Andrii Nakryiko 55d00c37eb libbpf: generalize virtual __kconfig externs and use it for USDT ... Libbpf supports single virtual __kconfig extern currently: LINUX_KERNEL_VERSION. LINUX_KERNEL_VERSION isn't coming from /proc/kconfig.gz and is intead customly filled out by libbpf. This patch generalizes this approach to support more such virtual __kconfig externs. One such extern added in this patch is LINUX_HAS_BPF_COOKIE which is used for BPF-side USDT supporting code in usdt.bpf.h instead of using CO-RE-based enum detection approach for detecting bpf_get_attach_cookie() BPF helper. This allows to remove otherwise not needed CO-RE dependency and keeps user-space and BPF-side parts of libbpf's USDT support strictly in sync in terms of their feature detection. We'll use similar approach for syscall wrapper detection for BPF_KSYSCALL() BPF-side macro in follow up patch. Generally, currently libbpf reserves CONFIG_ prefix for Kconfig values and LINUX_ for virtual libbpf-backed externs. In the future we might extend the set of prefixes that are supported. This can be done without any breaking changes, as currently any __kconfig extern with unrecognized name is rejected. For LINUX_xxx externs we support the normal "weak rule": if libbpf doesn't recognize given LINUX_xxx extern but such extern is marked as __weak, it is not rejected and defaults to zero. This follows CONFIG_xxx handling logic and will allow BPF applications to opportunistically use newer libbpf virtual externs without breaking on older libbpf versions unnecessarily. Tested-by: Alan Maguire <alan.maguire@oracle.com> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20220714070755.3235561-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>		2022-07-19 09:33:17 -07:00
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api	Kbuild updates for v5.18	2022-03-31 11:59:03 -07:00
bpf	libbpf: generalize virtual __kconfig externs and use it for USDT	2022-07-19 09:33:17 -07:00
perf	libperf evsel: Open shouldn't leak fd on failure	2022-06-19 10:41:43 -03:00
subcmd	libsubcmd: Fix OPTION_GROUP sorting	2022-04-22 12:32:01 +02:00
symbol	libsymbols kallsyms: Move hex2u64 out of header	2020-05-05 16:35:32 -03:00
thermal	tools/lib/thermal: remove unneeded semicolon	2022-05-19 12:11:52 +02:00
traceevent	libtraceevent: Add __rel_loc relative location attribute support	2021-12-06 15:37:22 -05:00
argv_split.c	tools lib: Move argv_{split,free} from tools/perf/util/	2019-07-01 22:50:40 -03:00
bitmap.c	bitmap: Fix return values to be unsigned	2022-06-03 06:52:58 -07:00
ctype.c
find_bit.c	tools: sync tools/bitmap with mother linux	2022-01-15 08:47:31 -08:00
hweight.c
list_sort.c	tools lib: Adopt list_sort() from the kernel sources	2021-10-20 10:30:59 -03:00
rbtree.c	tools/: replace HTTP links with HTTPS ones	2020-08-07 11:33:21 -07:00
slab.c	tools: Move gfp.h and slab.h from radix-tree to lib	2022-02-20 08:44:37 +02:00
str_error_r.c
string.c	tools lib: Adopt memchr_inv() from kernel	2020-11-27 08:34:52 -03:00
vsprintf.c
zalloc.c	tools lib: Adopt zalloc()/zfree() from tools/perf	2019-07-09 10:13:26 -03:00