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, 210 insertions, 0 deletions

diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
new file mode 100644
index 000000000..daeac4889
--- /dev/null
+++ b/fs/Kconfig.binfmt
@@ -0,0 +1,210 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menu "Executable file formats"
+
+config BINFMT_ELF
+	bool "Kernel support for ELF binaries"
+	depends on MMU
+	select ELFCORE
+	default y
+	help
+	  ELF (Executable and Linkable Format) is a format for libraries and
+	  executables used across different architectures and operating
+	  systems. Saying Y here will enable your kernel to run ELF binaries
+	  and enlarge it by about 13 KB. ELF support under Linux has now all
+	  but replaced the traditional Linux a.out formats (QMAGIC and ZMAGIC)
+	  because it is portable (this does *not* mean that you will be able
+	  to run executables from different architectures or operating systems
+	  however) and makes building run-time libraries very easy. Many new
+	  executables are distributed solely in ELF format. You definitely
+	  want to say Y here.
+
+	  Information about ELF is contained in the ELF HOWTO available from
+	  <http://www.tldp.org/docs.html#howto>.
+
+	  If you find that after upgrading from Linux kernel 1.2 and saying Y
+	  here, you still can't run any ELF binaries (they just crash), then
+	  you'll have to install the newest ELF runtime libraries, including
+	  ld.so (check the file <file:Documentation/Changes> for location and
+	  latest version).
+
+config BINFMT_ELF_KUNIT_TEST
+	bool "Build KUnit tests for ELF binary support" if !KUNIT_ALL_TESTS
+	depends on KUNIT=y && BINFMT_ELF=y
+	default KUNIT_ALL_TESTS
+	help
+	  This builds the ELF loader KUnit tests, which try to gather
+	  prior bug fixes into a regression test collection. This is really
+	  only needed for debugging. Note that with CONFIG_COMPAT=y, the
+	  compat_binfmt_elf KUnit test is also created.
+
+config COMPAT_BINFMT_ELF
+	def_bool y
+	depends on COMPAT && BINFMT_ELF
+	select ELFCORE
+
+config ARCH_BINFMT_ELF_STATE
+	bool
+
+config ARCH_BINFMT_ELF_EXTRA_PHDRS
+	bool
+
+config ARCH_HAVE_ELF_PROT
+	bool
+
+config ARCH_USE_GNU_PROPERTY
+	bool
+
+config BINFMT_ELF_FDPIC
+	bool "Kernel support for FDPIC ELF binaries"
+	default y if !BINFMT_ELF
+	depends on ARM || ((M68K || RISCV || SUPERH || XTENSA) && !MMU)
+	select ELFCORE
+	help
+	  ELF FDPIC binaries are based on ELF, but allow the individual load
+	  segments of a binary to be located in memory independently of each
+	  other. This makes this format ideal for use in environments where no
+	  MMU is available as it still permits text segments to be shared,
+	  even if data segments are not.
+
+	  It is also possible to run FDPIC ELF binaries on MMU linux also.
+
+config ELFCORE
+	bool
+	help
+	  This option enables kernel/elfcore.o.
+
+config CORE_DUMP_DEFAULT_ELF_HEADERS
+	bool "Write ELF core dumps with partial segments"
+	default y
+	depends on BINFMT_ELF && ELF_CORE
+	help
+	  ELF core dump files describe each memory mapping of the crashed
+	  process, and can contain or omit the memory contents of each one.
+	  The contents of an unmodified text mapping are omitted by default.
+
+	  For an unmodified text mapping of an ELF object, including just
+	  the first page of the file in a core dump makes it possible to
+	  identify the build ID bits in the file, without paying the i/o
+	  cost and disk space to dump all the text.  However, versions of
+	  GDB before 6.7 are confused by ELF core dump files in this format.
+
+	  The core dump behavior can be controlled per process using
+	  the /proc/PID/coredump_filter pseudo-file; this setting is
+	  inherited.  See Documentation/filesystems/proc.rst for details.
+
+	  This config option changes the default setting of coredump_filter
+	  seen at boot time.  If unsure, say Y.
+
+config BINFMT_SCRIPT
+	tristate "Kernel support for scripts starting with #!"
+	default y
+	help
+	  Say Y here if you want to execute interpreted scripts starting with
+	  #! followed by the path to an interpreter.
+
+	  You can build this support as a module; however, until that module
+	  gets loaded, you cannot run scripts.  Thus, if you want to load this
+	  module from an initramfs, the portion of the initramfs before loading
+	  this module must consist of compiled binaries only.
+
+	  Most systems will not boot if you say M or N here.  If unsure, say Y.
+
+config ARCH_HAS_BINFMT_FLAT
+	bool
+
+config BINFMT_FLAT
+	bool "Kernel support for flat binaries"
+	depends on ARCH_HAS_BINFMT_FLAT
+	help
+	  Support uClinux FLAT format binaries.
+
+config BINFMT_FLAT_ARGVP_ENVP_ON_STACK
+	bool
+
+config BINFMT_FLAT_OLD_ALWAYS_RAM
+	bool
+
+config BINFMT_FLAT_NO_DATA_START_OFFSET
+	bool
+
+config BINFMT_FLAT_OLD
+	bool "Enable support for very old legacy flat binaries"
+	depends on BINFMT_FLAT
+	help
+	  Support decade old uClinux FLAT format binaries.  Unless you know
+	  you have some of those say N here.
+
+config BINFMT_ZFLAT
+	bool "Enable ZFLAT support"
+	depends on BINFMT_FLAT
+	select ZLIB_INFLATE
+	help
+	  Support FLAT format compressed binaries
+
+config BINFMT_MISC
+	tristate "Kernel support for MISC binaries"
+	help
+	  If you say Y here, it will be possible to plug wrapper-driven binary
+	  formats into the kernel. You will like this especially when you use
+	  programs that need an interpreter to run like Java, Python, .NET or
+	  Emacs-Lisp. It's also useful if you often run DOS executables under
+	  the Linux DOS emulator DOSEMU (read the DOSEMU-HOWTO, available from
+	  <http://www.tldp.org/docs.html#howto>). Once you have
+	  registered such a binary class with the kernel, you can start one of
+	  those programs simply by typing in its name at a shell prompt; Linux
+	  will automatically feed it to the correct interpreter.
+
+	  You can do other nice things, too. Read the file
+	  <file:Documentation/admin-guide/binfmt-misc.rst> to learn how to use this
+	  feature, <file:Documentation/admin-guide/java.rst> for information about how
+	  to include Java support. and <file:Documentation/admin-guide/mono.rst> for
+          information about how to include Mono-based .NET support.
+
+          To use binfmt_misc, you will need to mount it:
+		mount binfmt_misc -t binfmt_misc /proc/sys/fs/binfmt_misc
+
+	  You may say M here for module support and later load the module when
+	  you have use for it; the module is called binfmt_misc. If you
+	  don't know what to answer at this point, say Y.
+
+config BINFMT_MISC_BPF
+	bool "BPF-selected interpreters for misc binaries"
+	depends on BINFMT_MISC=y
+	depends on BPF_SYSCALL && BPF_JIT && DEBUG_INFO_BTF
+	help
+	  Allow binfmt_misc binary type handlers to be implemented as bpf
+	  struct_ops programs. Instead of matching a fixed magic and
+	  redirecting to a fixed interpreter recorded at registration time
+	  such handlers match binaries programmatically and compute the
+	  interpreter to use per binary, e.g. relative to the location of
+	  the binary itself.
+
+	  If you don't know what to answer at this point, say N.
+
+config COREDUMP
+	bool "Enable core dump support" if EXPERT
+	default y
+	help
+	  This option enables support for performing core dumps. You almost
+	  certainly want to say Y here. Not necessary on systems that never
+	  need debugging or only ever run flawless code.
+
+config EXEC_KUNIT_TEST
+	bool "Build execve tests" if !KUNIT_ALL_TESTS
+	depends on KUNIT=y
+	default KUNIT_ALL_TESTS
+	help
+	  This builds the exec KUnit tests, which tests boundary conditions
+	  of various aspects of the exec internals.
+
+config ARCH_HAS_ELF_CORE_EFLAGS
+	bool
+	depends on BINFMT_ELF && ELF_CORE
+	default n
+	help
+	  Select this option if the architecture makes use of the e_flags
+	  field in the ELF header to store ABI or other architecture-specific
+	  information that should be preserved in core dumps.
+
+endmenu