linux.git/arch/s390/kernel/debug.c, branch v6.16

s390: Remove optional third argument of strscpy() if possible

2025-04-17T13:16:10+00:00

The third argument of strscpy() is optional and can be left away iff
the destination is an array and the maximum size of the copy is the
size of destination.
Remove the third argument for those cases where this is possible.

Acked-by: Alexander Gordeev 
Signed-off-by: Heiko Carstens

treewide: const qualify ctl_tables where applicable

2025-01-28T12:48:37+00:00

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

s390/pci: Add pci_msg debug view to PCI report

2024-12-16T15:14:27+00:00

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 
Co-developed-by: Halil Pasic 
Signed-off-by: Halil Pasic 
Signed-off-by: Niklas Schnelle 
Signed-off-by: Alexander Gordeev

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

2024-12-16T15:14:26+00:00

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 
Co-developed-by: Halil Pasic 
Signed-off-by: Halil Pasic 
Signed-off-by: Niklas Schnelle 
Signed-off-by: Alexander Gordeev

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

2024-12-16T15:14:26+00:00

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 
Co-developed-by: Halil Pasic 
Signed-off-by: Halil Pasic 
Signed-off-by: Niklas Schnelle 
Signed-off-by: Alexander Gordeev

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

2024-12-16T15:14:26+00:00

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 
Signed-off-by: Niklas Schnelle 
Signed-off-by: Alexander Gordeev

s390/debug: Simplify and document debug_next_entry() logic

2024-12-16T15:14:26+00:00

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 
Signed-off-by: Niklas Schnelle 
Signed-off-by: Alexander Gordeev

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