The function sets the global-bit on cloned PMD entries, which only makes
sense when the permissions are identical between the user and the kernel
page-table. Further, only write-permissions are cleared for entry-text and
kernel-text sections, which are not writeable at the end of the boot
process.

The reason why this RW clearing exists is that in the early PTI
implementations the cloned kernel areas were set up during early boot
before the kernel text is set to read only and not touched afterwards.

This is not longer true. The cloned areas are still set up early to get the
entry code working for interrupts and other things, but after the kernel
text has been set RO the clone is repeated which copies the RO PMD/PTEs
over to the user visible clone. That means the initial clearing of the
writable bit can be avoided.

[ tglx: Amended changelog ]
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: linux-mm@kvack.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Waiman Long <llong@redhat.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
Cc: joro@8bytes.org
Link: https://lkml.kernel.org/r/1533637471-30953-3-git-send-email-joro@8bytes.org

The check uses the wrong operator and causes false positive
warnings in the kernel log on some systems.

Fixes: 5e810595 ('x86/mm/pti: Add Warning when booting on a PCID capable CPU')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: linux-mm@kvack.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Waiman Long <llong@redhat.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "David H . Gutteridge" <dhgutteridge@sympatico.ca>
Cc: joro@8bytes.org
Link: https://lkml.kernel.org/r/1533637471-30953-2-git-send-email-joro@8bytes.org

Integrate the PTI Global bit fixes which conflict with the 32bit PTI
support.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

The kernel image is mapped into two places in the virtual address space
(addresses without KASLR, of course):

	1. The kernel direct map (0xffff880000000000)
	2. The "high kernel map" (0xffffffff81000000)

We actually execute out of #2.  If we get the address of a kernel symbol,
it points to #2, but almost all physical-to-virtual translations point to

Parts of the "high kernel map" alias are mapped in the userspace page
tables with the Global bit for performance reasons.  The parts that we map
to userspace do not (er, should not) have secrets. When PTI is enabled then
the global bit is usually not set in the high mapping and just used to
compensate for poor performance on systems which lack PCID.

This is fine, except that some areas in the kernel image that are adjacent
to the non-secret-containing areas are unused holes.  We free these holes
back into the normal page allocator and reuse them as normal kernel memory.
The memory will, of course, get *used* via the normal map, but the alias
mapping is kept.

This otherwise unused alias mapping of the holes will, by default keep the
Global bit, be mapped out to userspace, and be vulnerable to Meltdown.

Remove the alias mapping of these pages entirely.  This is likely to
fracture the 2M page mapping the kernel image near these areas, but this
should affect a minority of the area.

The pageattr code changes *all* aliases mapping the physical pages that it
operates on (by default).  We only want to modify a single alias, so we
need to tweak its behavior.

This unmapping behavior is currently dependent on PTI being in place.
Going forward, we should at least consider doing this for all
configurations.  Having an extra read-write alias for memory is not exactly
ideal for debugging things like random memory corruption and this does
undercut features like DEBUG_PAGEALLOC or future work like eXclusive Page
Frame Ownership (XPFO).

Before this patch:

current_kernel:---[ High Kernel Mapping ]---
current_kernel-0xffffffff80000000-0xffffffff81000000          16M                               pmd
current_kernel-0xffffffff81000000-0xffffffff81e00000          14M     ro         PSE     GLB x  pmd
current_kernel-0xffffffff81e00000-0xffffffff81e11000          68K     ro                 GLB x  pte
current_kernel-0xffffffff81e11000-0xffffffff82000000        1980K     RW                     NX pte
current_kernel-0xffffffff82000000-0xffffffff82600000           6M     ro         PSE     GLB NX pmd
current_kernel-0xffffffff82600000-0xffffffff82c00000           6M     RW         PSE         NX pmd
current_kernel-0xffffffff82c00000-0xffffffff82e00000           2M     RW                     NX pte
current_kernel-0xffffffff82e00000-0xffffffff83200000           4M     RW         PSE         NX pmd
current_kernel-0xffffffff83200000-0xffffffffa0000000         462M                               pmd

  current_user:---[ High Kernel Mapping ]---
  current_user-0xffffffff80000000-0xffffffff81000000          16M                               pmd
  current_user-0xffffffff81000000-0xffffffff81e00000          14M     ro         PSE     GLB x  pmd
  current_user-0xffffffff81e00000-0xffffffff81e11000          68K     ro                 GLB x  pte
  current_user-0xffffffff81e11000-0xffffffff82000000        1980K     RW                     NX pte
  current_user-0xffffffff82000000-0xffffffff82600000           6M     ro         PSE     GLB NX pmd
  current_user-0xffffffff82600000-0xffffffffa0000000         474M                               pmd

After this patch:

current_kernel:---[ High Kernel Mapping ]---
current_kernel-0xffffffff80000000-0xffffffff81000000          16M                               pmd
current_kernel-0xffffffff81000000-0xffffffff81e00000          14M     ro         PSE     GLB x  pmd
current_kernel-0xffffffff81e00000-0xffffffff81e11000          68K     ro                 GLB x  pte
current_kernel-0xffffffff81e11000-0xffffffff82000000        1980K                               pte
current_kernel-0xffffffff82000000-0xffffffff82400000           4M     ro         PSE     GLB NX pmd
current_kernel-0xffffffff82400000-0xffffffff82488000         544K     ro                     NX pte
current_kernel-0xffffffff82488000-0xffffffff82600000        1504K                               pte
current_kernel-0xffffffff82600000-0xffffffff82c00000           6M     RW         PSE         NX pmd
current_kernel-0xffffffff82c00000-0xffffffff82c0d000          52K     RW                     NX pte
current_kernel-0xffffffff82c0d000-0xffffffff82dc0000        1740K                               pte

  current_user:---[ High Kernel Mapping ]---
  current_user-0xffffffff80000000-0xffffffff81000000          16M                               pmd
  current_user-0xffffffff81000000-0xffffffff81e00000          14M     ro         PSE     GLB x  pmd
  current_user-0xffffffff81e00000-0xffffffff81e11000          68K     ro                 GLB x  pte
  current_user-0xffffffff81e11000-0xffffffff82000000        1980K                               pte
  current_user-0xffffffff82000000-0xffffffff82400000           4M     ro         PSE     GLB NX pmd
  current_user-0xffffffff82400000-0xffffffff82488000         544K     ro                     NX pte
  current_user-0xffffffff82488000-0xffffffff82600000        1504K                               pte
  current_user-0xffffffff82600000-0xffffffffa0000000         474M                               pmd

[ tglx: Do not unmap on 32bit as there is only one mapping ]

Fixes: 0f561fce ("x86/pti: Enable global pages for shared areas")
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Link: https://lkml.kernel.org/r/20180802225831.5F6A2BFC@viggo.jf.intel.com

When chunks of the kernel image are freed, free_init_pages() is used
directly.  Consolidate the three sites that do this.  Also update the
string to give an incrementally better description of that memory versus
what was there before.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: keescook@google.com
Cc: aarcange@redhat.com
Cc: jgross@suse.com
Cc: jpoimboe@redhat.com
Cc: gregkh@linuxfoundation.org
Cc: peterz@infradead.org
Cc: hughd@google.com
Cc: torvalds@linux-foundation.org
Cc: bp@alien8.de
Cc: luto@kernel.org
Cc: ak@linux.intel.com
Cc: Kees Cook <keescook@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/20180802225829.FE0E32EA@viggo.jf.intel.com

The x86 code has several places where it frees parts of kernel image:

 1. Unused SMP alternative
 2. __init code
 3. The hole between text and rodata
 4. The hole between rodata and data

We call free_init_pages() to do this.  Strangely, we convert the symbol
addresses to kernel direct map addresses in some cases (#3, #4) but not
others (#1, #2).

The virt_to_page() and the other code in free_reserved_area() now works
fine for for symbol addresses on x86, so don't bother converting the
addresses to direct map addresses before freeing them.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: keescook@google.com
Cc: aarcange@redhat.com
Cc: jgross@suse.com
Cc: jpoimboe@redhat.com
Cc: gregkh@linuxfoundation.org
Cc: peterz@infradead.org
Cc: hughd@google.com
Cc: torvalds@linux-foundation.org
Cc: bp@alien8.de
Cc: luto@kernel.org
Cc: ak@linux.intel.com
Cc: Kees Cook <keescook@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/20180802225828.89B2D0E2@viggo.jf.intel.com

free_reserved_area() takes pointers as arguments to show which addresses
should be freed.  However, it does this in a somewhat ambiguous way.  If it
gets a kernel direct map address, it always works.  However, if it gets an
address that is part of the kernel image alias mapping, it can fail.

It fails if all of the following happen:
 * The specified address is part of the kernel image alias
 * Poisoning is requested (forcing a memset())
 * The address is in a read-only portion of the kernel image

The memset() fails on the read-only mapping, of course.
free_reserved_area() *is* called both on the direct map and on kernel image
alias addresses.  We've just lucked out thus far that the kernel image
alias areas it gets used on are read-write.  I'm fairly sure this has been
just a happy accident.

It is quite easy to make free_reserved_area() work for all cases: just
convert the address to a direct map address before doing the memset(), and
do this unconditionally.  There is little chance of a regression here
because we previously did a virt_to_page() on the address for the memset,
so we know these are not highmem pages for which virt_to_page() would fail.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: keescook@google.com
Cc: aarcange@redhat.com
Cc: jgross@suse.com
Cc: jpoimboe@redhat.com
Cc: gregkh@linuxfoundation.org
Cc: peterz@infradead.org
Cc: hughd@google.com
Cc: torvalds@linux-foundation.org
Cc: bp@alien8.de
Cc: luto@kernel.org
Cc: ak@linux.intel.com
Cc: Kees Cook <keescook@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/20180802225826.1287AE3E@viggo.jf.intel.com

The kernel image starts out with the Global bit set across the entire
kernel image.  The bit is cleared with set_memory_nonglobal() in the
configurations with PCIDs where the performance benefits of the Global bit
are not needed.

However, this is fragile.  It means that we are stuck opting *out* of the
less-secure (Global bit set) configuration, which seems backwards.  Let's
start more secure (Global bit clear) and then let things opt back in if
they want performance, or are truly mapping common data between kernel and
userspace.

This fixes a bug.  Before this patch, there are areas that are unmapped
from the user page tables (like like everything above 0xffffffff82600000 in
the example below).  These have the hallmark of being a wrong Global area:
they are not identical in the 'current_kernel' and 'current_user' page
table dumps.  They are also read-write, which means they're much more
likely to contain secrets.

Before this patch:

current_kernel:---[ High Kernel Mapping ]---
current_kernel-0xffffffff80000000-0xffffffff81000000          16M                               pmd
current_kernel-0xffffffff81000000-0xffffffff81e00000          14M     ro         PSE     GLB x  pmd
current_kernel-0xffffffff81e00000-0xffffffff81e11000          68K     ro                 GLB x  pte
current_kernel-0xffffffff81e11000-0xffffffff82000000        1980K     RW                 GLB NX pte
current_kernel-0xffffffff82000000-0xffffffff82600000           6M     ro         PSE     GLB NX pmd
current_kernel-0xffffffff82600000-0xffffffff82c00000           6M     RW         PSE     GLB NX pmd
current_kernel-0xffffffff82c00000-0xffffffff82e00000           2M     RW                 GLB NX pte
current_kernel-0xffffffff82e00000-0xffffffff83200000           4M     RW         PSE     GLB NX pmd
current_kernel-0xffffffff83200000-0xffffffffa0000000         462M                               pmd

 current_user:---[ High Kernel Mapping ]---
 current_user-0xffffffff80000000-0xffffffff81000000          16M                               pmd
 current_user-0xffffffff81000000-0xffffffff81e00000          14M     ro         PSE     GLB x  pmd
 current_user-0xffffffff81e00000-0xffffffff81e11000          68K     ro                 GLB x  pte
 current_user-0xffffffff81e11000-0xffffffff82000000        1980K     RW                 GLB NX pte
 current_user-0xffffffff82000000-0xffffffff82600000           6M     ro         PSE     GLB NX pmd
 current_user-0xffffffff82600000-0xffffffffa0000000         474M                               pmd

After this patch:

current_kernel:---[ High Kernel Mapping ]---
current_kernel-0xffffffff80000000-0xffffffff81000000          16M                               pmd
current_kernel-0xffffffff81000000-0xffffffff81e00000          14M     ro         PSE     GLB x  pmd
current_kernel-0xffffffff81e00000-0xffffffff81e11000          68K     ro                 GLB x  pte
current_kernel-0xffffffff81e11000-0xffffffff82000000        1980K     RW                     NX pte
current_kernel-0xffffffff82000000-0xffffffff82600000           6M     ro         PSE     GLB NX pmd
current_kernel-0xffffffff82600000-0xffffffff82c00000           6M     RW         PSE         NX pmd
current_kernel-0xffffffff82c00000-0xffffffff82e00000           2M     RW                     NX pte
current_kernel-0xffffffff82e00000-0xffffffff83200000           4M     RW         PSE         NX pmd
current_kernel-0xffffffff83200000-0xffffffffa0000000         462M                               pmd

  current_user:---[ High Kernel Mapping ]---
  current_user-0xffffffff80000000-0xffffffff81000000          16M                               pmd
  current_user-0xffffffff81000000-0xffffffff81e00000          14M     ro         PSE     GLB x  pmd
  current_user-0xffffffff81e00000-0xffffffff81e11000          68K     ro                 GLB x  pte
  current_user-0xffffffff81e11000-0xffffffff82000000        1980K     RW                     NX pte
  current_user-0xffffffff82000000-0xffffffff82600000           6M     ro         PSE     GLB NX pmd
  current_user-0xffffffff82600000-0xffffffffa0000000         474M                               pmd

Fixes: 0f561fce ("x86/pti: Enable global pages for shared areas")
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: keescook@google.com
Cc: aarcange@redhat.com
Cc: jgross@suse.com
Cc: jpoimboe@redhat.com
Cc: gregkh@linuxfoundation.org
Cc: peterz@infradead.org
Cc: torvalds@linux-foundation.org
Cc: bp@alien8.de
Cc: luto@kernel.org
Cc: ak@linux.intel.com
Cc: Kees Cook <keescook@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/20180802225825.A100C071@viggo.jf.intel.com

Pull x86 fix from Thomas Gleixner:
 "A single fix, which addresses boot failures on machines which do not
  report EBDA correctly, which can place the trampoline into reserved
  memory regions. Validating against E820 prevents that"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot/compressed/64: Validate trampoline placement against E820

Pull timer fixes from Thomas Gleixner:
 "Two oneliners addressing NOHZ failures:

   - Use a bitmask to check for the pending timer softirq and not the
     bit number. The existing code using the bit number checked for
     the wrong bit, which caused timers to either expire late or stop
     completely.

   - Make the nohz evaluation on interrupt exit more robust. The
     existing code did not re-arm the hardware when interrupting a
     running softirq in task context (ksoftirqd or tail of
     local_bh_enable()), which caused timers to either expire late
     or stop completely"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  nohz: Fix missing tick reprogram when interrupting an inline softirq
  nohz: Fix local_timer_softirq_pending()

Pull perf fixes from Thomas Gleixner:
 "A set of fixes for perf:

  Kernel side:

   - Fix the hardcoded index of extra PCI devices on Broadwell which
     caused a resource conflict and triggered warnings on CPU hotplug.

  Tooling:

   - Update the tools copy of several files, including perf_event.h,
     powerpc's asm/unistd.h (new io_pgetevents syscall), bpf.h and x86's
     memcpy_64.s (used in 'perf bench mem'), silencing the respective
     warnings during the perf tools build.

   - Fix the build on the alpine:edge distro"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/uncore: Fix hardcoded index of Broadwell extra PCI devices
  perf tools: Fix the build on the alpine:edge distro
  tools arch: Update arch/x86/lib/memcpy_64.S copy used in 'perf bench mem memcpy'
  tools headers uapi: Refresh linux/bpf.h copy
  tools headers powerpc: Update asm/unistd.h copy to pick new
  tools headers uapi: Update tools's copy of linux/perf_event.h

Pull irq fix from Thomas Gleixner:
 "A single bugfix for the irq core to prevent silent data corruption and
  malfunction of threaded interrupts under certain conditions"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Make force irq threading setup more robust

Pull networking fixes from David Miller:

 1) Handle frames in error situations properly in AF_XDP, from Jakub
    Kicinski.

 2) tcp_mmap test case only tests ipv6 due to a thinko, fix from
    Maninder Singh.

 3) Session refcnt fix in l2tp_ppp, from Guillaume Nault.

 4) Fix regression in netlink bind handling of multicast gruops, from
    Dmitry Safonov.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  netlink: Don't shift on 64 for ngroups
  net/smc: no cursor update send in state SMC_INIT
  l2tp: fix missing refcount drop in pppol2tp_tunnel_ioctl()
  mlxsw: core_acl_flex_actions: Remove redundant mirror resource destruction
  mlxsw: core_acl_flex_actions: Remove redundant counter destruction
  mlxsw: core_acl_flex_actions: Remove redundant resource destruction
  mlxsw: core_acl_flex_actions: Return error for conflicting actions
  selftests/bpf: update test_lwt_seg6local.sh according to iproute2
  drivers: net: lmc: fix case value for target abort error
  selftest/net: fix protocol family to work for IPv4.
  net: xsk: don't return frames via the allocator on error
  tools/bpftool: fix a percpu_array map dump problem

Pull usercopy whitelisting fix from Kees Cook:
 "Bart Massey discovered that the usercopy whitelist for JFS was
  incomplete: the inline inode data may intentionally "overflow" into
  the neighboring "extended area", so the size of the whitelist needed
  to be raised to include the neighboring field"

* tag 'usercopy-fix-v4.18-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  jfs: Fix usercopy whitelist for inline inode data

Pull xfs bugfix from Darrick Wong:
 "One more patch for 4.18 to fix a coding error in the iomap_bmap()
  function introduced in -rc1: fix incorrect shifting"

* tag 'xfs-4.18-fixes-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  fs: fix iomap_bmap position calculation

It turns out that commit 721c7fc7 ("block: fail op_is_write()
requests to read-only partitions"), while obviously correct, causes
problems for some older lvm2 installations.

The reason is that the lvm snapshotting will continue to write to the
snapshow COW volume, even after the volume has been marked read-only.
End result: snapshot failure.

This has actually been fixed in newer version of the lvm2 tool, but the
old tools still exist, and the breakage was reported both in the kernel
bugzilla and in the Debian bugzilla:

  https://bugzilla.kernel.org/show_bug.cgi?id=200439
  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=900442

The lvm2 fix is here

  https://sourceware.org/git/?p=lvm2.git;a=commit;h=a6fdb9d9d70f51c49ad11a87ab4243344e6701a3

but until everybody has updated to recent versions, we'll have to weaken
the "never write to read-only partitions" check.  It now allows the
write to happen, but causes a warning, something like this:

  generic_make_request: Trying to write to read-only block-device dm-3 (partno X)
  Modules linked in: nf_tables xt_cgroup xt_owner kvm_intel iwlmvm kvm irqbypass iwlwifi
  CPU: 1 PID: 77 Comm: kworker/1:1 Not tainted 4.17.9-gentoo #3
  Hardware name: LENOVO 20B6A019RT/20B6A019RT, BIOS GJET91WW (2.41 ) 09/21/2016
  Workqueue: ksnaphd do_metadata
  RIP: 0010:generic_make_request_checks+0x4ac/0x600
  ...
  Call Trace:
   generic_make_request+0x64/0x400
   submit_bio+0x6c/0x140
   dispatch_io+0x287/0x430
   sync_io+0xc3/0x120
   dm_io+0x1f8/0x220
   do_metadata+0x1d/0x30
   process_one_work+0x1b9/0x3e0
   worker_thread+0x2b/0x3c0
   kthread+0x113/0x130
   ret_from_fork+0x35/0x40

Note that this is a "revert" in behavior only.  I'm leaving alone the
actual code cleanups in commit 721c7fc7, but letting the previously
uncaught request go through with a warning instead of stopping it.

Fixes: 721c7fc7 ("block: fail op_is_write() requests to read-only partitions")
Reported-and-tested-by: WGH <wgh@torlan.ru>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Zdenek Kabelac <zkabelac@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

It's legal to have 64 groups for netlink_sock.

As user-supplied nladdr->nl_groups is __u32, it's possible to subscribe
only to first 32 groups.

The check for correctness of .bind() userspace supplied parameter
is done by applying mask made from ngroups shift. Which broke Android
as they have 64 groups and the shift for mask resulted in an overflow.

Fixes: 61f4b237 ("netlink: Don't shift with UB on nlk->ngroups")
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: netdev@vger.kernel.org
Cc: stable@vger.kernel.org
Reported-and-Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
pull-request: bpf 2018-08-05

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Fix bpftool percpu_array dump by using correct roundup to next
   multiple of 8 for the value size, from Yonghong.

2) Fix in AF_XDP's __xsk_rcv_zc() to not returning frames back to
   allocator since driver will recycle frame anyway in case of an
   error, from Jakub.

3) Fix up BPF test_lwt_seg6local test cases to final iproute2
   syntax, from Mathieu.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

If a writer blocked condition is received without data, the current
consumer cursor is immediately sent. Servers could already receive this
condition in state SMC_INIT without finished tx-setup. This patch
avoids sending a consumer cursor update in this case.
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Bart Massey reported what turned out to be a usercopy whitelist false
positive in JFS when symlink contents exceeded 128 bytes. The inline
inode data (i_inline) is actually designed to overflow into the "extended
area" following it (i_inline_ea) when needed. So the whitelist needed to
be expanded to include both i_inline and i_inline_ea (the whole size
of which is calculated internally using IDATASIZE, 256, instead of
sizeof(i_inline), 128).

$ cd /mnt/jfs
$ touch $(perl -e 'print "B" x 250')
$ ln -s B* b
$ ls -l >/dev/null

[  249.436410] Bad or missing usercopy whitelist? Kernel memory exposure attempt detected from SLUB object 'jfs_ip' (offset 616, size 250)!
Reported-by: Bart Massey <bart.massey@gmail.com>
Fixes: 8d2704d3 ("jfs: Define usercopy region in jfs_ip slab cache")
Cc: Dave Kleikamp <shaggy@kernel.org>
Cc: jfs-discussion@lists.sourceforge.net
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

Pull KVM fixes from Paolo Bonzini:
 "Two vmx bugfixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm: x86: vmx: fix vpid leak
  KVM: vmx: use local variable for current_vmptr when emulating VMPTRST

If 'session' is not NULL and is not a PPP pseudo-wire, then we fail to
drop the reference taken by l2tp_session_get().

Fixes: ecd012e4 ("l2tp: filter out non-PPP sessions in pppol2tp_tunnel_ioctl()")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ido Schimmel says:

====================
mlxsw: Fix ACL actions error condition handling

Nir says:

Two issues were lately noticed within mlxsw ACL actions error condition
handling. The first patch deals with conflicting actions such as:

 # tc filter add dev swp49 parent ffff: \
   protocol ip pref 10 flower skip_sw dst_ip 192.168.101.1 \
   action goto chain 100 \
   action mirred egress redirect dev swp4

The second action will never execute, however SW model allows this
configuration, while the mlxsw driver cannot allow for it as it
implements actions in sets of up to three actions per set with a single
termination marking. Conflicting actions create a contradiction over
this single marking and thus cannot be configured. The fix replaces a
misplaced warning with an error code to be returned.

Patches 2-4 fix a condition of duplicate destruction of resources. Some
actions require allocation of specific resource prior to setting the
action itself. On error condition this resource was destroyed twice,
leading to a crash when using mirror action, and to a redundant
destruction in other cases, since for error condition rule destruction
also takes care of resource destruction. In order to fix this state a
symmetry in behavior is added and resource destruction also takes care
of removing the resource from rule's resource list.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

In previous patch mlxsw_afa_resource_del() was added to avoid a duplicate
resource detruction scenario.
For mirror actions, such duplicate destruction leads to a crash as in:

 # tc qdisc add dev swp49 ingress
 # tc filter add dev swp49 parent ffff: \
   protocol ip chain 100 pref 10 \
   flower skip_sw dst_ip 192.168.101.1 action drop
 # tc filter add dev swp49 parent ffff: \
   protocol ip pref 10 \
   flower skip_sw dst_ip 192.168.101.1 action goto chain 100 \
   action mirred egress mirror dev swp4

Therefore add a call to mlxsw_afa_resource_del() in
mlxsw_afa_mirror_destroy() in order to clear that resource
from rule's resources.

Fixes: d0d13c18 ("mlxsw: spectrum_acl: Add support for mirror action")
Signed-off-by: Nir Dotan <nird@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Each tc flower rule uses a hidden count action. As counter resource may
not be available due to limited HW resources, update _counter_create()
and _counter_destroy() pair to follow previously introduced symmetric
error condition handling, add a call to mlxsw_afa_resource_del() as part
of the counter resource destruction.

Fixes: c18c1e18 ("mlxsw: core: Make counter index allocated inside the action append")
Signed-off-by: Nir Dotan <nird@mellanox.com>
Reviewed-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some ACL actions require the allocation of a separate resource
prior to applying the action itself. When facing an error condition
during the setup phase of the action, resource should be destroyed.
For such actions the destruction was done twice which is dangerous
and lead to a potential crash.
The destruction took place first upon error on action setup phase
and then as the rule was destroyed.

The following sequence generated a crash:

 # tc qdisc add dev swp49 ingress
 # tc filter add dev swp49 parent ffff: \
   protocol ip chain 100 pref 10 \
   flower skip_sw dst_ip 192.168.101.1 action drop
 # tc filter add dev swp49 parent ffff: \
   protocol ip pref 10 \
   flower skip_sw dst_ip 192.168.101.1 action goto chain 100 \
   action mirred egress mirror dev swp4

Therefore add mlxsw_afa_resource_del() as a complement of
mlxsw_afa_resource_add() to add symmetry to resource_list membership
handling. Call this from mlxsw_afa_fwd_entry_ref_destroy() to make the
_fwd_entry_ref_create() and _fwd_entry_ref_destroy() pair of calls a
NOP.

Fixes: 140ce421 ("mlxsw: core: Convert fwd_entry_ref list to be generic per-block resource list")
Signed-off-by: Nir Dotan <nird@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Spectrum switch ACL action set is built in groups of three actions
which may point to additional actions. A group holds a single record
which can be set as goto record for pointing at a following group
or can be set to mark the termination of the lookup. This is perfectly
adequate for handling a series of actions to be executed on a packet.
While the SW model allows configuration of conflicting actions
where it is clear that some actions will never execute, the mlxsw
driver must block such configurations as it creates a conflict
over the single terminate/goto record value.

For a conflicting actions configuration such as:

 # tc filter add dev swp49 parent ffff: \
   protocol ip pref 10 \
   flower skip_sw dst_ip 192.168.101.1 \
   action goto chain 100 \
   action mirred egress mirror dev swp4

Where it is clear that the last action will never execute, the
mlxsw driver was issuing a warning instead of returning an error.
Therefore replace that warning with an error for this specific
case.

Fixes: 4cda7d8d ("mlxsw: core: Introduce flexible actions support")
Signed-off-by: Nir Dotan <nird@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull rdma fix from Jason Gunthorpe:
 "One bug for missing user input validation: refuse invalid port numbers
  in the modify_qp system call"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  RDMA/uverbs: Expand primary and alt AV port checks

Pull block fix from Jens Axboe:
 "Just a single fix, from Ming, fixing a regression in this cycle where
  the busy tag iteration was changed to only calling the callback
  function for requests that are started. We really want all non-free
  requests.

  This fixes a boot regression on certain VM setups"

* tag 'for-linus-20180803' of git://git.kernel.dk/linux-block:
  blk-mq: fix blk_mq_tagset_busy_iter

Pull NFS client bugfix from Trond Myklebust:
 "Fix a NFSv4 file locking regression"

* tag 'nfs-for-4.18-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4: Fix _nfs4_do_setlk()

Pull powerpc fixes from Michael Ellerman:
 "One fix for a regression in a recent TLB flush optimisation, which
  caused us to incorrectly not send TLB invalidations to coprocessors.

  Thanks to Frederic Barrat, Nicholas Piggin, Vaibhav Jain"

* tag 'powerpc-4.18-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s/radix: Fix missing global invalidations when removing copro

Pull drm fixes from Dave Airlie:
 "Nothing too major at this late stage:

   - adv7511: reset fix

   - vc4: scaling fix

   - two atomic core fixes

   - one legacy core error handling fix

  I had a bunch of driver fixes from hdlcd but I think I'll leave them
  for -next at this point"

* tag 'drm-fixes-2018-08-03' of git://anongit.freedesktop.org/drm/drm:
  drm/vc4: Reset ->{x, y}_scaling[1] when dealing with uniplanar formats
  drm/atomic: Initialize variables in drm_atomic_helper_async_check() to make gcc happy
  drm/atomic: Check old_plane_state->crtc in drm_atomic_helper_async_check()
  drm: re-enable error handling
  drm/bridge: adv7511: Reset registers on hotplug

Pull crypto fix from Herbert Xu:
 "Fix a memory corruption in the padlock-aes driver"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: padlock-aes - Fix Nano workaround data corruption

The full nohz tick is reprogrammed in irq_exit() only if the exit is not in
a nesting interrupt. This stands as an optimization: whether a hardirq or a
softirq is interrupted, the tick is going to be reprogrammed when necessary
at the end of the inner interrupt, with even potential new updates on the
timer queue.

When soft interrupts are interrupted, it's assumed that they are executing
on the tail of an interrupt return. In that case tick_nohz_irq_exit() is
called after softirq processing to take care of the tick reprogramming.

But the assumption is wrong: softirqs can be processed inline as well, ie:
outside of an interrupt, like in a call to local_bh_enable() or from
ksoftirqd.

Inline softirqs don't reprogram the tick once they are done, as opposed to
interrupt tail softirq processing. So if a tick interrupts an inline
softirq processing, the next timer will neither be reprogrammed from the
interrupting tick's irq_exit() nor after the interrupted softirq
processing. This situation may leave the tick unprogrammed while timers are
armed.

To fix this, simply keep reprogramming the tick even if a softirq has been
interrupted. That can be optimized further, but for now correctness is more
important.

Note that new timers enqueued in nohz_full mode after a softirq gets
interrupted will still be handled just fine through self-IPIs triggered by
the timer code.
Reported-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: stable@vger.kernel.org # 4.14+
Link: https://lkml.kernel.org/r/1533303094-15855-1-git-send-email-frederic@kernel.org

The support of force threading interrupts which are set up with both a
primary and a threaded handler wreckaged the setup of regular requested
threaded interrupts (primary handler == NULL).

The reason is that it does not check whether the primary handler is set to
the default handler which wakes the handler thread. Instead it replaces the
thread handler with the primary handler as it would do with force threaded
interrupts which have been requested via request_irq(). So both the primary
and the thread handler become the same which then triggers the warnon that
the thread handler tries to wakeup a not configured secondary thread.

Fortunately this only happens when the driver omits the IRQF_ONESHOT flag
when requesting the threaded interrupt, which is normaly caught by the
sanity checks when force irq threading is disabled.

Fix it by skipping the force threading setup when a regular threaded
interrupt is requested. As a consequence the interrupt request which lacks
the IRQ_ONESHOT flag is rejected correctly instead of silently wreckaging
it.

Fixes: 2a1d3ab8 ("genirq: Handle force threading of irqs with primary and thread handler")
Reported-by: Kurt Kanzenbach <kurt.kanzenbach@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kurt Kanzenbach <kurt.kanzenbach@linutronix.de>
Cc: stable@vger.kernel.org

Future Intel processors will support "Enhanced IBRS" which is an "always
on" mode i.e. IBRS bit in SPEC_CTRL MSR is enabled once and never
disabled.

From the specification [1]:

 "With enhanced IBRS, the predicted targets of indirect branches
  executed cannot be controlled by software that was executed in a less
  privileged predictor mode or on another logical processor. As a
  result, software operating on a processor with enhanced IBRS need not
  use WRMSR to set IA32_SPEC_CTRL.IBRS after every transition to a more
  privileged predictor mode. Software can isolate predictor modes
  effectively simply by setting the bit once. Software need not disable
  enhanced IBRS prior to entering a sleep state such as MWAIT or HLT."

If Enhanced IBRS is supported by the processor then use it as the
preferred spectre v2 mitigation mechanism instead of Retpoline. Intel's
Retpoline white paper [2] states:

 "Retpoline is known to be an effective branch target injection (Spectre
  variant 2) mitigation on Intel processors belonging to family 6
  (enumerated by the CPUID instruction) that do not have support for
  enhanced IBRS. On processors that support enhanced IBRS, it should be
  used for mitigation instead of retpoline."

The reason why Enhanced IBRS is the recommended mitigation on processors
which support it is that these processors also support CET which
provides a defense against ROP attacks. Retpoline is very similar to ROP
techniques and might trigger false positives in the CET defense.

If Enhanced IBRS is selected as the mitigation technique for spectre v2,
the IBRS bit in SPEC_CTRL MSR is set once at boot time and never
cleared. Kernel also has to make sure that IBRS bit remains set after
VMEXIT because the guest might have cleared the bit. This is already
covered by the existing x86_spec_ctrl_set_guest() and
x86_spec_ctrl_restore_host() speculation control functions.

Enhanced IBRS still requires IBPB for full mitigation.

[1] Speculative-Execution-Side-Channel-Mitigations.pdf
[2] Retpoline-A-Branch-Target-Injection-Mitigation.pdf
Both documents are available at:
https://bugzilla.kernel.org/show_bug.cgi?id=199511Originally-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim C Chen <tim.c.chen@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Link: https://lkml.kernel.org/r/1533148945-24095-1-git-send-email-sai.praneeth.prakhya@intel.com

The shell file for test_lwt_seg6local contains an early iproute2 syntax
for installing a seg6local End.BPF route. iproute2 support for this
feature has recently been upstreamed, but with an additional keyword
required. This patch updates test_lwt_seg6local.sh to the definitive
iproute2 syntax
Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Pull media fixes from Mauro Carvalho Chehab:

 - a deadlock regression at vsp1 driver

 - some Remote Controller fixes related to the new BPF filter logic
   added on it for Kernel 4.18.

* tag 'media/v4.18-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  media: v4l: vsp1: Fix deadlock in VSPDL DRM pipelines
  media: rc: read out of bounds if bpf reports high protocol number
  media: bpf: ensure bpf program is freed on detach
  media: rc: be less noisy when driver misbehaves

Pull ARC fixes from Vineet Gupta:
 "Another batch of fixes for ARC, this time mainly DMA API rework
  wreckage:

   - Fix software managed DMA wreckage after rework in 4.17 [Euginey]
      * missing cache flush
      * SMP_CACHE_BYTES vs cache_line_size

   - Fix allmodconfig build errors [Randy]

   - Maintainer update for Mellanox (EZChip) NPS platform"

* tag 'arc-4.18-final' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  arc: fix type warnings in arc/mm/cache.c
  arc: fix build errors in arc/include/asm/delay.h
  arc: [plat-eznps] fix printk warning in arc/plat-eznps/mtm.c
  arc: [plat-eznps] fix data type errors in platform headers
  ARC: [plat-eznps] Add missing struct nps_host_reg_aux_dpc
  ARC: add SMP_CACHE_BYTES value validate
  ARC: dma [non-IOC] setup SMP_CACHE_BYTES and cache_line_size
  ARC: dma [non IOC]: fix arc_dma_sync_single_for_(device|cpu)
  ARC: Add Ofer Levi as plat-eznps maintainer