Fix relocation addend sign extension on 32-bit platforms#4846
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sumleo wants to merge 1 commit intobytecodealliance:mainfrom
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Fix relocation addend sign extension on 32-bit platforms#4846sumleo wants to merge 1 commit intobytecodealliance:mainfrom
sumleo wants to merge 1 commit intobytecodealliance:mainfrom
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When loading relocations on 32-bit platforms, the addend is read as uint32 and zero-extended to uint64, which corrupts negative addends. For example, -4 (0xFFFFFFFC) becomes 4294967292 instead of remaining -4. Use int32 with sign extension to int64, matching the Windows code path which already handles this correctly.
sumleo
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TianlongLiang,
lum1n0us,
no1wudi and
yamt
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Summary
On 32-bit platforms,
load_relocation_sectionreads the relocation addend asuint32and zero-extends it touint64. This corrupts negative addends — for example, an addend of -4 (0xFFFFFFFCas a 32-bit value) becomes4294967292instead of remaining-4(0xFFFFFFFFFFFFFFFCas a 64-bit value).The Windows code path (around line 3616) already handles this correctly by declaring the addend as
int32and casting toint64, which performs proper sign extension.Changes
addend32fromuint32toint32soread_uint32populates it with the correct bit pattern(uint64)to(int64)so negative values are sign-extended rather than zero-extendedoffset32variable remainsuint32since relocation offsets are unsignedTest plan
sizeof(void *) != 8)