Rewrite endianness check to use "more canonical" way, using
compiler-defined macros, similar to few other places in libbpf. It also
is more obvious and shorter.
Acked-by: Song Liu <songliubrav...@fb.com>
Signed-off-by: Andrii Nakryiko <andr...@fb.com>
---
tools/lib/bpf/libbpf.c | 37 ++++++++++++-------------------------
1 file changed, 12 insertions(+), 25 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 5af331cb8e4f..fe700ef1135d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -607,31 +607,18 @@ static int bpf_object__elf_init(struct bpf_object *obj)
return err;
}
-static int
-bpf_object__check_endianness(struct bpf_object *obj)
-{
- static unsigned int const endian = 1;
-
- switch (obj->efile.ehdr.e_ident[EI_DATA]) {
- case ELFDATA2LSB:
- /* We are big endian, BPF obj is little endian. */
- if (*(unsigned char const *)&endian != 1)
- goto mismatch;
- break;
-
- case ELFDATA2MSB:
- /* We are little endian, BPF obj is big endian. */
- if (*(unsigned char const *)&endian != 0)
- goto mismatch;
- break;
- default:
- return -LIBBPF_ERRNO__ENDIAN;
- }
-
- return 0;
-
-mismatch:
- pr_warning("Error: endianness mismatch.\n");
+static int bpf_object__check_endianness(struct bpf_object *obj)
+{
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2LSB)
+ return 0;
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+ if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2MSB)
+ return 0;
+#else
+# error "Unrecognized __BYTE_ORDER__"
+#endif
+ pr_warning("endianness mismatch.\n");
return -LIBBPF_ERRNO__ENDIAN;
}
--
2.17.1
