Re: [PATCH v2] s390/debug: Do not register views for failed static debug areas

[Heiko Carstens <hca@linux.ibm.com>]

On Fri, Sep 18, 2026 at 05:13:51PM +0200, Mikhail Zaslonko wrote:
> __REGISTER_STATIC_DEBUG_INFO() calls debug_register_view()
> unconditionally, even when debug_register_static() has failed. In that
> case _debug_register() was never reached and id->debugfs_root_entry is
> still NULL, so debugfs_create_file() places the view file in the debugfs
> root directory. For sclp_err this leaves a /sys/kernel/debug/hex_ascii
> file with nothing to indicate which debug log it belongs to.
> 
> debug_register_static() is not exported and the macro is its only
> caller, so let it return an error code and skip the view registration
> when it fails. No debugfs files are created for such an area then.
> 
> Reproduce by booting with s390dbf=sclp_err::100000000. The sclp_err
> registration fails, no s390dbf/sclp_err/ directory is created, and a
> hex_ascii file appears in the debugfs root instead.
> 
> Fixes: d72541f94512 ("s390/debug: add early tracing support")
> Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
> ---
> v2:
> - Resend as regular patch, no functional changes since RFC
> 
>  arch/s390/include/asm/debug.h |  8 ++++++--
>  arch/s390/kernel/debug.c      | 12 +++++++++---
>  2 files changed, 15 insertions(+), 5 deletions(-)

Applied, thanks!