Re: [PATCH v3 1/7] vmlinux.lds.h: add linker section for KUnit test suites

Brendan Higgins
2020-02-28T07:22:31Z

On Thu, Feb 27, 2020 at 5:20 PM Brendan Higgins
<brendanhiggins@google.com> wrote:
>
> Add a linker section where KUnit can put references to its test suites.
> This patch is the first step in transitioning to dispatching all KUnit
> tests from a centralized executor rather than having each as its own
> separate late_initcall.
>
> Co-developed-by: Iurii Zaikin <yzaikin@google.com>
> Signed-off-by: Iurii Zaikin <yzaikin@google.com>
> Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
> Reviewed-by: Stephen Boyd <sboyd@kernel.org>
> ---
> include/asm-generic/vmlinux.lds.h | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
> index e00f41aa8ec4f..99a866f49cb3d 100644
> --- a/include/asm-generic/vmlinux.lds.h
> +++ b/include/asm-generic/vmlinux.lds.h
> @@ -856,6 +856,13 @@
> KEEP(*(.con_initcall.init)) \
> __con_initcall_end = .;
>
> +/* Alignment must be consistent with (kunit_suite *) in include/kunit/test.h */
> +#define KUNIT_TEST_SUITES \
> + . = ALIGN(8); \

After posting this, I saw I had gotten an email from 0day[1]. After
some investigation, I discovered that this 8 byte alignment works for
x86 64 bit fine, but only *sometimes* for 32 bit. 4 byte alignment
seems to work in all cases (so far). I am not sure why we went with
such a large alignment in hindsight. In any case, I should have a
fixed revision out pretty soon.

> + __kunit_suites_start = .; \
> + KEEP(*(.kunit_test_suites)) \
> + __kunit_suites_end = .;
> +
> #ifdef CONFIG_BLK_DEV_INITRD
> #define INIT_RAM_FS \
> . = ALIGN(4); \
> @@ -1024,6 +1031,7 @@
> INIT_CALLS \
> CON_INITCALL \
> INIT_RAM_FS \
> + KUNIT_TEST_SUITES \
> }
>
> #define BSS_SECTION(sbss_align, bss_align, stop_align) \
> --

[1] https://lists.01.org/hyperkitty/list/lkp@lists.01.org/thread/4I4UW4OAT63ETMIEUJQTOF3BFTMO6ROD/