From: Ilya Leoshkevich <iii@linux.ibm.com>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: bpf@vger.kernel.org, Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Ilya Leoshkevich <iii@linux.ibm.com>
Subject: [PATCH bpf-next v3 1/6] libbpf: Fix endianness detection in BPF_CORE_READ_BITFIELD_PROBED()
Date: Tue, 26 Oct 2021 03:08:26 +0200 [thread overview]
Message-ID: <20211026010831.748682-2-iii@linux.ibm.com> (raw)
In-Reply-To: <20211026010831.748682-1-iii@linux.ibm.com>
__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 <iii@linux.ibm.com>
---
tools/lib/bpf/bpf_core_read.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h
index 09ebe3db5f2f..e4aa9996a550 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, \
--
2.31.1
next prev parent reply other threads:[~2021-10-26 1:08 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-26 1:08 [PATCH bpf-next v3 0/6] core_reloc fixes for s390 Ilya Leoshkevich
2021-10-26 1:08 ` Ilya Leoshkevich [this message]
2021-10-26 1:08 ` [PATCH bpf-next v3 2/6] libbpf: Use __BYTE_ORDER__ Ilya Leoshkevich
2021-10-27 19:05 ` Arnaldo Carvalho de Melo
2021-10-26 1:08 ` [PATCH bpf-next v3 3/6] selftests/bpf: " Ilya Leoshkevich
2021-10-26 1:08 ` [PATCH bpf-next v3 4/6] samples: seccomp: use __BYTE_ORDER__ Ilya Leoshkevich
2021-10-26 1:08 ` [PATCH bpf-next v3 5/6] selftests/seccomp: Use __BYTE_ORDER__ Ilya Leoshkevich
2021-10-26 1:08 ` [PATCH bpf-next v3 6/6] selftests/bpf: Fix test_core_reloc_mods on big-endian machines Ilya Leoshkevich
2021-10-26 3:40 ` [PATCH bpf-next v3 0/6] core_reloc fixes for s390 Andrii Nakryiko
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