Getting a compiler warning, Wstringop-overflow, in
arch/nds32/kernel/vdso.c when kernel is built by gcc-8. Declaring
vdso_start and vdso_end as a pointer to fix this compiler warning.
Signed-off-by: Vincent Chen <vincentc@andestech.com>
Reviewed-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>

In order to ensure that all data in source page has been written back
to memory before copy_page, the local irq shall be disabled before
calling cpu_dcache_wb_page(). In addition, removing unneeded page
invalidation for 'to' page.
Signed-off-by: Vincent Chen <vincentc@andestech.com>
Reviewed-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>

According to Documentation/cachetlb.txt, the cache of the page at vmaddr
shall be flushed in flush_anon_page instead of the cache of the page at
page_address(page).
Signed-off-by: Vincent Chen <vincentc@andestech.com>
Reviewed-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>

1. Disable local irq before d-cache write-back and invalidate.
   The cpu_dcache_wbinval_page function is composed of d-cache
write-back and invalidate. If the local irq is enabled when calling
cpu_dcache_wbinval_page, the content of d-cache is possibly updated
between write-back and invalidate. In this case, the updated data will
be dropped due to the following d-cache invalidation. Therefore, we
disable the local irq before calling cpu_dcache_wbinval_page.

2. Correct the data write-back for page aliasing case.
   Only the page whose (page->index << PAGE_SHIFT) is located at the
same page color as page_address(page) needs to execute data write-back
in flush_dcache_page function.
Signed-off-by: Vincent Chen <vincentc@andestech.com>
Reviewed-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>

If the kernel config 'CONFIG_ALIGNMENT_TRAP' and the file
'/proc/sys/nds32/unaligned_access/enable' are set, the kernel
unaligned access handler does not handle correctly when the
value of immediate field is negative. This commit fixes the
unaligned access handler in kernel.
Signed-off-by: Nickhu <nickhu@andestech.com>
Reviewed-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>

Change the name of the file '/proc/sys/nds32/unaligned_acess'
to '/proc/sys/nds32/unaligned_access'
Signed-off-by: Nickhu <nickhu@andestech.com>
Reviewed-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>

The nds32 architecture will use physical memory when interrupt or
exception comes and it will use the setting of NTC0-4. The original
implementation didn't consider the DRAM start address may start from 1GB,
2GB or 3GB to cause this issue. It will write the data to DRAM if it is
running in physical address however kernel will read the data with
virtaul address through data cache. In this case, the data of DRAM is
latest.

This fix will set the correct cacheability to let kernel write/read the
latest data in cache instead of DRAM.
Signed-off-by: Greentime Hu <greentime@andestech.com>

Refine readability of INT_MASK_INITAIAL_VAL with meaningful macro instead
of magic number.
Signed-off-by: Greentime Hu <greentime@andestech.com>

We use tlbop to map virtual address in the first beginning, however it
may map too much if DRAM size is not that big. We have to invalidate the
mapping when the page table is created.
Signed-off-by: Greentime Hu <greentime@andestech.com>

This way we can build kernel with CONFIG_CPU_LITTLE_ENDIAN=y. Build allmodconfig
and allnoconfig are available too. It also fixes the endian mismatch issue
because AFLAGS and LDFLAGS is not passed correctly.
Signed-off-by: Vincent Ren-Wei Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>

It broke the 'allmodconfig' build when CONFIG_TRACE_IRQFLAGS is enabled.
Signed-off-by: Nick Chun-Ming Hu <nickhu@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

It broke the 'allmodconfig' build.
We need to include <linux/types.h> to make sure the type is defined
before using it.
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

It broke the 'allmodconfig' build.
  LD      vmlinux
  SYSMAP  System.map
  Building modules, stage 2.
  MODPOST 5028 modules
ERROR: "flush_dcache_page" [net/sunrpc/xprtrdma/rpcrdma.ko] undefined!
ERROR: "empty_zero_page" [net/ceph/libceph.ko] undefined!
ERROR: "save_stack_trace" [kernel/backtracetest.ko] undefined!
ERROR: "clear_page" [fs/ocfs2/dlm/ocfs2_dlm.ko] undefined!
ERROR: "copy_page" [fs/nilfs2/nilfs2.ko] undefined!
...
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

It broke the 'allmodconfig' build.
fs/xfs/xfs_buf.c: In function 'xfs_buf_bio_end_io':
fs/xfs/xfs_buf.c:1242:3: error: implicit declaration of function 'invalidate_kernel_vmap_range' [-Werror=implicit-function-declaration]
   invalidate_kernel_vmap_range(bp->b_addr, xfs_buf_vmap_len(bp));
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/xfs/xfs_buf.c: In function 'xfs_buf_ioapply_map':
fs/xfs/xfs_buf.c:1312:4: error: implicit declaration of function 'flush_kernel_vmap_range' [-Werror=implicit-function-declaration]
    flush_kernel_vmap_range(bp->b_addr,
    ^~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

It broke the 'allmodconfig' build.
drivers/gpu/drm/udl/udl_fb.c: In function 'udl_fb_mmap':
drivers/gpu/drm/udl/udl_fb.c:183:52: error: 'PAGE_SHARED' undeclared (first use in this function)
   if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED))
                                                    ^~~~~~~~~~~
drivers/gpu/drm/udl/udl_fb.c:183:52: note: each undeclared identifier is reported only once for each function it appears in
make[4]: *** [drivers/gpu/drm/udl/udl_fb.o] Error 1
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

When I compiled with allmodconfig, it caused this building failed.
crypto/xor.c:25:21: fatal error: asm/xor.h: No such file or directory
 #include <asm/xor.h>
                     ^
compilation terminated.
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

To include kernel/Kconfig.freezer to make sure the dependency between
CONFIG_CGROUP_FREEZER and CONFIG_FREEZER

It will cause building error when I make allmodconfig.

kernel/cgroup/freezer.c: In function 'freezer_css_online':
kernel/cgroup/freezer.c:116:15: error: 'system_freezing_cnt' undeclared (first use in this function)
   atomic_inc(&system_freezing_cnt);
               ^~~~~~~~~~~~~~~~~~~
kernel/cgroup/freezer.c:116:15: note: each undeclared identifier is reported only once for each function it appears in
kernel/cgroup/freezer.c: In function 'freezer_css_offline':
kernel/cgroup/freezer.c:137:15: error: 'system_freezing_cnt' undeclared (first use in this function)
   atomic_dec(&system_freezing_cnt);
               ^~~~~~~~~~~~~~~~~~~
kernel/cgroup/freezer.c: In function 'freezer_attach':
kernel/cgroup/freezer.c:181:4: error: implicit declaration of function 'freeze_task' [-Werror=implicit-function-declaration]
    freeze_task(task);
    ^~~~~~~~~~~
kernel/cgroup/freezer.c: In function 'freezer_apply_state':
kernel/cgroup/freezer.c:360:16: error: 'system_freezing_cnt' undeclared (first use in this function)
    atomic_inc(&system_freezing_cnt);
                ^~~~~~~~~~~~~~~~~~~
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

We can use the generic lib to fix these error because the symbol of
libgcc in toolchain is not exported.

ERROR: "__ucmpdi2" [fs/xfs/xfs.ko] undefined!
ERROR: "__ashrdi3" [fs/xfs/xfs.ko] undefined!
ERROR: "__lshrdi3" [fs/xfs/xfs.ko] undefined!
ERROR: "__ashldi3" [fs/ntfs/ntfs.ko] undefined!
...
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

Pull parisc fixlets from Helge Deller:
 "Three small section mismatch fixes, one of them was found by 0-day
  test infrastructure"

* 'parisc-4.17-5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Move ccio_cujo20_fixup() into init section
  parisc: Move setup_profiling_timer() out of init section
  parisc: Move find_pa_parent_type() out of init section

Pull btrfs fixes from David Sterba:
 "We've accumulated some fixes during the last week, some of them were
  in the works for a longer time but there are some newer ones too.

  Most of the fixes have a reproducer and fix user visible problems,
  also candidates for stable kernels. They IMHO qualify for a late rc,
  though I did not expect that many"

* tag 'for-4.17-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix crash when trying to resume balance without the resume flag
  btrfs: Fix delalloc inodes invalidation during transaction abort
  btrfs: Split btrfs_del_delalloc_inode into 2 functions
  btrfs: fix reading stale metadata blocks after degraded raid1 mounts
  btrfs: property: Set incompat flag if lzo/zstd compression is set
  Btrfs: fix duplicate extents after fsync of file with prealloc extents
  Btrfs: fix xattr loss after power failure
  Btrfs: send, fix invalid access to commit roots due to concurrent snapshotting

Pull ARM fixes from Russell King:

 - Łukasz Stelmach spotted a couple of issues with the decompressor.

 - a couple of kdump fixes found while testing kdump

 - replace some perl with shell code

 - resolve SIGFPE breakage

 - kprobes fixes

* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: fix kill( ,SIGFPE) breakage
  ARM: 8772/1: kprobes: Prohibit kprobes on get_user functions
  ARM: 8771/1: kprobes: Prohibit kprobes on do_undefinstr
  ARM: 8770/1: kprobes: Prohibit probing on optimized_callback
  ARM: 8769/1: kprobes: Fix to use get_kprobe_ctlblk after irq-disabed
  ARM: replace unnecessary perl with sed and the shell $(( )) operator
  ARM: kexec: record parent context registers for non-crash CPUs
  ARM: kexec: fix kdump register saving on panic()
  ARM: 8758/1: decompressor: restore r1 and r2 just before jumping to the kernel
  ARM: 8753/1: decompressor: add a missing parameter to the addruart macro

Pull x86 fixes from Thomas Gleixner:
 "An unfortunately larger set of fixes, but a large portion is
  selftests:

   - Fix the missing clusterid initializaiton for x2apic cluster
     management which caused boot failures due to IPIs being sent to the
     wrong cluster

   - Drop TX_COMPAT when a 64bit executable is exec()'ed from a compat
     task

   - Wrap access to __supported_pte_mask in __startup_64() where clang
     compile fails due to a non PC relative access being generated.

   - Two fixes for 5 level paging fallout in the decompressor:

      - Handle GOT correctly for paging_prepare() and
        cleanup_trampoline()

      - Fix the page table handling in cleanup_trampoline() to avoid
        page table corruption.

   - Stop special casing protection key 0 as this is inconsistent with
     the manpage and also inconsistent with the allocation map handling.

   - Override the protection key wen moving away from PROT_EXEC to
     prevent inaccessible memory.

   - Fix and update the protection key selftests to address breakage and
     to cover the above issue

   - Add a MOV SS self test"

[ Part of the x86 fixes were in the earlier core pull due to dependencies ]

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  x86/mm: Drop TS_COMPAT on 64-bit exec() syscall
  x86/apic/x2apic: Initialize cluster ID properly
  x86/boot/compressed/64: Fix moving page table out of trampoline memory
  x86/boot/compressed/64: Set up GOT for paging_prepare() and cleanup_trampoline()
  x86/pkeys: Do not special case protection key 0
  x86/pkeys/selftests: Add a test for pkey 0
  x86/pkeys/selftests: Save off 'prot' for allocations
  x86/pkeys/selftests: Fix pointer math
  x86/pkeys: Override pkey when moving away from PROT_EXEC
  x86/pkeys/selftests: Fix pkey exhaustion test off-by-one
  x86/pkeys/selftests: Add PROT_EXEC test
  x86/pkeys/selftests: Factor out "instruction page"
  x86/pkeys/selftests: Allow faults on unknown keys
  x86/pkeys/selftests: Avoid printf-in-signal deadlocks
  x86/pkeys/selftests: Remove dead debugging code, fix dprint_in_signal
  x86/pkeys/selftests: Stop using assert()
  x86/pkeys/selftests: Give better unexpected fault error messages
  x86/selftests: Add mov_to_ss test
  x86/mpx/selftests: Adjust the self-test to fresh distros that export the MPX ABI
  x86/pkeys/selftests: Adjust the self-test to fresh distros that export the pkeys ABI
  ...

Pull UP timer fix from Thomas Gleixner:
 "Work around the for_each_cpu() oddity on UP kernels in the tick
  broadcast code which causes boot failures because the CPU0 bit is
  always reported as set independent of the cpumask content"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/broadcast: Use for_each_cpu() specially on UP kernels

Pull scheduler fixlets from Thomas Gleixner:
 "Three trivial fixlets for the scheduler:

   - move print_rt_rq() and print_dl_rq() declarations to the right
     place

   - make grub_reclaim() static

   - fix the bogus documentation reference in Kconfig"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix documentation file path
  sched/deadline: Make the grub_reclaim() function static
  sched/debug: Move the print_rt_rq() and print_dl_rq() declarations to kernel/sched/sched.h

Pull RAS fix from Thomas Gleixner:
 "Fix a regression in the new AMD SMCA code which issues an SMP function
  call from the early interrupt disabled region of CPU hotplug. To avoid
  that, use cached block addresses which can be used directly"

* 'ras-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/MCE/AMD: Cache SMCA MISC block addresses

Pull perf tooling fixes from Thomas Gleixner:

 - fix segfault when processing unknown threads in cs-etm

 - fix "perf test inet_pton" on s390 failing due to missing inline

 - display all available events on 'perf annotate --stdio'

 - add missing newline when parsing an empty BPF program

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf tools: Add missing newline when parsing empty BPF proggie
  perf cs-etm: Remove redundant space
  perf cs-etm: Support unknown_thread in cs_etm_auxtrace
  perf annotate: Display all available events on --stdio
  perf test: "probe libc's inet_pton" fails on s390 due to missing inline

Pull locking fixes from Thomas Gleixner:
 "Two fixes to address shortcomings of the rwsem/percpu-rwsem lock
  debugging code which emits false positive warnings when the rwsem is
  anonymously locked and unlocked"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/percpu-rwsem: Annotate rwsem ownership transfer by setting RWSEM_OWNER_UNKNOWN
  locking/rwsem: Add a new RWSEM_ANONYMOUSLY_OWNED flag

Pull EFI fixes from Thomas Gleixner:

 - Use explicitely sized type for the romimage pointer in the 32bit EFI
   protocol struct so a 64bit kernel does not expand it to 64bit. Ditto
   for the 64bit struct to avoid the reverse issue on 32bit kernels.

 - Handle randomized tex offset correctly in the ARM64 EFI stub to avoid
   unaligned data resulting in stack corruption and other hard to
   diagnose wreckage.

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/libstub/arm64: Handle randomized TEXT_OFFSET
  efi: Avoid potential crashes, fix the 'struct efi_pci_io_protocol_32' definition for mixed mode

Pull core fixes from Thomas Gleixner:

 - Unbreak the BPF compilation which got broken by the unconditional
   requirement of asm-goto, which is not supported by clang.

 - Prevent probing on exception masking instructions in uprobes and
   kprobes to avoid the issues of the delayed exceptions instead of
   having an ugly workaround.

 - Prevent a double free_page() in the error path of do_kexec_load()

 - A set of objtool updates addressing various issues mostly related to
   switch tables and the noreturn detection for recursive sibling calls

 - Header sync for tools.

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Detect RIP-relative switch table references, part 2
  objtool: Detect RIP-relative switch table references
  objtool: Support GCC 8 switch tables
  objtool: Support GCC 8's cold subfunctions
  objtool: Fix "noreturn" detection for recursive sibling calls
  objtool, kprobes/x86: Sync the latest <asm/insn.h> header with tools/objtool/arch/x86/include/asm/insn.h
  x86/cpufeature: Guard asm_volatile_goto usage for BPF compilation
  uprobes/x86: Prohibit probing on MOV SS instruction
  kprobes/x86: Prohibit probing on exception masking instructions
  x86/kexec: Avoid double free_page() upon do_kexec_load() failure

Pull ARM SoC fixes from Olof Johansson:
 "A handful of fixes. I've been queuing them up a bit too long so the
  list is longer than it otherwise would have been spread out across a
  few -rcs.

  In general, it's a scattering of fixes across several platforms,
  nothing truly serious enough to point out.

  There's a slightly larger batch of them for the Davinci platforms due
  to work to bring them back to life after some time, so there's a
  handful of regressions, some of them going back very far, others more
  recent.

  There's also a few patches fixing DT on Renesas platforms since they
  changed some bindings without remaining backwards compatible,
  splitting up describing LVDS as a proper bridge instead of having it
  as part of the display unit.

  We could push for them to be backwards compatible with old device
  trees, but it's likely to regress eventually if nobody's actually
  using said compatibility"

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (36 commits)
  ARM: davinci: board-dm646x-evm: set VPIF capture card name
  ARM: davinci: board-dm646x-evm: pass correct I2C adapter id for VPIF
  ARM: davinci: dm646x: fix timer interrupt generation
  ARM: keystone: fix platform_domain_notifier array overrun
  arm64: dts: exynos: Fix interrupt type for I2S1 device on Exynos5433
  ARM: dts: imx51-zii-rdu1: fix touchscreen bindings
  firmware: arm_scmi: Use after free in scmi_create_protocol_device()
  ARM: dts: cygnus: fix irq type for arm global timer
  Revert "ARM: dts: logicpd-som-lv: Fix pinmux controller references"
  tee: check shm references are consistent in offset/size
  tee: shm: fix use-after-free via temporarily dropped reference
  ARM: dts: imx7s: Pass the 'fsl,sec-era' property
  ARM: dts: tegra20: Revert "Fix ULPI regression on Tegra20"
  ARM: dts: correct missing "compatible" entry for ti81xx SoCs
  ARM: OMAP1: ams-delta: fix deferred_fiq handler
  arm64: tegra: Make BCM89610 PHY interrupt as active low
  ARM: davinci: fix GPIO lookup for I2C
  ARM: dts: logicpd-som-lv: Fix pinmux controller references
  ARM: dts: logicpd-som-lv: Fix Audio Mute
  ARM: dts: logicpd-som-lv: Fix WL127x Startup Issues
  ...

Merge tag 'tegra-for-4.17-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into fixes

arm64: tegra: Device tree fixes for v4.17

This contains a one-line update to the device tree of the Tegra186 P3310
processor module, fixing the polarity of the PHY interrupt. Originally,
this was queued to go into v4.18, but the PHY ID matching patch has now
found its way into v4.17-rc5, which means that the PHY driver will know
how to identify the PHY on this board and try to use the interrupt. This
will unfortunately cause networking to break on P3310, hence why I think
this should go into v4.17.

* tag 'tegra-for-4.17-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
  arm64: tegra: Make BCM89610 PHY interrupt as active low
Signed-off-by: Olof Johansson <olof@lixom.net>

Commit 7771c664 ("signal/arm: Document conflicts with SI_USER and
SIGFPE") broke the siginfo structure for userspace triggered signals,
causing the strace testsuite to regress.  Fix this by eliminating
the FPE_FIXME definition (which is at the root of the breakage) and
use FPE_FLTINV instead for the case where the hardware appears to be
reporting nonsense.

Fixes: 7771c664 ("signal/arm: Document conflicts with SI_USER and SIGFPE")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Pull dmaengine fix from Vinod Koul:

 - qcom bam runtime_pm fix

 - email update for Vinod

* tag 'dmaengine-fix-4.17-rc6' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: qcom: bam_dma: check if the runtime pm enabled
  dmaengine: Update email address for Vinod

Commit be83bbf8 ("mmap: introduce sane default mmap limits") was
introduced to catch problems in various ad-hoc character device drivers
doing mmap and getting the size limits wrong.  In the process, it used
"known good" limits for the normal cases of mapping regular files and
block device drivers.

It turns out that the "s_maxbytes" limit was less "known good" than I
thought.  In particular, /proc doesn't set it, but exposes one regular
file to mmap: /proc/vmcore.  As a result, that file got limited to the
default MAX_INT s_maxbytes value.

This went unnoticed for a while, because apparently the only thing that
needs it is the s390 kernel zfcpdump, but there might be other tools
that use this too.

Vasily suggested just changing s_maxbytes for all of /proc, which isn't
wrong, but makes me nervous at this stage.  So instead, just make the
new mmap limit always be MAX_LFS_FILESIZE for regular files, which won't
affect anything else.  It wasn't the regular file case I was worried
about.

I'd really prefer for maxsize to have been per-inode, but that is not
how things are today.

Fixes: be83bbf8 ("mmap: introduce sane default mmap limits")
Reported-by: Vasily Gorbik <gor@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

... into a global, two-dimensional array and service subsequent reads from
that cache to avoid rdmsr_on_cpu() calls during CPU hotplug (IPIs with IRQs
disabled).

In addition, this fixes a KASAN slab-out-of-bounds read due to wrong usage
of the bank->blocks pointer.

Fixes: 27bd5950 ("x86/mce/AMD: Get address from already initialized block")
Reported-by: Johannes Hirte <johannes.hirte@datenkhaos.de>
Tested-by: Johannes Hirte <johannes.hirte@datenkhaos.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Yazen Ghannam <yazen.ghannam@amd.com>
Link: http://lkml.kernel.org/r/20180414004230.GA2033@probook

Since do_undefinstr() uses get_user to get the undefined
instruction, it can be called before kprobes processes
recursive check. This can cause an infinit recursive
exception.
Prohibit probing on get_user functions.

Fixes: 24ba613c ("ARM kprobes: core code")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Prohibit kprobes on do_undefinstr because kprobes on
arm is implemented by undefined instruction. This means
if we probe do_undefinstr(), it can cause infinit
recursive exception.

Fixes: 24ba613c ("ARM kprobes: core code")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Prohibit probing on optimized_callback() because
it is called from kprobes itself. If we put a kprobes
on it, that will cause a recursive call loop.
Mark it NOKPROBE_SYMBOL.

Fixes: 0dc016db ("ARM: kprobes: enable OPTPROBES for ARM 32")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Since get_kprobe_ctlblk() uses smp_processor_id() to access
per-cpu variable, it hits smp_processor_id sanity check as below.

[    7.006928] BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
[    7.007859] caller is debug_smp_processor_id+0x20/0x24
[    7.008438] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.16.0-rc1-00192-g4eb17253e4b5 #1
[    7.008890] Hardware name: Generic DT based system
[    7.009917] [<c0313f0c>] (unwind_backtrace) from [<c030e6d8>] (show_stack+0x20/0x24)
[    7.010473] [<c030e6d8>] (show_stack) from [<c0c64694>] (dump_stack+0x84/0x98)
[    7.010990] [<c0c64694>] (dump_stack) from [<c071ca5c>] (check_preemption_disabled+0x138/0x13c)
[    7.011592] [<c071ca5c>] (check_preemption_disabled) from [<c071ca80>] (debug_smp_processor_id+0x20/0x24)
[    7.012214] [<c071ca80>] (debug_smp_processor_id) from [<c03335e0>] (optimized_callback+0x2c/0xe4)
[    7.013077] [<c03335e0>] (optimized_callback) from [<bf0021b0>] (0xbf0021b0)

To fix this issue, call get_kprobe_ctlblk() right after
irq-disabled since that disables preemption.

Fixes: 0dc016db ("ARM: kprobes: enable OPTPROBES for ARM 32")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>