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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 | /* 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 r13,(p_sym - 0b)(r12) add r13,r13,r12 /* r13 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 r14,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 r14,r14,24 /* 24 == sizeof(elf64_sym) */ add r14,r14,r13 /* elf64_sym[ELF64_R_SYM] */ ld r14,8(r14) add r0,r0,r14 .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 |