From: Ilya Leoshkevich Date: Tue, 26 Oct 2021 01:08:26 +0000 (+0200) Subject: libbpf: Fix endianness detection in BPF_CORE_READ_BITFIELD_PROBED() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=d48715b25f2ef1f839eb9ee107d45dd029229f12;p=linux.git libbpf: Fix endianness detection in BPF_CORE_READ_BITFIELD_PROBED() [ Upstream commit 45f2bebc8079788f62f22d9e8b2819afb1789d7b ] __BYTE_ORDER is supposed to be defined by a libc, and __BYTE_ORDER__ - by a compiler. bpf_core_read.h checks __BYTE_ORDER == __LITTLE_ENDIAN, which is true if neither are defined, leading to incorrect behavior on big-endian hosts if libc headers are not included, which is often the case. Fixes: ee26dade0e3b ("libbpf: Add support for relocatable bitfields") Signed-off-by: Ilya Leoshkevich Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211026010831.748682-2-iii@linux.ibm.com Signed-off-by: Sasha Levin --- diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h index 09ebe3db5f2f8..e4aa9996a5501 100644 --- a/tools/lib/bpf/bpf_core_read.h +++ b/tools/lib/bpf/bpf_core_read.h @@ -40,7 +40,7 @@ enum bpf_enum_value_kind { #define __CORE_RELO(src, field, info) \ __builtin_preserve_field_info((src)->field, BPF_FIELD_##info) -#if __BYTE_ORDER == __LITTLE_ENDIAN +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ #define __CORE_BITFIELD_PROBE_READ(dst, src, fld) \ bpf_probe_read_kernel( \ (void *)dst, \