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>
eda1e32855