linux/tools/lib
Andrey Ignatov 306b267cb3 libbpf: Verify versioned symbols
Since ABI versioning info is kept separately from the code it's easy to
forget to update it while adding a new API.

Add simple verification that all global symbols exported with LIBBPF_API
are versioned in libbpf.map version script.

The idea is to check that number of global symbols in libbpf-in.o, that
is the input to the linker, matches with number of unique versioned
symbols in libbpf.so, that is the output of the linker. If these numbers
don't match, it may mean some symbol was not versioned and make will
fail.

"Unique" means that if a symbol is present in more than one version of
ABI due to ABI changes, it'll be counted once.

Another option to calculate number of global symbols in the "input"
could be to count number of LIBBPF_ABI entries in C headers but it seems
to be fragile.

Example of output when a symbol is missing in version script:

    ...
    LD       libbpf-in.o
    LINK     libbpf.a
    LINK     libbpf.so
  Warning: Num of global symbols in libbpf-in.o (115) does NOT match
  with num of versioned symbols in libbpf.so (114). Please make sure all
  LIBBPF_API symbols are versioned in libbpf.map.
  make: *** [check_abi] Error 1

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-26 18:57:14 -08:00
..
api perf tools: Fix tracing_path_mount proper path 2018-10-16 12:27:46 -03:00
bpf libbpf: Verify versioned symbols 2018-11-26 18:57:14 -08:00
lockdep tools lib traceevent, tools lib lockdep: Rename 'enum pevent_errno' to 'enum tep_errno' 2018-08-13 15:23:07 -03:00
subcmd tools lib subcmd: Introduce OPTION_ULONG 2018-10-19 11:56:58 -03:00
symbol tools lib symbols: Introduce kallsyms__is_function() 2018-04-26 13:47:14 -03:00
traceevent tools lib traceevent, perf tools: Move struct tep_handler definition in a local header file 2018-10-08 15:05:37 -03:00
bitmap.c tools lib: Add bitmap_and function 2016-08-02 16:33:27 -03:00
find_bit.c lib: optimize cpumask_next_and() 2018-02-06 18:32:44 -08:00
hweight.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
rbtree.c tools: Copy lib/rbtree.c to tools/lib/ 2015-07-05 22:48:21 -03:00
str_error_r.c objtool, perf: Fix GCC 8 -Wrestrict error 2018-03-19 13:51:54 -03:00
string.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
vsprintf.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00