linux_dsm_epyc7002/tools
Wang Nan 7b6982ce4b perf test: Add libbpf relocation checker
There's a bug in LLVM that it can generate unneeded relocation
information. See [1] and [2]. Libbpf should check the target section of
a relocation symbol.

This patch adds a testcase which references a global variable (BPF
doesn't support global variables). Before fixing libbpf, the new test
case can be loaded into kernel, the global variable acts like the first
map. It is incorrect.

Result:

  # ~/perf test BPF
  37: Test BPF filter                                          :
  37.1: Test basic BPF filtering                               : Ok
  37.2: Test BPF prologue generation                           : Ok
  37.3: Test BPF relocation checker                            : FAILED!

  # ~/perf test -v BPF
  ...
  libbpf: loading object '[bpf_relocation_test]' from buffer
  libbpf: section .strtab, size 126, link 0, flags 0, type=3
  libbpf: section .text, size 0, link 0, flags 6, type=1
  libbpf: section .data, size 0, link 0, flags 3, type=1
  libbpf: section .bss, size 0, link 0, flags 3, type=8
  libbpf: section func=sys_write, size 104, link 0, flags 6, type=1
  libbpf: found program func=sys_write
  libbpf: section .relfunc=sys_write, size 16, link 10, flags 0, type=9
  libbpf: section maps, size 16, link 0, flags 3, type=1
  libbpf: maps in [bpf_relocation_test]: 16 bytes
  libbpf: section license, size 4, link 0, flags 3, type=1
  libbpf: license of [bpf_relocation_test] is GPL
  libbpf: section version, size 4, link 0, flags 3, type=1
  libbpf: kernel version of [bpf_relocation_test] is 40400
  libbpf: section .symtab, size 144, link 1, flags 0, type=2
  libbpf: map 0 is "my_table"
  libbpf: collecting relocating info for: 'func=sys_write'
  libbpf: relocation: insn_idx=7
  Success unexpectedly: libbpf error when dealing with relocation
  test child finished with -1
  ---- end ----
  Test BPF filter subtest 2: FAILED!

[1] https://llvm.org/bugs/show_bug.cgi?id=26243
[2] https://patchwork.ozlabs.org/patch/571385/

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1453715801-7732-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-01-26 12:10:55 -03:00
..
arch tools include: Add basic atomic.h implementation from the kernel sources 2015-05-08 16:11:05 -03:00
build tools build: Add BPF feature check to test-all 2016-01-11 19:22:21 -03:00
cgroup
firewire
hv tools: hv: vss: fix the write()'s argument: error -> vss_msg 2015-12-14 19:15:05 -08:00
iio iio: generic_buffer: be helpful about enabling channels 2015-08-16 10:51:26 +01:00
include tools: Make list.h self-sufficient 2016-01-12 12:42:07 -03:00
laptop/freefall Move freefall program from Documentation/ to tools/ 2015-06-08 16:42:07 -06:00
lguest tools/lguest: Clean up include dir 2015-08-26 06:12:35 +02:00
lib tools subcmd: Add missing NORETURN define for parse-options.h 2016-01-12 12:42:07 -03:00
net tools/net: Use include/uapi with __EXPORTED_HEADERS__ 2015-11-15 17:24:33 -05:00
nfsd
perf perf test: Add libbpf relocation checker 2016-01-26 12:10:55 -03:00
power Merge branches 'pm-sleep' and 'pm-tools' 2016-01-12 01:12:03 +01:00
scripts tools: Move Makefile.arch from perf/config to tools/scripts 2016-01-11 19:22:20 -03:00
spi spi: spidev_test: Fix typo in error message 2015-12-08 17:58:56 +00:00
testing Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-01-14 11:57:22 -08:00
thermal/tmon tools/thermal: tmon: use pkg-config also for CFLAGS 2015-10-10 11:32:31 +08:00
time
usb usb: patches for v4.4 merge window 2015-10-22 17:19:33 -07:00
virtio tools/virtio: fix byteswap logic 2015-12-07 17:28:10 +02:00
vm tools/vm/page-types.c: support KPF_IDLE 2015-11-20 16:17:32 -08:00
Makefile Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-01-14 11:39:09 -08:00