Merge branch 'bpf-direct-pkt-access'

Alexei Starovoitov says:

====================
bpf: introduce direct packet access

This set of patches introduce 'direct packet access' from
cls_bpf and act_bpf

Merge branch 'bpf-direct-pkt-access'

Alexei Starovoitov says:

====================
bpf: introduce direct packet access

This set of patches introduce 'direct packet access' from
cls_bpf and act_bpf programs (which are root only).

Current bpf programs use LD_ABS, LD_INS instructions which have
to do 'if (off < skb_headlen)' for every packet access.
It's ok for socket filters, but too slow for XDP, since single
LD_ABS insn consumes 3% of cpu. Therefore we have to amortize the cost
of length check over multiple packet accesses via direct access
to skb->data, data_end pointers.

The existing packet parser typically look like:
if (load_half(skb, offsetof(struct ethhdr, h_proto)) != ETH_P_IP)
return 0;
if (load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol)) != IPPROTO_UDP ||
load_byte(skb, ETH_HLEN) != 0x45)
return 0;
...
with 'direct packet access' the bpf program becomes:
void *data = (void *)(long)skb->data;
void *data_end = (void *)(long)skb->data_end;
struct eth_hdr *eth = data;
struct iphdr *iph = data + sizeof(*eth);

if (data + sizeof(*eth) + sizeof(*iph) + sizeof(*udp) > data_end)
return 0;
if (eth->h_proto != htons(ETH_P_IP))
return 0;
if (iph->protocol != IPPROTO_UDP || iph->ihl != 5)
return 0;
...
which is more natural to write and significantly faster.
See patch 6 for performance tests:
21Mpps(old) vs 24Mpps(new) with just 5 loads.
For more complex parsers the performance gain is higher.

The other approach implemented in [1] was adding two new instructions
to interpreter and JITs and was too hard to use from llvm side.
The approach presented here doesn't need any instruction changes,
but the verifier has to work harder to check safety of the packet access.

Patch 1 prepares the code and Patch 2 adds new checks for direct
packet access and all of them are gated with 'env->allow_ptr_leaks'
which is true for root only.
Patch 3 improves search pruning for large programs.
Patch 4 wires in verifier's changes with net/core/filter side.
Patch 5 updates docs
Patches 6 and 7 add tests.

[1] https://git.kernel.org/cgit/linux/kernel/git/ast/bpf.git/?h=ld_abs_dw
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

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samples/bpf: add 'pointer to packet' tests

parse_simple.c - packet parser exapmle with single length check that
filters out udp packets for port 9

parse_varlen.c - variable length parser that under

samples/bpf: add 'pointer to packet' tests

parse_simple.c - packet parser exapmle with single length check that
filters out udp packets for port 9

parse_varlen.c - variable length parser that understand multiple vlan headers,
ipip, ipip6 and ip options to filter out udp or tcp packets on port 9.
The packet is parsed layer by layer with multitple length checks.

parse_ldabs.c - classic style of packet parsing using LD_ABS instruction.
Same functionality as parse_simple.

simple = 24.1Mpps per core
varlen = 22.7Mpps
ldabs = 21.4Mpps

Parser with LD_ABS instructions is slower than full direct access parser
which does more packet accesses and checks.

These examples demonstrate the choice bpf program authors can make between
flexibility of the parser vs speed.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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Merge tag 'v4.6-rc6' into locking/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'v4.6-rc6' into x86/cpu, to refresh the tree

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'v4.6-rc5' into spi-rockchip

Linux 4.6-rc5

Merge tag 'v4.6-rc6' into x86/platform, to refresh the tree

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge branch 'for-4.7/pwm-regulator' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm into regulator-pwm

Merge tag 'v4.6-rc6' into ras/core, to refresh the tree

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'asoc-fix-v4.6-rc5' into asoc-intel

ASoC: Fixes for v4.6

This is a fairly large collection of fixes but almost all driver
specific ones, especially to the new Intel drivers which have had

Merge tag 'asoc-fix-v4.6-rc5' into asoc-intel

ASoC: Fixes for v4.6

This is a fairly large collection of fixes but almost all driver
specific ones, especially to the new Intel drivers which have had a lot
of recent development. The one core fix is a change to the debugfs code
to avoid crashes in some relatively unusual configurations.

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Merge tag 'v4.6-rc6' into patchwork

Linux 4.6-rc6

* tag 'v4.6-rc6': (762 commits)
Linux 4.6-rc6
EDAC: i7core, sb_edac: Don't return NOTIFY_BAD from mce_decoder callback
Documentation/sysctl/v

Merge tag 'v4.6-rc6' into patchwork

Linux 4.6-rc6

* tag 'v4.6-rc6': (762 commits)
Linux 4.6-rc6
EDAC: i7core, sb_edac: Don't return NOTIFY_BAD from mce_decoder callback
Documentation/sysctl/vm.txt: update numa_zonelist_order description
lib/stackdepot.c: allow the stack trace hash to be zero
rapidio: fix potential NULL pointer dereference
mm/memory-failure: fix race with compound page split/merge
ocfs2/dlm: return zero if deref_done message is successfully handled
Ananth has moved
kcov: don't profile branches in kcov
kcov: don't trace the code coverage code
mm: wake kcompactd before kswapd's short sleep
.mailmap: add Frank Rowand
mm/hwpoison: fix wrong num_poisoned_pages accounting
mm: call swap_slot_free_notify() with page lock held
mm: vmscan: reclaim highmem zone if buffer_heads is over limit
numa: fix /proc/<pid>/numa_maps for THP
mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check
mailmap: fix Krzysztof Kozlowski's misspelled name
thp: keep huge zero page pinned until tlb flush
mm: exclude HugeTLB pages from THP page_mapped() logic
...

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Merge branch 'samples-bpf-user-experience'

Jesper Dangaard Brouer says:

====================
samples/bpf: Improve user experience

It is a steep learning curve getting started with using the eBPF
e

Merge branch 'samples-bpf-user-experience'

Jesper Dangaard Brouer says:

====================
samples/bpf: Improve user experience

It is a steep learning curve getting started with using the eBPF
examples in samples/bpf/. There are several dependencies, and
specific versions of these dependencies. Invoking make in the correct
manor is also slightly obscure.

This patchset cleanup, document and hopefully improves the first time
user experience with the eBPF samples directory by auto-detecting
certain scenarios.

V4:
- Address Naveen's nitpicks
- Handle/fail if extra args are passed in LLC or CLANG (David Laight)

V3:
- Add Alexei's ACKs
- Remove README paragraph about LLVM experimental BPF target
as it only existed between LLVM version 3.6 to 3.7.

V2:
- Adjusted recommend minimum versions to 3.7.1
- Included clang build instructions
- New patch adding CLANG variable and validation of command
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

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samples/bpf: like LLC also verify and allow redefining CLANG command

Users are likely to manually compile both LLVM 'llc' and 'clang'
tools. Thus, also allow redefining CLANG and verify command exi

samples/bpf: like LLC also verify and allow redefining CLANG command

Users are likely to manually compile both LLVM 'llc' and 'clang'
tools. Thus, also allow redefining CLANG and verify command exist.

Makefile implementation wise, the target that verify the command have
been generalized.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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samples/bpf: allow make to be run from samples/bpf/ directory

It is not intuitive that 'make' must be run from the top level
directory with argument "samples/bpf/" to compile these eBPF samples.

In

samples/bpf: allow make to be run from samples/bpf/ directory

It is not intuitive that 'make' must be run from the top level
directory with argument "samples/bpf/" to compile these eBPF samples.

Introduce a kbuild make file trick that allow make to be run from the
"samples/bpf/" directory itself. It basically change to the top level
directory and call "make samples/bpf/" with the "/" slash after the
directory name.

Also add a clean target that only cleans this directory, by taking
advantage of the kbuild external module setting M=$PWD.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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samples/bpf: Makefile verify LLVM compiler avail and bpf target is supported

Make compiling samples/bpf more user friendly, by detecting if LLVM
compiler tool 'llc' is available, and also detect if

samples/bpf: Makefile verify LLVM compiler avail and bpf target is supported

Make compiling samples/bpf more user friendly, by detecting if LLVM
compiler tool 'llc' is available, and also detect if the 'bpf' target
is available in this version of LLVM.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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samples/bpf: add back functionality to redefine LLC command

It is practical to be-able-to redefine the location of the LLVM
command 'llc', because not all distros have a LLVM version with bpf
target

samples/bpf: add back functionality to redefine LLC command

It is practical to be-able-to redefine the location of the LLVM
command 'llc', because not all distros have a LLVM version with bpf
target support. Thus, it is sometimes required to compile LLVM from
source, and sometimes it is not desired to overwrite the distros
default LLVM version.

This feature was removed with 128d1514be35 ("samples/bpf: Use llc in
PATH, rather than a hardcoded value").

Add this features back. Note that it is possible to redefine the LLC
on the make command like:

make samples/bpf/ LLC=~/git/llvm/build/bin/llc

Fixes: 128d1514be35 ("samples/bpf: Use llc in PATH, rather than a hardcoded value")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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Merge tag 'asoc-fix-v4.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Fixes for v4.6

This is a fairly large collection of fixes but almost all driver
spe

Merge tag 'asoc-fix-v4.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Fixes for v4.6

This is a fairly large collection of fixes but almost all driver
specific ones, especially to the new Intel drivers which have had a lot
of recent development. The one core fix is a change to the debugfs code
to avoid crashes in some relatively unusual configurations.

show more ...

Merge back cpufreq changes for v4.7.

Merge tag 'v4.6-rc4' into sched/core, to refresh the tree

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'v4.6-rc3' into drm-next

Backmerge 4.6-rc3 for i915.

Linux 4.6-rc3

Merge tag 'v4.6-rc4' into x86/asm, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge 4.6-rc4 into driver-core-next

We want those fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge 4.6-rc4 into char-misc-next

We want the fixes in there to build off of for other dependant patches.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge branch 'master' into for-next

Sync with Linus' tree so that patches against newer codebase can be applied.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Merge tag 'v4.6-rc3' into perf/core, to refresh the tree

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'v4.6-rc3' into drm-intel-next-queued

Linux 4.6-rc3

Backmerge requested by Chris Wilson to make his patches apply cleanly.
Tiny conflict in vmalloc.c with the (properly acked and all) pat

Merge tag 'v4.6-rc3' into drm-intel-next-queued

Linux 4.6-rc3

Backmerge requested by Chris Wilson to make his patches apply cleanly.
Tiny conflict in vmalloc.c with the (properly acked and all) patch in
drm-intel-next:

commit 4da56b99d99e5a7df2b7f11e87bfea935f909732
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon Apr 4 14:46:42 2016 +0100

mm/vmap: Add a notifier for when we run out of vmap address space

and Linus' tree.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

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