linux-toradex.git/arch/s390/kernel, branch v5.17

s390/ftrace: fix arch_ftrace_get_regs implementation

2022-03-01T19:41:28+00:00

arch_ftrace_get_regs is supposed to return a struct pt_regs pointer
only if the pt_regs structure contains all register contents, which
means it must have been populated when created via ftrace_regs_caller.

If it was populated via ftrace_caller the contents are not complete
(the psw mask part is missing), and therefore a NULL pointer needs be
returned.

The current code incorrectly always returns a struct pt_regs pointer.

Fix this by adding another pt_regs flag which indicates if the
contents are complete, and fix arch_ftrace_get_regs accordingly.

Fixes: 894979689d3a ("s390/ftrace: provide separate ftrace_caller/ftrace_regs_caller implementations")
Reported-by: Christophe Leroy 
Reported-by: Naveen N. Rao 
Reviewed-by: Sven Schnelle 
Acked-by: Ilya Leoshkevich 
Signed-off-by: Heiko Carstens 
Signed-off-by: Vasily Gorbik

s390/ftrace: fix ftrace_caller/ftrace_regs_caller generation

2022-03-01T19:41:28+00:00

ftrace_caller was used for both ftrace_caller and ftrace_regs_caller,
which means that the target address of the hotpatch trampoline was
never updated.

With commit 894979689d3a ("s390/ftrace: provide separate
ftrace_caller/ftrace_regs_caller implementations") a separate
ftrace_regs_caller entry point was implemeted, however it was
forgotten to implement the necessary changes for ftrace_modify_call
and ftrace_make_call, where the branch target has to be modified
accordingly.

Therefore add the missing code now.

Fixes: 894979689d3a ("s390/ftrace: provide separate ftrace_caller/ftrace_regs_caller implementations")
Reviewed-by: Sven Schnelle 
Acked-by: Ilya Leoshkevich 
Signed-off-by: Heiko Carstens 
Signed-off-by: Vasily Gorbik

s390/setup: preserve memory at OLDMEM_BASE and OLDMEM_SIZE

2022-03-01T19:41:28+00:00

We need to preserve the values at OLDMEM_BASE and OLDMEM_SIZE which are
used by zgetdump in case when kdump crashes. In that case zgetdump will
attempt to read OLDMEM_BASE and OLDMEM_SIZE in order to find out where
the memory range [0 - OLDMEM_SIZE] belonging to the production kernel is.

Fixes: f1a546947431 ("s390/setup: don't reserve memory that occupied decompressor's head")
Cc: stable@vger.kernel.org # 5.15+
Signed-off-by: Alexander Egorenkov 
Acked-by: Vasily Gorbik 
Signed-off-by: Vasily Gorbik

s390/module: fix loading modules with a lot of relocations

2022-01-24T08:10:37+00:00

If the size of the PLT entries generated by apply_rela() exceeds
64KiB, the first ones can no longer reach __jump_r1 with brc. Fix by
using brcl. An alternative solution is to add a __jump_r1 copy after
every 64KiB, however, the space savings are quite small and do not
justify the additional complexity.

Fixes: f19fbd5ed642 ("s390: introduce execute-trampolines for branches")
Cc: stable@vger.kernel.org
Reported-by: Andrea Righi 
Signed-off-by: Ilya Leoshkevich 
Reviewed-by: Heiko Carstens 
Cc: Vasily Gorbik 
Cc: Christian Borntraeger 
Signed-off-by: Heiko Carstens

s390/nmi: handle vector validity failures for KVM guests

2022-01-23T09:20:03+00:00

The machine check validity bit tells about the context. If a KVM guest
was running the bit tells about the guest validity and the host state is
not affected. As a guest can disable the guest validity this might
result in unwanted host errors on machine checks.

Cc: stable@vger.kernel.org
Fixes: c929500d7a5a ("s390/nmi: s390: New low level handling for machine check happening in guest")
Signed-off-by: Christian Borntraeger 
Reviewed-by: Heiko Carstens 
Signed-off-by: Heiko Carstens

s390/nmi: handle guarded storage validity failures for KVM guests

2022-01-23T09:20:02+00:00

machine check validity bits reflect the state of the machine check. If a
guest does not make use of guarded storage, the validity bit might be
off. We can not use the host CR bit to decide if the validity bit must
be on. So ignore "invalid" guarded storage controls for KVM guests in
the host and rely on the machine check being forwarded to the guest.  If
no other errors happen from a host perspective everything is fine and no
process must be killed and the host can continue to run.

Cc: stable@vger.kernel.org
Fixes: c929500d7a5a ("s390/nmi: s390: New low level handling for machine check happening in guest")
Reported-by: Carsten Otte 
Signed-off-by: Christian Borntraeger 
Tested-by: Carsten Otte 
Reviewed-by: Heiko Carstens 
Signed-off-by: Heiko Carstens

Merge tag 's390-5.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2022-01-21T06:57:15+00:00

Pull more s390 updates from Heiko Carstens:

 - add Sven Schnelle as reviewer for s390 code

 - make uaccess code more readable

 - change cpu measurement facility code to also support counter second
   version number 7, and add discard support for limited samples

* tag 's390-5.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390: add Sven Schnelle as reviewer
  s390/uaccess: introduce bit field for OAC specifier
  s390/cpumf: Support for CPU Measurement Sampling Facility LS bit
  s390/cpumf: Support for CPU Measurement Facility CSVN 7

s390/cpumf: Support for CPU Measurement Sampling Facility LS bit

2022-01-17T13:13:08+00:00

Adds support for the CPU Measurement Sampling Facility limit sampling
bit in the sampling device driver.
Limited samples have no valueable information are not collected.

Signed-off-by: Thomas Richter 
Acked-by: Sumanth Korikkar 
Signed-off-by: Heiko Carstens

s390/cpumf: Support for CPU Measurement Facility CSVN 7

2022-01-17T13:13:08+00:00

Adds support for the CPU Measurement Counter Facility second version
number 7.

Signed-off-by: Thomas Richter 
Acked-by: Sumanth Korikkar 
Signed-off-by: Heiko Carstens

Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2022-01-17T03:49:30+00:00

Pull signal/exit/ptrace updates from Eric Biederman:
 "This set of changes deletes some dead code, makes a lot of cleanups
  which hopefully make the code easier to follow, and fixes bugs found
  along the way.

  The end-game which I have not yet reached yet is for fatal signals
  that generate coredumps to be short-circuit deliverable from
  complete_signal, for force_siginfo_to_task not to require changing
  userspace configured signal delivery state, and for the ptrace stops
  to always happen in locations where we can guarantee on all
  architectures that the all of the registers are saved and available on
  the stack.

  Removal of profile_task_ext, profile_munmap, and profile_handoff_task
  are the big successes for dead code removal this round.

  A bunch of small bug fixes are included, as most of the issues
  reported were small enough that they would not affect bisection so I
  simply added the fixes and did not fold the fixes into the changes
  they were fixing.

  There was a bug that broke coredumps piped to systemd-coredump. I
  dropped the change that caused that bug and replaced it entirely with
  something much more restrained. Unfortunately that required some
  rebasing.

  Some successes after this set of changes: There are few enough calls
  to do_exit to audit in a reasonable amount of time. The lifetime of
  struct kthread now matches the lifetime of struct task, and the
  pointer to struct kthread is no longer stored in set_child_tid. The
  flag SIGNAL_GROUP_COREDUMP is removed. The field group_exit_task is
  removed. Issues where task->exit_code was examined with
  signal->group_exit_code should been examined were fixed.

  There are several loosely related changes included because I am
  cleaning up and if I don't include them they will probably get lost.

  The original postings of these changes can be found at:
     https://lkml.kernel.org/r/87a6ha4zsd.fsf@email.froward.int.ebiederm.org
     https://lkml.kernel.org/r/87bl1kunjj.fsf@email.froward.int.ebiederm.org
     https://lkml.kernel.org/r/87r19opkx1.fsf_-_@email.froward.int.ebiederm.org

  I trimmed back the last set of changes to only the obviously correct
  once. Simply because there was less time for review than I had hoped"

* 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (44 commits)
  ptrace/m68k: Stop open coding ptrace_report_syscall
  ptrace: Remove unused regs argument from ptrace_report_syscall
  ptrace: Remove second setting of PT_SEIZED in ptrace_attach
  taskstats: Cleanup the use of task->exit_code
  exit: Use the correct exit_code in /proc//stat
  exit: Fix the exit_code for wait_task_zombie
  exit: Coredumps reach do_group_exit
  exit: Remove profile_handoff_task
  exit: Remove profile_task_exit & profile_munmap
  signal: clean up kernel-doc comments
  signal: Remove the helper signal_group_exit
  signal: Rename group_exit_task group_exec_task
  coredump: Stop setting signal->group_exit_task
  signal: Remove SIGNAL_GROUP_COREDUMP
  signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process
  signal: Make coredump handling explicit in complete_signal
  signal: Have prepare_signal detect coredumps using signal->core_state
  signal: Have the oom killer detect coredumps using signal->core_state
  exit: Move force_uaccess back into do_exit
  exit: Guarantee make_task_dead leaks the tsk when calling do_task_exit
  ...