Pull parisc updates from Helge Deller:

 - fix panic when halting system via "shutdown -h now"

 - drop own coding in favour of generic CONFIG_COMPAT_BINFMT_ELF
   implementation

 - add FPE_CONDTRAP constant: last outstanding parisc-specific cleanup
   for Eric Biedermans siginfo patches

 - move some functions to .init and some to .text.hot linker sections

* 'parisc-4.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Prevent panic at system halt
  parisc: Switch to generic COMPAT_BINFMT_ELF
  parisc: Move cache flush functions into .text.hot section
  parisc/signal: Add FPE_CONDTRAP for conditional trap handling

Both load_elf_interp and load_elf_binary rely on elf_map to map segments
on a controlled address and they use MAP_FIXED to enforce that.  This is
however dangerous thing prone to silent data corruption which can be
even exploitable.

Let's take CVE-2017-1000253 as an example.  At the time (before commit
eab09532d400: "binfmt_elf: use ELF_ET_DYN_BASE only for PIE")
ELF_ET_DYN_BASE was at TASK_SIZE / 3 * 2 which is not that far away from
the stack top on 32b (legacy) memory layout (only 1GB away).  Therefore
we could end up mapping over the existing stack with some luck.

The issue has been fixed since then (a87938b2e246: "fs/binfmt_elf.c: fix
bug in loading of PIE binaries"), ELF_ET_DYN_BASE moved moved much
further from the stack (eab09532d400 and later by c715b72c1ba4: "mm:
revert x86_64 and arm64 ELF_ET_DYN_BASE base changes") and excessive
stack consumption early during execve fully stopped by da029c11e6b1
("exec: Limit arg stack to at most 75% of _STK_LIM").  So we should be
safe and any attack should be impractical.  On the other hand this is
just too subtle assumption so it can break quite easily and hard to
spot.

I believe that the MAP_FIXED usage in load_elf_binary (et. al) is still
fundamentally dangerous.  Moreover it shouldn't be even needed.  We are
at the early process stage and so there shouldn't be unrelated mappings
(except for stack and loader) existing so mmap for a given address should
succeed even without MAP_FIXED.  Something is terribly wrong if this is
not the case and we should rather fail than silently corrupt the
underlying mapping.

Address this issue by changing MAP_FIXED to the newly added
MAP_FIXED_NOREPLACE.  This will mean that mmap will fail if there is an
existing mapping clashing with the requested one without clobbering it.

[mhocko@suse.com: fix build]
[akpm@linux-foundation.org: coding-style fixes]
[avagin@openvz.org: don't use the same value for MAP_FIXED_NOREPLACE and MAP_SYNC]
  Link: http://lkml.kernel.org/r/20171218184916.24445-1-avagin@openvz.org
Link: http://lkml.kernel.org/r/20171213092550.2774-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "mm: introduce MAP_FIXED_NOREPLACE", v2.

This has started as a follow up discussion [3][4] resulting in the
runtime failure caused by hardening patch [5] which removes MAP_FIXED
from the elf loader because MAP_FIXED is inherently dangerous as it
might silently clobber an existing underlying mapping (e.g.  stack).
The reason for the failure is that some architectures enforce an
alignment for the given address hint without MAP_FIXED used (e.g.  for
shared or file backed mappings).

One way around this would be excluding those archs which do alignment
tricks from the hardening [6].  The patch is really trivial but it has
been objected, rightfully so, that this screams for a more generic
solution.  We basically want a non-destructive MAP_FIXED.

The first patch introduced MAP_FIXED_NOREPLACE which enforces the given
address but unlike MAP_FIXED it fails with EEXIST if the given range
conflicts with an existing one.  The flag is introduced as a completely
new one rather than a MAP_FIXED extension because of the backward
compatibility.  We really want a never-clobber semantic even on older
kernels which do not recognize the flag.  Unfortunately mmap sucks
wrt flags evaluation because we do not EINVAL on unknown flags.  On
those kernels we would simply use the traditional hint based semantic so
the caller can still get a different address (which sucks) but at least
not silently corrupt an existing mapping.  I do not see a good way
around that.  Except we won't export expose the new semantic to the
userspace at all.

It seems there are users who would like to have something like that.
Jemalloc has been mentioned by Michael Ellerman [7]

Florian Weimer has mentioned the following:
: glibc ld.so currently maps DSOs without hints.  This means that the kernel
: will map right next to each other, and the offsets between them a completely
: predictable.  We would like to change that and supply a random address in a
: window of the address space.  If there is a conflict, we do not want the
: kernel to pick a non-random address. Instead, we would try again with a
: random address.

John Hubbard has mentioned CUDA example
: a) Searches /proc/<pid>/maps for a "suitable" region of available
: VA space.  "Suitable" generally means it has to have a base address
: within a certain limited range (a particular device model might
: have odd limitations, for example), it has to be large enough, and
: alignment has to be large enough (again, various devices may have
: constraints that lead us to do this).
:
: This is of course subject to races with other threads in the process.
:
: Let's say it finds a region starting at va.
:
: b) Next it does:
:     p = mmap(va, ...)
:
: *without* setting MAP_FIXED, of course (so va is just a hint), to
: attempt to safely reserve that region. If p != va, then in most cases,
: this is a failure (almost certainly due to another thread getting a
: mapping from that region before we did), and so this layer now has to
: call munmap(), before returning a "failure: retry" to upper layers.
:
:     IMPROVEMENT: --> if instead, we could call this:
:
:             p = mmap(va, ... MAP_FIXED_NOREPLACE ...)
:
:         , then we could skip the munmap() call upon failure. This
:         is a small thing, but it is useful here. (Thanks to Piotr
:         Jaroszynski and Mark Hairgrove for helping me get that detail
:         exactly right, btw.)
:
: c) After that, CUDA suballocates from p, via:
:
:      q = mmap(sub_region_start, ... MAP_FIXED ...)
:
: Interestingly enough, "freeing" is also done via MAP_FIXED, and
: setting PROT_NONE to the subregion. Anyway, I just included (c) for
: general interest.

Atomic address range probing in the multithreaded programs in general
sounds like an interesting thing to me.

The second patch simply replaces MAP_FIXED use in elf loader by
MAP_FIXED_NOREPLACE.  I believe other places which rely on MAP_FIXED
should follow.  Actually real MAP_FIXED usages should be docummented
properly and they should be more of an exception.

[1] http://lkml.kernel.org/r/20171116101900.13621-1-mhocko@kernel.org
[2] http://lkml.kernel.org/r/20171129144219.22867-1-mhocko@kernel.org
[3] http://lkml.kernel.org/r/20171107162217.382cd754@canb.auug.org.au
[4] http://lkml.kernel.org/r/1510048229.12079.7.camel@abdul.in.ibm.com
[5] http://lkml.kernel.org/r/20171023082608.6167-1-mhocko@kernel.org
[6] http://lkml.kernel.org/r/20171113094203.aofz2e7kueitk55y@dhcp22.suse.cz
[7] http://lkml.kernel.org/r/87efp1w7vy.fsf@concordia.ellerman.id.au

This patch (of 2):

MAP_FIXED is used quite often to enforce mapping at the particular range.
The main problem of this flag is, however, that it is inherently dangerous
because it unmaps existing mappings covered by the requested range.  This
can cause silent memory corruptions.  Some of them even with serious
security implications.  While the current semantic might be really
desiderable in many cases there are others which would want to enforce the
given range but rather see a failure than a silent memory corruption on a
clashing range.  Please note that there is no guarantee that a given range
is obeyed by the mmap even when it is free - e.g.  arch specific code is
allowed to apply an alignment.

Introduce a new MAP_FIXED_NOREPLACE flag for mmap to achieve this
behavior.  It has the same semantic as MAP_FIXED wrt.  the given address
request with a single exception that it fails with EEXIST if the requested
address is already covered by an existing mapping.  We still do rely on
get_unmaped_area to handle all the arch specific MAP_FIXED treatment and
check for a conflicting vma after it returns.

The flag is introduced as a completely new one rather than a MAP_FIXED
extension because of the backward compatibility.  We really want a
never-clobber semantic even on older kernels which do not recognize the
flag.  Unfortunately mmap sucks wrt.  flags evaluation because we do not
EINVAL on unknown flags.  On those kernels we would simply use the
traditional hint based semantic so the caller can still get a different
address (which sucks) but at least not silently corrupt an existing
mapping.  I do not see a good way around that.

[mpe@ellerman.id.au: fix whitespace]
[fail on clashing range with EEXIST as per Florian Weimer]
[set MAP_FIXED before round_hint_to_min as per Khalid Aziz]
Link: http://lkml.kernel.org/r/20171213092550.2774-2-mhocko@kernel.org
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Russell King - ARM Linux <linux@armlinux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Jason Evans <jasone@google.com>
Cc: David Goldblatt <davidtgoldblatt@gmail.com>
Cc: Edward Tomasz Napierała <trasz@FreeBSD.org>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Posix and common sense requires that SI_USER not be a signal specific
si_code. Thus add a new FPE_CONDTRAP si_code for conditional traps.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>

Pull siginfo updates from Eric Biederman:
 "The work on cleaning up and getting the bugs out of siginfo generation
  was largely stalled this round. The progress that was made was the
  definition of FPE_FLTUNK. Which is usable to fix many of the cases
  where siginfo generation is erroneously generating SI_USER by setting
  si_code to 0, that has recently been tagged as FPE_FIXME.

  You already have the change by way of the arm64 tree as that
  definition was pulled into the arm64 tree to allow fixing the problem
  there.

  What remains is the second round of fixing for what I thought was a
  trivial change to the struct siginfo when put the union in _sigfault
  where it belongs. Do to historical reasons 32bit m68k only ensures
  that pointers are 2 byte aligned. So I have added a m68k test case
  made of BUILD_BUG_ONs to verify I have this fix correct and possibly
  catch problems, and I have computed the number of bytes of padding
  needed for the _addr_bnd and _addr_pkey cases and just use an array of
  characters that size.

  For pure paranoia I have written the code so if there is an
  architecture out there that does not perform any alignment of
  structures it should still work.

  With the removal of all of the stale arechitectures this cycle future
  work on cleaning up struct siginfo should be much easier. Almost all
  of the conflicting si_code definitions have been removed with the
  removal of (blackfin, tile, and frv). Plus some of the most difficult
  to test cases have simply been removed from the tree.

  Which means that with a little luck copy_siginfo_to_user can become a
  light weight wrapper around copy_to_user in the next cycle"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  m68k: Verify the offsets in struct siginfo never change.
  signal: Correct the offset of si_pkey and si_lower in struct siginfo on m68k

Pull arm64 updates from Will Deacon:
 "Nothing particularly stands out here, probably because people were
  tied up with spectre/meltdown stuff last time around. Still, the main
  pieces are:

   - Rework of our CPU features framework so that we can whitelist CPUs
     that don't require kpti even in a heterogeneous system

   - Support for the IDC/DIC architecture extensions, which allow us to
     elide instruction and data cache maintenance when writing out
     instructions

   - Removal of the large memory model which resulted in suboptimal
     codegen by the compiler and increased the use of literal pools,
     which could potentially be used as ROP gadgets since they are
     mapped as executable

   - Rework of forced signal delivery so that the siginfo_t is
     well-formed and handling of show_unhandled_signals is consolidated
     and made consistent between different fault types

   - More siginfo cleanup based on the initial patches from Eric
     Biederman

   - Workaround for Cortex-A55 erratum #1024718

   - Some small ACPI IORT updates and cleanups from Lorenzo Pieralisi

   - Misc cleanups and non-critical fixes"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (70 commits)
  arm64: uaccess: Fix omissions from usercopy whitelist
  arm64: fpsimd: Split cpu field out from struct fpsimd_state
  arm64: tlbflush: avoid writing RES0 bits
  arm64: cmpxchg: Include linux/compiler.h in asm/cmpxchg.h
  arm64: move percpu cmpxchg implementation from cmpxchg.h to percpu.h
  arm64: cmpxchg: Include build_bug.h instead of bug.h for BUILD_BUG
  arm64: lse: Include compiler_types.h and export.h for out-of-line LL/SC
  arm64: fpsimd: include <linux/init.h> in fpsimd.h
  drivers/perf: arm_pmu_platform: do not warn about affinity on uniprocessor
  perf: arm_spe: include linux/vmalloc.h for vmap()
  Revert "arm64: Revert L1_CACHE_SHIFT back to 6 (64-byte cache line size)"
  arm64: cpufeature: Avoid warnings due to unused symbols
  arm64: Add work around for Arm Cortex-A55 Erratum 1024718
  arm64: Delay enabling hardware DBM feature
  arm64: Add MIDR encoding for Arm Cortex-A55 and Cortex-A35
  arm64: capabilities: Handle shared entries
  arm64: capabilities: Add support for checks based on a list of MIDRs
  arm64: Add helpers for checking CPU MIDR against a range
  arm64: capabilities: Clean up midr range helpers
  arm64: capabilities: Change scope of VHE to Boot CPU feature
  ...

Pull sparc updates from David Miller:

 1) Add support for ADI (Application Data Integrity) found in more
    recent sparc64 cpus. Essentially this is keyed based access to
    virtual memory, and if the key encoded in the virual address is
    wrong you get a trap.

    The mm changes were reviewed by Andrew Morton and others.

    Work by Khalid Aziz.

 2) Validate DAX completion index range properly, from Rob Gardner.

 3) Add proper Kconfig deps for DAX driver. From Guenter Roeck.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next:
  sparc64: Make atomic_xchg() an inline function rather than a macro.
  sparc64: Properly range check DAX completion index
  sparc: Make auxiliary vectors for ADI available on 32-bit as well
  sparc64: Oracle DAX driver depends on SPARC64
  sparc64: Update signal delivery to use new helper functions
  sparc64: Add support for ADI (Application Data Integrity)
  mm: Allow arch code to override copy_highpage()
  mm: Clear arch specific VM flags on protection change
  mm: Add address parameter to arch_validate_prot()
  sparc64: Add auxiliary vectors to report platform ADI properties
  sparc64: Add handler for "Memory Corruption Detected" trap
  sparc64: Add HV fault type handlers for ADI related faults
  sparc64: Add support for ADI register fields, ASIs and traps
  mm, swap: Add infrastructure for saving page metadata on swap
  signals, sparc: Add signal codes for ADI violations

Pul removal of obsolete architecture ports from Arnd Bergmann:
 "This removes the entire architecture code for blackfin, cris, frv,
  m32r, metag, mn10300, score, and tile, including the associated device
  drivers.

  I have been working with the (former) maintainers for each one to
  ensure that my interpretation was right and the code is definitely
  unused in mainline kernels. Many had fond memories of working on the
  respective ports to start with and getting them included in upstream,
  but also saw no point in keeping the port alive without any users.

  In the end, it seems that while the eight architectures are extremely
  different, they all suffered the same fate: There was one company in
  charge of an SoC line, a CPU microarchitecture and a software
  ecosystem, which was more costly than licensing newer off-the-shelf
  CPU cores from a third party (typically ARM, MIPS, or RISC-V). It
  seems that all the SoC product lines are still around, but have not
  used the custom CPU architectures for several years at this point. In
  contrast, CPU instruction sets that remain popular and have actively
  maintained kernel ports tend to all be used across multiple licensees.

  [ See the new nds32 port merged in the previous commit for the next
    generation of "one company in charge of an SoC line, a CPU
    microarchitecture and a software ecosystem"   - Linus ]

  The removal came out of a discussion that is now documented at
  https://lwn.net/Articles/748074/. Unlike the original plans, I'm not
  marking any ports as deprecated but remove them all at once after I
  made sure that they are all unused. Some architectures (notably tile,
  mn10300, and blackfin) are still being shipped in products with old
  kernels, but those products will never be updated to newer kernel
  releases.

  After this series, we still have a few architectures without mainline
  gcc support:

   - unicore32 and hexagon both have very outdated gcc releases, but the
     maintainers promised to work on providing something newer. At least
     in case of hexagon, this will only be llvm, not gcc.

   - openrisc, risc-v and nds32 are still in the process of finishing
     their support or getting it added to mainline gcc in the first
     place. They all have patched gcc-7.3 ports that work to some
     degree, but complete upstream support won't happen before gcc-8.1.
     Csky posted their first kernel patch set last week, their situation
     will be similar

  [ Palmer Dabbelt points out that RISC-V support is in mainline gcc
    since gcc-7, although gcc-7.3.0 is the recommended minimum  - Linus ]"

This really says it all:

 2498 files changed, 95 insertions(+), 467668 deletions(-)

* tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (74 commits)
  MAINTAINERS: UNICORE32: Change email account
  staging: iio: remove iio-trig-bfin-timer driver
  tty: hvc: remove tile driver
  tty: remove bfin_jtag_comm and hvc_bfin_jtag drivers
  serial: remove tile uart driver
  serial: remove m32r_sio driver
  serial: remove blackfin drivers
  serial: remove cris/etrax uart drivers
  usb: Remove Blackfin references in USB support
  usb: isp1362: remove blackfin arch glue
  usb: musb: remove blackfin port
  usb: host: remove tilegx platform glue
  pwm: remove pwm-bfin driver
  i2c: remove bfin-twi driver
  spi: remove blackfin related host drivers
  watchdog: remove bfin_wdt driver
  can: remove bfin_can driver
  mmc: remove bfin_sdh driver
  input: misc: remove blackfin rotary driver
  input: keyboard: remove bf54x driver
  ...

The change moving addr_lsb into the _sigfault union failed to take
into account that _sigfault._addr_bnd._lower being a pointer forced
the entire union to have pointer alignment.  The fix for
_sigfault._addr_bnd._lower having pointer alignment failed to take
into account that m68k has a pointer alignment less than the size
of a pointer.  So simply making the padding members pointers changed
the location of later members in the structure.

Fix this by directly computing the needed size of the padding members,
and making the padding members char arrays of the needed size.  AKA
if __alignof__(void *) is 1 sizeof(short) otherwise __alignof__(void *).
Which should be exactly the same rules the compiler whould have
used when computing the padding.

I have tested this change by adding BUILD_BUG_ONs to m68k to verify
the offset of every member of struct siginfo, and with those testing
that the offsets of the fields in struct siginfo is the same before
I changed the generic _sigfault member and after the correction
to the _sigfault member.

I have also verified that the x86 with it's own BUILD_BUG_ONs to verify
the offsets of the siginfo members also compiles cleanly.

Cc: stable@vger.kernel.org
Reported-by: Eugene Syromiatnikov <esyr@redhat.com>
Fixes: 859d880cf544 ("signal: Correct the offset of si_pkey in struct siginfo")
Fixes: b68a68d3dcc1 ("signal: Move addr_lsb into the _sigfault union for clarity")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

The score architecture used a number of old system calls for compatibility
with a traditional libc port, all architectures that got added later
skip these. With score out of the way, we can finally clean up the
syscall list to no longer provide these.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>