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, 278 insertions, 0 deletions

diff --git a/net/sunrpc/socklib.c b/net/sunrpc/socklib.c
new file mode 100644
index 000000000..d8d8842c7
--- /dev/null
+++ b/net/sunrpc/socklib.c
@@ -0,0 +1,278 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/net/sunrpc/socklib.c
+ *
+ * Common socket helper routines for RPC client and server
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/compiler.h>
+#include <linux/netdevice.h>
+#include <linux/gfp.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+#include <linux/pagemap.h>
+#include <linux/udp.h>
+#include <linux/sunrpc/msg_prot.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/export.h>
+
+#include "socklib.h"
+
+/*
+ * Helper structure for copying from an sk_buff.
+ */
+struct xdr_skb_reader {
+	struct sk_buff	*skb;
+	unsigned int	offset;
+	bool		need_checksum;
+	size_t		count;
+	__wsum		csum;
+};
+
+/**
+ * xdr_skb_read_bits - copy some data bits from skb to internal buffer
+ * @desc: sk_buff copy helper
+ * @to: copy destination
+ * @len: number of bytes to copy
+ *
+ * Possibly called several times to iterate over an sk_buff and copy data out of
+ * it.
+ */
+static size_t
+xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len)
+{
+	len = min(len, desc->count);
+
+	if (desc->need_checksum) {
+		__wsum csum;
+
+		csum = skb_copy_and_csum_bits(desc->skb, desc->offset, to, len);
+		desc->csum = csum_block_add(desc->csum, csum, desc->offset);
+	} else {
+		if (unlikely(skb_copy_bits(desc->skb, desc->offset, to, len)))
+			return 0;
+	}
+
+	desc->count -= len;
+	desc->offset += len;
+	return len;
+}
+
+static ssize_t
+xdr_partial_copy_from_skb(struct xdr_buf *xdr, struct xdr_skb_reader *desc)
+{
+	struct page **ppage = xdr->pages + (xdr->page_base >> PAGE_SHIFT);
+	unsigned int poff = xdr->page_base & ~PAGE_MASK;
+	unsigned int pglen = xdr->page_len;
+	ssize_t copied = 0;
+	size_t ret;
+
+	if (xdr->head[0].iov_len == 0)
+		return 0;
+
+	ret = xdr_skb_read_bits(desc, xdr->head[0].iov_base,
+				xdr->head[0].iov_len);
+	if (ret != xdr->head[0].iov_len || !desc->count)
+		return ret;
+	copied += ret;
+
+	while (pglen) {
+		unsigned int len = min(PAGE_SIZE - poff, pglen);
+		char *kaddr;
+
+		/* ACL likes to be lazy in allocating pages - ACLs
+		 * are small by default but can get huge. */
+		if ((xdr->flags & XDRBUF_SPARSE_PAGES) && *ppage == NULL) {
+			*ppage = alloc_page(GFP_NOWAIT);
+			if (unlikely(*ppage == NULL)) {
+				if (copied == 0)
+					return -ENOMEM;
+				return copied;
+			}
+		}
+
+		kaddr = kmap_atomic(*ppage);
+		ret = xdr_skb_read_bits(desc, kaddr + poff, len);
+		flush_dcache_page(*ppage);
+		kunmap_atomic(kaddr);
+
+		copied += ret;
+		if (ret != len || !desc->count)
+			return copied;
+		ppage++;
+		pglen -= len;
+		poff = 0;
+	}
+
+	if (xdr->tail[0].iov_len) {
+		copied += xdr_skb_read_bits(desc, xdr->tail[0].iov_base,
+					xdr->tail[0].iov_len);
+	}
+
+	return copied;
+}
+
+/**
+ * csum_partial_copy_to_xdr - checksum and copy data
+ * @xdr: target XDR buffer
+ * @skb: source skb
+ *
+ * We have set things up such that we perform the checksum of the UDP
+ * packet in parallel with the copies into the RPC client iovec.  -DaveM
+ */
+int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
+{
+	struct xdr_skb_reader desc = {
+		.skb		= skb,
+		.count		= skb->len - desc.offset,
+	};
+
+	if (skb_csum_unnecessary(skb)) {
+		if (xdr_partial_copy_from_skb(xdr, &desc) < 0)
+			return -1;
+		if (desc.count)
+			return -1;
+		return 0;
+	}
+
+	desc.need_checksum = true;
+	desc.csum = csum_partial(skb->data, desc.offset, skb->csum);
+	if (xdr_partial_copy_from_skb(xdr, &desc) < 0)
+		return -1;
+	if (desc.offset != skb->len) {
+		__wsum csum2;
+		csum2 = skb_checksum(skb, desc.offset, skb->len - desc.offset, 0);
+		desc.csum = csum_block_add(desc.csum, csum2, desc.offset);
+	}
+	if (desc.count)
+		return -1;
+	if (csum_fold(desc.csum))
+		return -1;
+	if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
+	    !skb->csum_complete_sw)
+		netdev_rx_csum_fault(skb->dev, skb);
+	return 0;
+}
+
+static inline int xprt_sendmsg(struct socket *sock, struct msghdr *msg,
+			       size_t seek)
+{
+	if (seek)
+		iov_iter_advance(&msg->msg_iter, seek);
+	return sock_sendmsg(sock, msg);
+}
+
+static int xprt_send_kvec(struct socket *sock, struct msghdr *msg,
+			  struct kvec *vec, size_t seek)
+{
+	iov_iter_kvec(&msg->msg_iter, ITER_SOURCE, vec, 1, vec->iov_len);
+	return xprt_sendmsg(sock, msg, seek);
+}
+
+static int xprt_send_pagedata(struct socket *sock, struct msghdr *msg,
+			      struct xdr_buf *xdr, size_t base)
+{
+	iov_iter_bvec(&msg->msg_iter, ITER_SOURCE, xdr->bvec, xdr_buf_pagecount(xdr),
+		      xdr->page_len + xdr->page_base);
+	return xprt_sendmsg(sock, msg, base + xdr->page_base);
+}
+
+/* Common case:
+ *  - stream transport
+ *  - sending from byte 0 of the message
+ *  - the message is wholly contained in @xdr's head iovec
+ */
+static int xprt_send_rm_and_kvec(struct socket *sock, struct msghdr *msg,
+				 rpc_fraghdr marker, struct kvec *vec,
+				 size_t base)
+{
+	struct kvec iov[2] = {
+		[0] = {
+			.iov_base	= &marker,
+			.iov_len	= sizeof(marker)
+		},
+		[1] = *vec,
+	};
+	size_t len = iov[0].iov_len + iov[1].iov_len;
+
+	iov_iter_kvec(&msg->msg_iter, ITER_SOURCE, iov, 2, len);
+	return xprt_sendmsg(sock, msg, base);
+}
+
+/**
+ * xprt_sock_sendmsg - write an xdr_buf directly to a socket
+ * @sock: open socket to send on
+ * @msg: socket message metadata
+ * @xdr: xdr_buf containing this request
+ * @base: starting position in the buffer
+ * @marker: stream record marker field
+ * @sent_p: return the total number of bytes successfully queued for sending
+ *
+ * Return values:
+ *   On success, returns zero and fills in @sent_p.
+ *   %-ENOTSOCK if  @sock is not a struct socket.
+ */
+int xprt_sock_sendmsg(struct socket *sock, struct msghdr *msg,
+		      struct xdr_buf *xdr, unsigned int base,
+		      rpc_fraghdr marker, unsigned int *sent_p)
+{
+	unsigned int rmsize = marker ? sizeof(marker) : 0;
+	unsigned int remainder = rmsize + xdr->len - base;
+	unsigned int want;
+	int err = 0;
+
+	*sent_p = 0;
+
+	if (unlikely(!sock))
+		return -ENOTSOCK;
+
+	msg->msg_flags |= MSG_MORE;
+	want = xdr->head[0].iov_len + rmsize;
+	if (base < want) {
+		unsigned int len = want - base;
+
+		remainder -= len;
+		if (remainder == 0)
+			msg->msg_flags &= ~MSG_MORE;
+		if (rmsize)
+			err = xprt_send_rm_and_kvec(sock, msg, marker,
+						    &xdr->head[0], base);
+		else
+			err = xprt_send_kvec(sock, msg, &xdr->head[0], base);
+		if (remainder == 0 || err != len)
+			goto out;
+		*sent_p += err;
+		base = 0;
+	} else {
+		base -= want;
+	}
+
+	if (base < xdr->page_len) {
+		unsigned int len = xdr->page_len - base;
+
+		remainder -= len;
+		if (remainder == 0)
+			msg->msg_flags &= ~MSG_MORE;
+		err = xprt_send_pagedata(sock, msg, xdr, base);
+		if (remainder == 0 || err != len)
+			goto out;
+		*sent_p += err;
+		base = 0;
+	} else {
+		base -= xdr->page_len;
+	}
+
+	if (base >= xdr->tail[0].iov_len)
+		return 0;
+	msg->msg_flags &= ~MSG_MORE;
+	err = xprt_send_kvec(sock, msg, &xdr->tail[0], base);
+out:
+	if (err > 0) {
+		*sent_p += err;
+		err = 0;
+	}
+	return err;
+}