diff options
Diffstat (limited to 'arch/powerpc/kernel/reloc_64.S')
| -rw-r--r-- | arch/powerpc/kernel/reloc_64.S | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/reloc_64.S b/arch/powerpc/kernel/reloc_64.S new file mode 100644 index 000000000..efd52f2e7 --- /dev/null +++ b/arch/powerpc/kernel/reloc_64.S @@ -0,0 +1,111 @@ +/* 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 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 + |