linux/tools/lib
Wang Nan 6371ca3b54 bpf tools: Improve libbpf error reporting
In this patch, a series of libbpf specific error numbers and
libbpf_strerror() are introduced to help reporting errors.

Functions are updated to pass correct the error number through the
CHECK_ERR() macro.

All users of bpf_object__open{_buffer}() and bpf_program__title() in
perf are modified accordingly. In addition, due to the error codes
changing, bpf__strerror_load() is also modified to use them.

bpf__strerror_head() is also changed accordingly so it can parse libbpf
errors. bpf_loader_strerror() is introduced for that purpose, and will
be improved by the following patch.

load_program() is improved not to dump log buffer if it is empty. log
buffer is also used to deduce whether the error was caused by an invalid
program or other problem.

v1 -> v2:

 - Using macro for error code.

 - Fetch error message based on array index, eliminate for-loop.

 - Use log buffer to detect the reason of failure. 3 new error code
   are introduced to replace LIBBPF_ERRNO__LOAD.

In v1:

  # perf record -e ./test_ill_program.o ls
  event syntax error: './test_ill_program.o'
                       \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object
  SKIP

  # perf record -e ./test_kversion_nomatch_program.o ls
  event syntax error: './test_kversion_nomatch_program.o'
                       \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object
  SKIP

  # perf record -e ./test_big_program.o ls
  event syntax error: './test_big_program.o'
                       \___ Failed to load program: Validate your program and check 'license'/'version' sections in your object
  SKIP

  In v2:

  # perf record -e ./test_ill_program.o ls
  event syntax error: './test_ill_program.o'
                       \___ Kernel verifier blocks program loading
  SKIP

  # perf record -e ./test_kversion_nomatch_program.o
  event syntax error: './test_kversion_nomatch_program.o'
                       \___ Incorrect kernel version
  SKIP
  (Will be further improved by following patches)

  # perf record -e ./test_big_program.o
  event syntax error: './test_big_program.o'
                       \___ Program too big
  SKIP

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446817783-86722-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-06 15:52:41 -03:00
..
api tools lib api fs: No need to use PATH_MAX + 1 2015-10-05 16:12:09 -03:00
bpf bpf tools: Improve libbpf error reporting 2015-11-06 15:52:41 -03:00
lockdep tools build: Build fixdep helper from perf and basic libs 2015-09-28 15:50:55 -03:00
symbol tools lib symbol: Introduce kallsyms2elf_type 2015-09-30 18:34:31 -03:00
traceevent tools lib traceevent: Support %ps/%pS 2015-10-22 15:39:42 -03:00
util tools lib: Move asm-generic/bitops/find.h code to tools/include and tools/lib 2014-12-17 11:14:48 -03:00
hweight.c tools: Copy lib/hweight.c from the kernel sources 2015-07-09 16:29:56 -03:00
rbtree.c tools: Copy lib/rbtree.c to tools/lib/ 2015-07-05 22:48:21 -03:00