net *sn;
+
+	dprintk("RPC:       registering /proc/net/rpc\n");
+	sn = net_generic(net, sunrpc_net_id);
+	sn->proc_net_rpc = proc_mkdir("rpc", net->proc_net);
+	if (sn->proc_net_rpc == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void rpc_proc_exit(struct net *net)
+{
+	dprintk("RPC:       unregistering /proc/net/rpc\n");
+	remove_proc_entry("rpc", net->proc_net);
+}