The sysfs core now allows instances of 'struct bin_attribute' to be
moved into read-only memory. Make use of that to protect them against
accidental or malicious modifications.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/r/20241211-sysfs-const-bin_attr-s390-v1-4-be01f66bfcf7@weissschuh.net
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Due to a bug in some firmware versions, Store Data requests might not
get an event response in certain situations. As a result, the boot
process will be blocked indefinitely.
Fix this by introducing timeout handling for Store Data requests. In
case a timeout occurs, the Store Data operation is halted and no data
is retrieved from the SCLP facility.
Note: A minority of installed systems rely on Store Data result for
device auto-configuration. These systems will fail to boot in case of a
Store Data timeout and will need to be switched to manual device
configuration as workaround.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
When a task waiting for completion of a Store Data operation is
interrupted, an attempt is made to halt this operation. If this attempt
fails due to a hardware or firmware problem, there is a chance that the
SCLP facility might store data into buffers referenced by the original
operation at a later time.
Handle this situation by not releasing the referenced data buffers if
the halt attempt fails. For current use cases, this might result in a
leak of few pages of memory in case of a rare hardware/firmware
malfunction.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
On systems that do not support Store Data events (such as when running
as KVM guest) the following warning message appears during boot:
sclp_sd: Store Data request failed (eq=2, di=3, response=0x40f0,
flags=0x00, status=0, rc=-5)
This warning does not add any useful information since the result is
expected due to missing support for that event type.
Suppress this message by checking the associated masks of supported
events before issuing a Store Data event.
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
There are currently 2 ways to create a set of sysfs files for a
kobj_type, through the default_attrs field, and the default_groups
field. Move the sclp_sd sysfs code to use default_groups field which
has been the preferred way since commit aa30f47cf6 ("kobject: Add
support for default attribute groups to kobj_type") so that we can
soon get rid of the obsolete default_attrs field.
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220106095252.3273905-1-gregkh@linuxfoundation.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Provide physical addresses whenever the hardware interface
expects it or a 32-bit value used for tracking.
Variable sclp_early_sccb gets initialized in the decompressor
and points to an address in physcal memory. Yet, it is used
as virtual memory pointer and therefore should be converted.
Note, the other two __bootdata variables sclp_info_sccb and
sclp_info_sccb_valid contain plain data, but no pointers and
do need any special care.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Fix these warnings that are reported when compiling with W=1:
drivers/s390/char/sclp_sd.c:132: warning: Function parameter or member 'listener' not described in 'sclp_sd_listener_init'
drivers/s390/char/sclp_sd.c:408: warning: Function parameter or member 'cookie' not described in 'sclp_sd_file_update_async'
drivers/s390/char/sclp_sd.c:422: warning: Function parameter or member 'attr' not described in 'reload_store'
drivers/s390/char/sclp_sd.c:422: warning: Function parameter or member 'buf' not described in 'reload_store'
drivers/s390/char/sclp_sd.c:422: warning: Function parameter or member 'count' not described in 'reload_store'
drivers/s390/char/sclp_sd.c:457: warning: Function parameter or member 'file' not described in 'data_read'
drivers/s390/char/sclp_sd.c:457: warning: Function parameter or member 'attr' not described in 'data_read'
Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Add functions to retrieve data associated with an SCLP Store Data
entity. Automatically retrieve data for the "config" entity during
boot and make that data available to user-space via sysfs:
/sys/firmware/sclp_sd/config/data
Reading from this file will return config data contents.
/sys/firmware/sclp_sd/config/reload
Writing to this file will cause the latest version of data
related to the config entity to be read from the SCLP interface.
Generate a KOBJ_CHANGE whenever new data is retrieved.
Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Thomas Weißschuh
Peter Oberparleiter
Greg Kroah-Hartman
Alexander Gordeev
Kees Cook
Peter Oberparleiter