commit 751971af2e3615dc5bd12674080bc795505fefeb upstream.

When building ARCH=csky defconfig:

arch/csky/kernel/traps.c: In function 'die':
arch/csky/kernel/traps.c:112:17: error: implicit declaration of function
'make_dead_task' [-Werror=implicit-function-declaration]
  112 |                 make_dead_task(SIGSEGV);
      |                 ^~~~~~~~~~~~~~

The function's name is make_task_dead(), change it so there is no more
build error.

Fixes: 0e25498f8cd4 ("exit: Add and use make_task_dead.")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lkml.kernel.org/r/20211227184851.2297759-4-nathan@kernel.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 0e25498f8cd43c1b5aa327f373dd094e9a006da7 upstream.

There are two big uses of do_exit.  The first is it's design use to be
the guts of the exit(2) system call.  The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.

Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure.  In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.

Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.

As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 9c0e343d7654a329d1f9b53d253cbf7fb6eff85d ]

We should get psr value from regs->psr in stack, not directly get
it from phyiscal register then save the vector number in
tsk->trap_no.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Pull arch/csky pupdates from Guo Ren:
 "This round of csky subsystem gives two features (ASID algorithm
  update, Perf pmu record support) and some fixups.

  ASID updates:
   - Revert mmu ASID mechanism
   - Add new asid lib code from arm
   - Use generic asid algorithm to implement switch_mm
   - Improve tlb operation with help of asid

  Perf pmu record support:
   - Init pmu as a device
   - Add count-width property for csky pmu
   - Add pmu interrupt support
   - Fix perf record in kernel/user space
   - dt-bindings: Add csky PMU bindings

  Fixes:
   - Fixup no panic in kernel for some traps
   - Fixup some error count in 810 & 860.
   - Fixup abiv1 memset error"

* tag 'csky-for-linus-5.3-rc1' of git://github.com/c-sky/csky-linux:
  csky: Fixup abiv1 memset error
  csky: Improve tlb operation with help of asid
  csky: Use generic asid algorithm to implement switch_mm
  csky: Add new asid lib code from arm
  csky: Revert mmu ASID mechanism
  dt-bindings: csky: Add csky PMU bindings
  dt-bindings: interrupt-controller: Update csky mpintc
  csky: Fixup some error count in 810 & 860.
  csky: Fix perf record in kernel/user space
  csky: Add pmu interrupt support
  csky: Add count-width property for csky pmu
  csky: Init pmu as a device
  csky: Fixup no panic in kernel for some traps
  csky: Select intc & timer drivers

These traps couldn't be hanppen in kernel and we must panic there not
send a signal to userspace.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Arnd Bergmann <arnd@arndb.de>

As synchronous exceptions really only make sense against the current
task (otherwise how are you synchronous) remove the task parameter
from from force_sig_fault to make it explicit that is what is going
on.

The two known exceptions that deliver a synchronous exception to a
stopped ptraced task have already been changed to
force_sig_fault_to_task.

The callers have been changed with the following emacs regular expression
(with obvious variations on the architectures that take more arguments)
to avoid typos:

force_sig_fault[(]\([^,]+\)[,]\([^,]+\)[,]\([^,]+\)[,]\W+current[)]
->
force_sig_fault(\1,\2,\3)

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Cleanup struct cpuinfo_csky and struct thread_struct, remove all esp0
related code. We could get pt_regs from sp and backtrace could use fp
in switch_stack.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>

This patch adds exception handling code, cpuinfo and mm-fault code.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>