libbpf: Add BTF_KIND_FLOAT support

The logic follows that of BTF_KIND_INT most of the time. Sanitization
replaces BTF_KIND_FLOATs with equally-sized empty BTF_KIND_STRUCTs on
older kernels, for example, the following:

    [4] FLOAT 'float' size=4

becomes the following:

    [4] STRUCT '(anon)' size=4 vlen=0

With dwarves patch [1] and this patch, the older kernels, which were
failing with the floating-point-related errors, will now start working
correctly.

[1] https://github.com/iii-i/dwarves/commit/btf-kind-float-v2

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210226202256.116518-4-iii@linux.ibm.com
This commit is contained in:
Ilya Leoshkevich
2021-02-26 21:22:49 +01:00
committed by Andrii Nakryiko
parent 617f781804
commit 471e7c241d
6 changed files with 94 additions and 1 deletions

View File

@@ -350,3 +350,8 @@ LIBBPF_0.3.0 {
xsk_setup_xdp_prog;
xsk_socket__update_xskmap;
} LIBBPF_0.2.0;
LIBBPF_0.4.0 {
global:
btf__add_float;
} LIBBPF_0.3.0;