Repository navigation
[X86] Support i386 GOT-base relocations - #2032
Open
Bhoumik Patidar (BhoumikPatidar) wants to merge 3 commits into
Open
Bhoumik Patidar (BhoumikPatidar) wants to merge 3 commits into
Bhoumik Patidar (BhoumikPatidar) wants to merge 3 commits into
Conversation
Bhoumik Patidar (BhoumikPatidar)
requested a review
from Parth (parth-07)
as a code owner
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>
Bhoumik Patidar (BhoumikPatidar)
force-pushed
the
x86_32_got_base_relocations
branch
from
October 5, 2026 10:24
99076a7 to
1b99881
Compare
Steven Ramirez Rosa (Steven6798)
approved these changes
Oct 5, 2026
Shankar Easwaran (quic-seaswara)
approved these changes
Oct 7, 2026
This branch has not been deployed
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Add the
ELF32dynamic-section and GOT-base support required byi386links.i386dynamic relocation sections useElf32_Relrecords and 4-byte alignment. Configure the generic dynamic-section builder accordingly, then implementR_386_GOTOFFas S + A - GOT andR_386_GOTPCasGOT + A - P.Create
_GLOBAL_OFFSET_TABLE_only when a supported GOT-base relocation needs it. The symbol points to the generatedGOTPLT0fragment, 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