Merge tag 'trace-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "There's not much changes for the tracing system this release. Mostly
  small clean ups and fixes.

  The biggest change is to how bprintf works. bprintf is used by
  trace_printk() to just save the format and args of a printf call, and
  the formatting is done when the trace buffer is read. This is done to
  keep the formatting out of the fast path (this was recommended by
  you). The issue is when arguments are de-referenced.

  If a pointer is saved, and the format has something like "%*pbl", when
  the buffer is read, it will de-reference the argument then. The
  problem is if the data no longer exists. This can cause the kernel to
  oops.

  The fix for this was to make these de-reference pointes do the
  formatting at the time it is called (the fast path), as this
  guarantees that the data exists (and doesn't change later)"

* tag 'trace-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  vsprintf: Do not have bprintf dereference pointers
  ftrace: Mark function tracer test functions noinline/noclone
  trace_uprobe: Display correct offset in uprobe_events
  tracing: Make sure the parsed string always terminates with '\0'
  tracing: Clear parser->idx if only spaces are read
  tracing: Detect the string nul character when parsing user input string

kernel/trace/ftrace.c

@@ -5015,7 +5015,6 @@ int ftrace_regex_release(struct inode *inode, struct file *file)
 
 	parser = &iter->parser;
 	if (trace_parser_loaded(parser)) {
-		parser->buffer[parser->idx] = 0;
 		ftrace_match_records(iter->hash, parser->buffer, parser->idx);
 	}
 
@@ -5329,7 +5328,6 @@ ftrace_graph_release(struct inode *inode, struct file *file)
 		parser = &fgd->parser;
 
 		if (trace_parser_loaded((parser))) {
-			parser->buffer[parser->idx] = 0;
 			ret = ftrace_graph_set_hash(fgd->new_hash,
 						    parser->buffer);
 		}

kernel/trace/trace.c

@@ -530,8 +530,6 @@ int trace_pid_write(struct trace_pid_list *filtered_pids,
 		ubuf += ret;
 		cnt -= ret;
 
-		parser.buffer[parser.idx] = 0;
-
 		ret = -EINVAL;
 		if (kstrtoul(parser.buffer, 0, &val))
 			break;
@@ -1236,18 +1234,18 @@ int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
 			cnt--;
 		}
 
+		parser->idx = 0;
+
 		/* only spaces were written */
-		if (isspace(ch)) {
+		if (isspace(ch) || !ch) {
 			*ppos += read;
 			ret = read;
 			goto out;
 		}
-
-		parser->idx = 0;
 	}
 
 	/* read the non-space input */
-	while (cnt && !isspace(ch)) {
+	while (cnt && !isspace(ch) && ch) {
 		if (parser->idx < parser->size - 1)
 			parser->buffer[parser->idx++] = ch;
 		else {
@@ -1262,12 +1260,14 @@ int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
 	}
 
 	/* We either got finished input or we have to wait for another call. */
-	if (isspace(ch)) {
+	if (isspace(ch) || !ch) {
 		parser->buffer[parser->idx] = 0;
 		parser->cont = false;
 	} else if (parser->idx < parser->size - 1) {
 		parser->cont = true;
 		parser->buffer[parser->idx++] = ch;
+		/* Make sure the parsed string always terminates with '\0'. */
+		parser->buffer[parser->idx] = 0;
 	} else {
 		ret = -EINVAL;
 		goto out;

kernel/trace/trace_events.c

@@ -885,8 +885,6 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
 		if (*parser.buffer == '!')
 			set = 0;
 
-		parser.buffer[parser.idx] = 0;
-
 		ret = ftrace_set_clr_event(tr, parser.buffer + !set, set);
 		if (ret)
 			goto out_put;

kernel/trace/trace_selftest_dynamic.c

 // SPDX-License-Identifier: GPL-2.0
+#include <linux/compiler.h>
 #include "trace.h"
 
-int DYN_FTRACE_TEST_NAME(void)
+noinline __noclone int DYN_FTRACE_TEST_NAME(void)
 {
 	/* used to call mcount */
 	return 0;
 }
 
-int DYN_FTRACE_TEST_NAME2(void)
+noinline __noclone int DYN_FTRACE_TEST_NAME2(void)
 {
 	/* used to call mcount */
 	return 0;

kernel/trace/trace_uprobe.c

@@ -608,7 +608,7 @@ static int probes_seq_show(struct seq_file *m, void *v)
 
 	/* Don't print "0x  (null)" when offset is 0 */
 	if (tu->offset) {
-		seq_printf(m, "0x%p", (void *)tu->offset);
+		seq_printf(m, "0x%px", (void *)tu->offset);
 	} else {
 		switch (sizeof(void *)) {
 		case 4:

lib/vsprintf.c

@@ -2517,29 +2517,34 @@ int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
 {
 	struct printf_spec spec = {0};
 	char *str, *end;
+	int width;
 
 	str = (char *)bin_buf;
 	end = (char *)(bin_buf + size);
 
 #define save_arg(type)							\
-do {									\
-	if (sizeof(type) == 8) {					\
+({									\
 	unsigned long long value;					\
+	if (sizeof(type) == 8) {					\
+		unsigned long long val8;				\
 		str = PTR_ALIGN(str, sizeof(u32));			\
-		value = va_arg(args, unsigned long long);		\
+		val8 = va_arg(args, unsigned long long);		\
 		if (str + sizeof(type) <= end) {			\
-			*(u32 *)str = *(u32 *)&value;			\
-			*(u32 *)(str + 4) = *((u32 *)&value + 1);	\
+			*(u32 *)str = *(u32 *)&val8;			\
+			*(u32 *)(str + 4) = *((u32 *)&val8 + 1);	\
 		}							\
+		value = val8;						\
 	} else {							\
-		unsigned long value;					\
+		unsigned int val4;					\
 		str = PTR_ALIGN(str, sizeof(type));			\
-		value = va_arg(args, int);				\
+		val4 = va_arg(args, int);				\
 		if (str + sizeof(type) <= end)				\
-			*(typeof(type) *)str = (type)value;		\
+			*(typeof(type) *)str = (type)(long)val4;	\
+		value = (unsigned long long)val4;			\
 	}								\
 	str += sizeof(type);						\
-} while (0)
+	value;								\
+})
 
 	while (*fmt) {
 		int read = format_decode(fmt, &spec);
@@ -2555,7 +2560,10 @@ do {									\
 
 		case FORMAT_TYPE_WIDTH:
 		case FORMAT_TYPE_PRECISION:
-			save_arg(int);
+			width = (int)save_arg(int);
+			/* Pointers may require the width */
+			if (*fmt == 'p')
+				set_field_width(&spec, width);
 			break;
 
 		case FORMAT_TYPE_CHAR:
@@ -2577,7 +2585,27 @@ do {									\
 		}
 
 		case FORMAT_TYPE_PTR:
+			/* Dereferenced pointers must be done now */
+			switch (*fmt) {
+			/* Dereference of functions is still OK */
+			case 'S':
+			case 's':
+			case 'F':
+			case 'f':
 				save_arg(void *);
+				break;
+			default:
+				if (!isalnum(*fmt)) {
+					save_arg(void *);
+					break;
+				}
+				str = pointer(fmt, str, end, va_arg(args, void *),
+					      spec);
+				if (str + 1 < end)
+					*str++ = '\0';
+				else
+					end[-1] = '\0'; /* Must be nul terminated */
+			}
 			/* skip all alphanumeric pointer suffixes */
 			while (isalnum(*fmt))
 				fmt++;
@@ -2729,11 +2757,39 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
 			break;
 		}
 
-		case FORMAT_TYPE_PTR:
+		case FORMAT_TYPE_PTR: {
+			bool process = false;
+			int copy, len;
+			/* Non function dereferences were already done */
+			switch (*fmt) {
+			case 'S':
+			case 's':
+			case 'F':
+			case 'f':
+				process = true;
+				break;
+			default:
+				if (!isalnum(*fmt)) {
+					process = true;
+					break;
+				}
+				/* Pointer dereference was already processed */
+				if (str < end) {
+					len = copy = strlen(args);
+					if (copy > end - str)
+						copy = end - str;
+					memcpy(str, args, copy);
+					str += len;
+					args += len;
+				}
+			}
+			if (process)
 				str = pointer(fmt, str, end, get_arg(void *), spec);
+
 			while (isalnum(*fmt))
 				fmt++;
 			break;
+		}
 
 		case FORMAT_TYPE_PERCENT_CHAR:
 			if (str < end)