ti-linux-kernel/ti-linux-kernel-next.git
3 years agoMerge branch 'ti-linux-4.4.y-next' of git.ti.com:ti-linux-kernel/ti-linux-kernel... ti-rt-linux-4.4.y-next ti-rt-linux-4.4.y-next-20180109
LCPD Auto Merger [Tue, 9 Jan 2018 09:47:26 +0000 (03:47 -0600)]
Merge branch 'ti-linux-4.4.y-next' of git.ti.com:ti-linux-kernel/ti-linux-kernel-next into ti-rt-linux-4.4.y-next

TI-Feature: ti_linux_base_rt
TI-Tree: git@git.ti.com:ti-linux-kernel/ti-linux-kernel-next.git
TI-Branch: ti-linux-4.4.y-next

* 'ti-linux-4.4.y-next' of git.ti.com:ti-linux-kernel/ti-linux-kernel-next: (50 commits)
  Linux 4.4.111-rc1
  Map the vsyscall page with _PAGE_USER
  proc: much faster /proc/vmstat
  module: Issue warnings when tainting kernel
  module: keep percpu symbols in module's symtab
  genksyms: Handle string literals with spaces in reference files
  x86/tlb: Drop the _GPL from the cpu_tlbstate export
  parisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernel
  x86/microcode/AMD: Add support for fam17h microcode loading
  Input: elantech - add new icbody type 15
  ARC: uaccess: dont use "l" gcc inline asm constraint modifier
  kernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()
  kernel/signal.c: protect the SIGNAL_UNKILLABLE tasks from !sig_kernel_only() signals
  kernel/signal.c: protect the traced SIGNAL_UNKILLABLE tasks from SIGKILL
  kernel: make groups_sort calling a responsibility group_info allocators
  fscache: Fix the default for fscache_maybe_release_page()
  sunxi-rsb: Include OF based modalias in device uevent
  crypto: pcrypt - fix freeing pcrypt instances
  crypto: chacha20poly1305 - validate the digest size
  crypto: n2 - cure use after free
  ...

Signed-off-by: LCPD Auto Merger <lcpd_integration@list.ti.com>
3 years agoMerge branch 'peter/ti-linux-4.4.y/for-next' of https://github.com/omap-audio/linux... ti-linux-4.4.y-next ti-linux-4.4.y-next-20180109
LCPD Auto Merger [Tue, 9 Jan 2018 08:57:35 +0000 (02:57 -0600)]
Merge branch 'peter/ti-linux-4.4.y/for-next' of https://github.com/omap-audio/linux-audio into ti-linux-4.4.y-next

TI-Feature: ujfalusi_next
TI-Tree: https://github.com/omap-audio/linux-audio.git
TI-Branch: peter/ti-linux-4.4.y/for-next

* 'peter/ti-linux-4.4.y/for-next' of https://github.com/omap-audio/linux-audio:
  ARM: dts: am335x-evmsk: Add phandle for the backlight for the panel

Signed-off-by: LCPD Auto Merger <lcpd_integration@list.ti.com>
3 years agoMerge branch 'ti/for-next' of http://git.kernel.org/pub/scm/linux/kernel/git/tomba...
LCPD Auto Merger [Tue, 9 Jan 2018 08:57:33 +0000 (02:57 -0600)]
Merge branch 'ti/for-next' of git./linux/kernel/git/tomba/linux into ti-linux-4.4.y-next

TI-Feature: tomba_next
TI-Tree: http://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux.git
TI-Branch: ti/for-next

* 'ti/for-next' of http://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux:
  rpmsg: rpc: remove range-based dmabuf flush
  dma-buf: Add ioctls to allow userspace to flush
  dma-buf: Remove range-based flush

Signed-off-by: LCPD Auto Merger <lcpd_integration@list.ti.com>
3 years agoMerge branch 'integration-ti-linux-4.4.y-next' of git://git.ti.com/ti-linux-kernel...
LCPD Auto Merger [Tue, 9 Jan 2018 08:57:31 +0000 (02:57 -0600)]
Merge branch 'integration-ti-linux-4.4.y-next' of git://git.ti.com/ti-linux-kernel/kernel-integration-tree into ti-linux-4.4.y-next

TI-Feature: integration
TI-Tree: git://git.ti.com/ti-linux-kernel/kernel-integration-tree.git
TI-Branch: integration-ti-linux-4.4.y-next

* 'integration-ti-linux-4.4.y-next' of git://git.ti.com/ti-linux-kernel/kernel-integration-tree:
  net: netcp: Fix build warning in gbe_probe

Signed-off-by: LCPD Auto Merger <lcpd_integration@list.ti.com>
3 years agoMerge branch 'mugunthan-next' of git://git.ti.com/~mugunthanvnm/ti-linux-kernel/linux...
LCPD Auto Merger [Tue, 9 Jan 2018 08:57:06 +0000 (02:57 -0600)]
Merge branch 'mugunthan-next' of git://git.ti.com/~mugunthanvnm/ti-linux-kernel/linux into ti-linux-4.4.y-next

TI-Feature: mugunthan_next
TI-Tree: git://git.ti.com/~mugunthanvnm/ti-linux-kernel/linux.git
TI-Branch: mugunthan-next

* 'mugunthan-next' of git://git.ti.com/~mugunthanvnm/ti-linux-kernel/linux: (23 commits)
  iommu/omap: fix a build warning in OMAP IOMMU header file
  remoteproc/omap: fix build warnings for !CONFIG_PM_SLEEP
  ARM: omap: timers: reduce rating of gp_timer clocksource
  clocksource: kconfig: allow to select arm global timer manually
  clocksource/drivers/arm_global_timer: Fix suspend resume
  ti_config_fragments: Add android config options to the defconfig_map
  ti_config_frags: defconfig_builder: Exit if fragments do not exist
  ti_config_fragments: Add SDK release defconfig options
  ti_config_fragments: Fix defconfig_map for dra7 builds
  dts: dra7: mcasp updtaes from upstream
  hwmod: dra7: mcasp updates from upstream
  dmaengine: omap-dma: Do not suppress interrupts for memcpy
  media: omap3isp: Use dma_request_chan() to requesting DMA channel
  ASoC: davinci-mcasp: dai format runtime reconfiguration
  ASoC: davinci-mcasp: Add workaround for errata i868 (dra7xx family)
  ASoC: davinci-mcasp: HACK interface to handle dra7-evm's i2c2/HDMI mux
  ASoC: simple-card: Support for selecting system clocks by ID
  ASoC: simple-card: Add system-clock-direction DT parameter to dai nodes
  ASoC: davinci-mcasp: Improve the sysclk selection
  ASoC: davinci-mcasp: Use defines for clkdiv IDs via DT binding header
  ...

Signed-off-by: LCPD Auto Merger <lcpd_integration@list.ti.com>
3 years agoMerge branch 'linux-4.4.y' of http://git.kernel.org/pub/scm/linux/kernel/git/stable...
LCPD Auto Merger [Tue, 9 Jan 2018 08:55:58 +0000 (02:55 -0600)]
Merge branch 'linux-4.4.y' of git./linux/kernel/git/stable/linux-stable-rc into ti-linux-4.4.y-next

TI-Feature: linux-stable-4.4
TI-Tree: http://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
TI-Branch: linux-4.4.y

* 'linux-4.4.y' of http://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc: (22 commits)
  Linux 4.4.111-rc1
  Map the vsyscall page with _PAGE_USER
  proc: much faster /proc/vmstat
  module: Issue warnings when tainting kernel
  module: keep percpu symbols in module's symtab
  genksyms: Handle string literals with spaces in reference files
  x86/tlb: Drop the _GPL from the cpu_tlbstate export
  parisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernel
  x86/microcode/AMD: Add support for fam17h microcode loading
  Input: elantech - add new icbody type 15
  ARC: uaccess: dont use "l" gcc inline asm constraint modifier
  kernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()
  kernel/signal.c: protect the SIGNAL_UNKILLABLE tasks from !sig_kernel_only() signals
  kernel/signal.c: protect the traced SIGNAL_UNKILLABLE tasks from SIGKILL
  kernel: make groups_sort calling a responsibility group_info allocators
  fscache: Fix the default for fscache_maybe_release_page()
  sunxi-rsb: Include OF based modalias in device uevent
  crypto: pcrypt - fix freeing pcrypt instances
  crypto: chacha20poly1305 - validate the digest size
  crypto: n2 - cure use after free
  ...

Signed-off-by: LCPD Auto Merger <lcpd_integration@list.ti.com>
3 years agoMerge branch 'v4.4-rt' of http://git.kernel.org/pub/scm/linux/kernel/git/rt/linux...
Dan Murphy [Mon, 8 Jan 2018 21:00:35 +0000 (15:00 -0600)]
Merge branch 'v4.4-rt' of git./linux/kernel/git/rt/linux-stable-rt into ti-rt-linux-4.4.y

TI-Feature: linux_rt-4-4
TI-Tree: https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git
TI-Branch: v4.4-rt

* 'v4.4-rt' of http://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt: (1009 commits)
  Linux 4.4.110-rt125
  Linux 4.4.109-rt124
  Linux 4.4.108-rt123
  Linux 4.4.107-rt122
  Linux 4.4.106-rt121
  Linux 4.4.110
  kaiser: Set _PAGE_NX only if supported
  x86/kasan: Clear kasan_zero_page after TLB flush
  x86/vdso: Get pvclock data from the vvar VMA instead of the fixmap
  x86, vdso, pvclock: Simplify and speed up the vdso pvclock reader
  KPTI: Report when enabled
  KPTI: Rename to PAGE_TABLE_ISOLATION
  x86/kaiser: Move feature detection up
  kaiser: disabled on Xen PV
  x86/kaiser: Reenable PARAVIRT
  x86/paravirt: Dont patch flush_tlb_single
  kaiser: kaiser_flush_tlb_on_return_to_user() check PCID
  kaiser: asm/tlbflush.h handle noPGE at lower level
  kaiser: drop is_atomic arg to kaiser_pagetable_walk()
  kaiser: use ALTERNATIVE instead of x86_cr3_pcid_noflush
  ...

Signed-off-by: Dan Murphy <dmurphy@ti.com>
3 years agoLinux 4.4.111-rc1
Greg Kroah-Hartman [Mon, 8 Jan 2018 16:29:06 +0000 (17:29 +0100)]
Linux 4.4.111-rc1

3 years agoMap the vsyscall page with _PAGE_USER
Borislav Petkov [Thu, 4 Jan 2018 16:42:45 +0000 (17:42 +0100)]
Map the vsyscall page with _PAGE_USER

This needs to happen early in kaiser_pagetable_walk(), before the
hierarchy is established so that _PAGE_USER permission can be really
set.

A proper fix would be to teach kaiser_pagetable_walk() to update those
permissions but the vsyscall page is the only exception here so ...

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoproc: much faster /proc/vmstat
Alexey Dobriyan [Sat, 8 Oct 2016 00:02:14 +0000 (17:02 -0700)]
proc: much faster /proc/vmstat

commit 68ba0326b4e14988f9e0c24a6e12a85cf2acd1ca upstream.

Every current KDE system has process named ksysguardd polling files
below once in several seconds:

$ strace -e trace=open -p $(pidof ksysguardd)
Process 1812 attached
open("/etc/mtab", O_RDONLY|O_CLOEXEC)   = 8
open("/etc/mtab", O_RDONLY|O_CLOEXEC)   = 8
open("/proc/net/dev", O_RDONLY)         = 8
open("/proc/net/wireless", O_RDONLY)    = -1 ENOENT (No such file or directory)
open("/proc/stat", O_RDONLY)            = 8
open("/proc/vmstat", O_RDONLY)          = 8

Hell knows what it is doing but speed up reading /proc/vmstat by 33%!

Benchmark is open+read+close 1.000.000 times.

BEFORE
$ perf stat -r 10 taskset -c 3 ./proc-vmstat

 Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs):

      13146.768464      task-clock (msec)         #    0.960 CPUs utilized            ( +-  0.60% )
                15      context-switches          #    0.001 K/sec                    ( +-  1.41% )
                 1      cpu-migrations            #    0.000 K/sec                    ( +- 11.11% )
               104      page-faults               #    0.008 K/sec                    ( +-  0.57% )
    45,489,799,349      cycles                    #    3.460 GHz                      ( +-  0.03% )
     9,970,175,743      stalled-cycles-frontend   #   21.92% frontend cycles idle     ( +-  0.10% )
     2,800,298,015      stalled-cycles-backend    #   6.16% backend cycles idle       ( +-  0.32% )
    79,241,190,850      instructions              #    1.74  insn per cycle
                                                  #    0.13  stalled cycles per insn  ( +-  0.00% )
    17,616,096,146      branches                  # 1339.956 M/sec                    ( +-  0.00% )
       176,106,232      branch-misses             #    1.00% of all branches          ( +-  0.18% )

      13.691078109 seconds time elapsed                                          ( +-  0.03% )
      ^^^^^^^^^^^^

AFTER
$ perf stat -r 10 taskset -c 3 ./proc-vmstat

 Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs):

       8688.353749      task-clock (msec)         #    0.950 CPUs utilized            ( +-  1.25% )
                10      context-switches          #    0.001 K/sec                    ( +-  2.13% )
                 1      cpu-migrations            #    0.000 K/sec
               104      page-faults               #    0.012 K/sec                    ( +-  0.56% )
    30,384,010,730      cycles                    #    3.497 GHz                      ( +-  0.07% )
    12,296,259,407      stalled-cycles-frontend   #   40.47% frontend cycles idle     ( +-  0.13% )
     3,370,668,651      stalled-cycles-backend    #  11.09% backend cycles idle       ( +-  0.69% )
    28,969,052,879      instructions              #    0.95  insn per cycle
                                                  #    0.42  stalled cycles per insn  ( +-  0.01% )
     6,308,245,891      branches                  #  726.058 M/sec                    ( +-  0.00% )
       214,685,502      branch-misses             #    3.40% of all branches          ( +-  0.26% )

       9.146081052 seconds time elapsed                                          ( +-  0.07% )
       ^^^^^^^^^^^

vsnprintf() is slow because:

1. format_decode() is busy looking for format specifier: 2 branches
   per character (not in this case, but in others)

2. approximately million branches while parsing format mini language
   and everywhere

3.  just look at what string() does /proc/vmstat is good case because
   most of its content are strings

Link: http://lkml.kernel.org/r/20160806125455.GA1187@p183.telecom.by
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agomodule: Issue warnings when tainting kernel
Libor Pechacek [Wed, 13 Apr 2016 01:36:12 +0000 (11:06 +0930)]
module: Issue warnings when tainting kernel

commit 3205c36cf7d96024626f92d65f560035df1abcb2 upstream.

While most of the locations where a kernel taint bit is set are accompanied
with a warning message, there are two which set their bits silently.  If
the tainting module gets unloaded later on, it is almost impossible to tell
what was the reason for setting the flag.

Signed-off-by: Libor Pechacek <lpechacek@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agomodule: keep percpu symbols in module's symtab
Miroslav Benes [Thu, 26 Nov 2015 02:48:06 +0000 (13:18 +1030)]
module: keep percpu symbols in module's symtab

commit e0224418516b4d8a6c2160574bac18447c354ef0 upstream.

Currently, percpu symbols from .data..percpu ELF section of a module are
not copied over and stored in final symtab array of struct module.
Consequently such symbol cannot be returned via kallsyms API (for
example kallsyms_lookup_name). This can be especially confusing when the
percpu symbol is exported. Only its __ksymtab et al. are present in its
symtab.

The culprit is in layout_and_allocate() function where SHF_ALLOC flag is
dropped for .data..percpu section. There is in fact no need to copy the
section to final struct module, because kernel module loader allocates
extra percpu section by itself. Unfortunately only symbols from
SHF_ALLOC sections are copied due to a check in is_core_symbol().

The patch changes is_core_symbol() function to copy over also percpu
symbols (their st_shndx points to .data..percpu ELF section). We do it
only if CONFIG_KALLSYMS_ALL is set to be consistent with the rest of the
function (ELF section is SHF_ALLOC but !SHF_EXECINSTR). Finally
elf_type() returns type 'a' for a percpu symbol because its address is
absolute.

Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agogenksyms: Handle string literals with spaces in reference files
Michal Marek [Wed, 9 Dec 2015 14:08:21 +0000 (15:08 +0100)]
genksyms: Handle string literals with spaces in reference files

commit a78f70e8d65e88b9f631d073f68cb26dcd746298 upstream.

The reference files use spaces to separate tokens, however, we must
preserve spaces inside string literals. Currently the only case in the
tree is struct edac_raw_error_desc in <linux/edac.h>:

$ KBUILD_SYMTYPES=1 make -s drivers/edac/amd64_edac.symtypes
$ mv drivers/edac/amd64_edac.{symtypes,symref}
$ KBUILD_SYMTYPES=1 make -s drivers/edac/amd64_edac.symtypes
drivers/edac/amd64_edac.c:527: warning: amd64_get_dram_hole_info: modversion changed because of changes in struct edac_raw_error_desc

Signed-off-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agox86/tlb: Drop the _GPL from the cpu_tlbstate export
Thomas Gleixner [Thu, 4 Jan 2018 21:19:04 +0000 (22:19 +0100)]
x86/tlb: Drop the _GPL from the cpu_tlbstate export

commit 1e5476815fd7f98b888e01a0f9522b63085f96c9 upstream.

The recent changes for PTI touch cpu_tlbstate from various tlb_flush
inlines. cpu_tlbstate is exported as GPL symbol, so this causes a
regression when building out of tree drivers for certain graphics cards.

Aside of that the export was wrong since it was introduced as it should
have been EXPORT_PER_CPU_SYMBOL_GPL().

Use the correct PER_CPU export and drop the _GPL to restore the previous
state which allows users to utilize the cards they payed for.

As always I'm really thrilled to make this kind of change to support the
#friends (or however the hot hashtag of today is spelled) from that closet
sauce graphics corp.

Fixes: 1e02ce4cccdc ("x86: Store a per-cpu shadow copy of CR4")
Fixes: 6fd166aae78c ("x86/mm: Use/Fix PCID to optimize user/kernel switches")
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Backlund <tmb@mageia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoparisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernel
Helge Deller [Tue, 2 Jan 2018 19:36:44 +0000 (20:36 +0100)]
parisc: Fix alignment of pa_tlb_lock in assembly on 32-bit SMP kernel

commit 88776c0e70be0290f8357019d844aae15edaa967 upstream.

Qemu for PARISC reported on a 32bit SMP parisc kernel strange failures
about "Not-handled unaligned insn 0x0e8011d6 and 0x0c2011c9."

Those opcodes evaluate to the ldcw() assembly instruction which requires
(on 32bit) an alignment of 16 bytes to ensure atomicity.

As it turns out, qemu is correct and in our assembly code in entry.S and
pacache.S we don't pay attention to the required alignment.

This patch fixes the problem by aligning the lock offset in assembly
code in the same manner as we do in our C-code.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agox86/microcode/AMD: Add support for fam17h microcode loading
Tom Lendacky [Thu, 30 Nov 2017 22:46:40 +0000 (16:46 -0600)]
x86/microcode/AMD: Add support for fam17h microcode loading

commit f4e9b7af0cd58dd039a0fb2cd67d57cea4889abf upstream.

The size for the Microcode Patch Block (MPB) for an AMD family 17h
processor is 3200 bytes.  Add a #define for fam17h so that it does
not default to 2048 bytes and fail a microcode load/update.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20171130224640.15391.40247.stgit@tlendack-t1.amdoffice.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Alice Ferrazzi <alicef@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoInput: elantech - add new icbody type 15
Aaron Ma [Sun, 26 Nov 2017 00:48:41 +0000 (16:48 -0800)]
Input: elantech - add new icbody type 15

commit 10d900303f1c3a821eb0bef4e7b7ece16768fba4 upstream.

The touchpad of Lenovo Thinkpad L480 reports it's version as 15.

Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoARC: uaccess: dont use "l" gcc inline asm constraint modifier
Vineet Gupta [Fri, 8 Dec 2017 16:26:58 +0000 (08:26 -0800)]
ARC: uaccess: dont use "l" gcc inline asm constraint modifier

commit 79435ac78d160e4c245544d457850a56f805ac0d upstream.

This used to setup the LP_COUNT register automatically, but now has been
removed.

There was an earlier fix 3c7c7a2fc8811 which fixed instance in delay.h but
somehow missed this one as gcc change had not made its way into
production toolchains and was not pedantic as it is now !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()
Oleg Nesterov [Fri, 17 Nov 2017 23:30:08 +0000 (15:30 -0800)]
kernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()

commit 426915796ccaf9c2bd9bb06dc5702225957bc2e5 upstream.

complete_signal() checks SIGNAL_UNKILLABLE before it starts to destroy
the thread group, today this is wrong in many ways.

If nothing else, fatal_signal_pending() should always imply that the
whole thread group (except ->group_exit_task if it is not NULL) is
killed, this check breaks the rule.

After the previous changes we can rely on sig_task_ignored();
sig_fatal(sig) && SIGNAL_UNKILLABLE can only be true if we actually want
to kill this task and sig == SIGKILL OR it is traced and debugger can
intercept the signal.

This should hopefully fix the problem reported by Dmitry.  This
test-case

static int init(void *arg)
{
for (;;)
pause();
}

int main(void)
{
char stack[16 * 1024];

for (;;) {
int pid = clone(init, stack + sizeof(stack)/2,
CLONE_NEWPID | SIGCHLD, NULL);
assert(pid > 0);

assert(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0);
assert(waitpid(-1, NULL, WSTOPPED) == pid);

assert(ptrace(PTRACE_DETACH, pid, 0, SIGSTOP) == 0);
assert(syscall(__NR_tkill, pid, SIGKILL) == 0);
assert(pid == wait(NULL));
}
}

triggers the WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING)) in
task_participate_group_stop().  do_signal_stop()->signal_group_exit()
checks SIGNAL_GROUP_EXIT and return false, but task_set_jobctl_pending()
checks fatal_signal_pending() and does not set JOBCTL_STOP_PENDING.

And his should fix the minor security problem reported by Kyle,
SECCOMP_RET_TRACE can miss fatal_signal_pending() the same way if the
task is the root of a pid namespace.

Link: http://lkml.kernel.org/r/20171103184246.GD21036@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Kyle Huey <me@kylehuey.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kyle Huey <me@kylehuey.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokernel/signal.c: protect the SIGNAL_UNKILLABLE tasks from !sig_kernel_only() signals
Oleg Nesterov [Fri, 17 Nov 2017 23:30:04 +0000 (15:30 -0800)]
kernel/signal.c: protect the SIGNAL_UNKILLABLE tasks from !sig_kernel_only() signals

commit ac25385089f673560867eb5179228a44ade0cfc1 upstream.

Change sig_task_ignored() to drop the SIG_DFL && !sig_kernel_only()
signals even if force == T.  This simplifies the next change and this
matches the same check in get_signal() which will drop these signals
anyway.

Link: http://lkml.kernel.org/r/20171103184227.GC21036@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Kyle Huey <me@kylehuey.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokernel/signal.c: protect the traced SIGNAL_UNKILLABLE tasks from SIGKILL
Oleg Nesterov [Fri, 17 Nov 2017 23:30:01 +0000 (15:30 -0800)]
kernel/signal.c: protect the traced SIGNAL_UNKILLABLE tasks from SIGKILL

commit 628c1bcba204052d19b686b5bac149a644cdb72e upstream.

The comment in sig_ignored() says "Tracers may want to know about even
ignored signals" but SIGKILL can not be reported to debugger and it is
just wrong to return 0 in this case: SIGKILL should only kill the
SIGNAL_UNKILLABLE task if it comes from the parent ns.

Change sig_ignored() to ignore ->ptrace if sig == SIGKILL and rely on
sig_task_ignored().

SISGTOP coming from within the namespace is not really right too but at
least debugger can intercept it, and we can't drop it here because this
will break "gdb -p 1": ptrace_attach() won't work.  Perhaps we will add
another ->ptrace check later, we will see.

Link: http://lkml.kernel.org/r/20171103184206.GB21036@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Tested-by: Kyle Huey <me@kylehuey.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokernel: make groups_sort calling a responsibility group_info allocators
Thiago Rafael Becker [Thu, 14 Dec 2017 23:33:12 +0000 (15:33 -0800)]
kernel: make groups_sort calling a responsibility group_info allocators

commit bdcf0a423ea1c40bbb40e7ee483b50fc8aa3d758 upstream.

In testing, we found that nfsd threads may call set_groups in parallel
for the same entry cached in auth.unix.gid, racing in the call of
groups_sort, corrupting the groups for that entry and leading to
permission denials for the client.

This patch:
 - Make groups_sort globally visible.
 - Move the call to groups_sort to the modifiers of group_info
 - Remove the call to groups_sort from set_groups

Link: http://lkml.kernel.org/r/20171211151420.18655-1-thiago.becker@gmail.com
Signed-off-by: Thiago Rafael Becker <thiago.becker@gmail.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Acked-by: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agofscache: Fix the default for fscache_maybe_release_page()
David Howells [Tue, 2 Jan 2018 10:02:19 +0000 (10:02 +0000)]
fscache: Fix the default for fscache_maybe_release_page()

commit 98801506552593c9b8ac11021b0cdad12cab4f6b upstream.

Fix the default for fscache_maybe_release_page() for when the cookie isn't
valid or the page isn't cached.  It mustn't return false as that indicates
the page cannot yet be freed.

The problem with the default is that if, say, there's no cache, but a
network filesystem's pages are using up almost all the available memory, a
system can OOM because the filesystem ->releasepage() op will not allow
them to be released as fscache_maybe_release_page() incorrectly prevents
it.

This can be tested by writing a sequence of 512MiB files to an AFS mount.
It does not affect NFS or CIFS because both of those wrap the call in a
check of PG_fscache and it shouldn't bother Ceph as that only has
PG_private set whilst writeback is in progress.  This might be an issue for
9P, however.

Note that the pages aren't entirely stuck.  Removing a file or unmounting
will clear things because that uses ->invalidatepage() instead.

Fixes: 201a15428bd5 ("FS-Cache: Handle pages pending storage that get evicted under OOM conditions")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agosunxi-rsb: Include OF based modalias in device uevent
Stefan Brüns [Mon, 27 Nov 2017 19:05:34 +0000 (20:05 +0100)]
sunxi-rsb: Include OF based modalias in device uevent

commit e2bf801ecd4e62222a46d1ba9e57e710171d29c1 upstream.

Include the OF-based modalias in the uevent sent when registering devices
on the sunxi RSB bus, so that user space has a chance to autoload the
kernel module for the device.

Fixes a regression caused by commit 3f241bfa60bd ("arm64: allwinner: a64:
pine64: Use dcdc1 regulator for mmc0"). When the axp20x-rsb module for
the AXP803 PMIC is built as a module, it is not loaded and the system
ends up with an disfunctional MMC controller.

Fixes: d787dcdb9c8f ("bus: sunxi-rsb: Add driver for Allwinner Reduced Serial Bus")
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agocrypto: pcrypt - fix freeing pcrypt instances
Eric Biggers [Wed, 20 Dec 2017 22:28:25 +0000 (14:28 -0800)]
crypto: pcrypt - fix freeing pcrypt instances

commit d76c68109f37cb85b243a1cf0f40313afd2bae68 upstream.

pcrypt is using the old way of freeing instances, where the ->free()
method specified in the 'struct crypto_template' is passed a pointer to
the 'struct crypto_instance'.  But the crypto_instance is being
kfree()'d directly, which is incorrect because the memory was actually
allocated as an aead_instance, which contains the crypto_instance at a
nonzero offset.  Thus, the wrong pointer was being kfree()'d.

Fix it by switching to the new way to free aead_instance's where the
->free() method is specified in the aead_instance itself.

Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 0496f56065e0 ("crypto: pcrypt - Add support for new AEAD interface")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agocrypto: chacha20poly1305 - validate the digest size
Eric Biggers [Mon, 11 Dec 2017 20:15:17 +0000 (12:15 -0800)]
crypto: chacha20poly1305 - validate the digest size

commit e57121d08c38dabec15cf3e1e2ad46721af30cae upstream.

If the rfc7539 template was instantiated with a hash algorithm with
digest size larger than 16 bytes (POLY1305_DIGEST_SIZE), then the digest
overran the 'tag' buffer in 'struct chachapoly_req_ctx', corrupting the
subsequent memory, including 'cryptlen'.  This caused a crash during
crypto_skcipher_decrypt().

Fix it by, when instantiating the template, requiring that the
underlying hash algorithm has the digest size expected for Poly1305.

Reproducer:

    #include <linux/if_alg.h>
    #include <sys/socket.h>
    #include <unistd.h>

    int main()
    {
            int algfd, reqfd;
            struct sockaddr_alg addr = {
                    .salg_type = "aead",
                    .salg_name = "rfc7539(chacha20,sha256)",
            };
            unsigned char buf[32] = { 0 };

            algfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
            bind(algfd, (void *)&addr, sizeof(addr));
            setsockopt(algfd, SOL_ALG, ALG_SET_KEY, buf, sizeof(buf));
            reqfd = accept(algfd, 0, 0);
            write(reqfd, buf, 16);
            read(reqfd, buf, 16);
    }

Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 71ebc4d1b27d ("crypto: chacha20poly1305 - Add a ChaCha20-Poly1305 AEAD construction, RFC7539")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agocrypto: n2 - cure use after free
Jan Engelhardt [Tue, 19 Dec 2017 18:09:07 +0000 (19:09 +0100)]
crypto: n2 - cure use after free

commit 203f45003a3d03eea8fa28d74cfc74c354416fdb upstream.

queue_cache_init is first called for the Control Word Queue
(n2_crypto_probe). At that time, queue_cache[0] is NULL and a new
kmem_cache will be allocated. If the subsequent n2_register_algs call
fails, the kmem_cache will be released in queue_cache_destroy, but
queue_cache_init[0] is not set back to NULL.

So when the Module Arithmetic Unit gets probed next (n2_mau_probe),
queue_cache_init will not allocate a kmem_cache again, but leave it
as its bogus value, causing a BUG() to trigger when queue_cache[0] is
eventually passed to kmem_cache_zalloc:

n2_crypto: Found N2CP at /virtual-devices@100/n2cp@7
n2_crypto: Registered NCS HVAPI version 2.0
called queue_cache_init
n2_crypto: md5 alg registration failed
n2cp f028687c: /virtual-devices@100/n2cp@7: Unable to register algorithms.
called queue_cache_destroy
n2cp: probe of f028687c failed with error -22
n2_crypto: Found NCP at /virtual-devices@100/ncp@6
n2_crypto: Registered NCS HVAPI version 2.0
called queue_cache_init
kernel BUG at mm/slab.c:2993!
Call Trace:
 [0000000000604488] kmem_cache_alloc+0x1a8/0x1e0
                  (inlined) kmem_cache_zalloc
                  (inlined) new_queue
                  (inlined) spu_queue_setup
                  (inlined) handle_exec_unit
 [0000000010c61eb4] spu_mdesc_scan+0x1f4/0x460 [n2_crypto]
 [0000000010c62b80] n2_mau_probe+0x100/0x220 [n2_crypto]
 [000000000084b174] platform_drv_probe+0x34/0xc0

Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokernel/acct.c: fix the acct->needcheck check in check_free_space()
Oleg Nesterov [Fri, 5 Jan 2018 00:17:49 +0000 (16:17 -0800)]
kernel/acct.c: fix the acct->needcheck check in check_free_space()

commit 4d9570158b6260f449e317a5f9ed030c2504a615 upstream.

As Tsukada explains, the time_is_before_jiffies(acct->needcheck) check
is very wrong, we need time_is_after_jiffies() to make sys_acct() work.

Ignoring the overflows, the code should "goto out" if needcheck >
jiffies, while currently it checks "needcheck < jiffies" and thus in the
likely case check_free_space() does nothing until jiffies overflow.

In particular this means that sys_acct() is simply broken, acct_on()
sets acct->needcheck = jiffies and expects that check_free_space()
should set acct->active = 1 after the free-space check, but this won't
happen if jiffies increments in between.

This was broken by commit 32dc73086015 ("get rid of timer in
kern/acct.c") in 2011, then another (correct) commit 795a2f22a8ea
("acct() should honour the limits from the very beginning") made the
problem more visible.

Link: http://lkml.kernel.org/r/20171213133940.GA6554@redhat.com
Fixes: 32dc73086015 ("get rid of timer in kern/acct.c")
Reported-by: TSUKADA Koutaro <tsukada@ascade.co.jp>
Suggested-by: TSUKADA Koutaro <tsukada@ascade.co.jp>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agox86/kasan: Write protect kasan zero shadow
Andrey Ryabinin [Mon, 11 Jan 2016 12:51:19 +0000 (15:51 +0300)]
x86/kasan: Write protect kasan zero shadow

commit 063fb3e56f6dd29b2633b678b837e1d904200e6f upstream.

After kasan_init() executed, no one is allowed to write to kasan_zero_page,
so write protect it.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1452516679-32040-3-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoMerge tag 'v4.4.110' of http://git.kernel.org/pub/scm/linux/kernel/git/stable/linux...
Dan Murphy [Mon, 8 Jan 2018 13:19:35 +0000 (07:19 -0600)]
Merge tag 'v4.4.110' of git./linux/kernel/git/stable/linux-stable into ti-linux-4.4.y

This is the 4.4.110 stable release

* tag 'v4.4.110' of http://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable: (965 commits)
  Linux 4.4.110
  kaiser: Set _PAGE_NX only if supported
  x86/kasan: Clear kasan_zero_page after TLB flush
  x86/vdso: Get pvclock data from the vvar VMA instead of the fixmap
  x86, vdso, pvclock: Simplify and speed up the vdso pvclock reader
  KPTI: Report when enabled
  KPTI: Rename to PAGE_TABLE_ISOLATION
  x86/kaiser: Move feature detection up
  kaiser: disabled on Xen PV
  x86/kaiser: Reenable PARAVIRT
  x86/paravirt: Dont patch flush_tlb_single
  kaiser: kaiser_flush_tlb_on_return_to_user() check PCID
  kaiser: asm/tlbflush.h handle noPGE at lower level
  kaiser: drop is_atomic arg to kaiser_pagetable_walk()
  kaiser: use ALTERNATIVE instead of x86_cr3_pcid_noflush
  x86/kaiser: Check boottime cmdline params
  x86/kaiser: Rename and simplify X86_FEATURE_KAISER handling
  kaiser: add "nokaiser" boot option, using ALTERNATIVE
  kaiser: fix unlikely error in alloc_ldt_struct()
  kaiser: _pgd_alloc() without __GFP_REPEAT to avoid stalls
  ...

Signed-off-by: Dan Murphy <dmurphy@ti.com>
3 years agoLinux 4.4.110-rt125
Steven Rostedt (VMware) [Fri, 5 Jan 2018 21:17:39 +0000 (16:17 -0500)]
Linux 4.4.110-rt125

3 years agoMerge tag 'v4.4.110' into v4.4-rt
Steven Rostedt (VMware) [Fri, 5 Jan 2018 21:17:21 +0000 (16:17 -0500)]
Merge tag 'v4.4.110' into v4.4-rt

This is the 4.4.110 stable release

3 years agoLinux 4.4.109-rt124
Steven Rostedt (VMware) [Fri, 5 Jan 2018 21:14:51 +0000 (16:14 -0500)]
Linux 4.4.109-rt124

3 years agoMerge tag 'v4.4.109' into v4.4-rt
Steven Rostedt (VMware) [Fri, 5 Jan 2018 21:14:00 +0000 (16:14 -0500)]
Merge tag 'v4.4.109' into v4.4-rt

This is the 4.4.109 stable release

3 years agoLinux 4.4.108-rt123
Steven Rostedt (VMware) [Fri, 5 Jan 2018 21:13:41 +0000 (16:13 -0500)]
Linux 4.4.108-rt123

3 years agoMerge tag 'v4.4.108' into v4.4-rt
Steven Rostedt (VMware) [Fri, 5 Jan 2018 21:13:30 +0000 (16:13 -0500)]
Merge tag 'v4.4.108' into v4.4-rt

This is the 4.4.108 stable release

3 years agoLinux 4.4.107-rt122
Steven Rostedt (VMware) [Fri, 5 Jan 2018 21:13:17 +0000 (16:13 -0500)]
Linux 4.4.107-rt122

3 years agoMerge tag 'v4.4.107' into v4.4-rt
Steven Rostedt (VMware) [Fri, 5 Jan 2018 21:13:05 +0000 (16:13 -0500)]
Merge tag 'v4.4.107' into v4.4-rt

This is the 4.4.107 stable release

3 years agoLinux 4.4.106-rt121
Steven Rostedt (VMware) [Fri, 5 Jan 2018 21:12:02 +0000 (16:12 -0500)]
Linux 4.4.106-rt121

3 years agoMerge tag 'v4.4.106' into v4.4-rt
Steven Rostedt (VMware) [Fri, 5 Jan 2018 21:11:18 +0000 (16:11 -0500)]
Merge tag 'v4.4.106' into v4.4-rt

This is the 4.4.106 stable release

3 years agoLinux 4.4.110
Greg Kroah-Hartman [Fri, 5 Jan 2018 14:44:27 +0000 (15:44 +0100)]
Linux 4.4.110

3 years agokaiser: Set _PAGE_NX only if supported
Guenter Roeck [Thu, 4 Jan 2018 21:41:55 +0000 (13:41 -0800)]
kaiser: Set _PAGE_NX only if supported

This resolves a crash if loaded under qemu + haxm under windows.
See https://www.spinics.net/lists/kernel/msg2689835.html for details.
Here is a boot log (the log is from chromeos-4.4, but Tao Wu says that
the same log is also seen with vanilla v4.4.110-rc1).

[    0.712750] Freeing unused kernel memory: 552K
[    0.721821] init: Corrupted page table at address 57b029b332e0
[    0.722761] PGD 80000000bb238067 PUD bc36a067 PMD bc369067 PTE 45d2067
[    0.722761] Bad pagetable: 000b [#1] PREEMPT SMP
[    0.722761] Modules linked in:
[    0.722761] CPU: 1 PID: 1 Comm: init Not tainted 4.4.96 #31
[    0.722761] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
[    0.722761] task: ffff8800bc290000 ti: ffff8800bc28c000 task.ti: ffff8800bc28c000
[    0.722761] RIP: 0010:[<ffffffff83f4129e>]  [<ffffffff83f4129e>] __clear_user+0x42/0x67
[    0.722761] RSP: 0000:ffff8800bc28fcf8  EFLAGS: 00010202
[    0.722761] RAX: 0000000000000000 RBX: 00000000000001a4 RCX: 00000000000001a4
[    0.722761] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000057b029b332e0
[    0.722761] RBP: ffff8800bc28fd08 R08: ffff8800bc290000 R09: ffff8800bb2f4000
[    0.722761] R10: ffff8800bc290000 R11: ffff8800bb2f4000 R12: 000057b029b332e0
[    0.722761] R13: 0000000000000000 R14: 000057b029b33340 R15: ffff8800bb1e2a00
[    0.722761] FS:  0000000000000000(0000) GS:ffff8800bfb00000(0000) knlGS:0000000000000000
[    0.722761] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[    0.722761] CR2: 000057b029b332e0 CR3: 00000000bb2f8000 CR4: 00000000000006e0
[    0.722761] Stack:
[    0.722761]  000057b029b332e0 ffff8800bb95fa80 ffff8800bc28fd18 ffffffff83f4120c
[    0.722761]  ffff8800bc28fe18 ffffffff83e9e7a1 ffff8800bc28fd68 0000000000000000
[    0.722761]  ffff8800bc290000 ffff8800bc290000 ffff8800bc290000 ffff8800bc290000
[    0.722761] Call Trace:
[    0.722761]  [<ffffffff83f4120c>] clear_user+0x2e/0x30
[    0.722761]  [<ffffffff83e9e7a1>] load_elf_binary+0xa7f/0x18f7
[    0.722761]  [<ffffffff83de2088>] search_binary_handler+0x86/0x19c
[    0.722761]  [<ffffffff83de389e>] do_execveat_common.isra.26+0x909/0xf98
[    0.722761]  [<ffffffff844febe0>] ? rest_init+0x87/0x87
[    0.722761]  [<ffffffff83de40be>] do_execve+0x23/0x25
[    0.722761]  [<ffffffff83c002e3>] run_init_process+0x2b/0x2d
[    0.722761]  [<ffffffff844fec4d>] kernel_init+0x6d/0xda
[    0.722761]  [<ffffffff84505b2f>] ret_from_fork+0x3f/0x70
[    0.722761]  [<ffffffff844febe0>] ? rest_init+0x87/0x87
[    0.722761] Code: 86 84 be 12 00 00 00 e8 87 0d e8 ff 66 66 90 48 89 d8 48 c1
eb 03 4c 89 e7 83 e0 07 48 89 d9 be 08 00 00 00 31 d2 48 85 c9 74 0a <48> 89 17
48 01 f7 ff c9 75 f6 48 89 c1 85 c9 74 09 88 17 48 ff
[    0.722761] RIP  [<ffffffff83f4129e>] __clear_user+0x42/0x67
[    0.722761]  RSP <ffff8800bc28fcf8>
[    0.722761] ---[ end trace def703879b4ff090 ]---
[    0.722761] BUG: sleeping function called from invalid context at /mnt/host/source/src/third_party/kernel/v4.4/kernel/locking/rwsem.c:21
[    0.722761] in_atomic(): 0, irqs_disabled(): 1, pid: 1, name: init
[    0.722761] CPU: 1 PID: 1 Comm: init Tainted: G      D         4.4.96 #31
[    0.722761] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
[    0.722761]  0000000000000086 dcb5d76098c89836 ffff8800bc28fa30 ffffffff83f34004
[    0.722761]  ffffffff84839dc2 0000000000000015 ffff8800bc28fa40 ffffffff83d57dc9
[    0.722761]  ffff8800bc28fa68 ffffffff83d57e6a ffffffff84a53640 0000000000000000
[    0.722761] Call Trace:
[    0.722761]  [<ffffffff83f34004>] dump_stack+0x4d/0x63
[    0.722761]  [<ffffffff83d57dc9>] ___might_sleep+0x13a/0x13c
[    0.722761]  [<ffffffff83d57e6a>] __might_sleep+0x9f/0xa6
[    0.722761]  [<ffffffff84502788>] down_read+0x20/0x31
[    0.722761]  [<ffffffff83cc5d9b>] __blocking_notifier_call_chain+0x35/0x63
[    0.722761]  [<ffffffff83cc5ddd>] blocking_notifier_call_chain+0x14/0x16
[    0.800374] usb 1-1: new full-speed USB device number 2 using uhci_hcd
[    0.722761]  [<ffffffff83cefe97>] profile_task_exit+0x1a/0x1c
[    0.802309]  [<ffffffff83cac84e>] do_exit+0x39/0xe7f
[    0.802309]  [<ffffffff83ce5938>] ? vprintk_default+0x1d/0x1f
[    0.802309]  [<ffffffff83d7bb95>] ? printk+0x57/0x73
[    0.802309]  [<ffffffff83c46e25>] oops_end+0x80/0x85
[    0.802309]  [<ffffffff83c7b747>] pgtable_bad+0x8a/0x95
[    0.802309]  [<ffffffff83ca7f4a>] __do_page_fault+0x8c/0x352
[    0.802309]  [<ffffffff83eefba5>] ? file_has_perm+0xc4/0xe5
[    0.802309]  [<ffffffff83ca821c>] do_page_fault+0xc/0xe
[    0.802309]  [<ffffffff84507682>] page_fault+0x22/0x30
[    0.802309]  [<ffffffff83f4129e>] ? __clear_user+0x42/0x67
[    0.802309]  [<ffffffff83f4127f>] ? __clear_user+0x23/0x67
[    0.802309]  [<ffffffff83f4120c>] clear_user+0x2e/0x30
[    0.802309]  [<ffffffff83e9e7a1>] load_elf_binary+0xa7f/0x18f7
[    0.802309]  [<ffffffff83de2088>] search_binary_handler+0x86/0x19c
[    0.802309]  [<ffffffff83de389e>] do_execveat_common.isra.26+0x909/0xf98
[    0.802309]  [<ffffffff844febe0>] ? rest_init+0x87/0x87
[    0.802309]  [<ffffffff83de40be>] do_execve+0x23/0x25
[    0.802309]  [<ffffffff83c002e3>] run_init_process+0x2b/0x2d
[    0.802309]  [<ffffffff844fec4d>] kernel_init+0x6d/0xda
[    0.802309]  [<ffffffff84505b2f>] ret_from_fork+0x3f/0x70
[    0.802309]  [<ffffffff844febe0>] ? rest_init+0x87/0x87
[    0.830559] Kernel panic - not syncing: Attempted to kill init!  exitcode=0x00000009
[    0.830559]
[    0.831305] Kernel Offset: 0x2c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[    0.831305] ---[ end Kernel panic - not syncing: Attempted to kill init!  exitcode=0x00000009

The crash part of this problem may be solved with the following patch
(thanks to Hugh for the hint). There is still another problem, though -
with this patch applied, the qemu session aborts with "VCPU Shutdown
request", whatever that means.

Cc: lepton <ytht.net@gmail.com>
Signed-off-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agox86/kasan: Clear kasan_zero_page after TLB flush
Andrey Ryabinin [Mon, 11 Jan 2016 12:51:18 +0000 (15:51 +0300)]
x86/kasan: Clear kasan_zero_page after TLB flush

commit 69e0210fd01ff157d332102219aaf5c26ca8069b upstream.

Currently we clear kasan_zero_page before __flush_tlb_all(). This
works with current implementation of native_flush_tlb[_global]()
because it doesn't cause do any writes to kasan shadow memory.
But any subtle change made in native_flush_tlb*() could break this.
Also current code seems doesn't work for paravirt guests (lguest).

Only after the TLB flush we can be sure that kasan_zero_page is not
used as early shadow anymore (instrumented code will not write to it).
So it should cleared it only after the TLB flush.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1452516679-32040-2-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Jamie Iles <jamie.iles@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agox86/vdso: Get pvclock data from the vvar VMA instead of the fixmap
Andy Lutomirski [Fri, 11 Dec 2015 03:20:20 +0000 (19:20 -0800)]
x86/vdso: Get pvclock data from the vvar VMA instead of the fixmap

commit dac16fba6fc590fa7239676b35ed75dae4c4cd2b upstream.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/9d37826fdc7e2d2809efe31d5345f97186859284.1449702533.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Jamie Iles <jamie.iles@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agox86, vdso, pvclock: Simplify and speed up the vdso pvclock reader
Andy Lutomirski [Fri, 11 Dec 2015 03:20:19 +0000 (19:20 -0800)]
x86, vdso, pvclock: Simplify and speed up the vdso pvclock reader

commit 6b078f5de7fc0851af4102493c7b5bb07e49c4cb upstream.

The pvclock vdso code was too abstracted to understand easily
and excessively paranoid.  Simplify it for a huge speedup.

This opens the door for additional simplifications, as the vdso
no longer accesses the pvti for any vcpu other than vcpu 0.

Before, vclock_gettime using kvm-clock took about 45ns on my
machine. With this change, it takes 29ns, which is almost as
fast as the pure TSC implementation.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/6b51dcc41f1b101f963945c5ec7093d72bdac429.1449702533.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Jamie Iles <jamie.iles@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoKPTI: Report when enabled
Kees Cook [Wed, 3 Jan 2018 18:43:32 +0000 (10:43 -0800)]
KPTI: Report when enabled

Make sure dmesg reports when KPTI is enabled.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoKPTI: Rename to PAGE_TABLE_ISOLATION
Kees Cook [Wed, 3 Jan 2018 18:43:15 +0000 (10:43 -0800)]
KPTI: Rename to PAGE_TABLE_ISOLATION

This renames CONFIG_KAISER to CONFIG_PAGE_TABLE_ISOLATION.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agox86/kaiser: Move feature detection up
Borislav Petkov [Mon, 25 Dec 2017 12:57:16 +0000 (13:57 +0100)]
x86/kaiser: Move feature detection up

... before the first use of kaiser_enabled as otherwise funky
things happen:

  about to get started...
  (XEN) d0v0 Unhandled page fault fault/trap [#14, ec=0000]
  (XEN) Pagetable walk from ffff88022a449090:
  (XEN)  L4[0x110] = 0000000229e0e067 0000000000001e0e
  (XEN)  L3[0x008] = 0000000000000000 ffffffffffffffff
  (XEN) domain_crash_sync called from entry.S: fault at ffff82d08033fd08
  entry.o#create_bounce_frame+0x135/0x14d
  (XEN) Domain 0 (vcpu#0) crashed on cpu#0:
  (XEN) ----[ Xen-4.9.1_02-3.21  x86_64  debug=n   Not tainted ]----
  (XEN) CPU:    0
  (XEN) RIP:    e033:[<ffffffff81007460>]
  (XEN) RFLAGS: 0000000000000286   EM: 1   CONTEXT: pv guest (d0v0)

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: disabled on Xen PV
Jiri Kosina [Tue, 2 Jan 2018 13:19:49 +0000 (14:19 +0100)]
kaiser: disabled on Xen PV

Kaiser cannot be used on paravirtualized MMUs (namely reading and writing CR3).
This does not work with KAISER as the CR3 switch from and to user space PGD
would require to map the whole XEN_PV machinery into both.

More importantly, enabling KAISER on Xen PV doesn't make too much sense, as PV
guests use distinct %cr3 values for kernel and user already.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agox86/kaiser: Reenable PARAVIRT
Borislav Petkov [Tue, 2 Jan 2018 13:19:49 +0000 (14:19 +0100)]
x86/kaiser: Reenable PARAVIRT

Now that the required bits have been addressed, reenable
PARAVIRT.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agox86/paravirt: Dont patch flush_tlb_single
Thomas Gleixner [Mon, 4 Dec 2017 14:07:30 +0000 (15:07 +0100)]
x86/paravirt: Dont patch flush_tlb_single

commit a035795499ca1c2bd1928808d1a156eda1420383 upstream

native_flush_tlb_single() will be changed with the upcoming
PAGE_TABLE_ISOLATION feature. This requires to have more code in
there than INVLPG.

Remove the paravirt patching for it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.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: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>
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: linux-mm@kvack.org
Cc: michael.schwarz@iaik.tugraz.at
Cc: moritz.lipp@iaik.tugraz.at
Cc: richard.fellner@student.tugraz.at
Link: https://lkml.kernel.org/r/20171204150606.828111617@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: kaiser_flush_tlb_on_return_to_user() check PCID
Hugh Dickins [Sun, 5 Nov 2017 01:43:06 +0000 (18:43 -0700)]
kaiser: kaiser_flush_tlb_on_return_to_user() check PCID

Let kaiser_flush_tlb_on_return_to_user() do the X86_FEATURE_PCID
check, instead of each caller doing it inline first: nobody needs
to optimize for the noPCID case, it's clearer this way, and better
suits later changes.  Replace those no-op X86_CR3_PCID_KERN_FLUSH lines
by a BUILD_BUG_ON() in load_new_mm_cr3(), in case something changes.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: asm/tlbflush.h handle noPGE at lower level
Hugh Dickins [Sun, 5 Nov 2017 01:23:24 +0000 (18:23 -0700)]
kaiser: asm/tlbflush.h handle noPGE at lower level

I found asm/tlbflush.h too twisty, and think it safer not to avoid
__native_flush_tlb_global_irq_disabled() in the kaiser_enabled case,
but instead let it handle kaiser_enabled along with cr3: it can just
use __native_flush_tlb() for that, no harm in re-disabling preemption.

(This is not the same change as Kirill and Dave have suggested for
upstream, flipping PGE in cr4: that's neat, but needs a cpu_has_pge
check; cr3 is enough for kaiser, and thought to be cheaper than cr4.)

Also delete the X86_FEATURE_INVPCID invpcid_flush_all_nonglobals()
preference from __native_flush_tlb(): unlike the invpcid_flush_all()
preference in __native_flush_tlb_global(), it's not seen in upstream
4.14, and was recently reported to be surprisingly slow.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: drop is_atomic arg to kaiser_pagetable_walk()
Hugh Dickins [Sun, 29 Oct 2017 18:36:19 +0000 (11:36 -0700)]
kaiser: drop is_atomic arg to kaiser_pagetable_walk()

I have not observed a might_sleep() warning from setup_fixmap_gdt()'s
use of kaiser_add_mapping() in our tree (why not?), but like upstream
we have not provided a way for that to pass is_atomic true down to
kaiser_pagetable_walk(), and at startup it's far from a likely source
of trouble: so just delete the walk's is_atomic arg and might_sleep().

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: use ALTERNATIVE instead of x86_cr3_pcid_noflush
Hugh Dickins [Wed, 4 Oct 2017 03:49:04 +0000 (20:49 -0700)]
kaiser: use ALTERNATIVE instead of x86_cr3_pcid_noflush

Now that we're playing the ALTERNATIVE game, use that more efficient
method: instead of user-mapping an extra page, and reading an extra
cacheline each time for x86_cr3_pcid_noflush.

Neel has found that __stringify(bts $X86_CR3_PCID_NOFLUSH_BIT, %rax)
is a working substitute for the "bts $63, %rax" in these ALTERNATIVEs;
but the one line with $63 in looks clearer, so let's stick with that.

Worried about what happens with an ALTERNATIVE between the jump and
jump label in another ALTERNATIVE?  I was, but have checked the
combinations in SWITCH_KERNEL_CR3_NO_STACK at entry_SYSCALL_64,
and it does a good job.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agox86/kaiser: Check boottime cmdline params
Borislav Petkov [Tue, 2 Jan 2018 13:19:48 +0000 (14:19 +0100)]
x86/kaiser: Check boottime cmdline params

AMD (and possibly other vendors) are not affected by the leak
KAISER is protecting against.

Keep the "nopti" for traditional reasons and add pti=<on|off|auto>
like upstream.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agox86/kaiser: Rename and simplify X86_FEATURE_KAISER handling
Borislav Petkov [Tue, 2 Jan 2018 13:19:48 +0000 (14:19 +0100)]
x86/kaiser: Rename and simplify X86_FEATURE_KAISER handling

Concentrate it in arch/x86/mm/kaiser.c and use the upstream string "nopti".

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: add "nokaiser" boot option, using ALTERNATIVE
Hugh Dickins [Sun, 24 Sep 2017 23:59:49 +0000 (16:59 -0700)]
kaiser: add "nokaiser" boot option, using ALTERNATIVE

Added "nokaiser" boot option: an early param like "noinvpcid".
Most places now check int kaiser_enabled (#defined 0 when not
CONFIG_KAISER) instead of #ifdef CONFIG_KAISER; but entry_64.S
and entry_64_compat.S are using the ALTERNATIVE technique, which
patches in the preferred instructions at runtime.  That technique
is tied to x86 cpu features, so X86_FEATURE_KAISER is fabricated.

Prior to "nokaiser", Kaiser #defined _PAGE_GLOBAL 0: revert that,
but be careful with both _PAGE_GLOBAL and CR4.PGE: setting them when
nokaiser like when !CONFIG_KAISER, but not setting either when kaiser -
neither matters on its own, but it's hard to be sure that _PAGE_GLOBAL
won't get set in some obscure corner, or something add PGE into CR4.
By omitting _PAGE_GLOBAL from __supported_pte_mask when kaiser_enabled,
all page table setup which uses pte_pfn() masks it out of the ptes.

It's slightly shameful that the same declaration versus definition of
kaiser_enabled appears in not one, not two, but in three header files
(asm/kaiser.h, asm/pgtable.h, asm/tlbflush.h).  I felt safer that way,
than with #including any of those in any of the others; and did not
feel it worth an asm/kaiser_enabled.h - kernel/cpu/common.c includes
them all, so we shall hear about it if they get out of synch.

Cleanups while in the area: removed the silly #ifdef CONFIG_KAISER
from kaiser.c; removed the unused native_get_normal_pgd(); removed
the spurious reg clutter from SWITCH_*_CR3 macro stubs; corrected some
comments.  But more interestingly, set CR4.PSE in secondary_startup_64:
the manual is clear that it does not matter whether it's 0 or 1 when
4-level-pts are enabled, but I was distracted to find cr4 different on
BSP and auxiliaries - BSP alone was adding PSE, in probe_page_size_mask().

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: fix unlikely error in alloc_ldt_struct()
Hugh Dickins [Tue, 5 Dec 2017 04:13:35 +0000 (20:13 -0800)]
kaiser: fix unlikely error in alloc_ldt_struct()

An error from kaiser_add_mapping() here is not at all likely, but
Eric Biggers rightly points out that __free_ldt_struct() relies on
new_ldt->size being initialized: move that up.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: _pgd_alloc() without __GFP_REPEAT to avoid stalls
Hugh Dickins [Fri, 13 Oct 2017 19:10:00 +0000 (12:10 -0700)]
kaiser: _pgd_alloc() without __GFP_REPEAT to avoid stalls

Synthetic filesystem mempressure testing has shown softlockups, with
hour-long page allocation stalls, and pgd_alloc() trying for order:1
with __GFP_REPEAT in one of the backtraces each time.

That's _pgd_alloc() going for a Kaiser double-pgd, using the __GFP_REPEAT
common to all page table allocations, but actually having no effect on
order:0 (see should_alloc_oom() and should_continue_reclaim() in this
tree, but beware that ports to another tree might behave differently).

Order:1 stack allocation has been working satisfactorily without
__GFP_REPEAT forever, and page table allocation only asks __GFP_REPEAT
for awkward occasions in a long-running process: it's not appropriate
at fork or exec time, and seems to be doing much more harm than good:
getting those contiguous pages under very heavy mempressure can be
hard (though even without it, Kaiser does generate more mempressure).

Mask out that __GFP_REPEAT inside _pgd_alloc().  Why not take it out
of the PGALLOG_GFP altogether, as v4.7 commit a3a9a59d2067 ("x86: get
rid of superfluous __GFP_REPEAT") did?  Because I think that might
make a difference to our page table memcg charging, which I'd prefer
not to interfere with at this time.

hughd adds: __alloc_pages_slowpath() in the 4.4.89-stable tree handles
__GFP_REPEAT a little differently than in prod kernel or 3.18.72-stable,
so it may not always be exactly a no-op on order:0 pages, as said above;
but I think still appropriate to omit it from Kaiser or non-Kaiser pgd.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: paranoid_entry pass cr3 need to paranoid_exit
Hugh Dickins [Wed, 27 Sep 2017 01:43:07 +0000 (18:43 -0700)]
kaiser: paranoid_entry pass cr3 need to paranoid_exit

Neel Natu points out that paranoid_entry() was wrong to assume that
an entry that did not need swapgs would not need SWITCH_KERNEL_CR3:
paranoid_entry (used for debug breakpoint, int3, double fault or MCE;
though I think it's only the MCE case that is cause for concern here)
can break in at an awkward time, between cr3 switch and swapgs, but
its handling always needs kernel gs and kernel cr3.

Easy to fix in itself, but paranoid_entry() also needs to convey to
paranoid_exit() (and my reading of macro idtentry says paranoid_entry
and paranoid_exit are always paired) how to restore the prior state.
The swapgs state is already conveyed by %ebx (0 or 1), so extend that
also to convey when SWITCH_USER_CR3 will be needed (2 or 3).

(Yes, I'd much prefer that 0 meant no swapgs, whereas it's the other
way round: and a convention shared with error_entry() and error_exit(),
which I don't want to touch.  Perhaps I should have inverted the bit
for switch cr3 too, but did not.)

paranoid_exit() would be straightforward, except for TRACE_IRQS: it
did TRACE_IRQS_IRETQ when doing swapgs, but TRACE_IRQS_IRETQ_DEBUG
when not: which is it supposed to use when SWITCH_USER_CR3 is split
apart from that?  As best as I can determine, commit 5963e317b1e9
("ftrace/x86: Do not change stacks in DEBUG when calling lockdep")
missed the swapgs case, and should have used TRACE_IRQS_IRETQ_DEBUG
there too (the discrepancy has nothing to do with the liberal use
of _NO_STACK and _UNSAFE_STACK hereabouts: TRACE_IRQS_OFF_DEBUG has
just been used in all cases); discrepancy lovingly preserved across
several paranoid_exit() cleanups, but I'm now removing it.

Neel further indicates that to use SWITCH_USER_CR3_NO_STACK there in
paranoid_exit() is now not only unnecessary but unsafe: might corrupt
syscall entry's unsafe_stack_register_backup of %rax.  Just use
SWITCH_USER_CR3: and delete SWITCH_USER_CR3_NO_STACK altogether,
before we make the mistake of using it again.

hughd adds: this commit fixes an issue in the Kaiser-without-PCIDs
part of the series, and ought to be moved earlier, if you decided
to make a release of Kaiser-without-PCIDs.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: x86_cr3_pcid_noflush and x86_cr3_pcid_user
Hugh Dickins [Sun, 27 Aug 2017 23:24:27 +0000 (16:24 -0700)]
kaiser: x86_cr3_pcid_noflush and x86_cr3_pcid_user

Mostly this commit is just unshouting X86_CR3_PCID_KERN_VAR and
X86_CR3_PCID_USER_VAR: we usually name variables in lower-case.

But why does x86_cr3_pcid_noflush need to be __aligned(PAGE_SIZE)?
Ah, it's a leftover from when kaiser_add_user_map() once complained
about mapping the same page twice.  Make it __read_mostly instead.
(I'm a little uneasy about all the unrelated data which shares its
page getting user-mapped too, but that was so before, and not a big
deal: though we call it user-mapped, it's not mapped with _PAGE_USER.)

And there is a little change around the two calls to do_nmi().
Previously they set the NOFLUSH bit (if PCID supported) when
forcing to kernel context before do_nmi(); now they also have the
NOFLUSH bit set (if PCID supported) when restoring context after:
nothing done in do_nmi() should require a TLB to be flushed here.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: PCID 0 for kernel and 128 for user
Hugh Dickins [Sat, 9 Sep 2017 02:26:30 +0000 (19:26 -0700)]
kaiser: PCID 0 for kernel and 128 for user

Why was 4 chosen for kernel PCID and 6 for user PCID?
No good reason in a backport where PCIDs are only used for Kaiser.

If we continue with those, then we shall need to add Andy Lutomirski's
4.13 commit 6c690ee1039b ("x86/mm: Split read_cr3() into read_cr3_pa()
and __read_cr3()"), which deals with the problem of read_cr3() callers
finding stray bits in the cr3 that they expected to be page-aligned;
and for hibernation, his 4.14 commit f34902c5c6c0 ("x86/hibernate/64:
Mask off CR3's PCID bits in the saved CR3").

But if 0 is used for kernel PCID, then there's no need to add in those
commits - whenever the kernel looks, it sees 0 in the lower bits; and
0 for kernel seems an obvious choice.

And I naughtily propose 128 for user PCID.  Because there's a place
in _SWITCH_TO_USER_CR3 where it takes note of the need for TLB FLUSH,
but needs to reset that to NOFLUSH for the next occasion.  Currently
it does so with a "movb $(0x80)" into the high byte of the per-cpu
quadword, but that will cause a machine without PCID support to crash.
Now, if %al just happened to have 0x80 in it at that point, on a
machine with PCID support, but 0 on a machine without PCID support...

(That will go badly wrong once the pgd can be at a physical address
above 2^56, but even with 5-level paging, physical goes up to 2^52.)

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: load_new_mm_cr3() let SWITCH_USER_CR3 flush user
Hugh Dickins [Thu, 17 Aug 2017 22:00:37 +0000 (15:00 -0700)]
kaiser: load_new_mm_cr3() let SWITCH_USER_CR3 flush user

We have many machines (Westmere, Sandybridge, Ivybridge) supporting
PCID but not INVPCID: on these load_new_mm_cr3() simply crashed.

Flushing user context inside load_new_mm_cr3() without the use of
invpcid is difficult: momentarily switch from kernel to user context
and back to do so?  I'm not sure whether that can be safely done at
all, and would risk polluting user context with kernel internals,
and kernel context with stale user externals.

Instead, follow the hint in the comment that was there: change
X86_CR3_PCID_USER_VAR to be a per-cpu variable, then load_new_mm_cr3()
can leave a note in it, for SWITCH_USER_CR3 on return to userspace to
flush user context TLB, instead of default X86_CR3_PCID_USER_NOFLUSH.

Which works well enough that there's no need to do it this way only
when invpcid is unsupported: it's a good alternative to invpcid here.
But there's a couple of inlines in asm/tlbflush.h that need to do the
same trick, so it's best to localize all this per-cpu business in
mm/kaiser.c: moving that part of the initialization from setup_pcid()
to kaiser_setup_pcid(); with kaiser_flush_tlb_on_return_to_user() the
function for noting an X86_CR3_PCID_USER_FLUSH.  And let's keep a
KAISER_SHADOW_PGD_OFFSET in there, to avoid the extra OR on exit.

I did try to make the feature tests in asm/tlbflush.h more consistent
with each other: there seem to be far too many ways of performing such
tests, and I don't have a good grasp of their differences.  At first
I converted them all to be static_cpu_has(): but that proved to be a
mistake, as the comment in __native_flush_tlb_single() hints; so then
I reversed and made them all this_cpu_has().  Probably all gratuitous
change, but that's the way it's working at present.

I am slightly bothered by the way non-per-cpu X86_CR3_PCID_KERN_VAR
gets re-initialized by each cpu (before and after these changes):
no problem when (as usual) all cpus on a machine have the same
features, but in principle incorrect.  However, my experiment
to per-cpu-ify that one did not end well...

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: enhanced by kernel and user PCIDs
Dave Hansen [Wed, 30 Aug 2017 23:23:00 +0000 (16:23 -0700)]
kaiser: enhanced by kernel and user PCIDs

Merged performance improvements to Kaiser, using distinct kernel
and user Process Context Identifiers to minimize the TLB flushing.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: vmstat show NR_KAISERTABLE as nr_overhead
Hugh Dickins [Sun, 10 Sep 2017 04:27:32 +0000 (21:27 -0700)]
kaiser: vmstat show NR_KAISERTABLE as nr_overhead

The kaiser update made an interesting choice, never to free any shadow
page tables.  Contention on global spinlock was worrying, particularly
with it held across page table scans when freeing.  Something had to be
done: I was going to add refcounting; but simply never to free them is
an appealing choice, minimizing contention without complicating the code
(the more a page table is found already, the less the spinlock is used).

But leaking pages in this way is also a worry: can we get away with it?
At the very least, we need a count to show how bad it actually gets:
in principle, one might end up wasting about 1/256 of memory that way
(1/512 for when direct-mapped pages have to be user-mapped, plus 1/512
for when they are user-mapped from the vmalloc area on another occasion
(but we don't have vmalloc'ed stacks, so only large ldts are vmalloc'ed).

Add per-cpu stat NR_KAISERTABLE: including 256 at startup for the
shared pgd entries, and 1 for each intermediate page table added
thereafter for user-mapping - but leave out the 1 per mm, for its
shadow pgd, because that distracts from the monotonic increase.
Shown in /proc/vmstat as nr_overhead (0 if kaiser not enabled).

In practice, it doesn't look so bad so far: more like 1/12000 after
nine hours of gtests below; and movable pageblock segregation should
tend to cluster the kaiser tables into a subset of the address space
(if not, they will be bad for compaction too).  But production may
tell a different story: keep an eye on this number, and bring back
lighter freeing if it gets out of control (maybe a shrinker).

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: delete KAISER_REAL_SWITCH option
Hugh Dickins [Mon, 4 Sep 2017 01:30:43 +0000 (18:30 -0700)]
kaiser: delete KAISER_REAL_SWITCH option

We fail to see what CONFIG_KAISER_REAL_SWITCH is for: it seems to be
left over from early development, and now just obscures tricky parts
of the code.  Delete it before adding PCIDs, or nokaiser boot option.

(Or if there is some good reason to keep the option, then it needs
a help text - and a "depends on KAISER", so that all those without
KAISER are not asked the question.)

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: name that 0x1000 KAISER_SHADOW_PGD_OFFSET
Hugh Dickins [Sun, 10 Sep 2017 00:31:18 +0000 (17:31 -0700)]
kaiser: name that 0x1000 KAISER_SHADOW_PGD_OFFSET

There's a 0x1000 in various places, which looks better with a name.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: cleanups while trying for gold link
Hugh Dickins [Tue, 22 Aug 2017 03:11:43 +0000 (20:11 -0700)]
kaiser: cleanups while trying for gold link

While trying to get our gold link to work, four cleanups:
matched the gdt_page declaration to its definition;
in fiddling unsuccessfully with PERCPU_INPUT(), lined up backslashes;
lined up the backslashes according to convention in percpu-defs.h;
deleted the unused irq_stack_pointer addition to irq_stack_union.

Sad to report that aligning backslashes does not appear to help gold
align to 8192: but while these did not help, they are worth keeping.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: kaiser_remove_mapping() move along the pgd
Hugh Dickins [Mon, 2 Oct 2017 17:57:24 +0000 (10:57 -0700)]
kaiser: kaiser_remove_mapping() move along the pgd

When removing the bogus comment from kaiser_remove_mapping(),
I really ought to have checked the extent of its bogosity: as
Neel points out, there is nothing to stop unmap_pud_range_nofree()
from continuing beyond the end of a pud (and starting in the wrong
position on the next).

Fix kaiser_remove_mapping() to constrain the extent and advance pgd
pointer correctly: use pgd_addr_end() macro as used throughout base
mm (but don't assume page-rounded start and size in this case).

But this bug was very unlikely to trigger in this backport: since
any buddy allocation is contained within a single pud extent, and
we are not using vmapped stacks (and are only mapping one page of
stack anyway): the only way to hit this bug here would be when
freeing a large modified ldt.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: tidied up kaiser_add/remove_mapping slightly
Hugh Dickins [Mon, 4 Sep 2017 02:23:08 +0000 (19:23 -0700)]
kaiser: tidied up kaiser_add/remove_mapping slightly

Yes, unmap_pud_range_nofree()'s declaration ought to be in a
header file really, but I'm not sure we want to use it anyway:
so for now just declare it inside kaiser_remove_mapping().
And there doesn't seem to be such a thing as unmap_p4d_range(),
even in a 5-level paging tree.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: tidied up asm/kaiser.h somewhat
Hugh Dickins [Mon, 4 Sep 2017 02:18:07 +0000 (19:18 -0700)]
kaiser: tidied up asm/kaiser.h somewhat

Mainly deleting a surfeit of blank lines, and reflowing header comment.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: ENOMEM if kaiser_pagetable_walk() NULL
Hugh Dickins [Mon, 4 Sep 2017 01:48:02 +0000 (18:48 -0700)]
kaiser: ENOMEM if kaiser_pagetable_walk() NULL

kaiser_add_user_map() took no notice when kaiser_pagetable_walk() failed.
And avoid its might_sleep() when atomic (though atomic at present unused).

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: fix perf crashes
Hugh Dickins [Wed, 23 Aug 2017 21:21:14 +0000 (14:21 -0700)]
kaiser: fix perf crashes

Avoid perf crashes: place debug_store in the user-mapped per-cpu area
instead of allocating, and use page allocator plus kaiser_add_mapping()
to keep the BTS and PEBS buffers user-mapped (that is, present in the
user mapping, though visible only to kernel and hardware).  The PEBS
fixup buffer does not need this treatment.

The need for a user-mapped struct debug_store showed up before doing
any conscious perf testing: in a couple of kernel paging oopses on
Westmere, implicating the debug_store offset of the per-cpu area.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: fix regs to do_nmi() ifndef CONFIG_KAISER
Hugh Dickins [Fri, 22 Sep 2017 03:39:56 +0000 (20:39 -0700)]
kaiser: fix regs to do_nmi() ifndef CONFIG_KAISER

pjt has observed that nmi's second (nmi_from_kernel) call to do_nmi()
adjusted the %rdi regs arg, rightly when CONFIG_KAISER, but wrongly
when not CONFIG_KAISER.

Although the minimal change is to add an #ifdef CONFIG_KAISER around
the addq line, that looks cluttered, and I prefer how the first call
to do_nmi() handled it: prepare args in %rdi and %rsi before getting
into the CONFIG_KAISER block, since it does not touch them at all.

And while we're here, place the "#ifdef CONFIG_KAISER" that follows
each, to enclose the "Unconditionally restore CR3" comment: matching
how the "Unconditionally use kernel CR3" comment above is enclosed.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: KAISER depends on SMP
Hugh Dickins [Wed, 13 Sep 2017 21:03:10 +0000 (14:03 -0700)]
kaiser: KAISER depends on SMP

It is absurd that KAISER should depend on SMP, but apparently nobody
has tried a UP build before: which breaks on implicit declaration of
function 'per_cpu_offset' in arch/x86/mm/kaiser.c.

Now, you would expect that to be trivially fixed up; but looking at
the System.map when that block is #ifdef'ed out of kaiser_init(),
I see that in a UP build __per_cpu_user_mapped_end is precisely at
__per_cpu_user_mapped_start, and the items carefully gathered into
that section for user-mapping on SMP, dispersed elsewhere on UP.

So, some other kind of section assignment will be needed on UP,
but implementing that is not a priority: just make KAISER depend
on SMP for now.

Also inserted a blank line before the option, tidied up the
brief Kconfig help message, and added an "If unsure, Y".

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: fix build and FIXME in alloc_ldt_struct()
Hugh Dickins [Mon, 4 Sep 2017 00:09:44 +0000 (17:09 -0700)]
kaiser: fix build and FIXME in alloc_ldt_struct()

Include linux/kaiser.h instead of asm/kaiser.h to build ldt.c without
CONFIG_KAISER.  kaiser_add_mapping() does already return an error code,
so fix the FIXME.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: stack map PAGE_SIZE at THREAD_SIZE-PAGE_SIZE
Hugh Dickins [Mon, 4 Sep 2017 01:57:03 +0000 (18:57 -0700)]
kaiser: stack map PAGE_SIZE at THREAD_SIZE-PAGE_SIZE

Kaiser only needs to map one page of the stack; and
kernel/fork.c did not build on powerpc (no __PAGE_KERNEL).
It's all cleaner if linux/kaiser.h provides kaiser_map_thread_stack()
and kaiser_unmap_thread_stack() wrappers around asm/kaiser.h's
kaiser_add_mapping() and kaiser_remove_mapping().  And use
linux/kaiser.h in init/main.c to avoid the #ifdefs there.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: do not set _PAGE_NX on pgd_none
Hugh Dickins [Tue, 5 Sep 2017 19:05:01 +0000 (12:05 -0700)]
kaiser: do not set _PAGE_NX on pgd_none

native_pgd_clear() uses native_set_pgd(), so native_set_pgd() must
avoid setting the _PAGE_NX bit on an otherwise pgd_none() entry:
usually that just generated a warning on exit, but sometimes
more mysterious and damaging failures (our production machines
could not complete booting).

The original fix to this just avoided adding _PAGE_NX to
an empty entry; but eventually more problems surfaced with kexec,
and EFI mapping expected to be a problem too.  So now instead
change native_set_pgd() to update shadow only if _PAGE_USER:

A few places (kernel/machine_kexec_64.c, platform/efi/efi_64.c for sure)
use set_pgd() to set up a temporary internal virtual address space, with
physical pages remapped at what Kaiser regards as userspace addresses:
Kaiser then assumes a shadow pgd follows, which it will try to corrupt.

This appears to be responsible for the recent kexec and kdump failures;
though it's unclear how those did not manifest as a problem before.
Ah, the shadow pgd will only be assumed to "follow" if the requested
pgd is on an even-numbered page: so I suppose it was going wrong 50%
of the time all along.

What we need is a flag to set_pgd(), to tell it we're dealing with
userspace.  Er, isn't that what the pgd's _PAGE_USER bit is saying?
Add a test for that.  But we cannot do the same for pgd_clear()
(which may be called to clear corrupted entries - set aside the
question of "corrupt in which pgd?" until later), so there just
rely on pgd_clear() not being called in the problematic cases -
with a WARN_ON_ONCE() which should fire half the time if it is.

But this is getting too big for an inline function: move it into
arch/x86/mm/kaiser.c (which then demands a boot/compressed mod);
and de-void and de-space native_get_shadow/normal_pgd() while here.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agokaiser: merged update
Dave Hansen [Wed, 30 Aug 2017 23:23:00 +0000 (16:23 -0700)]
kaiser: merged update

Merged fixes and cleanups, rebased to 4.4.89 tree (no 5-level paging).

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoKAISER: Kernel Address Isolation
Richard Fellner [Thu, 4 May 2017 12:26:50 +0000 (14:26 +0200)]
KAISER: Kernel Address Isolation

This patch introduces our implementation of KAISER (Kernel Address Isolation to
have Side-channels Efficiently Removed), a kernel isolation technique to close
hardware side channels on kernel address information.

More information about the patch can be found on:

        https://github.com/IAIK/KAISER

From: Richard Fellner <richard.fellner@student.tugraz.at>
From: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
X-Subject: [RFC, PATCH] x86_64: KAISER - do not map kernel in user mode
Date: Thu, 4 May 2017 14:26:50 +0200
Link: http://marc.info/?l=linux-kernel&m=149390087310405&w=2
Kaiser-4.10-SHA1: c4b1831d44c6144d3762ccc72f0c4e71a0c713e5

To: <linux-kernel@vger.kernel.org>
To: <kernel-hardening@lists.openwall.com>
Cc: <clementine.maurice@iaik.tugraz.at>
Cc: <moritz.lipp@iaik.tugraz.at>
Cc: Michael Schwarz <michael.schwarz@iaik.tugraz.at>
Cc: Richard Fellner <richard.fellner@student.tugraz.at>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <kirill.shutemov@linux.intel.com>
Cc: <anders.fogh@gdata-adan.de>
After several recent works [1,2,3] KASLR on x86_64 was basically
considered dead by many researchers. We have been working on an
efficient but effective fix for this problem and found that not mapping
the kernel space when running in user mode is the solution to this
problem [4] (the corresponding paper [5] will be presented at ESSoS17).

With this RFC patch we allow anybody to configure their kernel with the
flag CONFIG_KAISER to add our defense mechanism.

If there are any questions we would love to answer them.
We also appreciate any comments!

Cheers,
Daniel (+ the KAISER team from Graz University of Technology)

[1] http://www.ieee-security.org/TC/SP2013/papers/4977a191.pdf
[2] https://www.blackhat.com/docs/us-16/materials/us-16-Fogh-Using-Undocumented-CPU-Behaviour-To-See-Into-Kernel-Mode-And-Break-KASLR-In-The-Process.pdf
[3] https://www.blackhat.com/docs/us-16/materials/us-16-Jang-Breaking-Kernel-Address-Space-Layout-Randomization-KASLR-With-Intel-TSX.pdf
[4] https://github.com/IAIK/KAISER
[5] https://gruss.cc/files/kaiser.pdf

[patch based also on
https://raw.githubusercontent.com/IAIK/KAISER/master/KAISER/0001-KAISER-Kernel-Address-Isolation.patch]

Signed-off-by: Richard Fellner <richard.fellner@student.tugraz.at>
Signed-off-by: Moritz Lipp <moritz.lipp@iaik.tugraz.at>
Signed-off-by: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
Signed-off-by: Michael Schwarz <michael.schwarz@iaik.tugraz.at>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agox86/boot: Add early cmdline parsing for options with arguments
Tom Lendacky [Mon, 17 Jul 2017 21:10:33 +0000 (16:10 -0500)]
x86/boot: Add early cmdline parsing for options with arguments

commit e505371dd83963caae1a37ead9524e8d997341be upstream.

Add a cmdline_find_option() function to look for cmdline options that
take arguments. The argument is returned in a supplied buffer and the
argument length (regardless of whether it fits in the supplied buffer)
is returned, with -1 indicating not found.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/36b5f97492a9745dce27682305f990fc20e5cf8a.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoLinux 4.4.109
Greg Kroah-Hartman [Tue, 2 Jan 2018 19:33:28 +0000 (20:33 +0100)]
Linux 4.4.109

3 years agomm/vmstat: Make NR_TLB_REMOTE_FLUSH_RECEIVED available even on UP
Andy Lutomirski [Mon, 5 Jun 2017 14:40:25 +0000 (07:40 -0700)]
mm/vmstat: Make NR_TLB_REMOTE_FLUSH_RECEIVED available even on UP

commit 5dd0b16cdaff9b94da06074d5888b03235c0bf17 upstream.

This fixes CONFIG_SMP=n, CONFIG_DEBUG_TLBFLUSH=y without introducing
further #ifdef soup.  Caught by a Kbuild bot randconfig build.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: ce4a4e565f52 ("x86/mm: Remove the UP asm/tlbflush.h code, always use the (formerly) SMP code")
Link: http://lkml.kernel.org/r/76da9a3cc4415996f2ad2c905b93414add322021.1496673616.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agon_tty: fix EXTPROC vs ICANON interaction with TIOCINQ (aka FIONREAD)
Linus Torvalds [Thu, 21 Dec 2017 01:57:06 +0000 (17:57 -0800)]
n_tty: fix EXTPROC vs ICANON interaction with TIOCINQ (aka FIONREAD)

commit 966031f340185eddd05affcf72b740549f056348 upstream.

We added support for EXTPROC back in 2010 in commit 26df6d13406d ("tty:
Add EXTPROC support for LINEMODE") and the intent was to allow it to
override some (all?) ICANON behavior.  Quoting from that original commit
message:

         There is a new bit in the termios local flag word, EXTPROC.
         When this bit is set, several aspects of the terminal driver
         are disabled.  Input line editing, character echo, and mapping
         of signals are all disabled.  This allows the telnetd to turn
         off these functions when in linemode, but still keep track of
         what state the user wants the terminal to be in.

but the problem turns out that "several aspects of the terminal driver
are disabled" is a bit ambiguous, and you can really confuse the n_tty
layer by setting EXTPROC and then causing some of the ICANON invariants
to no longer be maintained.

This fixes at least one such case (TIOCINQ) becoming unhappy because of
the confusion over whether ICANON really means ICANON when EXTPROC is set.

This basically makes TIOCINQ match the case of read: if EXTPROC is set,
we ignore ICANON.  Also, make sure to reset the ICANON state ie EXTPROC
changes, not just if ICANON changes.

Fixes: 26df6d13406d ("tty: Add EXTPROC support for LINEMODE")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Reported-by: syzkaller <syzkaller@googlegroups.com>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agox86/smpboot: Remove stale TLB flush invocations
Thomas Gleixner [Sat, 30 Dec 2017 21:13:53 +0000 (22:13 +0100)]
x86/smpboot: Remove stale TLB flush invocations

commit 322f8b8b340c824aef891342b0f5795d15e11562 upstream.

smpboot_setup_warm_reset_vector() and smpboot_restore_warm_reset_vector()
invoke local_flush_tlb() for no obvious reason.

Digging in history revealed that the original code in the 2.1 era added
those because the code manipulated a swapper_pg_dir pagetable entry. The
pagetable manipulation was removed long ago in the 2.3 timeframe, but the
TLB flush invocations stayed around forever.

Remove them along with the pointless pr_debug()s which come from the same 2.1
change.

Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20171230211829.586548655@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agonohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick()
Thomas Gleixner [Fri, 22 Dec 2017 14:51:13 +0000 (15:51 +0100)]
nohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick()

commit 5d62c183f9e9df1deeea0906d099a94e8a43047a upstream.

The conditions in irq_exit() to invoke tick_nohz_irq_exit() which
subsequently invokes tick_nohz_stop_sched_tick() are:

  if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu))

If need_resched() is not set, but a timer softirq is pending then this is
an indication that the softirq code punted and delegated the execution to
softirqd. need_resched() is not true because the current interrupted task
takes precedence over softirqd.

Invoking tick_nohz_irq_exit() in this case can cause an endless loop of
timer interrupts because the timer wheel contains an expired timer, but
softirqs are not yet executed. So it returns an immediate expiry request,
which causes the timer to fire immediately again. Lather, rinse and
repeat....

Prevent that by adding a check for a pending timer soft interrupt to the
conditions in tick_nohz_stop_sched_tick() which avoid calling
get_next_timer_interrupt(). That keeps the tick sched timer on the tick and
prevents a repetitive programming of an already expired timer.

Reported-by: Sebastian Siewior <bigeasy@linutronix.d>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712272156050.2431@nanos
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agousb: xhci: Add XHCI_TRUST_TX_LENGTH for Renesas uPD720201
Daniel Thompson [Thu, 21 Dec 2017 13:06:15 +0000 (15:06 +0200)]
usb: xhci: Add XHCI_TRUST_TX_LENGTH for Renesas uPD720201

commit da99706689481717998d1d48edd389f339eea979 upstream.

When plugging in a USB webcam I see the following message:
xhci_hcd 0000:04:00.0: WARN Successful completion on short TX: needs
XHCI_TRUST_TX_LENGTH quirk?
handle_tx_event: 913 callbacks suppressed

All is quiet again with this patch (and I've done a fair but of soak
testing with the camera since).

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoUSB: Fix off by one in type-specific length check of BOS SSP capability
Mathias Nyman [Tue, 19 Dec 2017 09:14:42 +0000 (11:14 +0200)]
USB: Fix off by one in type-specific length check of BOS SSP capability

commit 07b9f12864d16c3a861aef4817eb1efccbc5d0e6 upstream.

USB 3.1 devices are not detected as 3.1 capable since 4.15-rc3 due to a
off by one in commit 81cf4a45360f ("USB: core: Add type-specific length
check of BOS descriptors")

It uses USB_DT_USB_SSP_CAP_SIZE() to get SSP capability size which takes
the zero based SSAC as argument, not the actual count of sublink speed
attributes.

USB3 spec 9.6.2.5 says "The number of Sublink Speed Attributes = SSAC + 1."

The type-specific length check patch was added to stable and needs to be
fixed there as well

Fixes: 81cf4a45360f ("USB: core: Add type-specific length check of BOS descriptors")
CC: Masakazu Mokuno <masakazu.mokuno@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agousb: add RESET_RESUME for ELSA MicroLink 56K
Oliver Neukum [Tue, 12 Dec 2017 15:11:30 +0000 (16:11 +0100)]
usb: add RESET_RESUME for ELSA MicroLink 56K

commit b9096d9f15c142574ebebe8fbb137012bb9d99c2 upstream.

This modem needs this quirk to operate. It produces timeouts when
resumed without reset.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agousb: Add device quirk for Logitech HD Pro Webcam C925e
Dmitry Fleytman Dmitry Fleytman [Tue, 19 Dec 2017 04:02:04 +0000 (06:02 +0200)]
usb: Add device quirk for Logitech HD Pro Webcam C925e

commit 7f038d256c723dd390d2fca942919573995f4cfd upstream.

Commit e0429362ab15
("usb: Add device quirk for Logitech HD Pro Webcams C920 and C930e")
introduced quirk to workaround an issue with some Logitech webcams.

There is one more model that has the same issue - C925e, so applying
the same quirk as well.

See aforementioned commit message for detailed explanation of the problem.

Signed-off-by: Dmitry Fleytman <dmitry.fleytman@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoUSB: serial: option: adding support for YUGA CLM920-NC5
SZ Lin (林上智) [Tue, 19 Dec 2017 09:40:32 +0000 (17:40 +0800)]
USB: serial: option: adding support for YUGA CLM920-NC5

commit 3920bb713038810f25770e7545b79f204685c8f2 upstream.

This patch adds support for YUGA CLM920-NC5 PID 0x9625 USB modem to option
driver.

Interface layout:
0: QCDM/DIAG
1: ADB
2: MODEM
3: AT
4: RMNET

Signed-off-by: Taiyi Wu <taiyity.wu@moxa.com>
Signed-off-by: SZ Lin (林上智) <sz.lin@moxa.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoUSB: serial: option: add support for Telit ME910 PID 0x1101
Daniele Palmas [Thu, 14 Dec 2017 15:54:45 +0000 (16:54 +0100)]
USB: serial: option: add support for Telit ME910 PID 0x1101

commit 08933099e6404f588f81c2050bfec7313e06eeaf upstream.

This patch adds support for PID 0x1101 of Telit ME910.

Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoUSB: serial: qcserial: add Sierra Wireless EM7565
Reinhard Speyerer [Thu, 14 Dec 2017 23:39:27 +0000 (00:39 +0100)]
USB: serial: qcserial: add Sierra Wireless EM7565

commit 92a18a657fb2e2ffbfa0659af32cc18fd2346516 upstream.

Sierra Wireless EM7565 devices use the QCSERIAL_SWI layout for their
serial ports

T:  Bus=01 Lev=03 Prnt=29 Port=01 Cnt=02 Dev#= 31 Spd=480  MxCh= 0
D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=1199 ProdID=9091 Rev= 0.06
S:  Manufacturer=Sierra Wireless, Incorporated
S:  Product=Sierra Wireless EM7565 Qualcomm Snapdragon X16 LTE-A
S:  SerialNumber=xxxxxxxx
C:* #Ifs= 4 Cfg#= 1 Atr=a0 MxPwr=500mA
I:* If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=qcserial
E:  Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=01(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=qcserial
E:  Ad=83(I) Atr=03(Int.) MxPS=  10 Ivl=32ms
E:  Ad=82(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=qcserial
E:  Ad=85(I) Atr=03(Int.) MxPS=  10 Ivl=32ms
E:  Ad=84(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=03(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 8 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=qmi_wwan
E:  Ad=86(I) Atr=03(Int.) MxPS=   8 Ivl=32ms
E:  Ad=8e(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=0f(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms

but need sendsetup = true for the NMEA port to make it work properly.

Simplify the patch compared to v1 as suggested by Bjørn Mork by taking
advantage of the fact that existing devices work with sendsetup = true
too.

Use sendsetup = true for the NMEA interface of QCSERIAL_SWI and add
DEVICE_SWI entries for the EM7565 PID 0x9091 and the EM7565 QDL PID
0x9090.

Tests with several MC73xx/MC74xx/MC77xx devices have been performed in
order to verify backward compatibility.

Signed-off-by: Reinhard Speyerer <rspmn@arcor.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agoUSB: serial: ftdi_sio: add id for Airbus DS P8GR
Max Schulze [Wed, 20 Dec 2017 19:47:44 +0000 (20:47 +0100)]
USB: serial: ftdi_sio: add id for Airbus DS P8GR

commit c6a36ad383559a60a249aa6016cebf3cb8b6c485 upstream.

Add AIRBUS_DS_P8GR device IDs to ftdi_sio driver.

Signed-off-by: Max Schulze <max.schulze@posteo.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agousbip: vhci: stop printing kernel pointer addresses in messages
Shuah Khan [Tue, 19 Dec 2017 00:24:22 +0000 (17:24 -0700)]
usbip: vhci: stop printing kernel pointer addresses in messages

commit 8272d099d05f7ab2776cf56a2ab9f9443be18907 upstream.

Remove and/or change debug, info. and error messages to not print
kernel pointer addresses.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agousbip: stub: stop printing kernel pointer addresses in messages
Shuah Khan [Tue, 19 Dec 2017 00:23:37 +0000 (17:23 -0700)]
usbip: stub: stop printing kernel pointer addresses in messages

commit 248a22044366f588d46754c54dfe29ffe4f8b4df upstream.

Remove and/or change debug, info. and error messages to not print
kernel pointer addresses.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agousbip: fix usbip bind writing random string after command in match_busid
Juan Zea [Fri, 15 Dec 2017 09:21:20 +0000 (10:21 +0100)]
usbip: fix usbip bind writing random string after command in match_busid

commit 544c4605acc5ae4afe7dd5914147947db182f2fb upstream.

usbip bind writes commands followed by random string when writing to
match_busid attribute in sysfs, caused by using full variable size
instead of string length.

Signed-off-by: Juan Zea <juan.zea@qindel.com>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agosock: free skb in skb_complete_tx_timestamp on error
Willem de Bruijn [Wed, 13 Dec 2017 19:41:06 +0000 (14:41 -0500)]
sock: free skb in skb_complete_tx_timestamp on error

[ Upstream commit 35b99dffc3f710cafceee6c8c6ac6a98eb2cb4bf ]

skb_complete_tx_timestamp must ingest the skb it is passed. Call
kfree_skb if the skb cannot be enqueued.

Fixes: b245be1f4db1 ("net-timestamp: no-payload only sysctl")
Fixes: 9ac25fc06375 ("net: fix socket refcounting in skb_complete_tx_timestamp()")
Reported-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 years agonet: phy: micrel: ksz9031: reconfigure autoneg after phy autoneg workaround
Grygorii Strashko [Thu, 21 Dec 2017 00:45:10 +0000 (18:45 -0600)]
net: phy: micrel: ksz9031: reconfigure autoneg after phy autoneg workaround

[ Upstream commit c1a8d0a3accf64a014d605e6806ce05d1c17adf1 ]

Under some circumstances driver will perform PHY reset in
ksz9031_read_status() to fix autoneg failure case (idle error count =
0xFF). When this happens ksz9031 will not detect link status change any
more when connecting to Netgear 1G switch (link can be recovered sometimes by
restarting netdevice "ifconfig down up"). Reproduced with TI am572x board
equipped with ksz9031 PHY while connecting to Netgear 1G switch.

Fix the issue by reconfiguring autonegotiation after PHY reset in
ksz9031_read_status().

Fixes: d2fd719bcb0e ("net/phy: micrel: Add workaround for bad autoneg")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>