op.h: Add additional padding to struct opslab to ensure proper alignment #17875
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On m68k, the natural alignment is 16 bits which causes the opslab_opslot member of struct opslab to be aligned at a 16-bit offset. Other 32-bit and 64-bit architectures have a natural alignment of at least 32 bits, so the offset is always guaranteed to be at least 32-bit-aligned. Fix this by adding additional padding bytes before the opslab_opslot member, both for cases when PERL_DEBUG_READONLY_OPS defined and not defined to ensure the offset of oplab_slots is always 32-bit-aligned. On architectures which have a natural alignment of at least 32 bits, the padding does not affect the alignment, offsets or struct size.
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This is available for smoke-testing in the |
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I would like one of the reviewers to approve before merging, as we're in completely freeze and this is truly far past the very last minute for any change. |
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On IRC this received a +1 from Leon, Karl, and xenu. Merging it. |
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On m68k, the natural alignment is 16 bits which causes the opslab_opslot
member of "struct opslab" to be aligned at a 16-bit offset. Other 32-bit
and 64-bit architectures have a natural alignment of at least 32 bits, so
the offset is always guaranteed to be at least 32-bit-aligned.
Fix this by adding additional padding bytes before the opslab_opslot
member, both for cases when PERL_DEBUG_READONLY_OPS defined and not
defined to ensure the offset of oplab_slots is always 32-bit-aligned.
On architectures which have a natural alignment of at least 32 bits,
the padding does not affect the alignment, offsets or struct size.