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, 256 insertions, 0 deletions

diff --git a/scripts/dtc/util.h b/scripts/dtc/util.h
new file mode 100644
index 000000000..800f2e2c5
--- /dev/null
+++ b/scripts/dtc/util.h
@@ -0,0 +1,256 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef UTIL_H
+#define UTIL_H
+
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <getopt.h>
+
+/*
+ * Copyright 2011 The Chromium Authors, All Rights Reserved.
+ * Copyright 2008 Jon Loeliger, Freescale Semiconductor, Inc.
+ */
+
+#ifdef __GNUC__
+#ifdef __MINGW_PRINTF_FORMAT
+#define PRINTF(i, j)	__attribute__((format (__MINGW_PRINTF_FORMAT, i, j)))
+#elif __GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 4)
+#define PRINTF(i, j)	__attribute__((format (gnu_printf, i, j)))
+#else
+#define PRINTF(i, j)	__attribute__((format (printf, i, j)))
+#endif
+#define NORETURN	__attribute__((noreturn))
+#else
+#define PRINTF(i, j)
+#define NORETURN
+#endif
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+#define stringify(s)	stringify_(s)
+#define stringify_(s)	#s
+
+static inline void NORETURN PRINTF(1, 2) die(const char *str, ...)
+{
+	va_list ap;
+
+	va_start(ap, str);
+	fprintf(stderr, "FATAL ERROR: ");
+	vfprintf(stderr, str, ap);
+	va_end(ap);
+	exit(1);
+}
+
+/**
+ * Writes path to fp, escaping spaces with a backslash.
+ */
+void fprint_path_escaped(FILE *fp, const char *path);
+
+static inline void *xmalloc(size_t len)
+{
+	void *new = malloc(len);
+
+	if (!new)
+		die("malloc() failed\n");
+
+	return new;
+}
+
+static inline void *xrealloc(void *p, size_t len)
+{
+	void *new = realloc(p, len);
+
+	if (!new)
+		die("realloc() failed (len=%zd)\n", len);
+
+	return new;
+}
+
+extern char *xstrdup(const char *s);
+extern char *xstrndup(const char *s, size_t len);
+
+extern int PRINTF(2, 3) xasprintf(char **strp, const char *fmt, ...);
+extern int PRINTF(2, 3) xasprintf_append(char **strp, const char *fmt, ...);
+extern int PRINTF(2, 0) xavsprintf_append(char **strp, const char *fmt, va_list ap);
+extern char *join_path(const char *path, const char *name);
+
+/**
+ * Check a property of a given length to see if it is all printable and
+ * has a valid terminator. The property can contain either a single string,
+ * or multiple strings each of non-zero length.
+ *
+ * @param data	The string to check
+ * @param len	The string length including terminator
+ * @return 1 if a valid printable string, 0 if not
+ */
+bool util_is_printable_string(const void *data, int len);
+
+/*
+ * Parse an escaped character starting at index i in string s.  The resulting
+ * character will be returned and the index i will be updated to point at the
+ * character directly after the end of the encoding, this may be the '\0'
+ * terminator of the string.
+ */
+char get_escape_char(const char *s, int *i);
+
+/**
+ * Read a device tree file into a buffer. This will report any errors on
+ * stderr.
+ *
+ * @param filename	The filename to read, or - for stdin
+ * @param len		If non-NULL, the amount of data we managed to read
+ * @return Pointer to allocated buffer containing fdt, or NULL on error
+ */
+char *utilfdt_read(const char *filename, size_t *len);
+
+/**
+ * Read a device tree file into a buffer. Does not report errors, but only
+ * returns them. The value returned can be passed to strerror() to obtain
+ * an error message for the user.
+ *
+ * @param filename	The filename to read, or - for stdin
+ * @param buffp		Returns pointer to buffer containing fdt
+ * @param len		If non-NULL, the amount of data we managed to read
+ * @return 0 if ok, else an errno value representing the error
+ */
+int utilfdt_read_err(const char *filename, char **buffp, size_t *len);
+
+/**
+ * Write a device tree buffer to a file. This will report any errors on
+ * stderr.
+ *
+ * @param filename	The filename to write, or - for stdout
+ * @param blob		Pointer to buffer containing fdt
+ * @return 0 if ok, -1 on error
+ */
+int utilfdt_write(const char *filename, const void *blob);
+
+/**
+ * Write a device tree buffer to a file. Does not report errors, but only
+ * returns them. The value returned can be passed to strerror() to obtain
+ * an error message for the user.
+ *
+ * @param filename	The filename to write, or - for stdout
+ * @param blob		Pointer to buffer containing fdt
+ * @return 0 if ok, else an errno value representing the error
+ */
+int utilfdt_write_err(const char *filename, const void *blob);
+
+/**
+ * Decode a data type string. The purpose of this string
+ *
+ * The string consists of an optional character followed by the type:
+ *	Modifier characters:
+ *		hh or b	1 byte
+ *		h	2 byte
+ *		l	4 byte, default
+ *
+ *	Type character:
+ *		s	string
+ *		i	signed integer
+ *		u	unsigned integer
+ *		x	hex
+ *		r	raw
+ *
+ * TODO: Implement ll modifier (8 bytes)
+ * TODO: Implement o type (octal)
+ *
+ * @param fmt		Format string to process
+ * @param type		Returns type found(s/d/u/x), or 0 if none
+ * @param size		Returns size found(1,2,4,8) or 4 if none
+ * @return 0 if ok, -1 on error (no type given, or other invalid format)
+ */
+int utilfdt_decode_type(const char *fmt, int *type, int *size);
+
+/*
+ * This is a usage message fragment for the -t option. It is the format
+ * supported by utilfdt_decode_type.
+ */
+
+#define USAGE_TYPE_MSG \
+	"<type>\ts=string, i=int, u=unsigned, x=hex, r=raw\n" \
+	"\tOptional modifier prefix:\n" \
+	"\t\thh or b=byte, h=2 byte, l=4 byte (default)";
+
+/**
+ * Print property data in a readable format to stdout
+ *
+ * Properties that look like strings will be printed as strings. Otherwise
+ * the data will be displayed either as cells (if len is a multiple of 4
+ * bytes) or bytes.
+ *
+ * If len is 0 then this function does nothing.
+ *
+ * @param data	Pointers to property data
+ * @param len	Length of property data
+ */
+void utilfdt_print_data(const char *data, int len);
+
+/**
+ * Show source version and exit
+ */
+void NORETURN util_version(void);
+
+/**
+ * Show usage and exit
+ *
+ * This helps standardize the output of various utils.  You most likely want
+ * to use the usage() helper below rather than call this.
+ *
+ * @param errmsg	If non-NULL, an error message to display
+ * @param synopsis	The initial example usage text (and possible examples)
+ * @param short_opts	The string of short options
+ * @param long_opts	The structure of long options
+ * @param opts_help	An array of help strings (should align with long_opts)
+ */
+void NORETURN util_usage(const char *errmsg, const char *synopsis,
+			 const char *short_opts,
+			 struct option const long_opts[],
+			 const char * const opts_help[]);
+
+/**
+ * Show usage and exit
+ *
+ * If you name all your usage variables with usage_xxx, then you can call this
+ * help macro rather than expanding all arguments yourself.
+ *
+ * @param errmsg	If non-NULL, an error message to display
+ */
+#define usage(errmsg) \
+	util_usage(errmsg, usage_synopsis, usage_short_opts, \
+		   usage_long_opts, usage_opts_help)
+
+/**
+ * Call getopt_long() with standard options
+ *
+ * Since all util code runs getopt in the same way, provide a helper.
+ */
+#define util_getopt_long() getopt_long(argc, argv, usage_short_opts, \
+				       usage_long_opts, NULL)
+
+/* Helper for aligning long_opts array */
+#define a_argument required_argument
+
+/* Helper for usage_short_opts string constant */
+#define USAGE_COMMON_SHORT_OPTS "hV"
+
+/* Helper for usage_long_opts option array */
+#define USAGE_COMMON_LONG_OPTS \
+	{"help",      no_argument, NULL, 'h'}, \
+	{"version",   no_argument, NULL, 'V'}, \
+	{NULL,        no_argument, NULL, 0x0}
+
+/* Helper for usage_opts_help array */
+#define USAGE_COMMON_OPTS_HELP \
+	"Print this help and exit", \
+	"Print version and exit", \
+	NULL
+
+/* Helper for getopt case statements */
+#define case_USAGE_COMMON_FLAGS \
+	case 'h': usage(NULL); \
+	case 'V': util_version(); \
+	case '?': usage("unknown option");
+
+#endif /* UTIL_H */