[DTrace-devel] [PATCH 4/4] test: Do not depend on ext4

[Kris Van Hees]

I am not too sure about this patch...  We are not using kallmodsyms anymore
for newer kernels, and on older kernels that symbol certainly be listed as
[ext4].  So, if ext4_dir_operations *is* in the ext4 module code (compiled in
or loadable), then the proper ref to it would be ext4`ext4_dir_operations.
So the test should be able to use that - if not, that seems like a bug rather
than something to change in the test?

On Fri, Oct 04, 2024 at 12:43:55AM -0400, eugene.loh at oracle.com wrote:
> From: Eugene Loh <eugene.loh at oracle.com>
> 
> It is possible that there is no ext4 module, whether built-in or otherwise,
> even if its symbols are present.  E.g.,
>     # grep ext4_dir_operations /proc/kallmodsyms
>     ffffc45a59d9ee88 100 D ext4_dir_operations
>     # grep -w ext4 /proc/kallmodsyms
>     #
> 
> Meanwhile, in
>     ab883bae "tests, io, scalars: use kallsyms instead of kallmodsyms where possible"
> we read:
>     scalars/tst.misc.x needs adjusting to check for the presence of the actual
>     symbols we are looking up, since the modules might well be built-in, and
>     thus not show up in /proc/kallsyms.
> 
> With that patch, in test/unittest/scalars/tst.misc.x, we check:
>    -if ! $(grep -qw ext4 /proc/kallmodsyms); then
>    +if ! grep -qw ext4_dir_operations /proc/kallsyms; then
>         exit 1
>     fi
> 
> So it is possible for us to find
>         `ext4_dir_operations
> but not
>     ext4`ext4_dir_operations
> 
> Change the .d script to look simply for `ext4_dir_operations.
> 
> Signed-off-by: Eugene Loh <eugene.loh at oracle.com>
> ---
>  test/unittest/scalars/tst.misc.d | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/test/unittest/scalars/tst.misc.d b/test/unittest/scalars/tst.misc.d
> index 60edab45e..6a5f4ae2e 100644
> --- a/test/unittest/scalars/tst.misc.d
> +++ b/test/unittest/scalars/tst.misc.d
> @@ -20,7 +20,7 @@
>  BEGIN
>  {
>  	printf("\nr_cpu_ids = 0x%x\n", `nr_cpu_ids);
> -	printf("ext4`ext4_dir_operations = %p\n", &ext4`ext4_dir_operations);
> +	printf("ext4`ext4_dir_operations = %p\n", &`ext4_dir_operations);
>  	printf("isofs`isofs_dir_operations = %p\n", &isofs`isofs_dir_operations);
>  	printf("vmlinux`major_names = %p\n", &vmlinux`major_names);
>  	x = 123;
> -- 
> 2.43.5
>