| Message ID | 20190321194127.4ac47d99@gandalf.local.home (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 0f03474a17ac401fdd3c7d35ec7f111160dd4e9b |
| Headers | show |
| Series | trace-cmd: Have tracecmd_msg_data_send() return zero on zero size | expand |
On Thu, 2019-03-21 at 19:41 -0400, Steven Rostedt wrote: > From: "Steven Rostedt (VMware)" <rostedt@goodmis.org> > > If tracecmd_msg_data_send() is passed a size of zero, the loop is not > entered, nothing is sent, but the ret variable is not initialized and > garbage can be sent out. The option code can call this with a size of > zero, > which can cause an error report. > > Just don't do anything in this case, and return a success. > > Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> > --- > tracecmd/trace-msg.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/tracecmd/trace-msg.c b/tracecmd/trace-msg.c > index 51d0ac8b..382bd766 100644 > --- a/tracecmd/trace-msg.c > +++ b/tracecmd/trace-msg.c > @@ -590,6 +590,10 @@ int tracecmd_msg_data_send(struct > tracecmd_msg_handle *msg_handle, > int ret; > int count = 0; > > + /* Don't bother doing anything if there's nothing to do */ > + if (!size) > + return 0; > + > tracecmd_msg_init(MSG_SEND_DATA, &msg); > > msg.buf = malloc(MSG_MAX_DATA_LEN); Nice catch. Definitely a latent bug waiting for someone to step on it. Reviewed-by: Slavomir Kaslev <kaslevs@vmware.com> -- Slavi
On Fri, 22 Mar 2019 11:49:29 +0000 Slavomir Kaslev <kaslevs@vmware.com> wrote: > > diff --git a/tracecmd/trace-msg.c b/tracecmd/trace-msg.c > > index 51d0ac8b..382bd766 100644 > > --- a/tracecmd/trace-msg.c > > +++ b/tracecmd/trace-msg.c > > @@ -590,6 +590,10 @@ int tracecmd_msg_data_send(struct > > tracecmd_msg_handle *msg_handle, > > int ret; > > int count = 0; > > > > + /* Don't bother doing anything if there's nothing to do */ > > + if (!size) > > + return 0; > > + > > tracecmd_msg_init(MSG_SEND_DATA, &msg); > > > > msg.buf = malloc(MSG_MAX_DATA_LEN); > > Nice catch. Definitely a latent bug waiting for someone to step on it. > > Reviewed-by: Slavomir Kaslev <kaslevs@vmware.com> Yeah, it tripped me up, as I had a box that crashed because of it. Delaying the finishing of the testing. Which I'm rerunning now. -- Steve
diff --git a/tracecmd/trace-msg.c b/tracecmd/trace-msg.c index 51d0ac8b..382bd766 100644 --- a/tracecmd/trace-msg.c +++ b/tracecmd/trace-msg.c @@ -590,6 +590,10 @@ int tracecmd_msg_data_send(struct tracecmd_msg_handle *msg_handle, int ret; int count = 0; + /* Don't bother doing anything if there's nothing to do */ + if (!size) + return 0; + tracecmd_msg_init(MSG_SEND_DATA, &msg); msg.buf = malloc(MSG_MAX_DATA_LEN);