Add two-stage ARM64 trampoline allocation with instruction expansion#26
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Add two-stage ARM64 trampoline allocation with instruction expansion#26
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The previous fix used alloc_near with a fixed ±128MB range for ARM64 trampolines. This fails on some VM layouts where no free memory exists within that range. - Try ±128MB first (all relocations fit in-place), then ±4GB (covers ADRP), then unrestricted mmap as final fallback - When a relocated instruction overflows its immediate range, expand it to an absolute sequence (LDR X16 + BR X16 for branches, MOVZ/MOVK for address loads, inverted condition + absolute branch for conditionals) - Trampoline is now variable-length: Vec<u32> instead of fixed offsets - Dynamic error messages in alloc_near show actual max_range - 7 new unit tests for all expansion types (B, BL, ADR, ADRP, CBZ, TBZ, near-stays-single)
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The previous fix used alloc_near with a fixed ±128MB range for ARM64 trampolines. This fails on some VM layouts where no free memory exists within that range.