partition: fix unaligned access in load_mbr_header() #9
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load_mbr_header() casts an unaligned pointer to (mbr_entry_t *) then dereferences struct members with non-trivial alignment requirements. This causes a bl2 with BOOT_DEVICE=emmc to hang when compiled with clang 18.1.5, although it works when compiled with gcc 14.1.0. Presumably gcc's -mstrict-align papers over the undefined behaviour whereas clang's doesn't. Replace the unaligned cast with a safe memcpy() into an mbr_entry_t. Signed-off-by: Chris Webb <chris@arachsys.com>
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This bugfix has now also landed in upstream ARM trusted-firmware-a: |
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load_mbr_header()casts an unaligned pointer to(mbr_entry_t *)then dereferences struct members with non-trivial alignment requirements.This causes a bl2 with
BOOT_DEVICE=emmcto hang when compiled with clang 18.1.5, although it works when compiled with gcc 14.1.0, as described in #8. Presumably gcc's-mstrict-alignpapers over the undefined behaviour whereas clang's doesn't.Replace the unaligned cast with a safe
memcpy()into anmbr_entry_t.