If a change in the MMU notifier sequence number forces user_mem_abort()
to return early when attempting to handle a stage-2 fault, we return
uninitialised stack to kvm_handle_guest_abort(), which could potentially
result in the injection of an external abort into the guest or a spurious
return to userspace. Neither or these are what we want to do.
Initialise 'ret' to 0 in user_mem_abort() so that bailing due to a
change in the MMU notrifier sequence number is treated as though the
fault was handled.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20200930102442.16142-1-will@kernel.org
This patch removes a few ineffectual assignments from the function
crypto_poly1305_setdctxkey.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Daniel Borkmann says:
====================
pull-request: bpf-next 2020-10-01
The following pull-request contains BPF updates for your *net-next* tree.
We've added 90 non-merge commits during the last 8 day(s) which contain
a total of 103 files changed, 7662 insertions(+), 1894 deletions(-).
Note that once bpf(/net) tree gets merged into net-next, there will be a small
merge conflict in tools/lib/bpf/btf.c between commit 1245008122 ("libbpf: Fix
native endian assumption when parsing BTF") from the bpf tree and the commit
3289959b97 ("libbpf: Support BTF loading and raw data output in both endianness")
from the bpf-next tree. Correct resolution would be to stick with bpf-next, it
should look like:
[...]
/* check BTF magic */
if (fread(&magic, 1, sizeof(magic), f) < sizeof(magic)) {
err = -EIO;
goto err_out;
}
if (magic != BTF_MAGIC && magic != bswap_16(BTF_MAGIC)) {
/* definitely not a raw BTF */
err = -EPROTO;
goto err_out;
}
/* get file size */
[...]
The main changes are:
1) Add bpf_snprintf_btf() and bpf_seq_printf_btf() helpers to support displaying
BTF-based kernel data structures out of BPF programs, from Alan Maguire.
2) Speed up RCU tasks trace grace periods by a factor of 50 & fix a few race
conditions exposed by it. It was discussed to take these via BPF and
networking tree to get better testing exposure, from Paul E. McKenney.
3) Support multi-attach for freplace programs, needed for incremental attachment
of multiple XDP progs using libxdp dispatcher model, from Toke Høiland-Jørgensen.
4) libbpf support for appending new BTF types at the end of BTF object, allowing
intrusive changes of prog's BTF (useful for future linking), from Andrii Nakryiko.
5) Several BPF helper improvements e.g. avoid atomic op in cookie generator and add
a redirect helper into neighboring subsys, from Daniel Borkmann.
6) Allow map updates on sockmaps from bpf_iter context in order to migrate sockmaps
from one to another, from Lorenz Bauer.
7) Fix 32 bit to 64 bit assignment from latest alu32 bounds tracking which caused
a verifier issue due to type downgrade to scalar, from John Fastabend.
8) Follow-up on tail-call support in BPF subprogs which optimizes x64 JIT prologue
and epilogue sections, from Maciej Fijalkowski.
9) Add an option to perf RB map to improve sharing of event entries by avoiding remove-
on-close behavior. Also, add BPF_PROG_TEST_RUN for raw_tracepoint, from Song Liu.
10) Fix a crash in AF_XDP's socket_release when memory allocation for UMEMs fails,
from Magnus Karlsson.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull arm64 fix from Catalin Marinas:
"A previous commit to prevent AML memory opregions from accessing the
kernel memory turned out to be too restrictive. Relax the permission
check to permit the ACPI core to map kernel memory used for table
overrides"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: permit ACPI core to map kernel memory used for table overrides
TCR_EL1.HD is permitted to be cached in a TLB, so invalidate the local
TLB after setting the bit when detected support for the feature. Although
this isn't strictly necessary, since we can happily operate with the bit
effectively clear, the current code uses an ISB in a half-hearted attempt
to make the change effective, so let's just fix that up.
Link: https://lore.kernel.org/r/20201001110405.18617-1-will@kernel.org
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Commit a0e50aa3f4 ("KVM: arm64: Factor out stage 2 page table
data from struct kvm") dropped the ISB after __load_guest_stage2(),
only leaving the one that is required when the speculative AT
workaround is in effect.
As Andrew points it: "This alternative is 'backwards' to avoid a
double ISB as there is one in __load_guest_stage2 when the workaround
is active."
Restore the missing ISB, conditionned on the AT workaround not being
active.
Fixes: a0e50aa3f4 ("KVM: arm64: Factor out stage 2 page table data from struct kvm")
Reported-by: Andrew Scull <ascull@google.com>
Reported-by: Thomas Tai <thomas.tai@oracle.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Our use of broadcast TLB maintenance means that spurious page-faults
that have been handled already by another CPU do not require additional
TLB maintenance.
Make flush_tlb_fix_spurious_fault() a no-op and rely on the existing TLB
invalidation instead. Add an explicit flush_tlb_page() when making a page
dirty, as the TLB is permitted to cache the old read-only entry.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200728092220.GA21800@willie-the-truck
Signed-off-by: Will Deacon <will@kernel.org>
The CRn accessor functions use __force_order as a dummy operand to
prevent the compiler from reordering CRn reads/writes with respect to
each other.
The fact that the asm is volatile should be enough to prevent this:
volatile asm statements should be executed in program order. However GCC
4.9.x and 5.x have a bug that might result in reordering. This was fixed
in 8.1, 7.3 and 6.5. Versions prior to these, including 5.x and 4.9.x,
may reorder volatile asm statements with respect to each other.
There are some issues with __force_order as implemented:
- It is used only as an input operand for the write functions, and hence
doesn't do anything additional to prevent reordering writes.
- It allows memory accesses to be cached/reordered across write
functions, but CRn writes affect the semantics of memory accesses, so
this could be dangerous.
- __force_order is not actually defined in the kernel proper, but the
LLVM toolchain can in some cases require a definition: LLVM (as well
as GCC 4.9) requires it for PIE code, which is why the compressed
kernel has a definition, but also the clang integrated assembler may
consider the address of __force_order to be significant, resulting in
a reference that requires a definition.
Fix this by:
- Using a memory clobber for the write functions to additionally prevent
caching/reordering memory accesses across CRn writes.
- Using a dummy input operand with an arbitrary constant address for the
read functions, instead of a global variable. This will prevent reads
from being reordered across writes, while allowing memory loads to be
cached/reordered across CRn reads, which should be safe.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82602
Link: https://lore.kernel.org/lkml/20200527135329.1172644-1-arnd@arndb.de/
Link: https://lkml.kernel.org/r/20200902232152.3709896-1-nivedita@alum.mit.edu
Jonathan reports that the strict policy for memory mapped by the
ACPI core breaks the use case of passing ACPI table overrides via
initramfs. This is due to the fact that the memory type used for
loading the initramfs in memory is not recognized as a memory type
that is typically used by firmware to pass firmware tables.
Since the purpose of the strict policy is to ensure that no AML or
other ACPI code can manipulate any memory that is used by the kernel
to keep its internal state or the state of user tasks, we can relax
the permission check, and allow mappings of memory that is reserved
and marked as NOMAP via memblock, and therefore not covered by the
linear mapping to begin with.
Fixes: 1583052d11 ("arm64/acpi: disallow AML memory opregions to access kernel memory")
Fixes: 325f5585ec ("arm64/acpi: disallow writeable AML opregion mapping for EFI code regions")
Reported-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Link: https://lore.kernel.org/r/20200929132522.18067-1-ardb@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arch/mips/kernel/process.c:696:15: error: no previous prototype for 'arch_align_stack' [-Werror=missing-prototypes]
Signed-off-by: Pujin Shi <shipujin.t@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
This commit adds a prototype to fix warning at W=1:
arch/mips/kernel/process.c:95:5: error: no previous prototype for 'arch_dup_task_struct' [-Werror=missing-prototypes]
Signed-off-by: Pujin Shi <shipujin.t@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
The NoMMU kernel is broken for QEMU virt machine from Linux-5.9-rc6
because clint_time_val is used even before CLINT driver is probed
at following places:
1. rand_initialize() calls get_cycles() which in-turn uses
clint_time_val
2. boot_init_stack_canary() calls get_cycles() which in-turn
uses clint_time_val
The issue#1 (above) is fixed by providing custom random_get_entropy()
for RISC-V NoMMU kernel. For issue#2 (above), we remove dependency of
boot_init_stack_canary() on get_cycles() and this is aligned with the
boot_init_stack_canary() implementations of ARM, ARM64 and MIPS kernel.
Fixes: d5be89a8d1 ("RISC-V: Resurrect the MMIO timer implementation for M-mode systems")
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Tested-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
The commit eb1f00237a ("lockdep,trace: Expose tracepoints"), started to
expose us for tracepoints. For imx6q cpuidle, this leads to an RCU splat
according to below.
[6.870684] [<c0db7690>] (_raw_spin_lock) from [<c011f6a4>] (imx6q_enter_wait+0x18/0x9c)
[6.878846] [<c011f6a4>] (imx6q_enter_wait) from [<c09abfb0>] (cpuidle_enter_state+0x168/0x5e4)
To fix the problem, let's assign the corresponding idlestate->flags the
CPUIDLE_FLAG_RCU_IDLE bit, which enables us to call rcu_idle_enter|exit()
at the proper point.
Reported-by: Dong Aisheng <aisheng.dong@nxp.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The board uses lane 3 of SERDES for USB. Set the mux
accordingly.
The USB controller and EVM supports super-speed for USB0
on the Type-C port. However, the SERDES has a limitation
that upto 2 protocols can be used at a time. The SERDES is
wired for PCIe, QSGMII and USB super-speed. It has been
chosen to use PCI2 and QSGMII as default. So restrict
USB0 to high-speed mode.
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20200930122032.23481-7-rogerq@ti.com
First two lanes of SERDES is connected to PCIe, third lane is
connected to QSGMII and the last lane is connected to USB. However,
Cadence torrent SERDES doesn't support more than 2 protocols
at the same time. Configure it only for PCIe and QSGMII.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20200930122032.23481-6-rogerq@ti.com
arch/s390/pci/pci_bus.h: zpci_bus_init - only declaration left after
commit 05bc1be6db ("s390/pci: create zPCI bus")
arch/s390/include/asm/gmap.h: gmap_pte_notify - only declaration left
after commit 4be130a084 ("s390/mm: add shadow gmap support")
arch/s390/include/asm/pgalloc.h: rcu_table_freelist_finish - only
declaration left after commit 36409f6353 ("[S390] use generic RCU
page-table freeing code")
arch/s390/include/asm/tlbflush.h: smp_ptlb_all - only declaration left
after commit 5a79859ae0 ("s390: remove 31 bit support")
arch/s390/include/asm/vtimer.h: init_cpu_vtimer - only declaration left
after commit b5f87f15e2 ("s390/idle: consolidate idle functions and
definitions")
arch/s390/include/asm/pci.h: zpci_debug_info - only declaration left
after commit 386aa051fb ("s390/pci: remove per device debug attribute")
arch/s390/include/asm/vdso.h: vdso_alloc_boot_cpu - only declaration
left after commit 4bff8cb545 ("s390: convert to GENERIC_VDSO")
arch/s390/include/asm/smp.h: smp_vcpu_scheduled - only declaration left
after commit 67626fadd2 ("s390: enforce CONFIG_SMP")
arch/s390/kernel/entry.h: restart_call_handler - only declaration left
after commit 8b646bd759 ("[S390] rework smp code")
arch/s390/kernel/entry.h: startup_init_nobss - only declaration left
after commit 2e83e0eb85 ("s390: clean .bss before running uncompressed
kernel")
arch/s390/kernel/entry.h: s390_early_resume - only declaration left after
commit 394216275c ("s390: remove broken hibernate / power management
support")
drivers/s390/char/raw3270.h: raw3270_request_alloc_bootmem - only
declaration left after commit 33403dcfcd ("[S390] 3270 console:
convert from bootmem to slab")
drivers/s390/cio/device.h: ccw_device_schedule_sch_unregister - only
declaration left after commit 37de53bb52 ("[S390] cio: introduce ccw
device todos")
drivers/s390/char/tape.h: tape_hotplug_event - has only declaration
since recorded git history.
drivers/s390/char/tape.h: tape_oper_handler - has only declaration since
recorded git history.
drivers/s390/char/tape.h: tape_noper_handler - has only declaration
since recorded git history.
drivers/s390/char/tape_std.h: tape_std_check_locate - only declaration
left after commit 161beff8f4 ("s390/tape: remove tape block leftovers")
drivers/s390/char/tape_std.h: tape_std_default_handler - has only
declaration since recorded git history.
drivers/s390/char/tape_std.h: tape_std_unexpect_uchk_handler - has only
declaration since recorded git history.
drivers/s390/char/tape_std.h: tape_std_irq - has only declaration since
recorded git history.
drivers/s390/char/tape_std.h: tape_std_error_recovery - has only
declaration since recorded git history.
drivers/s390/char/tape_std.h: tape_std_error_recovery_has_failed -
has only declaration since recorded git history.
drivers/s390/char/tape_std.h: tape_std_error_recovery_succeded - has
only declaration since recorded git history.
drivers/s390/char/tape_std.h: tape_std_error_recovery_do_retry - has
only declaration since recorded git history.
drivers/s390/char/tape_std.h: tape_std_error_recovery_read_opposite -
has only declaration since recorded git history.
drivers/s390/char/tape_std.h: tape_std_error_recovery_HWBUG - has only
declaration since recorded git history.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
startup pgm check handler is active since the very beginning of kernel
code execution until uncompressed kernel sets up s390_base_pgm_handler.
It is useful not just for the decompressor debugging itself, but also for
early code of uncompressed kernel, in particular Kasan initialization. But
since there is no stack trace or symbolic representation of failing psw
address it is impossible to figure out faulty code location without
knowing Kaslr kernel base. So, let's add it to the startup pgm check
info printed as well.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Currently if just "dfltcc" is passed as a kernel command line option
"val" going to be NULL, this leads to reading at address 0 in
strcmp(val, "off")
Fix that by making sure "val" is not NULL. This does not affect option
handling logic.
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Remove couple of declarations which are unused since commit 4bff8cb545
("s390: convert to GENERIC_VDSO").
Acked-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
remove the cad command line option as the instruction was never
published and never used by userspace.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Alexei Starovoitov says:
====================
pull-request: bpf 2020-09-29
The following pull-request contains BPF updates for your *net* tree.
We've added 7 non-merge commits during the last 14 day(s) which contain
a total of 7 files changed, 28 insertions(+), 8 deletions(-).
The main changes are:
1) fix xdp loading regression in libbpf for old kernels, from Andrii.
2) Do not discard packet when NETDEV_TX_BUSY, from Magnus.
3) Fix corner cases in libbpf related to endianness and kconfig, from Tony.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add hyp percpu section to linker script and rename the corresponding ELF
sections of hyp/nvhe object files. This moves all nVHE-specific percpu
variables to the new hyp percpu section.
Allocate sufficient amount of memory for all percpu hyp regions at global KVM
init time and create corresponding hyp mappings.
The base addresses of hyp percpu regions are kept in a dynamically allocated
array in the kernel.
Add NULL checks in PMU event-reset code as it may run before KVM memory is
initialized.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-10-dbrazdil@google.com
Hyp keeps track of which cores require SSBD callback by accessing a
kernel-proper global variable. Create an nVHE symbol of the same name
and copy the value from kernel proper to nVHE as KVM is being enabled
on a core.
Done in preparation for separating percpu memory owned by kernel
proper and nVHE.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-8-dbrazdil@google.com
The hyp_adr/ldr_this_cpu helpers were introduced for use in hyp code
because they always needed to use TPIDR_EL2 for base, while
adr/ldr_this_cpu from kernel proper would select between TPIDR_EL2 and
_EL1 based on VHE/nVHE.
Simplify this now that the hyp mode case can be handled using the
__KVM_VHE/NVHE_HYPERVISOR__ macros.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Andrew Scull <ascull@google.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-6-dbrazdil@google.com
this_cpu_ptr is meant for use in kernel proper because it selects between
TPIDR_EL1/2 based on nVHE/VHE. __hyp_this_cpu_ptr was used in hyp to always
select TPIDR_EL2. Unify all users behind this_cpu_ptr and friends by
selecting _EL2 register under __KVM_NVHE_HYPERVISOR__. VHE continues
selecting the register using alternatives.
Under CONFIG_DEBUG_PREEMPT, the kernel helpers perform a preemption check
which is omitted by the hyp helpers. Preserve the behavior for nVHE by
overriding the corresponding macros under __KVM_NVHE_HYPERVISOR__. Extend
the checks into VHE hyp code.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Andrew Scull <ascull@google.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-5-dbrazdil@google.com
Relying on objcopy to prefix the ELF section names of the nVHE hyp code
is brittle and prevents us from using wildcards to match specific
section names.
Improve the build rules by partially linking all '.nvhe.o' files and
prefixing their ELF section names using a linker script. Continue using
objcopy for prefixing ELF symbol names.
One immediate advantage of this approach is that all subsections
matching a pattern can be merged into a single prefixed section, eg.
.text and .text.* can be linked into a single '.hyp.text'. This removes
the need for -fno-reorder-functions on GCC and will be useful in the
future too: LTO builds use .text subsections, compilers routinely
generate .rodata subsections, etc.
Partially linking all hyp code into a single object file also makes it
easier to analyze.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200922204910.7265-2-dbrazdil@google.com
The DT binding for Hisilicon system controllers require to have a
"syscon" compatible string.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>
Way back in v3.19 Intel and AMD shared the same machine check severity
grading code. So it made sense to add a case for AMD DEFERRED errors in
commit
e3480271f5 ("x86, mce, severity: Extend the the mce_severity mechanism to handle UCNA/DEFERRED error")
But later in v4.2 AMD switched to a separate grading function in
commit
bf80bbd7dc ("x86/mce: Add an AMD severities-grading function")
Belatedly drop the DEFERRED case from the Intel rule list.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200930021313.31810-3-tony.luck@intel.com
The patrol scrubber in Skylake and Cascade Lake systems can be configured
to report uncorrected errors using a special signature in the machine
check bank and to signal using CMCI instead of machine check.
Update the severity calculation mechanism to allow specifying the model,
minimum stepping and range of machine check bank numbers.
Add a new rule to detect the special signature (on model 0x55, stepping
>=4 in any of the memory controller banks).
[ bp: Rewrite it.
aegl: Productize it. ]
Suggested-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200930021313.31810-2-tony.luck@intel.com
As a preparation step for the offloading to ES0, let's create the
infrastructure for talking with this hardware block.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>