Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 187 insertions, 83 deletions

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index dcdade39e47..310c753cf83 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -60,6 +60,7 @@ struct ddebug_iter {
 static DEFINE_MUTEX(ddebug_lock);
 static LIST_HEAD(ddebug_tables);
 static int verbose = 0;
+module_param(verbose, int, 0644);
 
 /* Return the last part of a pathname */
 static inline const char *basename(const char *path)
@@ -68,12 +69,24 @@ static inline const char *basename(const char *path)
 	return tail ? tail+1 : path;
 }
 
+/* Return the path relative to source root */
+static inline const char *trim_prefix(const char *path)
+{
+	int skip = strlen(__FILE__) - strlen("lib/dynamic_debug.c");
+
+	if (strncmp(path, __FILE__, skip))
+		skip = 0; /* prefix mismatch, don't skip */
+
+	return path + skip;
+}
+
 static struct { unsigned flag:8; char opt_char; } opt_array[] = {
 	{ _DPRINTK_FLAGS_PRINT, 'p' },
 	{ _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
 	{ _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
 	{ _DPRINTK_FLAGS_INCL_LINENO, 'l' },
 	{ _DPRINTK_FLAGS_INCL_TID, 't' },
+	{ _DPRINTK_FLAGS_NONE, '_' },
 };
 
 /* format a string into buf[] which describes the _ddebug's flags */
@@ -83,58 +96,74 @@ static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
 	char *p = buf;
 	int i;
 
-	BUG_ON(maxlen < 4);
+	BUG_ON(maxlen < 6);
 	for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
 		if (dp->flags & opt_array[i].flag)
 			*p++ = opt_array[i].opt_char;
 	if (p == buf)
-		*p++ = '-';
+		*p++ = '_';
 	*p = '\0';
 
 	return buf;
 }
 
+#define vpr_info_dq(q, msg)						\
+do {									\
+	if (verbose)							\
+		/* trim last char off format print */			\
+		pr_info("%s: func=\"%s\" file=\"%s\" "			\
+			"module=\"%s\" format=\"%.*s\" "		\
+			"lineno=%u-%u",					\
+			msg,						\
+			q->function ? q->function : "",			\
+			q->filename ? q->filename : "",			\
+			q->module ? q->module : "",			\
+			(int)(q->format ? strlen(q->format) - 1 : 0),	\
+			q->format ? q->format : "",			\
+			q->first_lineno, q->last_lineno);		\
+} while (0)
+
 /*
- * Search the tables for _ddebug's which match the given
- * `query' and apply the `flags' and `mask' to them.  Tells
- * the user which ddebug's were changed, or whether none
- * were matched.
+ * Search the tables for _ddebug's which match the given `query' and
+ * apply the `flags' and `mask' to them.  Returns number of matching
+ * callsites, normally the same as number of changes.  If verbose,
+ * logs the changes.  Takes ddebug_lock.
  */
-static void ddebug_change(const struct ddebug_query *query,
-			   unsigned int flags, unsigned int mask)
+static int ddebug_change(const struct ddebug_query *query,
+			unsigned int flags, unsigned int mask)
 {
 	int i;
 	struct ddebug_table *dt;
 	unsigned int newflags;
 	unsigned int nfound = 0;
-	char flagbuf[8];
+	char flagbuf[10];
 
 	/* search for matching ddebugs */
 	mutex_lock(&ddebug_lock);
 	list_for_each_entry(dt, &ddebug_tables, link) {
 
 		/* match against the module name */
-		if (query->module != NULL &&
-		    strcmp(query->module, dt->mod_name))
+		if (query->module && strcmp(query->module, dt->mod_name))
 			continue;
 
 		for (i = 0 ; i < dt->num_ddebugs ; i++) {
 			struct _ddebug *dp = &dt->ddebugs[i];
 
 			/* match against the source filename */
-			if (query->filename != NULL &&
+			if (query->filename &&
 			    strcmp(query->filename, dp->filename) &&
-			    strcmp(query->filename, basename(dp->filename)))
+			    strcmp(query->filename, basename(dp->filename)) &&
+			    strcmp(query->filename, trim_prefix(dp->filename)))
 				continue;
 
 			/* match against the function */
-			if (query->function != NULL &&
+			if (query->function &&
 			    strcmp(query->function, dp->function))
 				continue;
 
 			/* match against the format */
-			if (query->format != NULL &&
-			    strstr(dp->format, query->format) == NULL)
+			if (query->format &&
+			    !strstr(dp->format, query->format))
 				continue;
 
 			/* match against the line number range */
@@ -151,13 +180,9 @@ static void ddebug_change(const struct ddebug_query *query,
 			if (newflags == dp->flags)
 				continue;
 			dp->flags = newflags;
-			if (newflags)
-				dp->enabled = 1;
-			else
-				dp->enabled = 0;
 			if (verbose)
-				pr_info("changed %s:%d [%s]%s %s\n",
-					dp->filename, dp->lineno,
+				pr_info("changed %s:%d [%s]%s =%s\n",
+					trim_prefix(dp->filename), dp->lineno,
 					dt->mod_name, dp->function,
 					ddebug_describe_flags(dp, flagbuf,
 							sizeof(flagbuf)));
@@ -167,6 +192,8 @@ static void ddebug_change(const struct ddebug_query *query,
 
 	if (!nfound && verbose)
 		pr_info("no matches for query\n");
+
+	return nfound;
 }
 
 /*
@@ -186,8 +213,10 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
 		buf = skip_spaces(buf);
 		if (!*buf)
 			break;	/* oh, it was trailing whitespace */
+		if (*buf == '#')
+			break;	/* token starts comment, skip rest of line */
 
-		/* Run `end' over a word, either whitespace separated or quoted */
+		/* find `end' of word, whitespace separated or quoted */
 		if (*buf == '"' || *buf == '\'') {
 			int quote = *buf++;
 			for (end = buf ; *end && *end != quote ; end++)
@@ -199,8 +228,8 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
 				;
 			BUG_ON(end == buf);
 		}
-		/* Here `buf' is the start of the word, `end' is one past the end */
 
+		/* `buf' is start of word, `end' is one past its end */
 		if (nwords == maxwords)
 			return -EINVAL;	/* ran out of words[] before bytes */
 		if (*end)
@@ -279,6 +308,19 @@ static char *unescape(char *str)
 	return str;
 }
 
+static int check_set(const char **dest, char *src, char *name)
+{
+	int rc = 0;
+
+	if (*dest) {
+		rc = -EINVAL;
+		pr_err("match-spec:%s val:%s overridden by %s",
+			name, *dest, src);
+	}
+	*dest = src;
+	return rc;
+}
+
 /*
  * Parse words[] as a ddebug query specification, which is a series
  * of (keyword, value) pairs chosen from these possibilities:
@@ -290,11 +332,15 @@ static char *unescape(char *str)
  * format <escaped-string-to-find-in-format>
  * line <lineno>
  * line <first-lineno>-<last-lineno> // where either may be empty
+ *
+ * Only 1 of each type is allowed.
+ * Returns 0 on success, <0 on error.
  */
 static int ddebug_parse_query(char *words[], int nwords,
 			       struct ddebug_query *query)
 {
 	unsigned int i;
+	int rc;
 
 	/* check we have an even number of words */
 	if (nwords % 2 != 0)
@@ -303,41 +349,43 @@ static int ddebug_parse_query(char *words[], int nwords,
 
 	for (i = 0 ; i < nwords ; i += 2) {
 		if (!strcmp(words[i], "func"))
-			query->function = words[i+1];
+			rc = check_set(&query->function, words[i+1], "func");
 		else if (!strcmp(words[i], "file"))
-			query->filename = words[i+1];
+			rc = check_set(&query->filename, words[i+1], "file");
 		else if (!strcmp(words[i], "module"))
-			query->module = words[i+1];
+			rc = check_set(&query->module, words[i+1], "module");
 		else if (!strcmp(words[i], "format"))
-			query->format = unescape(words[i+1]);
+			rc = check_set(&query->format, unescape(words[i+1]),
+				"format");
 		else if (!strcmp(words[i], "line")) {
 			char *first = words[i+1];
 			char *last = strchr(first, '-');
+			if (query->first_lineno || query->last_lineno) {
+				pr_err("match-spec:line given 2 times\n");
+				return -EINVAL;
+			}
 			if (last)
 				*last++ = '\0';
 			if (parse_lineno(first, &query->first_lineno) < 0)
 				return -EINVAL;
-			if (last != NULL) {
+			if (last) {
 				/* range <first>-<last> */
-				if (parse_lineno(last, &query->last_lineno) < 0)
+				if (parse_lineno(last, &query->last_lineno)
+				    < query->first_lineno) {
+					pr_err("last-line < 1st-line\n");
 					return -EINVAL;
+				}
 			} else {
 				query->last_lineno = query->first_lineno;
 			}
 		} else {
-			if (verbose)
-				pr_err("unknown keyword \"%s\"\n", words[i]);
+			pr_err("unknown keyword \"%s\"\n", words[i]);
 			return -EINVAL;
 		}
+		if (rc)
+			return rc;
 	}
-
-	if (verbose)
-		pr_info("q->function=\"%s\" q->filename=\"%s\" "
-			"q->module=\"%s\" q->format=\"%s\" q->lineno=%u-%u\n",
-			query->function, query->filename,
-			query->module, query->format, query->first_lineno,
-			query->last_lineno);
-
+	vpr_info_dq(query, "parsed");
 	return 0;
 }
 
@@ -375,8 +423,6 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
 		if (i < 0)
 			return -EINVAL;
 	}
-	if (flags == 0)
-		return -EINVAL;
 	if (verbose)
 		pr_info("flags=0x%x\n", flags);
 
@@ -405,7 +451,7 @@ static int ddebug_exec_query(char *query_string)
 	unsigned int flags = 0, mask = 0;
 	struct ddebug_query query;
 #define MAXWORDS 9
-	int nwords;
+	int nwords, nfound;
 	char *words[MAXWORDS];
 
 	nwords = ddebug_tokenize(query_string, words, MAXWORDS);
@@ -417,8 +463,47 @@ static int ddebug_exec_query(char *query_string)
 		return -EINVAL;
 
 	/* actually go and implement the change */
-	ddebug_change(&query, flags, mask);
-	return 0;
+	nfound = ddebug_change(&query, flags, mask);
+	vpr_info_dq((&query), (nfound) ? "applied" : "no-match");
+
+	return nfound;
+}
+
+/* handle multiple queries in query string, continue on error, return
+   last error or number of matching callsites.  Module name is either
+   in param (for boot arg) or perhaps in query string.
+*/
+static int ddebug_exec_queries(char *query)
+{
+	char *split;
+	int i, errs = 0, exitcode = 0, rc, nfound = 0;
+
+	for (i = 0; query; query = split) {
+		split = strpbrk(query, ";\n");
+		if (split)
+			*split++ = '\0';
+
+		query = skip_spaces(query);
+		if (!query || !*query || *query == '#')
+			continue;
+
+		if (verbose)
+			pr_info("query %d: \"%s\"\n", i, query);
+
+		rc = ddebug_exec_query(query);
+		if (rc < 0) {
+			errs++;
+			exitcode = rc;
+		} else
+			nfound += rc;
+		i++;
+	}
+	pr_info("processed %d queries, with %d matches, %d errs\n",
+		 i, nfound, errs);
+
+	if (exitcode)
+		return exitcode;
+	return nfound;
 }
 
 #define PREFIX_SIZE 64
@@ -452,7 +537,8 @@ static char *dynamic_emit_prefix(const struct _ddebug *desc, char *buf)
 		pos += snprintf(buf + pos, remaining(pos), "%s:",
 					desc->function);
 	if (desc->flags & _DPRINTK_FLAGS_INCL_LINENO)
-		pos += snprintf(buf + pos, remaining(pos), "%d:", desc->lineno);
+		pos += snprintf(buf + pos, remaining(pos), "%d:",
+					desc->lineno);
 	if (pos - pos_after_tid)
 		pos += snprintf(buf + pos, remaining(pos), " ");
 	if (pos >= PREFIX_SIZE)
@@ -527,14 +613,16 @@ EXPORT_SYMBOL(__dynamic_netdev_dbg);
 
 #endif
 
-static __initdata char ddebug_setup_string[1024];
+#define DDEBUG_STRING_SIZE 1024
+static __initdata char ddebug_setup_string[DDEBUG_STRING_SIZE];
+
 static __init int ddebug_setup_query(char *str)
 {
-	if (strlen(str) >= 1024) {
+	if (strlen(str) >= DDEBUG_STRING_SIZE) {
 		pr_warn("ddebug boot param string too large\n");
 		return 0;
 	}
-	strcpy(ddebug_setup_string, str);
+	strlcpy(ddebug_setup_string, str, DDEBUG_STRING_SIZE);
 	return 1;
 }
 
@@ -544,25 +632,33 @@ __setup("ddebug_query=", ddebug_setup_query);
  * File_ops->write method for <debugfs>/dynamic_debug/conrol.  Gathers the
  * command text from userspace, parses and executes it.
  */
+#define USER_BUF_PAGE 4096
 static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
 				  size_t len, loff_t *offp)
 {
-	char tmpbuf[256];
+	char *tmpbuf;
 	int ret;
 
 	if (len == 0)
 		return 0;
-	/* we don't check *offp -- multiple writes() are allowed */
-	if (len > sizeof(tmpbuf)-1)
+	if (len > USER_BUF_PAGE - 1) {
+		pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE);
 		return -E2BIG;
-	if (copy_from_user(tmpbuf, ubuf, len))
+	}
+	tmpbuf = kmalloc(len + 1, GFP_KERNEL);
+	if (!tmpbuf)
+		return -ENOMEM;
+	if (copy_from_user(tmpbuf, ubuf, len)) {
+		kfree(tmpbuf);
 		return -EFAULT;
+	}
 	tmpbuf[len] = '\0';
 	if (verbose)
 		pr_info("read %d bytes from userspace\n", (int)len);
 
-	ret = ddebug_exec_query(tmpbuf);
-	if (ret)
+	ret = ddebug_exec_queries(tmpbuf);
+	kfree(tmpbuf);
+	if (ret < 0)
 		return ret;
 
 	*offp += len;
@@ -668,7 +764,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 {
 	struct ddebug_iter *iter = m->private;
 	struct _ddebug *dp = p;
-	char flagsbuf[8];
+	char flagsbuf[10];
 
 	if (verbose)
 		pr_info("called m=%p p=%p\n", m, p);
@@ -679,10 +775,10 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 		return 0;
 	}
 
-	seq_printf(m, "%s:%u [%s]%s %s \"",
-		   dp->filename, dp->lineno,
-		   iter->table->mod_name, dp->function,
-		   ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
+	seq_printf(m, "%s:%u [%s]%s =%s \"",
+		trim_prefix(dp->filename), dp->lineno,
+		iter->table->mod_name, dp->function,
+		ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
 	seq_escape(m, dp->format, "\t\r\n\"");
 	seq_puts(m, "\"\n");
 
@@ -708,10 +804,11 @@ static const struct seq_operations ddebug_proc_seqops = {
 };
 
 /*
- * File_ops->open method for <debugfs>/dynamic_debug/control.  Does the seq_file
- * setup dance, and also creates an iterator to walk the _ddebugs.
- * Note that we create a seq_file always, even for O_WRONLY files
- * where it's not needed, as doing so simplifies the ->release method.
+ * File_ops->open method for <debugfs>/dynamic_debug/control.  Does
+ * the seq_file setup dance, and also creates an iterator to walk the
+ * _ddebugs.  Note that we create a seq_file always, even for O_WRONLY
+ * files where it's not needed, as doing so simplifies the ->release
+ * method.
  */
 static int ddebug_proc_open(struct inode *inode, struct file *file)
 {
@@ -846,33 +943,40 @@ static int __init dynamic_debug_init(void)
 	int ret = 0;
 	int n = 0;
 
-	if (__start___verbose != __stop___verbose) {
-		iter = __start___verbose;
-		modname = iter->modname;
-		iter_start = iter;
-		for (; iter < __stop___verbose; iter++) {
-			if (strcmp(modname, iter->modname)) {
-				ret = ddebug_add_module(iter_start, n, modname);
-				if (ret)
-					goto out_free;
-				n = 0;
-				modname = iter->modname;
-				iter_start = iter;
-			}
-			n++;
+	if (__start___verbose == __stop___verbose) {
+		pr_warn("_ddebug table is empty in a "
+			"CONFIG_DYNAMIC_DEBUG build");
+		return 1;
+	}
+	iter = __start___verbose;
+	modname = iter->modname;
+	iter_start = iter;
+	for (; iter < __stop___verbose; iter++) {
+		if (strcmp(modname, iter->modname)) {
+			ret = ddebug_add_module(iter_start, n, modname);
+			if (ret)
+				goto out_free;
+			n = 0;
+			modname = iter->modname;
+			iter_start = iter;
 		}
-		ret = ddebug_add_module(iter_start, n, modname);
+		n++;
 	}
+	ret = ddebug_add_module(iter_start, n, modname);
+	if (ret)
+		goto out_free;
 
 	/* ddebug_query boot param got passed -> set it up */
 	if (ddebug_setup_string[0] != '\0') {
-		ret = ddebug_exec_query(ddebug_setup_string);
-		if (ret)
+		ret = ddebug_exec_queries(ddebug_setup_string);
+		if (ret < 0)
 			pr_warn("Invalid ddebug boot param %s",
 				ddebug_setup_string);
 		else
-			pr_info("ddebug initialized with string %s",
-				ddebug_setup_string);
+			pr_info("%d changes by ddebug_query\n", ret);
+
+		/* keep tables even on ddebug_query parse error */
+		ret = 0;
 	}
 
 out_free: