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authorJiri Olsa <jolsa@redhat.com>2009-08-11 17:29:04 +0200
committerSteven Rostedt <rostedt@goodmis.org>2009-08-18 20:39:48 -0400
commiteda1e328556565e211b7450250e40d6de751563a (patch)
treea0d4d6c056f3c4452a9a7d0e4b9af52e7a2d089d
parentf2d84b65b9778e8a35dd904f7d3993f0a60c9756 (diff)
tracing: handle broken names in ftrace filter
If one filter item (for set_ftrace_filter and set_ftrace_notrace) is being setup by more than 1 consecutive writes (FTRACE_ITER_CONT flag), it won't be handled corretly. I used following program to test/verify: [snip] #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <string.h> int main(int argc, char **argv) { int fd, i; char *file = argv[1]; if (-1 == (fd = open(file, O_WRONLY))) { perror("open failed"); return -1; } for(i = 0; i < (argc - 2); i++) { int len = strlen(argv[2+i]); int cnt, off = 0; while(len) { cnt = write(fd, argv[2+i] + off, len); len -= cnt; off += cnt; } } close(fd); return 0; } [snip] before change: sh-4.0# echo > ./set_ftrace_filter sh-4.0# /test ./set_ftrace_filter "sys" "_open " sh-4.0# cat ./set_ftrace_filter #### all functions enabled #### sh-4.0# after change: sh-4.0# echo > ./set_ftrace_notrace sh-4.0# test ./set_ftrace_notrace "sys" "_open " sh-4.0# cat ./set_ftrace_notrace sys_open sh-4.0# Signed-off-by: Jiri Olsa <jolsa@redhat.com> LKML-Reference: <20090811152904.GA26065@jolsa.lab.eng.brq.redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--kernel/trace/ftrace.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1e1d23c2630..25edd5cc593 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2278,7 +2278,11 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
read++;
cnt--;
- if (!(iter->flags & ~FTRACE_ITER_CONT)) {
+ /*
+ * If the parser haven't finished with the last write,
+ * continue reading the user input without skipping spaces.
+ */
+ if (!(iter->flags & FTRACE_ITER_CONT)) {
/* skip white space */
while (cnt && isspace(ch)) {
ret = get_user(ch, ubuf++);
@@ -2288,8 +2292,9 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
cnt--;
}
+ /* only spaces were written */
if (isspace(ch)) {
- file->f_pos += read;
+ *ppos += read;
ret = read;
goto out;
}
@@ -2319,12 +2324,12 @@ ftrace_regex_write(struct file *file, const char __user *ubuf,
if (ret)
goto out;
iter->buffer_idx = 0;
- } else
+ } else {
iter->flags |= FTRACE_ITER_CONT;
+ iter->buffer[iter->buffer_idx++] = ch;
+ }
-
- file->f_pos += read;
-
+ *ppos += read;
ret = read;
out:
mutex_unlock(&ftrace_regex_lock);