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>
Jiri Olsa