Sorry for the delayed reply. I will be on vacation until Wednesday, October 16th.
On Wed, Oct 9, 2019 at 9:36 AM Alan Maguire alan.maguire@oracle.com wrote:
On Tue, 8 Oct 2019, Brendan Higgins wrote:
On Tue, Oct 08, 2019 at 03:55:44PM +0100, Alan Maguire wrote:
[...]
diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c index e6d17aa..e4f3a97 100644 --- a/lib/kunit/string-stream.c +++ b/lib/kunit/string-stream.c @@ -100,6 +100,7 @@ int string_stream_vadd(struct string_stream *stream,
return 0;} +EXPORT_SYMBOL_GPL(string_stream_vadd);
Is this actually needed by anything other than lib/kunit/test.c right now? Maybe we should move the include file into the kunit/ directory to hide these so no one else can use them.
I tried this, and it's the right answer I think but it exposes a problem with symbol visibility when kunit is compiled as a module. More on this below...
int string_stream_add(struct string_stream *stream, const char *fmt, ...) { @@ -112,6 +113,7 @@ int string_stream_add(struct string_stream *stream, const char *fmt, ...)
return result;} +EXPORT_SYMBOL_GPL(string_stream_add);
[...]
diff --git a/lib/kunit/test.c b/lib/kunit/test.c index c83c0fa..e7896f1 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c
[...]
@@ -50,6 +51,7 @@ static unsigned long kunit_test_timeout(void) * For more background on this topic, see: * https://mike-bland.com/2011/11/01/small-medium-large.html */ +#ifndef MODULE
Why is this block of code "ifndef MODULE"?
Symbol visibility is the problem again; sysctl_hung_task_timeout_secs isn't exported so when kunit is a module it can't find the symbol.
I think I saw Kees mentioned something about symbol lookup too; in KTF Knut solved this by defining ktf_find_symbol(). I'd suggest we may need a kunit_find_symbol() with a function signature
I thought we were just talking about exposing symbols for linking outside of a compilation unit (static vs. not static); nevertheless, I think you are right that it is relevant here. Kees, thoughts?
void *kunit_find_symbol(const char *modname, const char *symbol_name);
...which does a [module_]kallsyms_lookup_sym().
If the above makes sense I can look at adding it as a patch (and adding a test of it of course!). What do you think?
So that won't work if you are trying to link against a symbol not in a module, right? Also, it won't work against a static symbol, right?
Even so, I think it is pretty wonky to expect users to either a) export any symbol name to be tested, or b) have to access them via kunit_find_symbol. I think it is fine to have some tests that cannot be compiled as modules, if there is no other user friendly way to make this work in those cases.
Thoughts?