Ensure that output BTF endianness corresponds to target ELF's endianness. This
makes it finally possible to use pahole to generate BTF for cross-compiled
kernels with different endianness.
Signed-off-by: Andrii Nakryiko <andriin@xxxxxx>
---
libbtf.c | 24 ++++++++++++++++++++++--
1 file changed, 22 insertions(+), 2 deletions(-)
diff --git a/libbtf.c b/libbtf.c
index 4829651b76c4..6b0fb4e4c137 100644
--- a/libbtf.c
+++ b/libbtf.c
@@ -87,6 +87,8 @@ struct btf_elf *btf_elf__new(const char *filename, Elf *elf)
btfe->raw_btf = true;
btfe->wordsize = sizeof(long);
btfe->is_big_endian = BYTE_ORDER == BIG_ENDIAN;
+ btf__set_endianness(btfe->btf,
+ btfe->is_big_endian ? BTF_BIG_ENDIAN : BTF_LITTLE_ENDIAN);
return btfe;
}
@@ -117,8 +119,14 @@ struct btf_elf *btf_elf__new(const char *filename, Elf *elf)
}
switch (btfe->ehdr.e_ident[EI_DATA]) {
- case ELFDATA2LSB: btfe->is_big_endian = false; break;
- case ELFDATA2MSB: btfe->is_big_endian = true; break;
+ case ELFDATA2LSB:
+ btfe->is_big_endian = false;
+ btf__set_endianness(btfe->btf, BTF_LITTLE_ENDIAN);
+ break;
+ case ELFDATA2MSB:
+ btfe->is_big_endian = true;
+ btf__set_endianness(btfe->btf, BTF_BIG_ENDIAN);
+ break;
default:
fprintf(stderr, "%s: unknown elf endianness.\n", __func__);
goto errout;
@@ -701,6 +709,18 @@ static int btf_elf__write(const char *filename, struct btf *btf)
goto out;
}
+ switch (ehdr_mem.e_ident[EI_DATA]) {
+ case ELFDATA2LSB:
+ btf__set_endianness(btf, BTF_LITTLE_ENDIAN);
+ break;
+ case ELFDATA2MSB:
+ btf__set_endianness(btf, BTF_BIG_ENDIAN);
+ break;
+ default:
+ fprintf(stderr, "%s: unknown elf endianness.\n", __func__);
+ goto out;
+ }
+
/*
* First we look if there was already a .BTF section to overwrite.
*/
--
2.24.1
