examples/link-cp: avoid misaligned struct io_data access#1586
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examples/link-cp: avoid misaligned struct io_data access#1586rootvector2 wants to merge 1 commit into
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queue_rw_pair() placed struct io_data at ptr + size, so any block size not a multiple of 8 (the partial tail block of a copy) accessed the io_data members through a misaligned pointer, which is undefined behavior and faults under -fsanitize=alignment. Allocate the struct first and point iov_base at data + 1, matching io_uring-cp.c, and free data directly. Signed-off-by: rootvector2 <dxbnaveed.k@gmail.com>
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queue_rw_pair() places struct io_data at ptr + size, so for any block size not a multiple of 8 (the partial tail block of most copies) the io_data members are accessed through a misaligned pointer, which is undefined behavior and faults under -fsanitize=alignment. Allocate the struct first and point iov_base at data + 1, matching io_uring-cp.c; the free in handle_cqe then drops the base recomputation.