| /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| /* |
| * Code to process dynamic relocations in the kernel. |
| * |
| * Copyright 2008 Paul Mackerras, IBM Corp. |
| */ |
| |
| #include <asm/ppc_asm.h> |
| |
| RELA = 7 |
| RELASZ = 8 |
| RELAENT = 9 |
| R_PPC64_RELATIVE = 22 |
| R_PPC64_UADDR64 = 43 |
| |
| /* |
| * r3 = desired final address of kernel |
| */ |
| _GLOBAL(relocate) |
| mflr r0 |
| bcl 20,31,$+4 |
| 0: mflr r12 /* r12 has runtime addr of label 0 */ |
| mtlr r0 |
| ld r11,(p_dyn - 0b)(r12) |
| add r11,r11,r12 /* r11 has runtime addr of .dynamic section */ |
| ld r9,(p_rela - 0b)(r12) |
| add r9,r9,r12 /* r9 has runtime addr of .rela.dyn section */ |
| ld r10,(p_st - 0b)(r12) |
| add r10,r10,r12 /* r10 has runtime addr of _stext */ |
| ld r4,(p_sym - 0b)(r12) |
| add r4,r4,r12 /* r4 has runtime addr of .dynsym */ |
| |
| /* |
| * Scan the dynamic section for the RELA, RELASZ and RELAENT entries. |
| */ |
| li r7,0 |
| li r8,0 |
| .Ltags: |
| ld r6,0(r11) /* get tag */ |
| cmpdi r6,0 |
| beq .Lend_of_list /* end of list */ |
| cmpdi r6,RELA |
| bne 2f |
| ld r7,8(r11) /* get RELA pointer in r7 */ |
| b 4f |
| 2: cmpdi r6,RELASZ |
| bne 3f |
| ld r8,8(r11) /* get RELASZ value in r8 */ |
| b 4f |
| 3: cmpdi r6,RELAENT |
| bne 4f |
| ld r12,8(r11) /* get RELAENT value in r12 */ |
| 4: addi r11,r11,16 |
| b .Ltags |
| .Lend_of_list: |
| cmpdi r7,0 /* check we have RELA, RELASZ, RELAENT */ |
| cmpdi cr1,r8,0 |
| beq .Lout |
| beq cr1,.Lout |
| cmpdi r12,0 |
| beq .Lout |
| |
| /* |
| * Work out linktime address of _stext and hence the |
| * relocation offset to be applied. |
| * cur_offset [r7] = rela.run [r9] - rela.link [r7] |
| * _stext.link [r10] = _stext.run [r10] - cur_offset [r7] |
| * final_offset [r3] = _stext.final [r3] - _stext.link [r10] |
| */ |
| subf r7,r7,r9 /* cur_offset */ |
| subf r10,r7,r10 |
| subf r3,r10,r3 /* final_offset */ |
| |
| /* |
| * Run through the list of relocations and process the |
| * R_PPC64_RELATIVE and R_PPC64_UADDR64 ones. |
| */ |
| divd r8,r8,r12 /* RELASZ / RELAENT */ |
| mtctr r8 |
| .Lrels: ld r0,8(r9) /* ELF64_R_TYPE(reloc->r_info) */ |
| cmpdi r0,R_PPC64_RELATIVE |
| bne .Luaddr64 |
| ld r6,0(r9) /* reloc->r_offset */ |
| ld r0,16(r9) /* reloc->r_addend */ |
| b .Lstore |
| .Luaddr64: |
| srdi r5,r0,32 /* ELF64_R_SYM(reloc->r_info) */ |
| clrldi r0,r0,32 |
| cmpdi r0,R_PPC64_UADDR64 |
| bne .Lnext |
| ld r6,0(r9) |
| ld r0,16(r9) |
| mulli r5,r5,24 /* 24 == sizeof(elf64_sym) */ |
| add r5,r5,r4 /* elf64_sym[ELF64_R_SYM] */ |
| ld r5,8(r5) |
| add r0,r0,r5 |
| .Lstore: |
| add r0,r0,r3 |
| stdx r0,r7,r6 |
| .Lnext: |
| add r9,r9,r12 |
| bdnz .Lrels |
| .Lout: |
| blr |
| |
| .balign 8 |
| p_dyn: .8byte __dynamic_start - 0b |
| p_rela: .8byte __rela_dyn_start - 0b |
| p_sym: .8byte __dynamic_symtab - 0b |
| p_st: .8byte _stext - 0b |
| |
