diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2021-09-07 15:10:23 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-09-07 19:32:04 -0700 |
| commit | 006a5099fc18a43792b01d002e1e45c5541ea666 (patch) | |
| tree | 1340a5ef235ddf7b7bccce0e65ff0cbbcf84034a /tools/lib/bpf/libbpf_internal.h | |
| parent | d6be5947efddb7e760cf1c1554f5a1049d7ca118 (diff) | |
libbpf: Fix build with latest gcc/binutils with LTO
After updating to binutils 2.35, the build began to fail with an
assembler error. A bug was opened on the Red Hat Bugzilla a few days
later for the same issue.
Work around the problem by using the new `symver` attribute (introduced
in GCC 10) as needed instead of assembler directives.
This addresses Red Hat ([0]) and OpenSUSE ([1]) bug reports, as well as libbpf
issue ([2]).
[0]: https://bugzilla.redhat.com/show_bug.cgi?id=1863059
[1]: https://bugzilla.opensuse.org/show_bug.cgi?id=1188749
[2]: Closes: https://github.com/libbpf/libbpf/issues/338
Co-developed-by: Patrick McCarty <patrick.mccarty@intel.com>
Co-developed-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Patrick McCarty <patrick.mccarty@intel.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210907221023.2660953-1-andrii@kernel.org
Diffstat (limited to 'tools/lib/bpf/libbpf_internal.h')
| -rw-r--r-- | tools/lib/bpf/libbpf_internal.h | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index 533b0211f40a..4f6ff5c23695 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -90,17 +90,30 @@ /* Symbol versioning is different between static and shared library. * Properly versioned symbols are needed for shared library, but * only the symbol of the new version is needed for static library. + * Starting with GNU C 10, use symver attribute instead of .symver assembler + * directive, which works better with GCC LTO builds. */ -#ifdef SHARED -# define COMPAT_VERSION(internal_name, api_name, version) \ +#if defined(SHARED) && defined(__GNUC__) && __GNUC__ >= 10 + +#define DEFAULT_VERSION(internal_name, api_name, version) \ + __attribute__((symver(#api_name "@@" #version))) +#define COMPAT_VERSION(internal_name, api_name, version) \ + __attribute__((symver(#api_name "@" #version))) + +#elif defined(SHARED) + +#define COMPAT_VERSION(internal_name, api_name, version) \ asm(".symver " #internal_name "," #api_name "@" #version); -# define DEFAULT_VERSION(internal_name, api_name, version) \ +#define DEFAULT_VERSION(internal_name, api_name, version) \ asm(".symver " #internal_name "," #api_name "@@" #version); -#else -# define COMPAT_VERSION(internal_name, api_name, version) -# define DEFAULT_VERSION(internal_name, api_name, version) \ + +#else /* !SHARED */ + +#define COMPAT_VERSION(internal_name, api_name, version) +#define DEFAULT_VERSION(internal_name, api_name, version) \ extern typeof(internal_name) api_name \ __attribute__((alias(#internal_name))); + #endif extern void libbpf_print(enum libbpf_print_level level, |