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, 81 insertions, 0 deletions

diff --git a/drivers/net/slip/Kconfig b/drivers/net/slip/Kconfig
new file mode 100644
index 000000000..ea68fc15c
--- /dev/null
+++ b/drivers/net/slip/Kconfig
@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# SLIP network device configuration
+#
+
+config SLIP
+	tristate "SLIP (serial line) support"
+	depends on TTY
+	help
+	  Say Y if you intend to use SLIP or CSLIP (compressed SLIP) to
+	  connect to your Internet service provider or to connect to some
+	  other local Unix box or if you want to configure your Linux box as a
+	  Slip/CSlip server for other people to dial in. SLIP (Serial Line
+	  Internet Protocol) is a protocol used to send Internet traffic over
+	  serial connections such as telephone lines or null modem cables;
+	  nowadays, the protocol PPP is more commonly used for this same
+	  purpose.
+
+	  Normally, your access provider has to support SLIP in order for you
+	  to be able to use it, but there is now a SLIP emulator called SLiRP
+	  around (available from
+	  <ftp://ibiblio.org/pub/Linux/system/network/serial/>) which
+	  allows you to use SLIP over a regular dial up shell connection. If
+	  you plan to use SLiRP, make sure to say Y to CSLIP, below. The
+	  NET-3-HOWTO, available from
+	  <http://www.tldp.org/docs.html#howto>, explains how to
+	  configure SLIP. Note that you don't need this option if you just
+	  want to run term (term is a program which gives you almost full
+	  Internet connectivity if you have a regular dial up shell account on
+	  some Internet connected Unix computer. Read
+	  <http://www.bart.nl/~patrickr/term-howto/Term-HOWTO.html>). SLIP
+	  support will enlarge your kernel by about 4 KB. If unsure, say N.
+
+	  To compile this driver as a module, choose M here. The module
+	  will be called slip.
+
+config SLHC
+	tristate
+	help
+	  This option enables Van Jacobsen serial line header compression
+	  routines.
+
+if SLIP
+
+config SLIP_COMPRESSED
+	bool "CSLIP compressed headers"
+	depends on SLIP
+	select SLHC
+	help
+	  This protocol is faster than SLIP because it uses compression on the
+	  TCP/IP headers (not on the data itself), but it has to be supported
+	  on both ends. Ask your access provider if you are not sure and
+	  answer Y, just in case. You will still be able to use plain SLIP. If
+	  you plan to use SLiRP, the SLIP emulator (available from
+	  <ftp://ibiblio.org/pub/Linux/system/network/serial/>) which
+	  allows you to use SLIP over a regular dial up shell connection, you
+	  definitely want to say Y here. The NET-3-HOWTO, available from
+	  <http://www.tldp.org/docs.html#howto>, explains how to configure
+	  CSLIP. This won't enlarge your kernel.
+
+config SLIP_SMART
+	bool "Keepalive and linefill"
+	depends on SLIP
+	help
+	  Adds additional capabilities to the SLIP driver to support the
+	  RELCOM line fill and keepalive monitoring. Ideal on poor quality
+	  analogue lines.
+
+config SLIP_MODE_SLIP6
+	bool "Six bit SLIP encapsulation"
+	depends on SLIP
+	help
+	  Just occasionally you may need to run IP over hostile serial
+	  networks that don't pass all control characters or are only seven
+	  bit. Saying Y here adds an extra mode you can use with SLIP:
+	  "slip6". In this mode, SLIP will only send normal ASCII symbols over
+	  the serial device. Naturally, this has to be supported at the other
+	  end of the link as well. It's good enough, for example, to run IP
+	  over the async ports of a Camtec JNT Pad. If unsure, say N.
+
+endif # SLIP