s390/debug: Do not register views for failed static debug areas

__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>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

0 files changed, 0 insertions, 0 deletions