linux.git/arch/s390/kernel/debug.c, branch v6.13

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

2024-11-21T11:44:06+00:00

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 
Reviewed-by: Heiko Carstens 
Signed-off-by: Heiko Carstens

s390: Fix various typos

2024-10-25T14:03:23+00:00

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

Signed-off-by: Heiko Carstens

[tree-wide] finally take no_llseek out

2024-09-27T15:18:43+00:00

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 '/\/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 
Signed-off-by: Linus Torvalds

sysctl: treewide: constify the ctl_table argument of proc_handlers

2024-07-24T18:59:29+00:00

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 
Signed-off-by: Thomas Weißschuh 
Co-developed-by: Joel Granados 
Signed-off-by: Joel Granados

S390: Remove now superfluous sentinel elem from ctl_table arrays

2023-10-10T22:22:02+00:00

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%2FcBo@bombadil.infradead.org/)

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 
Acked-by: Heiko Carstens 
Signed-off-by: Joel Granados 
Signed-off-by: Luis Chamberlain

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

2023-04-13T15:36:28+00:00

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 
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 
Signed-off-by: Vasily Gorbik

s390: simplify one-level syctl registration for s390dbf_table

2023-03-20T09:56:48+00:00

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 
Link: https://lore.kernel.org/r/20230310234525.3986352-3-mcgrof@kernel.org
Reviewed-by: Vasily Gorbik 
Signed-off-by: Vasily Gorbik 
Signed-off-by: Heiko Carstens

s390/debug: remove function type cast

2022-11-23T15:24:07+00:00

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 
Signed-off-by: Alexander Gordeev

s390: move from strlcpy with unused retval to strscpy

2022-08-30T20:00:33+00:00

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 
Acked-by: Jakub Kicinski 
Acked-by: Benjamin Block 
Acked-by: Alexandra Winter 
Link: https://lore.kernel.org/r/20220818205948.6360-1-wsa+renesas@sang-engineering.com
Link: https://lore.kernel.org/r/20220818210102.7301-1-wsa+renesas@sang-engineering.com
[gor@linux.ibm.com: squashed two changes linked above together]
Signed-off-by: Vasily Gorbik

s390/sclp: add tracing of SCLP interactions

2021-08-25T09:03:35+00:00

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 
Signed-off-by: Heiko Carstens