On Wed, 10 Apr 2024 11:41:18 -0400
Chuck Lever <[email protected]> wrote:
> > 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.
I try to add self tests within the macros. As __assign_str() is going to
turn into just __assign_str(field) (instead of __assign_str(field, src)), I
added a test to make sure what was passed to __string() is also what
__assign_str() gets. But using strcpy() in place of __assign_str() really
is doing something that one should not be doing.
There's checks in the tracepoint code as well for things like referencing a
pointer that was not saved in the event, and other things. But a generic
test on a custom trace event, I don't really have.
Note, you could enable CONFIG_TRACE_EVENT_INJECT where an "inject" file is
created, and you can write into it:
# cd /sys/kernel/tracing
# echo 1 > events/rpcgss/rpcgss_context/enable
# echo 'expiry=123456 now=222' > events/rpcgss/rpcgss_context/inject
# cat trace
bash-843 [001] ..... 720.083189: rpcgss_context: win_size=0 expiry=123456 now=222 timeout=0 acceptor=
And you could use that for testing.
-- Steve