Explicitly specify an alignment for abitag. Without it, gcc specifies a

section alignnment of 16 bytes for amd64 and this breaks file(1).
Before:
./cp: ELF 64-bit LSB executable, AMD x86-64, version 1 (FreeBSD), for \
  FreeBSD 127.7.9, statically linked, stripped
after:    ^^^^^^^
./ls: ELF 64-bit LSB executable, AMD x86-64, version 1 (FreeBSD), for \
  FreeBSD 5.0.1, dynamically linked (uses shared libs), stripped

The reason for this is that the NOTE sections are not contiguous
internally.  If the note section has an alignment of 16, then anything
that looks for the data is supposed to round up the payload start to
the next multiple of the alignment.  But FreeBSD/amd64 broke because the
structure is declared as a single structure, not a (header,payload) group,
where the payload had an explicit alignment roundup.

The alternative is to change things like file(1) to ignore the ELF payload
alignment rules for the PT_NOTE section only for FreeBSD.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/csu/common/crtbrand.c b/lib/csu/common/crtbrand.c
index 9405f91..dde60b3 100644
--- a/lib/csu/common/crtbrand.c
+++ b/lib/csu/common/crtbrand.c
@@ -43,7 +43,7 @@ static const struct {
     int32_t	type;
     char	name[sizeof ABI_VENDOR];
     int32_t	desc;
-} abitag __attribute__ ((section (ABI_SECTION))) __unused = {
+} abitag __attribute__ ((section (ABI_SECTION), aligned(4))) __unused = {
     sizeof ABI_VENDOR,
     sizeof(int32_t),
     ABI_NOTETYPE,