[X86] Support i386 GOT-base relocations - #2032
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Bhoumik Patidar (BhoumikPatidar) wants to merge 3 commits into
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Bhoumik Patidar (BhoumikPatidar) wants to merge 3 commits into
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Bhoumik Patidar (BhoumikPatidar)
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October 1, 2026 14:59
Add the relocation layer for i386 links: R_386_NONE, R_386_8, R_386_16, and R_386_32. Unlike x86-64, i386 uses Elf32_Rel rather than Elf64_Rela. The addend is stored in the field being relocated, so it must be read and sign-extended from that field width before evaluating S + A. Normalize the result to the 32-bit ELF address space before checking narrow fields and writing the result back. This preserves valid full-width 32-bit bit patterns, including addresses with bit 31 set, while rejecting values that cannot be encoded in 8- or 16-bit fields. Signed-off-by: Bhoumik Patidar <bpatidar@qti.qualcomm.com>
Implement R_386_PC8, R_386_PC16, and R_386_PC32 for i386 ELF32 links. Use signed range checks for narrow PC-relative relocations. PC8 must fit in a signed 8-bit field, while PC16 accepts a signed 17-bit result before truncating it to 16 bits, as required by 16-bit real-mode code. PC32 uses the full 32-bit field. Signed-off-by: Bhoumik Patidar <bpatidar@qti.qualcomm.com>
Add the ELF32 dynamic-section and GOT-base support required by i386 links. i386 dynamic relocation sections use Elf32_Rel records and 4-byte alignment. Configure the generic dynamic-section builder accordingly, then implement R_386_GOTOFF as S + A - GOT and R_386_GOTPC as GOT + A - P. Create _GLOBAL_OFFSET_TABLE_ only when a supported GOT-base relocation needs it. The symbol points to the generated GOTPLT0 fragment, which is the GOT base used by these relocations. This patch provides only the GOT base and its linker-defined symbol. It does not provide individual symbol GOT entries or PLT support. Signed-off-by: Bhoumik Patidar <bpatidar@qti.qualcomm.com>
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October 5, 2026 10:24
Steven Ramirez Rosa (Steven6798)
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Oct 5, 2026
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Add the ELF32 dynamic-section and GOT-base support required by i386 links.
i386 dynamic relocation sections use Elf32_Rel records and 4-byte alignment. Configure the generic dynamic-section builder accordingly, then implement R_386_GOTOFF as S + A - GOT and R_386_GOTPC as GOT + A - P.
Create _GLOBAL_OFFSET_TABLE_ only when a supported GOT-base relocation needs it. The symbol points to the generated GOTPLT0 fragment, which is the GOT base used by these relocations.
This patch provides only the GOT base and its linker-defined symbol. It does not provide individual symbol GOT entries or PLT support.
Resolves #2031
Progress On #1961