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, 214 insertions, 0 deletions

diff --git a/drivers/usb/gadget/epautoconf.c b/drivers/usb/gadget/epautoconf.c
new file mode 100644
index 000000000..30016b805
--- /dev/null
+++ b/drivers/usb/gadget/epautoconf.c
@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * epautoconf.c -- endpoint autoconfiguration for usb gadget drivers
+ *
+ * Copyright (C) 2004 David Brownell
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/device.h>
+
+#include <linux/ctype.h>
+#include <linux/string.h>
+
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+
+/**
+ * usb_ep_autoconfig_ss() - choose an endpoint matching the ep
+ * descriptor and ep companion descriptor
+ * @gadget: The device to which the endpoint must belong.
+ * @desc: Endpoint descriptor, with endpoint direction and transfer mode
+ *    initialized.  For periodic transfers, the maximum packet
+ *    size must also be initialized.  This is modified on
+ *    success.
+ * @ep_comp: Endpoint companion descriptor, with the required
+ *    number of streams. Will be modified when the chosen EP
+ *    supports a different number of streams.
+ *
+ * This routine replaces the usb_ep_autoconfig when needed
+ * superspeed enhancments. If such enhancemnets are required,
+ * the FD should call usb_ep_autoconfig_ss directly and provide
+ * the additional ep_comp parameter.
+ *
+ * By choosing an endpoint to use with the specified descriptor,
+ * this routine simplifies writing gadget drivers that work with
+ * multiple USB device controllers.  The endpoint would be
+ * passed later to usb_ep_enable(), along with some descriptor.
+ *
+ * That second descriptor won't always be the same as the first one.
+ * For example, isochronous endpoints can be autoconfigured for high
+ * bandwidth, and then used in several lower bandwidth altsettings.
+ * Also, high and full speed descriptors will be different.
+ *
+ * Be sure to examine and test the results of autoconfiguration
+ * on your hardware.  This code may not make the best choices
+ * about how to use the USB controller, and it can't know all
+ * the restrictions that may apply. Some combinations of driver
+ * and hardware won't be able to autoconfigure.
+ *
+ * On success, this returns an claimed usb_ep, and modifies the endpoint
+ * descriptor bEndpointAddress.  For bulk endpoints, the wMaxPacket value
+ * is initialized as if the endpoint were used at full speed and
+ * the bmAttribute field in the ep companion descriptor is
+ * updated with the assigned number of streams if it is
+ * different from the original value. To prevent the endpoint
+ * from being returned by a later autoconfig call, claims it by
+ * assigning ep->claimed to true.
+ *
+ * On failure, this returns a null endpoint descriptor.
+ */
+struct usb_ep *usb_ep_autoconfig_ss(
+	struct usb_gadget		*gadget,
+	struct usb_endpoint_descriptor	*desc,
+	struct usb_ss_ep_comp_descriptor *ep_comp
+)
+{
+	struct usb_ep	*ep;
+
+	if (gadget->ops->match_ep) {
+		ep = gadget->ops->match_ep(gadget, desc, ep_comp);
+		if (ep)
+			goto found_ep;
+	}
+
+	/* Second, look at endpoints until an unclaimed one looks usable */
+	list_for_each_entry (ep, &gadget->ep_list, ep_list) {
+		if (usb_gadget_ep_match_desc(gadget, ep, desc, ep_comp))
+			goto found_ep;
+	}
+
+	/* Fail */
+	return NULL;
+found_ep:
+
+	/*
+	 * If the protocol driver hasn't yet decided on wMaxPacketSize
+	 * and wants to know the maximum possible, provide the info.
+	 */
+	if (desc->wMaxPacketSize == 0)
+		desc->wMaxPacketSize = cpu_to_le16(ep->maxpacket_limit);
+
+	/* report address */
+	desc->bEndpointAddress &= USB_DIR_IN;
+	if (isdigit(ep->name[2])) {
+		u8 num = simple_strtoul(&ep->name[2], NULL, 10);
+		desc->bEndpointAddress |= num;
+	} else if (desc->bEndpointAddress & USB_DIR_IN) {
+		if (++gadget->in_epnum > 15)
+			return NULL;
+		desc->bEndpointAddress = USB_DIR_IN | gadget->in_epnum;
+	} else {
+		if (++gadget->out_epnum > 15)
+			return NULL;
+		desc->bEndpointAddress |= gadget->out_epnum;
+	}
+
+	ep->address = desc->bEndpointAddress;
+	ep->desc = NULL;
+	ep->comp_desc = NULL;
+	ep->claimed = true;
+	return ep;
+}
+EXPORT_SYMBOL_GPL(usb_ep_autoconfig_ss);
+
+/**
+ * usb_ep_autoconfig() - choose an endpoint matching the
+ * descriptor
+ * @gadget: The device to which the endpoint must belong.
+ * @desc: Endpoint descriptor, with endpoint direction and transfer mode
+ *	initialized.  For periodic transfers, the maximum packet
+ *	size must also be initialized.  This is modified on success.
+ *
+ * By choosing an endpoint to use with the specified descriptor, this
+ * routine simplifies writing gadget drivers that work with multiple
+ * USB device controllers.  The endpoint would be passed later to
+ * usb_ep_enable(), along with some descriptor.
+ *
+ * That second descriptor won't always be the same as the first one.
+ * For example, isochronous endpoints can be autoconfigured for high
+ * bandwidth, and then used in several lower bandwidth altsettings.
+ * Also, high and full speed descriptors will be different.
+ *
+ * Be sure to examine and test the results of autoconfiguration on your
+ * hardware.  This code may not make the best choices about how to use the
+ * USB controller, and it can't know all the restrictions that may apply.
+ * Some combinations of driver and hardware won't be able to autoconfigure.
+ *
+ * On success, this returns an claimed usb_ep, and modifies the endpoint
+ * descriptor bEndpointAddress.  For bulk endpoints, the wMaxPacket value
+ * is initialized as if the endpoint were used at full speed. Because of
+ * that the users must consider adjusting the autoconfigured descriptor.
+ * To prevent the endpoint from being returned by a later autoconfig call,
+ * claims it by assigning ep->claimed to true.
+ *
+ * On failure, this returns a null endpoint descriptor.
+ */
+struct usb_ep *usb_ep_autoconfig(
+	struct usb_gadget		*gadget,
+	struct usb_endpoint_descriptor	*desc
+)
+{
+	struct usb_ep	*ep;
+	u8		type;
+
+	ep = usb_ep_autoconfig_ss(gadget, desc, NULL);
+	if (!ep)
+		return NULL;
+
+	type = usb_endpoint_type(desc);
+
+	/* report (variable) full speed bulk maxpacket */
+	if (type == USB_ENDPOINT_XFER_BULK) {
+		int size = ep->maxpacket_limit;
+
+		/* min() doesn't work on bitfields with gcc-3.5 */
+		if (size > 64)
+			size = 64;
+		desc->wMaxPacketSize = cpu_to_le16(size);
+	}
+
+	return ep;
+}
+EXPORT_SYMBOL_GPL(usb_ep_autoconfig);
+
+/**
+ * usb_ep_autoconfig_release - releases endpoint and set it to initial state
+ * @ep: endpoint which should be released
+ *
+ * This function can be used during function bind for endpoints obtained
+ * from usb_ep_autoconfig(). It unclaims endpoint claimed by
+ * usb_ep_autoconfig() to make it available for other functions. Endpoint
+ * which was released is no longer valid and shouldn't be used in
+ * context of function which released it.
+ */
+void usb_ep_autoconfig_release(struct usb_ep *ep)
+{
+	ep->claimed = false;
+	ep->driver_data = NULL;
+}
+EXPORT_SYMBOL_GPL(usb_ep_autoconfig_release);
+
+/**
+ * usb_ep_autoconfig_reset - reset endpoint autoconfig state
+ * @gadget: device for which autoconfig state will be reset
+ *
+ * Use this for devices where one configuration may need to assign
+ * endpoint resources very differently from the next one.  It clears
+ * state such as ep->claimed and the record of assigned endpoints
+ * used by usb_ep_autoconfig().
+ */
+void usb_ep_autoconfig_reset (struct usb_gadget *gadget)
+{
+	struct usb_ep	*ep;
+
+	list_for_each_entry (ep, &gadget->ep_list, ep_list) {
+		ep->claimed = false;
+		ep->driver_data = NULL;
+	}
+	gadget->in_epnum = 0;
+	gadget->out_epnum = 0;
+}
+EXPORT_SYMBOL_GPL(usb_ep_autoconfig_reset);