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  1. 16 1月, 2019 1 次提交
    • Y
      samples/bpf: workaround clang asm goto compilation errors · 6bf3bbe1
      由 Yonghong Song 提交于 
      x86 compilation has required asm goto support since 4.17.
Since clang does not support asm goto, at 4.17,
Commit b1ae32db ("x86/cpufeature: Guard asm_volatile_goto usage
for BPF compilation") worked around the issue by permitting an
alternative implementation without asm goto for clang.

At 5.0, more asm goto usages appeared.
  [yhs@148 x86]$ egrep -r asm_volatile_goto
  include/asm/cpufeature.h:     asm_volatile_goto("1: jmp 6f\n"
  include/asm/jump_label.h:     asm_volatile_goto("1:"
  include/asm/jump_label.h:     asm_volatile_goto("1:"
  include/asm/rmwcc.h:  asm_volatile_goto (fullop "; j" #cc " %l[cc_label]"     \
  include/asm/uaccess.h:        asm_volatile_goto("\n"                          \
  include/asm/uaccess.h:        asm_volatile_goto("\n"                          \
  [yhs@148 x86]$

Compiling samples/bpf directories, most bpf programs failed
compilation with error messages like:
  In file included from /home/yhs/work/bpf-next/samples/bpf/xdp_sample_pkts_kern.c:2:
  In file included from /home/yhs/work/bpf-next/include/linux/ptrace.h:6:
  In file included from /home/yhs/work/bpf-next/include/linux/sched.h:15:
  In file included from /home/yhs/work/bpf-next/include/linux/sem.h:5:
  In file included from /home/yhs/work/bpf-next/include/uapi/linux/sem.h:5:
  In file included from /home/yhs/work/bpf-next/include/linux/ipc.h:9:
  In file included from /home/yhs/work/bpf-next/include/linux/refcount.h:72:
  /home/yhs/work/bpf-next/arch/x86/include/asm/refcount.h:70:9: error: 'asm goto' constructs are not supported yet
        return GEN_BINARY_SUFFIXED_RMWcc(LOCK_PREFIX "subl",
               ^
  /home/yhs/work/bpf-next/arch/x86/include/asm/rmwcc.h:67:2: note: expanded from macro 'GEN_BINARY_SUFFIXED_RMWcc'
        __GEN_RMWcc(op " %[val], %[var]\n\t" suffix, var, cc,           \
        ^
  /home/yhs/work/bpf-next/arch/x86/include/asm/rmwcc.h:21:2: note: expanded from macro '__GEN_RMWcc'
        asm_volatile_goto (fullop "; j" #cc " %l[cc_label]"             \
        ^
  /home/yhs/work/bpf-next/include/linux/compiler_types.h:188:37: note: expanded from macro 'asm_volatile_goto'
  #define asm_volatile_goto(x...) asm goto(x)

Most implementation does not even provide an alternative
implementation. And it is also not practical to make changes
for each call site.

This patch workarounded the asm goto issue by redefining the macro like below:
  #define asm_volatile_goto(x...) asm volatile("invalid use of asm_volatile_goto")

If asm_volatile_goto is not used by bpf programs, which is typically the case, nothing bad
will happen. If asm_volatile_goto is used by bpf programs, which is incorrect, the compiler
will issue an error since "invalid use of asm_volatile_goto" is not valid assembly codes.

With this patch, all bpf programs under samples/bpf can pass compilation.

Note that bpf programs under tools/testing/selftests/bpf/ compiled fine as
they do not access kernel internal headers.

Fixes: e769742d ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"")
Fixes: 18fe5822 ("x86, asm: change the GEN_*_RMWcc() macros to not quote the condition")
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NYonghong Song <yhs@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      6bf3bbe1
  3. 23 12月, 2018 2 次提交
  5. 21 11月, 2018 1 次提交
  7. 01 9月, 2018 1 次提交
  9. 27 7月, 2018 3 次提交
  11. 18 7月, 2018 2 次提交
  13. 27 6月, 2018 1 次提交
  15. 25 5月, 2018 1 次提交
  17. 15 5月, 2018 3 次提交
  19. 14 5月, 2018 1 次提交
  21. 11 5月, 2018 4 次提交
  23. 04 5月, 2018 1 次提交
  25. 29 4月, 2018 1 次提交
  27. 27 4月, 2018 1 次提交
  29. 19 4月, 2018 1 次提交
  31. 29 3月, 2018 1 次提交
  33. 26 2月, 2018 1 次提交
    • L
      samples/bpf: Add program for CPU state statistics · c5350777
      由 Leo Yan 提交于 
      CPU is active when have running tasks on it and CPUFreq governor can
select different operating points (OPP) according to different workload;
we use 'pstate' to present CPU state which have running tasks with one
specific OPP.  On the other hand, CPU is idle which only idle task on
it, CPUIdle governor can select one specific idle state to power off
hardware logics; we use 'cstate' to present CPU idle state.

Based on trace events 'cpu_idle' and 'cpu_frequency' we can accomplish
the duration statistics for every state.  Every time when CPU enters
into or exits from idle states, the trace event 'cpu_idle' is recorded;
trace event 'cpu_frequency' records the event for CPU OPP changing, so
it's easily to know how long time the CPU stays in the specified OPP,
and the CPU must be not in any idle state.

This patch is to utilize the mentioned trace events for pstate and
cstate statistics.  To achieve more accurate profiling data, the program
uses below sequence to insure CPU running/idle time aren't missed:

- Before profiling the user space program wakes up all CPUs for once, so
  can avoid to missing account time for CPU staying in idle state for
  long time; the program forces to set 'scaling_max_freq' to lowest
  frequency and then restore 'scaling_max_freq' to highest frequency,
  this can ensure the frequency to be set to lowest frequency and later
  after start to run workload the frequency can be easily to be changed
  to higher frequency;

- User space program reads map data and update statistics for every 5s,
  so this is same with other sample bpf programs for avoiding big
  overload introduced by bpf program self;

- When send signal to terminate program, the signal handler wakes up
  all CPUs, set lowest frequency and restore highest frequency to
  'scaling_max_freq'; this is exactly same with the first step so
  avoid to missing account CPU pstate and cstate time during last
  stage.  Finally it reports the latest statistics.

The program has been tested on Hikey board with octa CA53 CPUs, below
is one example for statistics result, the format mainly follows up
Jesper Dangaard Brouer suggestion.

Jesper reminds to 'get printf to pretty print with thousands separators
use %' and setlocale(LC_NUMERIC, "en_US")', tried three different arm64
GCC toolchains (5.4.0 20160609, 6.2.1 20161016, 6.3.0 20170516) but all
of them cannot support printf flag character %' on arm64 platform, so go
back print number without grouping mode.

CPU states statistics:
state(ms)  cstate-0    cstate-1    cstate-2    pstate-0    pstate-1    pstate-2    pstate-3    pstate-4
CPU-0      767         6111        111863      561         31          756         853         190
CPU-1      241         10606       107956      484         125         646         990         85
CPU-2      413         19721       98735       636         84          696         757         89
CPU-3      84          11711       79989       17516       909         4811        5773        341
CPU-4      152         19610       98229       444         53          649         708         1283
CPU-5      185         8781        108697      666         91          671         677         1365
CPU-6      157         21964       95825       581         67          566         684         1284
CPU-7      125         15238       102704      398         20          665         786         1197

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: NLeo Yan <leo.yan@linaro.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      c5350777
  35. 03 2月, 2018 1 次提交
    • E
      libbpf: add error reporting in XDP · bbf48c18
      由 Eric Leblond 提交于 
      Parse netlink ext attribute to get the error message returned by
the card. Code is partially take from libnl.

We add netlink.h to the uapi include of tools. And we need to
avoid include of userspace netlink header to have a successful
build of sample so nlattr.h has a define to avoid
the inclusion. Using a direct define could have been an issue
as NLMSGERR_ATTR_MAX can change in the future.

We also define SOL_NETLINK if not defined to avoid to have to
copy socket.h for a fixed value.
Signed-off-by: NEric Leblond <eric@regit.org>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      bbf48c18
  37. 27 1月, 2018 1 次提交
  39. 11 1月, 2018 1 次提交
    • J
      samples/bpf: xdp2skb_meta shows transferring info from XDP to SKB · 36e04a2d
      由 Jesper Dangaard Brouer 提交于 
      Creating a bpf sample that shows howto use the XDP 'data_meta'
infrastructure, created by Daniel Borkmann.  Very few drivers support
this feature, but I wanted a functional sample to begin with, when
working on adding driver support.

XDP data_meta is about creating a communication channel between BPF
programs.  This can be XDP tail-progs, but also other SKB based BPF
hooks, like in this case the TC clsact hook. In this sample I show
that XDP can store info named "mark", and TC/clsact chooses to use
this info and store it into the skb->mark.

It is a bit annoying that XDP and TC samples uses different tools/libs
when attaching their BPF hooks.  As the XDP and TC programs need to
cooperate and agree on a struct-layout, it is best/easiest if the two
programs can be contained within the same BPF restricted-C file.

As the bpf-loader, I choose to not use bpf_load.c (or libbpf), but
instead wrote a bash shell scripted named xdp2skb_meta.sh, which
demonstrate howto use the iproute cmdline tools 'tc' and 'ip' for
loading BPF programs.  To make it easy for first time users, the shell
script have command line parsing, and support --verbose and --dry-run
mode, if you just want to see/learn the tc+ip command syntax:

 # ./xdp2skb_meta.sh --dev ixgbe2 --dry-run
 # Dry-run mode: enable VERBOSE and don't call TC+IP
 tc qdisc del dev ixgbe2 clsact
 tc qdisc add dev ixgbe2 clsact
 tc filter add dev ixgbe2 ingress prio 1 handle 1 bpf da obj ./xdp2skb_meta_kern.o sec tc_mark
 # Flush XDP on device: ixgbe2
 ip link set dev ixgbe2 xdp off
 ip link set dev ixgbe2 xdp obj ./xdp2skb_meta_kern.o sec xdp_mark
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      36e04a2d
  41. 06 1月, 2018 1 次提交
    • J
      samples/bpf: program demonstrating access to xdp_rxq_info · 0fca931a
      由 Jesper Dangaard Brouer 提交于 
      This sample program can be used for monitoring and reporting how many
packets per sec (pps) are received per NIC RX queue index and which
CPU processed the packet. In itself it is a useful tool for quickly
identifying RSS imbalance issues, see below.

The default XDP action is XDP_PASS in-order to provide a monitor
mode. For benchmarking purposes it is possible to specify other XDP
actions on the cmdline --action.

Output below shows an imbalance RSS case where most RXQ's deliver to
CPU-0 while CPU-2 only get packets from a single RXQ.  Looking at
things from a CPU level the two CPUs are processing approx the same
amount, BUT looking at the rx_queue_index levels it is clear that
RXQ-2 receive much better service, than other RXQs which all share CPU-0.

Running XDP on dev:i40e1 (ifindex:3) action:XDP_PASS
XDP stats       CPU     pps         issue-pps
XDP-RX CPU      0       900,473     0
XDP-RX CPU      2       906,921     0
XDP-RX CPU      total   1,807,395

RXQ stats       RXQ:CPU pps         issue-pps
rx_queue_index    0:0   180,098     0
rx_queue_index    0:sum 180,098
rx_queue_index    1:0   180,098     0
rx_queue_index    1:sum 180,098
rx_queue_index    2:2   906,921     0
rx_queue_index    2:sum 906,921
rx_queue_index    3:0   180,098     0
rx_queue_index    3:sum 180,098
rx_queue_index    4:0   180,082     0
rx_queue_index    4:sum 180,082
rx_queue_index    5:0   180,093     0
rx_queue_index    5:sum 180,093
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      0fca931a
  43. 13 12月, 2017 1 次提交
  45. 18 11月, 2017 1 次提交
  47. 11 11月, 2017 2 次提交
  49. 08 11月, 2017 1 次提交
  51. 05 11月, 2017 1 次提交
  53. 02 11月, 2017 1 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      由 Greg Kroah-Hartman 提交于 
      Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  55. 22 10月, 2017 1 次提交
  57. 18 10月, 2017 1 次提交
    • J
      samples/bpf: add cpumap sample program xdp_redirect_cpu · fad3917e
      由 Jesper Dangaard Brouer 提交于 
      This sample program show how to use cpumap and the associated
tracepoints.

It provides command line stats, which shows how the XDP-RX process,
cpumap-enqueue and cpumap kthread dequeue is cooperating on a per CPU
basis.  It also utilize the xdp_exception and xdp_redirect_err
transpoints to allow users quickly to identify setup issues.

One issue with ixgbe driver is that the driver reset the link when
loading XDP.  This reset the procfs smp_affinity settings.  Thus,
after loading the program, these must be reconfigured.  The easiest
workaround it to reduce the RX-queue to e.g. two via:

 # ethtool --set-channels ixgbe1 combined 2

And then add CPUs above 0 and 1, like:

 # xdp_redirect_cpu --dev ixgbe1 --prog 2 --cpu 2 --cpu 3 --cpu 4

Another issue with ixgbe is that the page recycle mechanism is tied to
the RX-ring size.  And the default setting of 512 elements is too
small.  This is the same issue with regular devmap XDP_REDIRECT.
To overcome this I've been using 1024 rx-ring size:

 # ethtool -G ixgbe1 rx 1024 tx 1024

V3:
 - whitespace cleanups
 - bpf tracepoint cannot access top part of struct

V4:
 - report on kthread sched events, according to tracepoint change
 - report average bulk enqueue size

V5:
 - bpf_map_lookup_elem on cpumap not allowed from bpf_prog
   use separate map to mark CPUs not available

V6:
 - correct kthread sched summary output

V7:
 - Added a --stress-mode for concurrently changing underlying cpumap
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fad3917e
  59. 17 10月, 2017 1 次提交