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  1. 29 6月, 2018 1 次提交
    • D
      bpf: Change bpf_fib_lookup to return lookup status · 4c79579b
      由 David Ahern 提交于 
      For ACLs implemented using either FIB rules or FIB entries, the BPF
program needs the FIB lookup status to be able to drop the packet.
Since the bpf_fib_lookup API has not reached a released kernel yet,
change the return code to contain an encoding of the FIB lookup
result and return the nexthop device index in the params struct.

In addition, inform the BPF program of any post FIB lookup reason as
to why the packet needs to go up the stack.

The fib result for unicast routes must have an egress device, so remove
the check that it is non-NULL.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      4c79579b
  3. 21 6月, 2018 1 次提交
  5. 16 6月, 2018 1 次提交
  7. 15 6月, 2018 3 次提交
  9. 13 6月, 2018 1 次提交
  11. 12 6月, 2018 3 次提交
  13. 08 6月, 2018 4 次提交
  15. 07 6月, 2018 1 次提交
  17. 06 6月, 2018 3 次提交
    • M
      rseq: Introduce restartable sequences system call · d7822b1e
      由 Mathieu Desnoyers 提交于 
      Expose a new system call allowing each thread to register one userspace
memory area to be used as an ABI between kernel and user-space for two
purposes: user-space restartable sequences and quick access to read the
current CPU number value from user-space.

* Restartable sequences (per-cpu atomics)

Restartables sequences allow user-space to perform update operations on
per-cpu data without requiring heavy-weight atomic operations.

The restartable critical sections (percpu atomics) work has been started
by Paul Turner and Andrew Hunter. It lets the kernel handle restart of
critical sections. [1] [2] The re-implementation proposed here brings a
few simplifications to the ABI which facilitates porting to other
architectures and speeds up the user-space fast path.

Here are benchmarks of various rseq use-cases.

Test hardware:

arm32: ARMv7 Processor rev 4 (v7l) "Cubietruck", 2-core
x86-64: Intel E5-2630 v3@2.40GHz, 16-core, hyperthreading

The following benchmarks were all performed on a single thread.

* Per-CPU statistic counter increment

                getcpu+atomic (ns/op)    rseq (ns/op)    speedup
arm32:                344.0                 31.4          11.0
x86-64:                15.3                  2.0           7.7

* LTTng-UST: write event 32-bit header, 32-bit payload into tracer
             per-cpu buffer

                getcpu+atomic (ns/op)    rseq (ns/op)    speedup
arm32:               2502.0                 2250.0         1.1
x86-64:               117.4                   98.0         1.2

* liburcu percpu: lock-unlock pair, dereference, read/compare word

                getcpu+atomic (ns/op)    rseq (ns/op)    speedup
arm32:                751.0                 128.5          5.8
x86-64:                53.4                  28.6          1.9

* jemalloc memory allocator adapted to use rseq

Using rseq with per-cpu memory pools in jemalloc at Facebook (based on
rseq 2016 implementation):

The production workload response-time has 1-2% gain avg. latency, and
the P99 overall latency drops by 2-3%.

* Reading the current CPU number

Speeding up reading the current CPU number on which the caller thread is
running is done by keeping the current CPU number up do date within the
cpu_id field of the memory area registered by the thread. This is done
by making scheduler preemption set the TIF_NOTIFY_RESUME flag on the
current thread. Upon return to user-space, a notify-resume handler
updates the current CPU value within the registered user-space memory
area. User-space can then read the current CPU number directly from
memory.

Keeping the current cpu id in a memory area shared between kernel and
user-space is an improvement over current mechanisms available to read
the current CPU number, which has the following benefits over
alternative approaches:

- 35x speedup on ARM vs system call through glibc
- 20x speedup on x86 compared to calling glibc, which calls vdso
  executing a "lsl" instruction,
- 14x speedup on x86 compared to inlined "lsl" instruction,
- Unlike vdso approaches, this cpu_id value can be read from an inline
  assembly, which makes it a useful building block for restartable
  sequences.
- The approach of reading the cpu id through memory mapping shared
  between kernel and user-space is portable (e.g. ARM), which is not the
  case for the lsl-based x86 vdso.

On x86, yet another possible approach would be to use the gs segment
selector to point to user-space per-cpu data. This approach performs
similarly to the cpu id cache, but it has two disadvantages: it is
not portable, and it is incompatible with existing applications already
using the gs segment selector for other purposes.

Benchmarking various approaches for reading the current CPU number:

ARMv7 Processor rev 4 (v7l)
Machine model: Cubietruck
- Baseline (empty loop):                                    8.4 ns
- Read CPU from rseq cpu_id:                               16.7 ns
- Read CPU from rseq cpu_id (lazy register):               19.8 ns
- glibc 2.19-0ubuntu6.6 getcpu:                           301.8 ns
- getcpu system call:                                     234.9 ns

x86-64 Intel(R) Xeon(R) CPU E5-2630 v3 @ 2.40GHz:
- Baseline (empty loop):                                    0.8 ns
- Read CPU from rseq cpu_id:                                0.8 ns
- Read CPU from rseq cpu_id (lazy register):                0.8 ns
- Read using gs segment selector:                           0.8 ns
- "lsl" inline assembly:                                   13.0 ns
- glibc 2.19-0ubuntu6 getcpu:                              16.6 ns
- getcpu system call:                                      53.9 ns

- Speed (benchmark taken on v8 of patchset)

Running 10 runs of hackbench -l 100000 seems to indicate, contrary to
expectations, that enabling CONFIG_RSEQ slightly accelerates the
scheduler:

Configuration: 2 sockets * 8-core Intel(R) Xeon(R) CPU E5-2630 v3 @
2.40GHz (directly on hardware, hyperthreading disabled in BIOS, energy
saving disabled in BIOS, turboboost disabled in BIOS, cpuidle.off=1
kernel parameter), with a Linux v4.6 defconfig+localyesconfig,
restartable sequences series applied.

* CONFIG_RSEQ=n

avg.:      41.37 s
std.dev.:   0.36 s

* CONFIG_RSEQ=y

avg.:      40.46 s
std.dev.:   0.33 s

- Size

On x86-64, between CONFIG_RSEQ=n/y, the text size increase of vmlinux is
567 bytes, and the data size increase of vmlinux is 5696 bytes.

[1] https://lwn.net/Articles/650333/
[2] http://www.linuxplumbersconf.org/2013/ocw/system/presentations/1695/original/LPC%20-%20PerCpu%20Atomics.pdfSigned-off-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <cl@linux.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Andrew Hunter <ahh@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-api@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20151027235635.16059.11630.stgit@pjt-glaptop.roam.corp.google.com
Link: http://lkml.kernel.org/r/20150624222609.6116.86035.stgit@kitami.mtv.corp.google.com
Link: https://lkml.kernel.org/r/20180602124408.8430-3-mathieu.desnoyers@efficios.com
      d7822b1e
    • M
      uapi/headers: Provide types_32_64.h · b575e837
      由 Mathieu Desnoyers 提交于 
      Provide helper macros for fields which represent pointers in
kernel-userspace ABI. This facilitates handling of 32-bit
user-space by 64-bit kernels by defining those fields as
32-bit 0-padding and 32-bit integer on 32-bit architectures,
which allows the kernel to treat those as 64-bit integers.
The order of padding and 32-bit integer depends on the
endianness.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <cl@linux.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Andrew Hunter <ahh@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: linux-api@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/20180602124408.8430-2-mathieu.desnoyers@efficios.com
      b575e837
    • G
      ncpfs: remove uapi .h files · 05e98465
      由 Greg Kroah-Hartman 提交于 
      Now that ncpfs is removed from the tree, there is no need to keep the
uapi header files around as no one uses them, and it is not a feature
that the kernel supports anymore.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      05e98465
  19. 05 6月, 2018 1 次提交
  21. 04 6月, 2018 4 次提交
    • B
      xsk: new descriptor addressing scheme · bbff2f32
      由 Björn Töpel 提交于 
      Currently, AF_XDP only supports a fixed frame-size memory scheme where
each frame is referenced via an index (idx). A user passes the frame
index to the kernel, and the kernel acts upon the data.  Some NICs,
however, do not have a fixed frame-size model, instead they have a
model where a memory window is passed to the hardware and multiple
frames are filled into that window (referred to as the "type-writer"
model).

By changing the descriptor format from the current frame index
addressing scheme, AF_XDP can in the future be extended to support
these kinds of NICs.

In the index-based model, an idx refers to a frame of size
frame_size. Addressing a frame in the UMEM is done by offseting the
UMEM starting address by a global offset, idx * frame_size + offset.
Communicating via the fill- and completion-rings are done by means of
idx.

In this commit, the idx is removed in favor of an address (addr),
which is a relative address ranging over the UMEM. To convert an
idx-based address to the new addr is simply: addr = idx * frame_size +
offset.

We also stop referring to the UMEM "frame" as a frame. Instead it is
simply called a chunk.

To transfer ownership of a chunk to the kernel, the addr of the chunk
is passed in the fill-ring. Note, that the kernel will mask addr to
make it chunk aligned, so there is no need for userspace to do
that. E.g., for a chunk size of 2k, passing an addr of 2048, 2050 or
3000 to the fill-ring will refer to the same chunk.

On the completion-ring, the addr will match that of the Tx descriptor,
passed to the kernel.

Changing the descriptor format to use chunks/addr will allow for
future changes to move to a type-writer based model, where multiple
frames can reside in one chunk. In this model passing one single chunk
into the fill-ring, would potentially result in multiple Rx
descriptors.

This commit changes the uapi of AF_XDP sockets, and updates the
documentation.
Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      bbff2f32
    • D
      bpf: flowlabel in bpf_fib_lookup should be flowinfo · bd3a08aa
      由 David Ahern 提交于 
      As Michal noted the flow struct takes both the flow label and priority.
Update the bpf_fib_lookup API to note that it is flowinfo and not just
the flow label.

Cc: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      bd3a08aa
    • Y
      bpf: implement bpf_get_current_cgroup_id() helper · bf6fa2c8
      由 Yonghong Song 提交于 
      bpf has been used extensively for tracing. For example, bcc
contains an almost full set of bpf-based tools to trace kernel
and user functions/events. Most tracing tools are currently
either filtered based on pid or system-wide.

Containers have been used quite extensively in industry and
cgroup is often used together to provide resource isolation
and protection. Several processes may run inside the same
container. It is often desirable to get container-level tracing
results as well, e.g. syscall count, function count, I/O
activity, etc.

This patch implements a new helper, bpf_get_current_cgroup_id(),
which will return cgroup id based on the cgroup within which
the current task is running.

The later patch will provide an example to show that
userspace can get the same cgroup id so it could
configure a filter or policy in the bpf program based on
task cgroup id.

The helper is currently implemented for tracing. It can
be added to other program types as well when needed.
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      bf6fa2c8
    • S
      rpmsg: char: Switch to SPDX license identifier · 136200f4
      由 Suman Anna 提交于 
      Use the appropriate SPDX license identifier in the rpmsg char driver
source file and drop the previous boilerplate license text. The uapi
header file already had the SPDX license identifier added as part of
a mass update but the license text removal was deferred for later,
and this patch drops the same.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>
      136200f4
  23. 03 6月, 2018 4 次提交
    • D
      bpf: make sure to clear unused fields in tunnel/xfrm state fetch · 1fbc2e0c
      由 Daniel Borkmann 提交于 
      Since the remaining bits are not filled in struct bpf_tunnel_key
resp. struct bpf_xfrm_state and originate from uninitialized stack
space, we should make sure to clear them before handing control
back to the program.

Also add a padding element to struct bpf_xfrm_state for future use
similar as we have in struct bpf_tunnel_key and clear it as well.

  struct bpf_xfrm_state {
      __u32                      reqid;            /*     0     4 */
      __u32                      spi;              /*     4     4 */
      __u16                      family;           /*     8     2 */

      /* XXX 2 bytes hole, try to pack */

      union {
          __u32              remote_ipv4;          /*           4 */
          __u32              remote_ipv6[4];       /*          16 */
      };                                           /*    12    16 */

      /* size: 28, cachelines: 1, members: 4 */
      /* sum members: 26, holes: 1, sum holes: 2 */
      /* last cacheline: 28 bytes */
  };
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      1fbc2e0c
    • D
      bpf: add bpf_skb_cgroup_id helper · cb20b08e
      由 Daniel Borkmann 提交于 
      Add a new bpf_skb_cgroup_id() helper that allows to retrieve the
cgroup id from the skb's socket. This is useful in particular to
enable bpf_get_cgroup_classid()-like behavior for cgroup v1 in
cgroup v2 by allowing ID based matching on egress. This can in
particular be used in combination with applying policy e.g. from
map lookups, and also complements the older bpf_skb_under_cgroup()
interface. In user space the cgroup id for a given path can be
retrieved through the f_handle as demonstrated in [0] recently.

  [0] https://lkml.org/lkml/2018/5/22/1190Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      cb20b08e
    • O
      PCI/DPC: Disable ERR_NONFATAL handling by DPC · 6927868e
      由 Oza Pawandeep 提交于 
      PCIe ERR_NONFATAL errors mean a particular transaction is unreliable but
the Link is otherwise fully functional (PCIe r4.0, sec 6.2.2).

The AER driver handles these by logging the error details and calling
driver-supplied pci_error_handlers callbacks.  It does not reset downstream
devices, does not remove them from the PCI subsystem, does not re-enumerate
them, and does not call their driver .remove() or .probe() methods.

But DPC driver previously enabled DPC on ERR_NONFATAL, so if the hardware
supports DPC, these errors caused a Link reset (performed automatically by
the hardware), followed by the DPC driver removing affected devices (which
calls their .remove() methods), bringing the Link back up, and
re-enumerating (which calls driver .probe() methods).

Disable ERR_NONFATAL DPC triggering so these errors will only be handled by
AER.  This means drivers won't have to deal with different usage of their
pci_error_handlers callbacks and .probe() and .remove() methods based on
whether the platform has DPC support.
Signed-off-by: NOza Pawandeep <poza@codeaurora.org>
[bhelgaas: changelog]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      6927868e
    • P
      netfilter: nf_tables: add connlimit support · 290180e2
      由 Pablo Neira Ayuso 提交于 
      This features which allows you to limit the maximum number of
connections per arbitrary key. The connlimit expression is stateful,
therefore it can be used from meters to dynamically populate a set, this
provides a mapping to the iptables' connlimit match. This patch also
comes that allows you define static connlimit policies.

This extension depends on the nf_conncount infrastructure.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
      290180e2
  25. 02 6月, 2018 1 次提交
    • D
      bpf: fix uapi hole for 32 bit compat applications · 36f9814a
      由 Daniel Borkmann 提交于 
      In 64 bit, we have a 4 byte hole between ifindex and netns_dev in the
case of struct bpf_map_info but also struct bpf_prog_info. In net-next
commit b85fab0e ("bpf: Add gpl_compatible flag to struct bpf_prog_info")
added a bitfield into it to expose some flags related to programs. Thus,
add an unnamed __u32 bitfield for both so that alignment keeps the same
in both 32 and 64 bit cases, and can be naturally extended from there
as in b85fab0e.

Before:

  # file test.o
  test.o: ELF 32-bit LSB relocatable, Intel 80386, version 1 (SYSV), not stripped
  # pahole test.o
  struct bpf_map_info {
	__u32                      type;                 /*     0     4 */
	__u32                      id;                   /*     4     4 */
	__u32                      key_size;             /*     8     4 */
	__u32                      value_size;           /*    12     4 */
	__u32                      max_entries;          /*    16     4 */
	__u32                      map_flags;            /*    20     4 */
	char                       name[16];             /*    24    16 */
	__u32                      ifindex;              /*    40     4 */
	__u64                      netns_dev;            /*    44     8 */
	__u64                      netns_ino;            /*    52     8 */

	/* size: 64, cachelines: 1, members: 10 */
	/* padding: 4 */
  };

After (same as on 64 bit):

  # file test.o
  test.o: ELF 32-bit LSB relocatable, Intel 80386, version 1 (SYSV), not stripped
  # pahole test.o
  struct bpf_map_info {
	__u32                      type;                 /*     0     4 */
	__u32                      id;                   /*     4     4 */
	__u32                      key_size;             /*     8     4 */
	__u32                      value_size;           /*    12     4 */
	__u32                      max_entries;          /*    16     4 */
	__u32                      map_flags;            /*    20     4 */
	char                       name[16];             /*    24    16 */
	__u32                      ifindex;              /*    40     4 */

	/* XXX 4 bytes hole, try to pack */

	__u64                      netns_dev;            /*    48     8 */
	__u64                      netns_ino;            /*    56     8 */
	/* --- cacheline 1 boundary (64 bytes) --- */

	/* size: 64, cachelines: 1, members: 10 */
	/* sum members: 60, holes: 1, sum holes: 4 */
  };
Reported-by: NDmitry V. Levin <ldv@altlinux.org>
Reported-by: NEugene Syromiatnikov <esyr@redhat.com>
Fixes: 52775b33 ("bpf: offload: report device information about offloaded maps")
Fixes: 675fc275 ("bpf: offload: report device information for offloaded programs")
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      36f9814a
  27. 01 6月, 2018 4 次提交
  29. 31 5月, 2018 5 次提交
  31. 30 5月, 2018 3 次提交