On Wed, Apr 10, 2024 at 11:36:14AM -0400, Steven Rostedt wrote: > On Mon, 01 Apr 2024 23:48:52 +0000 > Justin Stitt <[email protected]> wrote: > > > diff --git a/include/trace/events/rpcgss.h b/include/trace/events/rpcgss.h > > index ba2d96a1bc2f..274c297f1b15 100644 > > --- a/include/trace/events/rpcgss.h > > +++ b/include/trace/events/rpcgss.h > > @@ -618,7 +618,7 @@ TRACE_EVENT(rpcgss_context, > > __entry->timeout = timeout; > > __entry->window_size = window_size; > > __entry->len = len; > > - strncpy(__get_str(acceptor), data, len); > > + memcpy(__get_str(acceptor), data, len); > > ), > > > > TP_printk("win_size=%u expiry=%lu now=%lu timeout=%u acceptor=%.*s", > > WTF, that code is just buggy. Looking at the rpcgss_context event we have: > > > TRACE_EVENT(rpcgss_context, > > TP_PROTO( > > u32 window_size, > > unsigned long expiry, > > unsigned long now, > > unsigned int timeout, > > unsigned int len, > > const u8 *data > > ), > > > > TP_ARGS(window_size, expiry, now, timeout, len, data), > > > > TP_STRUCT__entry( > > __field(unsigned long, expiry) > > __field(unsigned long, now) > > __field(unsigned int, timeout) > > __field(u32, window_size) > > __field(int, len) > > __string(acceptor, data) > > The __string() macro expects "data" to be a string and does *not* check > length when copying. > > If anything, it needs to be: > > __string_len(acceptor, data, len) > > as the macro code has changed recently, and the current code will crash!
A general question: Is there a test suite we should run regularly to build some confidence in the kernel's observability apparatus? We're building a menagerie of tests around kdevops, and one area where we know there is a testing gap is the tracepoints in NFSD and SunRPC. > > ), > > > > TP_fast_assign( > > __entry->expiry = expiry; > > __entry->now = now; > > __entry->timeout = timeout; > > __entry->window_size = window_size; > > __entry->len = len; > > strncpy(__get_str(acceptor), data, len); > > Then this needs to be: > > __assign_str(acceptor, data); > > Note, the length is now saved via __string_len() and not needed here. > > I'll go send a patch to fix this. > > -- Steve > > > > ), -- Chuck Lever
