maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/lld/test/ELF/mips-n32-rels.s

72 lines
2.6 KiB
ArmAsm
Raw Normal View History

[ELF][MIPS] N32 ABI support In short the patch introduces support for linking object file conform MIPS N32 ABI [1]. This ABI is similar to N64 ABI but uses 32-bit pointer size. The most non-trivial requirement of this ABI is one more relocation packing format. N64 ABI puts multiple relocation type into the single relocation record. The N32 ABI uses series of successive relocations with the same offset for this purpose. In this patch, new function `mergeMipsN32RelTypes` handle this case and "convert" N32 relocation to the N64 relocation so the rest of the code keep unchanged. For now, linker does not support series of relocations applied to sections without SHF_ALLOC bit. Probably later I will add the support or insert some sort of assert into the `relocateNonAlloc` routine to catch this case. [1] ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/MIPS-N32-ABI-Handbook.pdf Differential revision: https://reviews.llvm.org/D26298 llvm-svn: 286052
2016-11-06 06:58:01 +08:00
# Check handling of N32 ABI relocation records.
# For now llvm-mc generates incorrect object files for N32 ABI.
# We use the binary input file generated by GNU tool.
# llvm-mc -filetype=obj -triple=mips64-unknown-linux \
# -target-abi n32 %s -o %t.o
# RUN: ld.lld %S/Inputs/mips-n32-rels.o -o %t.exe
# RUN: llvm-objdump -t -d -s %t.exe | FileCheck %s
# RUN: llvm-readobj -h %t.exe | FileCheck -check-prefix=ELF %s
# REQUIRES: mips
# .text
# .type __start, @function
# .global __start
# __start:
# lui $gp,%hi(%neg(%gp_rel(__start))) # R_MIPS_GPREL16
# # R_MIPS_SUB
# # R_MIPS_HI16
# loc:
# daddiu $gp,$gp,%lo(%neg(%gp_rel(__start))) # R_MIPS_GPREL16
# # R_MIPS_SUB
# # R_MIPS_LO16
#
# .section .rodata,"a",@progbits
# .gpword(loc) # R_MIPS_32
# CHECK: Disassembly of section .text:
# CHECK-NEXT: __start:
# CHECK-NEXT: 20000: 3c 1c 00 01 lui $gp, 1
# ^-- 0x20000 - 0x37ff0
# ^-- 0 - 0xfffe8010
# ^-- %hi(0x17ff0)
# CHECK: loc:
# CHECK-NEXT: 20004: 67 9c 7f f0 daddiu $gp, $gp, 32752
# ^-- 0x20000 - 0x37ff0
# ^-- 0 - 0xfffe8010
# ^-- %lo(0x17ff0)
# CHECK: Contents of section .rodata:
[ELF][MIPS] Exclude mips .got from PT_GNU_RELRO segment On MIPS .got section cannot be included into the PT_GNU_RELRO segment. Sometimes it might work, but in general it is unsupported. One of the problem is that all sections marked by SHF_MIPS_GPREL should be grouped together because data in these sections is addressable with a gp relative address, but such sections might be writable. This patch exclude mips .got from PT_GNU_RELRO segment and group SHF_MIPS_GPREL sections. llvm-svn: 292161
2017-01-17 05:17:23 +08:00
# CHECK-NEXT: 100d4 00020004
[ELF][MIPS] N32 ABI support In short the patch introduces support for linking object file conform MIPS N32 ABI [1]. This ABI is similar to N64 ABI but uses 32-bit pointer size. The most non-trivial requirement of this ABI is one more relocation packing format. N64 ABI puts multiple relocation type into the single relocation record. The N32 ABI uses series of successive relocations with the same offset for this purpose. In this patch, new function `mergeMipsN32RelTypes` handle this case and "convert" N32 relocation to the N64 relocation so the rest of the code keep unchanged. For now, linker does not support series of relocations applied to sections without SHF_ALLOC bit. Probably later I will add the support or insert some sort of assert into the `relocateNonAlloc` routine to catch this case. [1] ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/MIPS-N32-ABI-Handbook.pdf Differential revision: https://reviews.llvm.org/D26298 llvm-svn: 286052
2016-11-06 06:58:01 +08:00
# ^-- loc
# CHECK: 00020004 .text 00000000 loc
[ELF][MIPS] Make _gp, _gp_disp, __gnu_local_gp global symbols These MIPS specific symbols should be global because in general they can have an arbitrary value. By default this value is a fixed offset from .got section. This patch adds more checks to the mips-gp-local.s test case but marks it as XFAIL because LLD does not allow redefinition of absolute symbols value by a linker script. This should be fixed by D27276. Differential revision: https://reviews.llvm.org/D27524 llvm-svn: 289025
2016-12-08 14:19:47 +08:00
# CHECK: 00037ff0 *ABS* 00000000 .hidden _gp
[ELF][MIPS] N32 ABI support In short the patch introduces support for linking object file conform MIPS N32 ABI [1]. This ABI is similar to N64 ABI but uses 32-bit pointer size. The most non-trivial requirement of this ABI is one more relocation packing format. N64 ABI puts multiple relocation type into the single relocation record. The N32 ABI uses series of successive relocations with the same offset for this purpose. In this patch, new function `mergeMipsN32RelTypes` handle this case and "convert" N32 relocation to the N64 relocation so the rest of the code keep unchanged. For now, linker does not support series of relocations applied to sections without SHF_ALLOC bit. Probably later I will add the support or insert some sort of assert into the `relocateNonAlloc` routine to catch this case. [1] ftp://www.linux-mips.org/pub/linux/mips/doc/ABI/MIPS-N32-ABI-Handbook.pdf Differential revision: https://reviews.llvm.org/D26298 llvm-svn: 286052
2016-11-06 06:58:01 +08:00
# CHECK: 00020000 g F .text 00000000 __start
# ELF: Format: ELF32-mips
# ELF-NEXT: Arch: mips
# ELF-NEXT: AddressSize: 32bit
# ELF-NEXT: LoadName:
# ELF-NEXT: ElfHeader {
# ELF-NEXT: Ident {
# ELF-NEXT: Magic: (7F 45 4C 46)
# ELF-NEXT: Class: 32-bit (0x1)
# ELF-NEXT: DataEncoding: BigEndian (0x2)
# ELF-NEXT: FileVersion: 1
# ELF-NEXT: OS/ABI: SystemV (0x0)
# ELF-NEXT: ABIVersion: 0
# ELF-NEXT: Unused: (00 00 00 00 00 00 00)
# ELF-NEXT: }
# ELF-NEXT: Type: Executable (0x2)
# ELF-NEXT: Machine: EM_MIPS (0x8)
# ELF-NEXT: Version: 1
# ELF-NEXT: Entry: 0x20000
# ELF-NEXT: ProgramHeaderOffset:
# ELF-NEXT: SectionHeaderOffset:
# ELF-NEXT: Flags [
# ELF-NEXT: EF_MIPS_ABI2
# ELF-NEXT: EF_MIPS_ARCH_64R2
# ELF-NEXT: ]