Mark switch cases where we are expecting to fall through.

This patch fixes the following warning:

arch/arm/kernel/signal.c: In function 'do_signal':
arch/arm/kernel/signal.c:598:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
    restart -= 2;
    ~~~~~~~~^~~~
arch/arm/kernel/signal.c:599:3: note: here
   case -ERESTARTNOHAND:
   ^~~~

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Mark switch cases where we are expecting to fall through.

This patch fixes the following warnings:

arch/arm/kernel/hw_breakpoint.c: In function 'hw_breakpoint_arch_parse':
arch/arm/kernel/hw_breakpoint.c:609:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
      ^
arch/arm/kernel/hw_breakpoint.c:611:2: note: here
  case 3:
  ^~~~
arch/arm/kernel/hw_breakpoint.c:613:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
      ^
arch/arm/kernel/hw_breakpoint.c:615:2: note: here
  default:
  ^~~~~~~
arch/arm/kernel/hw_breakpoint.c: In function 'arch_build_bp_info':
arch/arm/kernel/hw_breakpoint.c:544:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if ((hw->ctrl.type != ARM_BREAKPOINT_EXECUTE)
      ^
arch/arm/kernel/hw_breakpoint.c:547:2: note: here
  default:
  ^~~~~~~
In file included from include/linux/kernel.h:11,
                 from include/linux/list.h:9,
                 from include/linux/preempt.h:11,
                 from include/linux/hardirq.h:5,
                 from arch/arm/kernel/hw_breakpoint.c:16:
arch/arm/kernel/hw_breakpoint.c: In function 'hw_breakpoint_pending':
include/linux/compiler.h:78:22: warning: this statement may fall through [-Wimplicit-fallthrough=]
 # define unlikely(x) __builtin_expect(!!(x), 0)
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~
include/asm-generic/bug.h:136:2: note: in expansion of macro 'unlikely'
  unlikely(__ret_warn_on);     \
  ^~~~~~~~
arch/arm/kernel/hw_breakpoint.c:863:3: note: in expansion of macro 'WARN'
   WARN(1, "Asynchronous watchpoint exception taken. Debugging results may be unreliable\n");
   ^~~~
arch/arm/kernel/hw_breakpoint.c:864:2: note: here
  case ARM_ENTRY_SYNC_WATCHPOINT:
  ^~~~
arch/arm/kernel/hw_breakpoint.c: In function 'core_has_os_save_restore':
arch/arm/kernel/hw_breakpoint.c:910:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (oslsr & ARM_OSLSR_OSLM0)
      ^
arch/arm/kernel/hw_breakpoint.c:912:2: note: here
  default:
  ^~~~~~~

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Pull module updates from Jessica Yu:
 "Summary of modules changes for the 5.3 merge window:

   - Code fixes and cleanups

   - Fix bug where set_memory_x() wasn't being called when rodata=n

   - Fix bug where -EEXIST was being returned for going modules

   - Allow arches to override module_exit_section()"

* tag 'modules-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  modules: fix compile error if don't have strict module rwx
  ARM: module: recognize unwind exit sections
  module: allow arch overrides for .exit section names
  modules: fix BUG when load module with rodata=n
  kernel/module: Fix mem leak in module_add_modinfo_attrs
  kernel: module: Use struct_size() helper
  kernel/module.c: Only return -EEXIST for modules that have finished loading

Converts ARM the text files to ReST, preparing them to be an
architecture book.

The conversion is actually:
  - add blank lines and identation in order to identify paragraphs;
  - fix tables markups;
  - add some lists markups;
  - mark literal blocks;
  - adjust title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Reviewed-by Corentin Labbe <clabbe.montjoie@gmail.com> # For sun4i-ss

Drop the pgtable_t variable from all implementation for pte_fn_t as none
of them use it.  apply_to_pte_range() should stop computing it as well.
Should help us save some cycles.

Link: http://lkml.kernel.org/r/1556803126-26596-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Matthew Wilcox <willy@infradead.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <jglisse@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull force_sig() argument change from Eric Biederman:
 "A source of error over the years has been that force_sig has taken a
  task parameter when it is only safe to use force_sig with the current
  task.

  The force_sig function is built for delivering synchronous signals
  such as SIGSEGV where the userspace application caused a synchronous
  fault (such as a page fault) and the kernel responded with a signal.

  Because the name force_sig does not make this clear, and because the
  force_sig takes a task parameter the function force_sig has been
  abused for sending other kinds of signals over the years. Slowly those
  have been fixed when the oopses have been tracked down.

  This set of changes fixes the remaining abusers of force_sig and
  carefully rips out the task parameter from force_sig and friends
  making this kind of error almost impossible in the future"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
  signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus
  signal: Remove the signal number and task parameters from force_sig_info
  signal: Factor force_sig_info_to_task out of force_sig_info
  signal: Generate the siginfo in force_sig
  signal: Move the computation of force into send_signal and correct it.
  signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal
  signal: Remove the task parameter from force_sig_fault
  signal: Use force_sig_fault_to_task for the two calls that don't deliver to current
  signal: Explicitly call force_sig_fault on current
  signal/unicore32: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from __do_user_fault
  signal/arm: Remove tsk parameter from ptrace_break
  signal/nds32: Remove tsk parameter from send_sigtrap
  signal/riscv: Remove tsk parameter from do_trap
  signal/sh: Remove tsk parameter from force_sig_info_fault
  signal/um: Remove task parameter from send_sigtrap
  signal/x86: Remove task parameter from send_sigtrap
  signal: Remove task parameter from force_sig_mceerr
  signal: Remove task parameter from force_sig
  signal: Remove task parameter from force_sigsegv
  ...

Pull ARM updates from Russell King:

 - Add a "cut here" to make it clearer where oops dumps should be cut
   from - we already have a marker for the end of the dumps.

 - Add logging severity to show_pte()

 - Drop unnecessary common-page-size linker flag

 - Errata workarounds for Cortex A12 857271, Cortex A17 857272 and
   Cortex A7 814220.

 - Remove some unused variables that had started to provoke a compiler
   warning.

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8863/1: stm32: select ARM errata 814220
  ARM: 8862/1: errata: 814220-B-Cache maintenance by set/way operations can execute out of order
  ARM: 8865/1: mm: remove unused variables
  ARM: 8864/1: Add workaround for I-Cache line size mismatch between CPU cores
  ARM: 8861/1: errata: Workaround errata A12 857271 / A17 857272
  ARM: 8860/1: VDSO: Drop implicit common-page-size linker flag
  ARM: arrange show_pte() to issue severity-based messages
  ARM: add "8<--- cut here ---" to kernel dumps

The 'struct sched_domain *sd' parameter to arch_scale_cpu_capacity() is
unused since commit:

  765d0af19f5f ("sched/topology: Remove the ::smt_gain field from 'struct sched_domain'")

Remove it.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: gregkh@linuxfoundation.org
Cc: linux@armlinux.org.uk
Cc: quentin.perret@arm.com
Cc: rafael@kernel.org
Link: https://lkml.kernel.org/r/1560783617-5827-1-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

In addition to the prefix ".exit", ".ARM.extab.exit" and ".ARM.exidx.exit"
must be recognized as exit sections as well. Otherwise, loading modules can
fail without CONFIG_MODULE_UNLOAD depending on the memory layout, when
relocations for the unwind sections refer to the .exit.text section:

  imx_sdma: section 16 reloc 0 sym '': relocation 42 out of range
  (0x7f015260 -> 0xc0f5a5e8)

where 0x7F000000 is the module load area and 0xC0000000 is the vmalloc
area. Relocation 42 refers to R_ARM_PREL31, which is limited to signed
31bit offsets.

Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>

Some big.LITTLE systems have I-Cache line size mismatch between
LITTLE and big cores. This patch adds a workaround for proper I-Cache
support on such systems. Without it, some class of the userspace code
(typically self-modifying) might suffer from random SIGILL failures.

Similar workaround already exists for ARM64 architecture. I has been
added by commit 116c81f427ff ("arm64: Work around systems with mismatched
cache line sizes").

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>