Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".

The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:

  #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
  # define HAVE_JUMP_LABEL
  #endif

We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.

Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>

Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull Xtensa updates from Max Filippov:

 - switch to generated syscall table

 - switch ptrace to regsets, use regsets for core dumps

 - complete tracehook implementation

 - add syscall tracepoints support

 - add jumplabels support

 - add memtest support

 - drop unused/duplicated code from entry.S, ptrace.c, coprocessor.S,
   elf.h and syscall.h

 - clean up warnings caused by WSR/RSR macros

 - clean up DTC warnings about SPI controller node names in xtfpga.dtsi

 - simplify coprocessor.S

 - get rid of explicit 'l32r' instruction usage in assembly

* tag 'xtensa-20181228' of git://github.com/jcmvbkbc/linux-xtensa: (25 commits)
  xtensa: implement jump_label support
  xtensa: implement syscall tracepoints
  xtensa: implement tracehook functions and enable HAVE_ARCH_TRACEHOOK
  xtensa: enable CORE_DUMP_USE_REGSET
  xtensa: implement TIE regset
  xtensa: implement task_user_regset_view
  xtensa: call do_syscall_trace_{enter,leave} selectively
  xtensa: use NO_SYSCALL instead of -1
  xtensa: define syscall_get_arch()
  Move EM_XTENSA to uapi/linux/elf-em.h
  xtensa: support memtest
  xtensa: don't use l32r opcode directly
  xtensa: xtfpga.dtsi: fix dtc warnings about SPI
  xtensa: don't clear cpenable unconditionally on release
  xtensa: simplify coprocessor.S
  xtensa: clean up WSR*/RSR*/get_sr/set_sr
  xtensa: drop unused declarations from elf.h
  xtensa: clean up syscall.h
  xtensa: drop unused coprocessor helper functions
  xtensa: drop custom PTRACE_{PEEK,POKE}{TEXT,DATA}
  ...

Pull DMA mapping updates from Christoph Hellwig:
 "A huge update this time, but a lot of that is just consolidating or
  removing code:

   - provide a common DMA_MAPPING_ERROR definition and avoid indirect
     calls for dma_map_* error checking

   - use direct calls for the DMA direct mapping case, avoiding huge
     retpoline overhead for high performance workloads

   - merge the swiotlb dma_map_ops into dma-direct

   - provide a generic remapping DMA consistent allocator for
     architectures that have devices that perform DMA that is not cache
     coherent. Based on the existing arm64 implementation and also used
     for csky now.

   - improve the dma-debug infrastructure, including dynamic allocation
     of entries (Robin Murphy)

   - default to providing chaining scatterlist everywhere, with opt-outs
     for the few architectures (alpha, parisc, most arm32 variants) that
     can't cope with it

   - misc sparc32 dma-related cleanups

   - remove the dma_mark_clean arch hook used by swiotlb on ia64 and
     replace it with the generic noncoherent infrastructure

   - fix the return type of dma_set_max_seg_size (Niklas Söderlund)

   - move the dummy dma ops for not DMA capable devices from arm64 to
     common code (Robin Murphy)

   - ensure dma_alloc_coherent returns zeroed memory to avoid kernel
     data leaks through userspace. We already did this for most common
     architectures, but this ensures we do it everywhere.
     dma_zalloc_coherent has been deprecated and can hopefully be
     removed after -rc1 with a coccinelle script"

* tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping: (73 commits)
  dma-mapping: fix inverted logic in dma_supported
  dma-mapping: deprecate dma_zalloc_coherent
  dma-mapping: zero memory returned from dma_alloc_*
  sparc/iommu: fix ->map_sg return value
  sparc/io-unit: fix ->map_sg return value
  arm64: default to the direct mapping in get_arch_dma_ops
  PCI: Remove unused attr variable in pci_dma_configure
  ia64: only select ARCH_HAS_DMA_COHERENT_TO_PFN if swiotlb is enabled
  dma-mapping: bypass indirect calls for dma-direct
  vmd: use the proper dma_* APIs instead of direct methods calls
  dma-direct: merge swiotlb_dma_ops into the dma_direct code
  dma-direct: use dma_direct_map_page to implement dma_direct_map_sg
  dma-direct: improve addressability error reporting
  swiotlb: remove dma_mark_clean
  swiotlb: remove SWIOTLB_MAP_ERROR
  ACPI / scan: Refactor _CCA enforcement
  dma-mapping: factor out dummy DMA ops
  dma-mapping: always build the direct mapping code
  dma-mapping: move dma_cache_sync out of line
  dma-mapping: move various slow path functions out of line
  ...

Use 3-byte 'nop' and 'j' instructions that are always present. Don't let
assembler mark a spot right after patchable 'j' instruction as
unreachable and later put literals or padding bytes there. Add separate
implementations of patch_text for SMP and UP cases, avoiding use of
atomics on UP.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

If we want to map memory from the DMA allocator to userspace it must be
zeroed at allocation time to prevent stale data leaks.   We already do
this on most common architectures, but some architectures don't do this
yet, fix them up, either by passing GFP_ZERO when we use the normal page
allocator or doing a manual memset otherwise.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Acked-by: Sam Ravnborg <sam@ravnborg.org> [sparc]

Add TIF_SYSCALL_TRACEPOINT flag definition; add _TIF_SYSCALL_TRACEPOINT
to _TIF_WORK_MASK. Call trace_sys_enter from do_syscall_trace_enter and
trace_sys_exit from do_syscall_trace_leave when TIF_SYSCALL_TRACEPOINT
flag is set.
Add declaration of sys_call_table to arch/xtensa/include/asm/syscall.h
Add definition of NR_syscalls to arch/xtensa/include/asm/unistd.h
Select HAVE_SYSCALL_TRACEPOINTS.

This change allows tracing each syscall entry and exit through the
ftrace mechanism.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Drop xtensa_elf_core_copy_regs function, ELF_CORE_COPY_REGS macro, and
dump_fpu function. Define CORE_DUMP_USE_REGSET to make ELF core dumper
use regset interface.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Put all coprocessors and non-coprocessor TIE state into the REGSET_TIE.
Mark TIE regset with NT_PRFPREG note type.
Reimplement ptrace_getxregs and ptrace_setxregs using REGSET_TIE.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

- define struct user_pt_regs in the arch/xtensa/include/uapi/asm/ptrace.h
  with the same layout as xtensa_gregset_t; make xtensa_gregset_t a
  typedef;
- define REGSET_GPR regset, implement register get and set functions;
- define task_user_regset_view function and expose REGSET_GPR.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>