[PATCH tip/master] tracing/probes: Fix a warning message to show correct maximum length

From: Masami Hiramatsu
Date: Mon Feb 06 2017 - 22:13:53 EST


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.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
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 8c0553d..7138fea 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -673,8 +673,9 @@ ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
*tmp = '\0';
size = tmp - kbuf + 1;
} else if (done + size < count) {
+ /* 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;
}