Messages in this thread Patch in this message | | | From | Masami Hiramatsu <> | Subject | [PATCH V2 1/2] tracing/probes: Fix a warning message to show correct maximum length | Date | Fri, 10 Feb 2017 22:21:55 +0900 |
| |
Since tracing/*probe_events will accept a probe definition up to 4096 - 2 ('\n' and '\0') bytes, it must show 4094 instead of 4096 in warning message.
Note that there is one possible case of exceed 4094. If user prepare 4096 bytes null-terminated string and syscall write it with the count == 4095, then it can be accepted. However, if user puts a '\n' after that, it must rejected. So IMHO, the warning message should indicate shorter one, since it is safer.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> --- kernel/trace/trace_probe.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 2a06f1f..847c1e0 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -678,8 +678,9 @@ ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer, if (done + size < count) { if (buf != kbuf) break; + /* This can accept WRITE_BUFSIZE - 2 ('\n' + '\0') */ pr_warn("Line length is too long: Should be less than %d\n", - WRITE_BUFSIZE); + WRITE_BUFSIZE - 2); ret = -EINVAL; goto out; }
| |