treewide: const qualify ctl_tables where applicable

Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysc

treewide: const qualify ctl_tables where applicable

Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.

Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide:
constify the ctl_table argument of proc_handlers") constified all the
proc_handlers.

Created this by running an spatch followed by a sed command:
Spatch:
virtual patch

@
depends on !(file in "net")
disable optional_qualifier
@

identifier table_name != {
watchdog_hardlockup_sysctl,
iwcm_ctl_table,
ucma_ctl_table,
memory_allocation_profiling_sysctls,
loadpin_sysctl_table
};
@@

+ const
struct ctl_table table_name [] = { ... };

sed:
sed --in-place \
-e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \
kernel/utsname_sysctl.c

Reviewed-by: Song Liu <[email protected]>
Acked-by: Steven Rostedt (Google) <[email protected]> # for kernel/trace/
Reviewed-by: Martin K. Petersen <[email protected]> # SCSI
Reviewed-by: Darrick J. Wong <[email protected]> # xfs
Acked-by: Jani Nikula <[email protected]>
Acked-by: Corey Minyard <[email protected]>
Acked-by: Wei Liu <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Reviewed-by: Bill O'Donnell <[email protected]>
Acked-by: Baoquan He <[email protected]>
Acked-by: Ashutosh Dixit <[email protected]>
Acked-by: Anna Schumaker <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

s390/pci: Add pci_msg debug view to PCI report

Using the newly introduced debug_dump() mechanism add formatted content
of pci_debug_msg_id to the PCI report. The formatting is based on the
existing

s390/pci: Add pci_msg debug view to PCI report

Using the newly introduced debug_dump() mechanism add formatted content
of pci_debug_msg_id to the PCI report. The formatting is based on the
existing sprintf format but removes caller pointer and area index and
adds an column header. This will allow the platform to collect this log
data together with hardware errors. This sets the reverse flag such that
the newest log entries get added to the PCI report even if not all debug
log entries fit.

Reviewed-by: Halil Pasic <[email protected]>
Co-developed-by: Halil Pasic <[email protected]>
Signed-off-by: Halil Pasic <[email protected]>
Signed-off-by: Niklas Schnelle <[email protected]>
Signed-off-by: Alexander Gordeev <[email protected]>

show more ...

s390/debug: Add a reverse mode for debug_dump()

In this mode debug_dump() writes the debug log starting at the newest
entry followed by earlier entries. To this end add a debug_prev_entry()
helper a

s390/debug: Add a reverse mode for debug_dump()

In this mode debug_dump() writes the debug log starting at the newest
entry followed by earlier entries. To this end add a debug_prev_entry()
helper analogous to debug_next_entry() a helper to get the latest entry
which is one before the active entry and a helper to iterate either
forward or backward.

Reviewed-by: Halil Pasic <[email protected]>
Co-developed-by: Halil Pasic <[email protected]>
Signed-off-by: Halil Pasic <[email protected]>
Signed-off-by: Niklas Schnelle <[email protected]>
Signed-off-by: Alexander Gordeev <[email protected]>

show more ...

s390/debug: Add debug_dump() to write debug view to a string buffer

The debug_dump() function allows to get the content of a debug log and
view pair in a string buffer. One future application of thi

s390/debug: Add debug_dump() to write debug view to a string buffer

The debug_dump() function allows to get the content of a debug log and
view pair in a string buffer. One future application of this is to
provide debug logs to the platform to be collected with hardware error
logs during recovery.

Reviewed-by: Halil Pasic <[email protected]>
Co-developed-by: Halil Pasic <[email protected]>
Signed-off-by: Halil Pasic <[email protected]>
Signed-off-by: Niklas Schnelle <[email protected]>
Signed-off-by: Alexander Gordeev <[email protected]>

show more ...

s390/debug: Split private data alloc/free out of file operations

Split the allocation respectively freeing of file_private_info_t out
of open() respectively close(). This will be used in a follow on

s390/debug: Split private data alloc/free out of file operations

Split the allocation respectively freeing of file_private_info_t out
of open() respectively close(). This will be used in a follow on change
to access to debug views without going through the s390dbf filesystem.

Reviewed-by: Halil Pasic <[email protected]>
Signed-off-by: Niklas Schnelle <[email protected]>
Signed-off-by: Alexander Gordeev <[email protected]>

show more ...

s390/debug: Simplify and document debug_next_entry() logic

Contrary to convention debug_next_entry() returns a falsy 0 value if
there are more entries and a truthy 1 value when there are no more
ent

s390/debug: Simplify and document debug_next_entry() logic

Contrary to convention debug_next_entry() returns a falsy 0 value if
there are more entries and a truthy 1 value when there are no more
entries. As there is only one caller just reverse this logic to be less
surprising and document the behavior in a kdoc comment. Also replace the
goto with an early return. In the future this allows using it in
a do {} while (debug_next_entry(...)) loop.

Reviewed-by: Halil Pasic <[email protected]>
Signed-off-by: Niklas Schnelle <[email protected]>
Signed-off-by: Alexander Gordeev <[email protected]>

show more ...

s390/debug: Pass in and enforce output buffer size for format handlers

The s390dbf format handler rely on being passed an output buffer sized
such that their output will always fit and then use plai

s390/debug: Pass in and enforce output buffer size for format handlers

The s390dbf format handler rely on being passed an output buffer sized
such that their output will always fit and then use plain sprintf() to
write to it. While only supplied data from other kernel components this
still potentially allows buffer overwrite if callers are not careful.
Instead just pass in the size of the output buffer and use scnprintf()
instead of sprintf() and strscpy() instead of strcpy(). The latter also
allows us to get rid of a separate strlen() call.

Signed-off-by: Niklas Schnelle <[email protected]>
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>

show more ...

s390: Fix various typos

Run codespell on arch/s390 and drivers/s390 and fix all typos.

Signed-off-by: Heiko Carstens <[email protected]>

[tree-wide] finally take no_llseek out

no_llseek had been defined to NULL two years ago, in commit 868941b14441
("fs: remove no_llseek")

To quote that commit,

At -rc1 we'll need do a mechanical

[tree-wide] finally take no_llseek out

no_llseek had been defined to NULL two years ago, in commit 868941b14441
("fs: remove no_llseek")

To quote that commit,

At -rc1 we'll need do a mechanical removal of no_llseek -

git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done

would do it.

Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.

Signed-off-by: Al Viro <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

sysctl: treewide: constify the ctl_table argument of proc_handlers

const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ct

sysctl: treewide: constify the ctl_table argument of proc_handlers

const qualify the struct ctl_table argument in the proc_handler function
signatures. This is a prerequisite to moving the static ctl_table
structs into .rodata data which will ensure that proc_handler function
pointers cannot be modified.

This patch has been generated by the following coccinelle script:

```
virtual patch

@r1@
identifier ctl, write, buffer, lenp, ppos;
identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)";
@@

int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int write, void *buffer, size_t *lenp, loff_t *ppos);

@r2@
identifier func, ctl, write, buffer, lenp, ppos;
@@

int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int write, void *buffer, size_t *lenp, loff_t *ppos)
{ ... }

@r3@
identifier func;
@@

int func(
- struct ctl_table *
+ const struct ctl_table *
,int , void *, size_t *, loff_t *);

@r4@
identifier func, ctl;
@@

int func(
- struct ctl_table *ctl
+ const struct ctl_table *ctl
,int , void *, size_t *, loff_t *);

@r5@
identifier func, write, buffer, lenp, ppos;
@@

int func(
- struct ctl_table *
+ const struct ctl_table *
,int write, void *buffer, size_t *lenp, loff_t *ppos);

```

* Code formatting was adjusted in xfs_sysctl.c to comply with code
conventions. The xfs_stats_clear_proc_handler,
xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where
adjusted.

* The ctl_table argument in proc_watchdog_common was const qualified.
This is called from a proc_handler itself and is calling back into
another proc_handler, making it necessary to change it as part of the
proc_handler migration.

Co-developed-by: Thomas Weißschuh <[email protected]>
Signed-off-by: Thomas Weißschuh <[email protected]>
Co-developed-by: Joel Granados <[email protected]>
Signed-off-by: Joel Granados <[email protected]>

show more ...

S390: Remove now superfluous sentinel elem from ctl_table arrays

This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) whi

S390: Remove now superfluous sentinel elem from ctl_table arrays

This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which will
reduce the overall build time size of the kernel and run time memory
bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%[email protected]/)

Remove the sentinel element from appldata_table, s390dbf_table,
topology_ctl_table, cmm_table and page_table_sysctl. Reduced the memory
allocation in appldata_register_ops by 1 effectively removing the
sentinel from ops->ctl_table.

This removal is safe because register_sysctl_sz and register_sysctl use
the array size in addition to checking for the sentinel.

Tested-by: Alexander Gordeev <[email protected]>
Acked-by: Heiko Carstens <[email protected]>
Signed-off-by: Joel Granados <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

show more ...

s390/debug: replace zero-length array with flexible-array member

There are numerous patches which convert zero-length arrays with a
flexible-array member. Convert the remaining s390 occurrences.

Su

s390/debug: replace zero-length array with flexible-array member

There are numerous patches which convert zero-length arrays with a
flexible-array member. Convert the remaining s390 occurrences.

Suggested-by: Gustavo A. R. Silva <[email protected]>
Link: https://github.com/KSPP/linux/issues/78
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

show more ...

s390: simplify one-level syctl registration for s390dbf_table

There is no need to declare an extra tables to just create directory,
this can be easily be done with a prefix path with register_sysctl

s390: simplify one-level syctl registration for s390dbf_table

There is no need to declare an extra tables to just create directory,
this can be easily be done with a prefix path with register_sysctl().

Simplify this registration.

Signed-off-by: Luis Chamberlain <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Vasily Gorbik <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>

show more ...

s390/debug: remove function type cast

clang warns about an incompatible function type cast:

CC arch/s390/kernel/debug.o
arch/s390/kernel/debug.c:142:2: error: cast from 'int (*)(debug_info_t

s390/debug: remove function type cast

clang warns about an incompatible function type cast:

CC arch/s390/kernel/debug.o
arch/s390/kernel/debug.c:142:2: error: cast from 'int (*)(debug_info_t *, struct debug_view *, char *, debug_sprintf_entry_t *)' (aka 'int (*)(struct debug_info *, struct debug_view *, char *, debug_sprintf_entry_t *)') to 'debug_format_proc_t *' (aka 'int (*)(struct debug_info *, struct debug_view *, char *, const char *)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
(debug_format_proc_t *)&debug_sprintf_format_fn,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Get rid of this warning by changing debug_sprintf_format_fn() so it matches
the debug_format_proc_t function type, and do the cast of the last
parameter within the function itself.
This is the standard way of handling such cases anyway.

Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Alexander Gordeev <[email protected]>

show more ...

s390: move from strlcpy with unused retval to strscpy

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by

s390: move from strlcpy with unused retval to strscpy

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <[email protected]>
Acked-by: Jakub Kicinski <[email protected]>
Acked-by: Benjamin Block <[email protected]>
Acked-by: Alexandra Winter <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Link: https://lore.kernel.org/r/[email protected]
[[email protected]: squashed two changes linked above together]
Signed-off-by: Vasily Gorbik <[email protected]>

show more ...

s390/sclp: add tracing of SCLP interactions

Add tracing of interactions between the SCLP base driver, firmware and
other drivers to support problem determination in case of SCLP-related
issues.

For

s390/sclp: add tracing of SCLP interactions

Add tracing of interactions between the SCLP base driver, firmware and
other drivers to support problem determination in case of SCLP-related
issues.

For that purpose this patch introduces two new s390dbf debug areas:

- sclp: An abbreviated log of all common interactions
- sclp_err: A full log of failed or abnormal interactions

Tracing of full SCCB contents can be enabled for the sclp area by
setting its debug level to maximum (6).

Overview of added trace events:

* Firmware interaction:
- SRV1: Service call about to be issued
- SRV2: Service call was issued
- INT: Interrupt received

* Driver interaction:
- RQAD: Request was added
- RQOK: Request success
- RQAB: Request aborted
- RQTM: Request timed out
- REG: Event listener registered
- UREG: Event listener unregistered
- EVNT: Event callback
- STCG: State-change callback

* Abnormal events:
- TMO: A timeout occurred
- UNEX: Unexpected SCCB completion

* Other (not traced at default level):
- SYN1: Synchronous wait start
- SYN2: Synchronous wait end

Since the SCLP interface is used by console drivers this patch also
moves s390dbf printks outside the critical section protected by debug
area locks to prevent a potential deadlock that would otherwise be
introduced between console_owner --> sclp_lock --> sclp_debug.lock.

Signed-off-by: Peter Oberparleiter <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>

show more ...

s390/debug: add early tracing support

Debug areas can currently only be used after s390dbf initialization
which occurs as a postcore_initcall. This is too late for tracing
earlier code such as that

s390/debug: add early tracing support

Debug areas can currently only be used after s390dbf initialization
which occurs as a postcore_initcall. This is too late for tracing
earlier code such as that related to console_init().

This patch introduces a macro for defining a statically initialized
debug area that can be used to trace very early code. The macro is made
available for built-in code only because modules are never running
during early boot.

Example usage:

1. Define static debug area:

DEFINE_STATIC_DEBUG_INFO(my_debug, "my_debug", 4, 1, 16,
&debug_hex_ascii_view);

2. Add trace entry:

debug_event(&my_debug, 0, "DATA", 4);

Note: The debug area is automatically registered in debugfs during boot.
A driver must not call any of the debug_register()/_unregister()
functions on a static debug_info_t!

Signed-off-by: Peter Oberparleiter <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>

show more ...

s390/debug: fix debug area life cycle

Currently allocation and registration of s390dbf debug areas are tied
together. As a result, a debug area cannot be unregistered and
re-registered while any pro

s390/debug: fix debug area life cycle

Currently allocation and registration of s390dbf debug areas are tied
together. As a result, a debug area cannot be unregistered and
re-registered while any process has an associated debugfs file open.

Fix this by splitting alloc/release from register/unregister.

Signed-off-by: Peter Oberparleiter <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>

show more ...

s390/debug: keep debug data on resize

Any previously recorded s390dbf debug data is reset when a debug area
is resized using the 'pages' sysfs attribute. This can make
live-debugging unnecessarily c

s390/debug: keep debug data on resize

Any previously recorded s390dbf debug data is reset when a debug area
is resized using the 'pages' sysfs attribute. This can make
live-debugging unnecessarily complex.

Fix this by copying existing debug data to the newly allocated debug
area when resizing.

Signed-off-by: Peter Oberparleiter <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>

show more ...

s390/debug: Remove pointer obfuscation

When read via debugfs, s390dbf debug-views print the kernel address of
the call-site that created a trace entry. The kernel's %p pointer
hashing feature obfusc

s390/debug: Remove pointer obfuscation

When read via debugfs, s390dbf debug-views print the kernel address of
the call-site that created a trace entry. The kernel's %p pointer
hashing feature obfuscates this address, and commit 860ec7c6e21c
("s390/debug: use pK for kernel pointers") made this obfuscation
configurable via the kptr_restrict sysctl.

Obfuscation of kernel address data printed via s390dbf debug-views does
not add any additional protection since the associated debugfs files are
only accessible to the root user that typically has enough other means
to obtain kernel address data.

Also trace payload data may contain binary representations of kernel
addresses as part of logged data structues. Requiring such payload data
to be obfuscated as well would be impractical and greatly diminish the
use of s390dbf.

Therefore completely remove pointer obfuscation from s390dbf
debug-views.

Reviewed-by: Steffen Maier <[email protected]>
Acked-by: Heiko Carstens <[email protected]>
Signed-off-by: Peter Oberparleiter <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

show more ...

s390/debug: use union tod_clock

Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

s390/debug: debug feature version 3

Change __debug_entry structure in the following way:
- remove redundant union
- Field containing cpuid is expanded to 16 bits. 8-bit width was not
enough sin

s390/debug: debug feature version 3

Change __debug_entry structure in the following way:
- remove redundant union
- Field containing cpuid is expanded to 16 bits. 8-bit width was not
enough since we already support up to 512 cpus.
- Field containing the timestamp is expanded to 60 bits. The timestamp
itself is now stored in the absolute Unix time format in microseconds
taking the Epoch Index into acount.
Adjust default header for debug entries by setting minimum width for cpuid
to 4 digits.

Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Mikhail Zaslonko <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>

show more ...

s390/debug: remove raw view

There is not a single user of the debug raw view. Therefore remove it
before anybody uses it. If anybody would make use of the view it would
expose the struct __debug_ent

s390/debug: remove raw view

There is not a single user of the debug raw view. Therefore remove it
before anybody uses it. If anybody would make use of the view it would
expose the struct __debug_entry definition to userspace and really
would make it uapi. This wouldn't be good, since the definition is
suboptimal and needs to be changed.

Right now the structure definition is only defined to be uapi, however
there is no user.

Signed-off-by: Heiko Carstens <[email protected]>

show more ...

s390/debug: avoid kernel warning on too large number of pages

When specifying insanely large debug buffers a kernel warning is
printed. The debug code does handle the error gracefully, though.
Inste

s390/debug: avoid kernel warning on too large number of pages

When specifying insanely large debug buffers a kernel warning is
printed. The debug code does handle the error gracefully, though.
Instead of duplicating the check let us silence the warning to
avoid crashes when panic_on_warn is used.

Signed-off-by: Christian Borntraeger <[email protected]>
Reviewed-by: Heiko Carstens <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>

show more ...

sysctl: pass kernel pointers to ->proc_handler

Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from u

sysctl: pass kernel pointers to ->proc_handler

Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from userspace in common code. This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.

As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.

Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Andrey Ignatov <[email protected]>
Signed-off-by: Al Viro <[email protected]>

show more ...