[PATCH 1/3] ftrace: Return EINVAL when writing invalid val to set_ftrace_filter

[PATCH 1/3] ftrace: Return EINVAL when writing invalid val to set_ftrace_filter

[Li Zefan]

Currently it doesn't warn user on invald value:

 # echo nonexist_symbol > set_ftrace_filter
or:
 # echo 'nonexist_symbol:mod:fuse' > set_ftrace_filter

Better make it return failure.

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
 kernel/trace/ftrace.c |   22 ++++++++++++++++------
 1 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 7cb6f19..c7fe869 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1724,7 +1724,7 @@ ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type)
 	return ftrace_match(str, regex, len, type);
 }
 
-static void ftrace_match_records(char *buff, int len, int enable)
+static int ftrace_match_records(char *buff, int len, int enable)
 {
 	unsigned int search_len;
 	struct ftrace_page *pg;
@@ -1733,6 +1733,7 @@ static void ftrace_match_records(char *buff, int len, int enable)
 	char *search;
 	int type;
 	int not;
+	int found = 0;
 
 	flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
 	type = filter_parse_regex(buff, len, &search, &not);
@@ -1750,6 +1751,7 @@ static void ftrace_match_records(char *buff, int len, int enable)
 				rec->flags &= ~flag;
 			else
 				rec->flags |= flag;
+			found = 1;
 		}
 		/*
 		 * Only enable filtering if we have a function that
@@ -1759,6 +1761,8 @@ static void ftrace_match_records(char *buff, int len, int enable)
 			ftrace_filtered = 1;
 	} while_for_each_ftrace_rec();
 	mutex_unlock(&ftrace_lock);
+
+	return found;
 }
 
 static int
@@ -1780,7 +1784,7 @@ ftrace_match_module_record(struct dyn_ftrace *rec, char *mod,
 		return 1;
 }
 
-static void ftrace_match_module_records(char *buff, char *mod, int enable)
+static int ftrace_match_module_records(char *buff, char *mod, int enable)
 {
 	unsigned search_len = 0;
 	struct ftrace_page *pg;
@@ -1789,6 +1793,7 @@ static void ftrace_match_module_records(char *buff, char *mod, int enable)
 	char *search = buff;
 	unsigned long flag;
 	int not = 0;
+	int found = 0;
 
 	flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
 
@@ -1819,12 +1824,15 @@ static void ftrace_match_module_records(char *buff, char *mod, int enable)
 				rec->flags &= ~flag;
 			else
 				rec->flags |= flag;
+			found = 1;
 		}
 		if (enable && (rec->flags & FTRACE_FL_FILTER))
 			ftrace_filtered = 1;
 
 	} while_for_each_ftrace_rec();
 	mutex_unlock(&ftrace_lock);
+
+	return found;
 }
 
 /*
@@ -1853,8 +1861,9 @@ ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
 	if (!strlen(mod))
 		return -EINVAL;
 
-	ftrace_match_module_records(func, mod, enable);
-	return 0;
+	if (ftrace_match_module_records(func, mod, enable))
+		return 0;
+	return -EINVAL;
 }
 
 static struct ftrace_func_command ftrace_mod_cmd = {
@@ -2151,8 +2160,9 @@ static int ftrace_process_regex(char *buff, int len, int enable)
 	func = strsep(&next, ":");
 
 	if (!next) {
-		ftrace_match_records(func, len, enable);
-		return 0;
+		if (ftrace_match_records(func, len, enable))
+			return 0;
+		return ret;
 	}
 
 	/* command found */
-- 
1.6.3

[PATCH 2/3] ftrace: Call trace_parser_clear() properly

[Li Zefan]

I found a weird behavior:

  # echo 'fuse:*' > set_ftrace_filter
  bash: echo: write error: Invalid argument
  # cat set_ftrace_filter
  fuse_dev_fasync
  fuse_dev_poll
  fuse_copy_do

We should call trace_parser_clear() no matter ftrace_process_regex()
returns 0 or -errno.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
 kernel/trace/ftrace.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index c7fe869..b1acfb1 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2208,10 +2208,9 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
 	    !trace_parser_cont(parser)) {
 		ret = ftrace_process_regex(parser->buffer,
 					   parser->idx, enable);
+		trace_parser_clear(parser);
 		if (ret)
 			goto out_unlock;
-
-		trace_parser_clear(parser);
 	}
 
 	ret = read;
-- 
1.6.3

[PATCH 3/3] function-graph: Allow writing the same val to set_graph_function

[Li Zefan]

 # echo 'do_open' > set_graph_function
 # echo 'do_open' >> set_graph_function
 bash: echo: write error: Invalid argument

Make it valid to write the same value to set_graph_function.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
 kernel/trace/ftrace.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index b1acfb1..13f256a 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2552,10 +2552,9 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer)
 					exists = true;
 					break;
 				}
-			if (!exists) {
+			if (!exists)
 				array[(*idx)++] = rec->ip;
-				found = 1;
-			}
+			found = 1;
 		}
 	} while_for_each_ftrace_rec();
 
-- 
1.6.3

[PATCH 3/3] function-graph: Allow writing the same val to set_graph_function

[Li Zefan]

 # echo 'do_open' > set_graph_function
 # echo 'do_open' >> set_graph_function
 bash: echo: write error: Invalid argument

Make it valid to write the same value to set_graph_function.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
 kernel/trace/ftrace.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index e0184b7..eaf6a4d 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2549,10 +2549,9 @@ ftrace_set_func(unsigned long *array, int *idx, char *buffer)
 					exists = true;
 					break;
 				}
-			if (!exists) {
+			if (!exists)
 				array[(*idx)++] = rec->ip;
-				found = 1;
-			}
+			found = 1;
 		}
 	} while_for_each_ftrace_rec();
 
-- 
1.6.3