system_call assembly code always pushes pointer to struct pt_regs as the
last additional parameter for all system calls. The only user of this
feature is xtensa_rt_sigreturn.
Avoid this special case. Define xtensa_rt_sigreturn as accepting no
argiments. Use current_pt_regs to get pointer to struct pt_regs in
xtensa_rt_sigreturn. Don't pass additional parameter from system_call
code.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Don't overwrite return value if system call was cancelled at entry by
ptrace. Return status code from do_syscall_trace_enter so that
pt_regs::syscall doesn't need to be changed to skip syscall.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

system_call saves and restores syscall number across system call to make
clone and execv entry and exit tracing match. This complicates things
when syscall code may be changed by ptrace.
Preserve syscall code in copy_thread and start_thread directly instead of
doing tricks in system_call.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

syscall return value is in the register a2, not a0.

Cc: stable@vger.kernel.org # v5.0+
Fixes: 9f24f3c1 ("xtensa: implement tracehook functions and enable HAVE_ARCH_TRACEHOOK")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

A bunch of irrelevant headers is included into coprocessor.S. Remove
them and add necessary asm/regs.h.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Since the enabling and disabling of IRQs within preempt_schedule_irq()
is contained in a need_resched() loop, we don't need the outer arch
code loop.
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Message-Id: <20190923143620.29334-10-valentin.schneider@arm.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

KASAN shadow map doesn't need to be accessible through the linear kernel
mapping, allocate its pages with MEMBLOCK_ALLOC_ANYWHERE so that high
memory can be used. This frees up to ~100MB of low memory on xtensa
configurations with KASAN and high memory.

Cc: stable@vger.kernel.org # v5.1+
Fixes: f240ec09 ("memblock: replace memblock_alloc_base(ANYWHERE) with memblock_phys_alloc")
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Virtual and translated addresses retrieved by the xtensa TLB sanity
checker must be consistent, i.e. correspond to the same state of the
checked TLB entry. KASAN shadow memory is mapped dynamically using
auto-refill TLB entries and thus may change TLB state between the
virtual and translated address retrieval, resulting in false TLB
insanity report.
Move read_xtlb_translation close to read_xtlb_virtual to make sure that
read values are consistent.

Cc: stable@vger.kernel.org
Fixes: a99e07ee ("xtensa: check TLB sanity on return to userspace")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa has 2-level page tables and already uses pgtable-nopmd for page
table folding.

Add walks of p4d level where appropriate and drop usage of
__ARCH_USE_5LEVEL_HACK.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Message-Id: <1572964400-16542-3-git-send-email-rppt@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> [fix up
               arch/xtensa/include/asm/fixmap.h and
               arch/xtensa/mm/tlb.c]

There was a definition of pmd_offset() in arch/xtensa/include/asm/pgtable.h
that shadowed the generic implementation defined in
include/asm-generic/pgtable-nopmd.h.

As the result, xtensa had shortcuts in page table traversal in several
places instead of doing level unfolding.

Remove local override for pmd_offset() and add page table unfolding where
necessary.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Message-Id: <1572964400-16542-2-git-send-email-rppt@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Introduce Kconfig symbol PRINT_STACK_DEPTH and use it to initialize
kstack_depth_to_print.
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Calculate printable stack size and use print_hex_dump instead of
opencoding it.
Drop extra newline output in show_trace as its output format does not
depend on CONFIG_KALLSYMS.
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Use "m" constraint instead of "r" for the address, as "m" allows
compiler to access adjacent locations using base + offset, while "r"
requires updating the base register every time.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Use "m" constraint instead of "r" for the address, as "m" allows
compiler to access adjacent locations using base + offset, while "r"
requires updating the base register every time.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Numeric assembly arguments are hard to understand and assembly code that
uses them is hard to modify. Use named arguments in __cmpxchg_u32 and
xchg_u32.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Use "m" constraint instead of "r" for the address, as "m" allows
compiler to access adjacent locations using base + offset, while "r"
requires updating the base register every time.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Numeric assembly arguments are hard to understand and assembly code that
uses them is hard to modify. Use named arguments in ATOMIC_OP,
ATOMIC_OP_RETURN and ATOMIC_FETCH_OP macros.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Use "m" constraint instead of "r" for the address, as "m" allows
compiler to access adjacent locations using base + offset, while "r"
requires updating the base register every time.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Numeric assembly arguments are hard to understand and assembly code that
uses them is hard to modify. Use named arguments in BIT_OP and
TEST_AND_BIT_OP macros.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Parameterize macros with function name, opcode and inversion pattern.
This reduces code duplication removing 2/3 of definitions.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Use "m" constraint instead of "r" for the address, as "m" allows
compiler to access adjacent locations using base + offset, while "r"
requires updating the base register every time.
Use %[mem] * 0 + v to replace offset part of %[mem] expansion with v.
It is impossible to change address alignment through the offset part on
xtensa, so just ignore offset in alignment checks.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Section .fixup contains pieces of code, merge it with the rest of the
.text section.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

XIP (eXecute In Place) kernel image is the image that can be run
directly from ROM, using RAM only for writable data.

XIP xtensa kernel differs from regular xtensa kernel in the following
ways:
- it has exception/IRQ vectors merged into text section. No vectors
  relocation takes place at kernel startup.
- .data/.bss location must be specified in the kernel configuration,
  its content is copied there in the _startup function.
- .init.text is merged with the rest of text and is executed from ROM.
- when MMU is used the virtual address where the kernel will be mapped
  must be specified in the kernel configuration. It may be in the KSEG
  or in the KIO, __pa macro is adjusted to be able to handle both.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Currently kernel memory layout settings are split between "Processor
type and features" and "Platform options" menus. Consolidate them under
"Platform options".
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Use correct symbol for the end of .rodata section when dumping virtual
memory layout. This fixes odd rodata size with XIP kernel.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

.data.init.refok has been removed from the kernel long ago, replaced
with __REFDATA. Fix start_info definition.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

MPU attribute mapping table is R/O, move it from .data to __REFCONST
(as the rest of the _startup code where initialize_cacheattr is used is
in the __REF section). This allows executing initialize_cacheattr before
the data section of the XIP kernel is relocated to its place.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

These address and size definitions define xtensa kernel memory layout,
move them from vectors.h to the kmem_layout.h
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Remove empty hw_irq.h and user.h from arch/xtensa/include/asm and use
generic versions instead.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa now supports tracehook, queued spinlocks and rwlocks. Update
corresponding Documentation/features entries.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

Merge tag 'kbuild-fixes-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull more Kbuild fixes from Masahiro Yamada:

 - fix a bashism of setlocalversion

 - do not use the too new --sort option of tar

* tag 'kbuild-fixes-v5.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kheaders: substituting --sort in archive creation
  scripts: setlocalversion: fix a bashism
  kbuild: update comment about KBUILD_ALLDIRS

Pull x86 fixes from Thomas Gleixner:
 "A small set of x86 fixes:

   - Prevent a NULL pointer dereference in the X2APIC code in case of a
     CPU hotplug failure.

   - Prevent boot failures on HP superdome machines by invalidating the
     level2 kernel pagetable entries outside of the kernel area as
     invalid so BIOS reserved space won't be touched unintentionally.

     Also ensure that memory holes are rounded up to the next PMD
     boundary correctly.

   - Enable X2APIC support on Hyper-V to prevent boot failures.

   - Set the paravirt name when running on Hyper-V for consistency

   - Move a function under the appropriate ifdef guard to prevent build
     warnings"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot/acpi: Move get_cmdline_acpi_rsdp() under #ifdef guard
  x86/hyperv: Set pv_info.name to "Hyper-V"
  x86/apic/x2apic: Fix a NULL pointer deref when handling a dying cpu
  x86/hyperv: Make vapic support x2apic mode
  x86/boot/64: Round memory hole size up to next PMD page
  x86/boot/64: Make level2_kernel_pgt pages invalid outside kernel area

Pull irq fixes from Thomas Gleixner:
 "A small set of irq chip driver fixes and updates:

   - Update the SIFIVE PLIC interrupt driver to use the fasteoi handler
     to address the shortcomings of the existing flow handling which was
     prone to lose interrupts

   - Use the proper limit for GIC interrupt line numbers

   - Add retrigger support for the recently merged Anapurna Labs Fabric
     interrupt controller to make it complete

   - Enable the ATMEL AIC5 interrupt controller driver on the new
     SAM9X60 SoC"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/sifive-plic: Switch to fasteoi flow
  irqchip/gic-v3: Fix GIC_LINE_NR accessor
  irqchip/atmel-aic5: Add support for sam9x60 irqchip
  irqchip/al-fic: Add support for irq retrigger

Pull hrtimer fixlet from Thomas Gleixner:
 "A single commit annotating the lockcless access to timer->base with
  READ_ONCE() and adding the WRITE_ONCE() counterparts for completeness"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimer: Annotate lockless access to timer->base

Pull stop-machine fix from Thomas Gleixner:
 "A single fix, amending stop machine with WRITE/READ_ONCE() to address
  the fallout of KCSAN"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  stop_machine: Avoid potential race behaviour

Pull networking fixes from David Miller:
 "I was battling a cold after some recent trips, so quite a bit piled up
  meanwhile, sorry about that.

  Highlights:

   1) Fix fd leak in various bpf selftests, from Brian Vazquez.

   2) Fix crash in xsk when device doesn't support some methods, from
      Magnus Karlsson.

   3) Fix various leaks and use-after-free in rxrpc, from David Howells.

   4) Fix several SKB leaks due to confusion of who owns an SKB and who
      should release it in the llc code. From Eric Biggers.

   5) Kill a bunc of KCSAN warnings in TCP, from Eric Dumazet.

   6) Jumbo packets don't work after resume on r8169, as the BIOS resets
      the chip into non-jumbo mode during suspend. From Heiner Kallweit.

   7) Corrupt L2 header during MPLS push, from Davide Caratti.

   8) Prevent possible infinite loop in tc_ctl_action, from Eric
      Dumazet.

   9) Get register bits right in bcmgenet driver, based upon chip
      version. From Florian Fainelli.

  10) Fix mutex problems in microchip DSA driver, from Marek Vasut.

  11) Cure race between route lookup and invalidation in ipv4, from Wei
      Wang.

  12) Fix performance regression due to false sharing in 'net'
      structure, from Eric Dumazet"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (145 commits)
  net: reorder 'struct net' fields to avoid false sharing
  net: dsa: fix switch tree list
  net: ethernet: dwmac-sun8i: show message only when switching to promisc
  net: aquantia: add an error handling in aq_nic_set_multicast_list
  net: netem: correct the parent's backlog when corrupted packet was dropped
  net: netem: fix error path for corrupted GSO frames
  macb: propagate errors when getting optional clocks
  xen/netback: fix error path of xenvif_connect_data()
  net: hns3: fix mis-counting IRQ vector numbers issue
  net: usb: lan78xx: Connect PHY before registering MAC
  vsock/virtio: discard packets if credit is not respected
  vsock/virtio: send a credit update when buffer size is changed
  mlxsw: spectrum_trap: Push Ethernet header before reporting trap
  net: ensure correct skb->tstamp in various fragmenters
  net: bcmgenet: reset 40nm EPHY on energy detect
  net: bcmgenet: soft reset 40nm EPHYs before MAC init
  net: phy: bcm7xxx: define soft_reset for 40nm EPHY
  net: bcmgenet: don't set phydev->link from MAC
  net: Update address for MediaTek ethernet driver in MAINTAINERS
  ipv4: fix race condition between route lookup and invalidation
  ...

Intel test robot reported a ~7% regression on TCP_CRR tests
that they bisected to the cited commit.

Indeed, every time a new TCP socket is created or deleted,
the atomic counter net->count is touched (via get_net(net)
and put_net(net) calls)

So cpus might have to reload a contended cache line in
net_hash_mix(net) calls.

We need to reorder 'struct net' fields to move @hash_mix
in a read mostly cache line.

We move in the first cache line fields that can be
dirtied often.

We probably will have to address in a followup patch
the __randomize_layout that was added in linux-4.13,
since this might break our placement choices.

Fixes: 355b9855 ("netns: provide pure entropy for net_hash_mix()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If there are multiple switch trees on the device, only the last one
will be listed, because the arguments of list_add_tail are swapped.

Fixes: 83c0afae ("net: dsa: Add new binding implementation")
Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Printing the info message every time more than the max number of mac
addresses are requested generates unnecessary log spam.  Showing it only
when the hw is not already in promiscous mode is equally informative
without being annoying.
Signed-off-by: Mans Rullgard <mans@mansr.com>
Signed-off-by: David S. Miller <davem@davemloft.net>