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author | Jiri Olsa <jolsa@redhat.com> | 2009-08-11 15:29:04 (GMT) |
---|---|---|
committer | Steven Rostedt <rostedt@goodmis.org> | 2009-08-19 00:39:48 (GMT) |
commit | eda1e328556565e211b7450250e40d6de751563a (patch) | |
tree | a0d4d6c056f3c4452a9a7d0e4b9af52e7a2d089d | |
parent | f2d84b65b9778e8a35dd904f7d3993f0a60c9756 (diff) | |
download | linux-fsl-qoriq-eda1e328556565e211b7450250e40d6de751563a.tar.xz |
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.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 1e1d23c..25edd5c 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); |