mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-26 05:34:13 +08:00
c14d31bae3
So far the RELACOUNT tag from the ELF header was containing the exact number of R_PPC_RELATIVE/R_PPC64_RELATIVE relocations. However the LLVM's recent change [1] make it equal-or-less than the actual number which makes it useless. This replaces RELACOUNT in zImage loader with a pair of RELASZ and RELAENT. The vmlinux relocation code is fixed in commitd799769188("powerpc/64: Add UADDR64 relocation support"). To make it more future proof, this walks through the entire .rela.dyn section instead of assuming that the section is sorter by a relocation type. Unliked799769188, this does not add unaligned UADDR/UADDR64 relocations as we are likely not to see those in practice - the zImage is small and very arch specific so there is a smaller chance that some generic feature (such as PRINK_INDEX) triggers unaligned relocations. [1] https://github.com/llvm/llvm-project/commit/da0e5b885b25cf4 Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220406070038.3704604-1-aik@ozlabs.ru
309 lines
6.6 KiB
ArmAsm
309 lines
6.6 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
/*
|
|
* Copyright (C) Paul Mackerras 1997.
|
|
*
|
|
* Adapted for 64 bit LE PowerPC by Andrew Tauferner
|
|
*/
|
|
|
|
#include "ppc_asm.h"
|
|
|
|
RELA = 7
|
|
RELASZ = 8
|
|
RELAENT = 9
|
|
|
|
.data
|
|
/* A procedure descriptor used when booting this as a COFF file.
|
|
* When making COFF, this comes first in the link and we're
|
|
* linked at 0x500000.
|
|
*/
|
|
.globl _zimage_start_opd
|
|
_zimage_start_opd:
|
|
.long 0x500000, 0, 0, 0
|
|
.text
|
|
b _zimage_start
|
|
|
|
#ifdef __powerpc64__
|
|
.balign 8
|
|
p_start: .8byte _start
|
|
p_etext: .8byte _etext
|
|
p_bss_start: .8byte __bss_start
|
|
p_end: .8byte _end
|
|
|
|
p_toc: .8byte .TOC. - p_base
|
|
p_dyn: .8byte __dynamic_start - p_base
|
|
p_rela: .8byte __rela_dyn_start - p_base
|
|
p_prom: .8byte 0
|
|
.weak _platform_stack_top
|
|
p_pstack: .8byte _platform_stack_top
|
|
#else
|
|
p_start: .long _start
|
|
p_etext: .long _etext
|
|
p_bss_start: .long __bss_start
|
|
p_end: .long _end
|
|
|
|
.weak _platform_stack_top
|
|
p_pstack: .long _platform_stack_top
|
|
#endif
|
|
|
|
.weak _zimage_start
|
|
_zimage_start:
|
|
.globl _zimage_start_lib
|
|
_zimage_start_lib:
|
|
/* Work out the offset between the address we were linked at
|
|
and the address where we're running. */
|
|
bl .+4
|
|
p_base: mflr r10 /* r10 now points to runtime addr of p_base */
|
|
#ifndef __powerpc64__
|
|
/* grab the link address of the dynamic section in r11 */
|
|
addis r11,r10,(_GLOBAL_OFFSET_TABLE_-p_base)@ha
|
|
lwz r11,(_GLOBAL_OFFSET_TABLE_-p_base)@l(r11)
|
|
cmpwi r11,0
|
|
beq 3f /* if not linked -pie */
|
|
/* get the runtime address of the dynamic section in r12 */
|
|
.weak __dynamic_start
|
|
addis r12,r10,(__dynamic_start-p_base)@ha
|
|
addi r12,r12,(__dynamic_start-p_base)@l
|
|
subf r11,r11,r12 /* runtime - linktime offset */
|
|
|
|
/* The dynamic section contains a series of tagged entries.
|
|
* We need the RELA and RELACOUNT entries. */
|
|
li r9,0
|
|
li r0,0
|
|
9: lwz r8,0(r12) /* get tag */
|
|
cmpwi r8,0
|
|
beq 10f /* end of list */
|
|
cmpwi r8,RELA
|
|
bne 11f
|
|
lwz r9,4(r12) /* get RELA pointer in r9 */
|
|
b 12f
|
|
11: cmpwi r8,RELASZ
|
|
bne .Lcheck_for_relaent
|
|
lwz r0,4(r12) /* get RELASZ value in r0 */
|
|
b 12f
|
|
.Lcheck_for_relaent:
|
|
cmpwi r8,RELAENT
|
|
bne 12f
|
|
lwz r14,4(r12) /* get RELAENT value in r14 */
|
|
12: addi r12,r12,8
|
|
b 9b
|
|
|
|
/* The relocation section contains a list of relocations.
|
|
* We now do the R_PPC_RELATIVE ones, which point to words
|
|
* which need to be initialized with addend + offset */
|
|
10: /* skip relocation if we don't have both */
|
|
cmpwi r0,0
|
|
beq 3f
|
|
cmpwi r9,0
|
|
beq 3f
|
|
cmpwi r14,0
|
|
beq 3f
|
|
|
|
add r9,r9,r11 /* Relocate RELA pointer */
|
|
divwu r0,r0,r14 /* RELASZ / RELAENT */
|
|
mtctr r0
|
|
2: lbz r0,4+3(r9) /* ELF32_R_INFO(reloc->r_info) */
|
|
cmpwi r0,22 /* R_PPC_RELATIVE */
|
|
bne .Lnext
|
|
lwz r12,0(r9) /* reloc->r_offset */
|
|
lwz r0,8(r9) /* reloc->r_addend */
|
|
add r0,r0,r11
|
|
stwx r0,r11,r12
|
|
.Lnext: add r9,r9,r14
|
|
bdnz 2b
|
|
|
|
/* Do a cache flush for our text, in case the loader didn't */
|
|
3: lwz r9,p_start-p_base(r10) /* note: these are relocated now */
|
|
lwz r8,p_etext-p_base(r10)
|
|
4: dcbf r0,r9
|
|
icbi r0,r9
|
|
addi r9,r9,0x20
|
|
cmplw cr0,r9,r8
|
|
blt 4b
|
|
sync
|
|
isync
|
|
|
|
/* Clear the BSS */
|
|
lwz r9,p_bss_start-p_base(r10)
|
|
lwz r8,p_end-p_base(r10)
|
|
li r0,0
|
|
5: stw r0,0(r9)
|
|
addi r9,r9,4
|
|
cmplw cr0,r9,r8
|
|
blt 5b
|
|
|
|
/* Possibly set up a custom stack */
|
|
lwz r8,p_pstack-p_base(r10)
|
|
cmpwi r8,0
|
|
beq 6f
|
|
lwz r1,0(r8)
|
|
li r0,0
|
|
stwu r0,-16(r1) /* establish a stack frame */
|
|
6:
|
|
#else /* __powerpc64__ */
|
|
/* Save the prom pointer at p_prom. */
|
|
std r5,(p_prom-p_base)(r10)
|
|
|
|
/* Set r2 to the TOC. */
|
|
ld r2,(p_toc-p_base)(r10)
|
|
add r2,r2,r10
|
|
|
|
/* Grab the link address of the dynamic section in r11. */
|
|
ld r11,-32768(r2)
|
|
cmpwi r11,0
|
|
beq 3f /* if not linked -pie then no dynamic section */
|
|
|
|
ld r11,(p_dyn-p_base)(r10)
|
|
add r11,r11,r10
|
|
ld r9,(p_rela-p_base)(r10)
|
|
add r9,r9,r10
|
|
|
|
li r13,0
|
|
li r8,0
|
|
9: ld r12,0(r11) /* get tag */
|
|
cmpdi r12,0
|
|
beq 12f /* end of list */
|
|
cmpdi r12,RELA
|
|
bne 10f
|
|
ld r13,8(r11) /* get RELA pointer in r13 */
|
|
b 11f
|
|
10: cmpwi r12,RELASZ
|
|
bne .Lcheck_for_relaent
|
|
lwz r8,8(r11) /* get RELASZ pointer in r8 */
|
|
b 11f
|
|
.Lcheck_for_relaent:
|
|
cmpwi r12,RELAENT
|
|
bne 11f
|
|
lwz r14,8(r11) /* get RELAENT pointer in r14 */
|
|
11: addi r11,r11,16
|
|
b 9b
|
|
12:
|
|
cmpdi r13,0 /* check we have both RELA, RELASZ, RELAENT*/
|
|
cmpdi cr1,r8,0
|
|
beq 3f
|
|
beq cr1,3f
|
|
cmpdi r14,0
|
|
beq 3f
|
|
|
|
/* Calcuate the runtime offset. */
|
|
subf r13,r13,r9
|
|
|
|
/* Run through the list of relocations and process the
|
|
* R_PPC64_RELATIVE ones. */
|
|
divdu r8,r8,r14 /* RELASZ / RELAENT */
|
|
mtctr r8
|
|
13: ld r0,8(r9) /* ELF64_R_TYPE(reloc->r_info) */
|
|
cmpdi r0,22 /* R_PPC64_RELATIVE */
|
|
bne .Lnext
|
|
ld r12,0(r9) /* reloc->r_offset */
|
|
ld r0,16(r9) /* reloc->r_addend */
|
|
add r0,r0,r13
|
|
stdx r0,r13,r12
|
|
.Lnext: add r9,r9,r14
|
|
bdnz 13b
|
|
|
|
/* Do a cache flush for our text, in case the loader didn't */
|
|
3: ld r9,p_start-p_base(r10) /* note: these are relocated now */
|
|
ld r8,p_etext-p_base(r10)
|
|
4: dcbf r0,r9
|
|
icbi r0,r9
|
|
addi r9,r9,0x20
|
|
cmpld cr0,r9,r8
|
|
blt 4b
|
|
sync
|
|
isync
|
|
|
|
/* Clear the BSS */
|
|
ld r9,p_bss_start-p_base(r10)
|
|
ld r8,p_end-p_base(r10)
|
|
li r0,0
|
|
5: std r0,0(r9)
|
|
addi r9,r9,8
|
|
cmpld cr0,r9,r8
|
|
blt 5b
|
|
|
|
/* Possibly set up a custom stack */
|
|
ld r8,p_pstack-p_base(r10)
|
|
cmpdi r8,0
|
|
beq 6f
|
|
ld r1,0(r8)
|
|
li r0,0
|
|
stdu r0,-112(r1) /* establish a stack frame */
|
|
6:
|
|
#endif /* __powerpc64__ */
|
|
/* Call platform_init() */
|
|
bl platform_init
|
|
|
|
/* Call start */
|
|
b start
|
|
|
|
#ifdef __powerpc64__
|
|
|
|
#define PROM_FRAME_SIZE 512
|
|
|
|
.macro OP_REGS op, width, start, end, base, offset
|
|
.Lreg=\start
|
|
.rept (\end - \start + 1)
|
|
\op .Lreg,\offset+\width*.Lreg(\base)
|
|
.Lreg=.Lreg+1
|
|
.endr
|
|
.endm
|
|
|
|
#define SAVE_GPRS(start, end, base) OP_REGS std, 8, start, end, base, 0
|
|
#define REST_GPRS(start, end, base) OP_REGS ld, 8, start, end, base, 0
|
|
#define SAVE_GPR(n, base) SAVE_GPRS(n, n, base)
|
|
#define REST_GPR(n, base) REST_GPRS(n, n, base)
|
|
|
|
/* prom handles the jump into and return from firmware. The prom args pointer
|
|
is loaded in r3. */
|
|
.globl prom
|
|
prom:
|
|
mflr r0
|
|
std r0,16(r1)
|
|
stdu r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */
|
|
|
|
SAVE_GPR(2, r1)
|
|
SAVE_GPRS(13, 31, r1)
|
|
mfcr r10
|
|
std r10,8*32(r1)
|
|
mfmsr r10
|
|
std r10,8*33(r1)
|
|
|
|
/* remove MSR_LE from msr but keep MSR_SF */
|
|
mfmsr r10
|
|
rldicr r10,r10,0,62
|
|
mtsrr1 r10
|
|
|
|
/* Load FW address, set LR to label 1, and jump to FW */
|
|
bl 0f
|
|
0: mflr r10
|
|
addi r11,r10,(1f-0b)
|
|
mtlr r11
|
|
|
|
ld r10,(p_prom-0b)(r10)
|
|
mtsrr0 r10
|
|
|
|
rfid
|
|
|
|
1: /* Return from OF */
|
|
FIXUP_ENDIAN
|
|
|
|
/* Restore registers and return. */
|
|
rldicl r1,r1,0,32
|
|
|
|
/* Restore the MSR (back to 64 bits) */
|
|
ld r10,8*(33)(r1)
|
|
mtmsr r10
|
|
isync
|
|
|
|
/* Restore other registers */
|
|
REST_GPR(2, r1)
|
|
REST_GPRS(13, 31, r1)
|
|
ld r10,8*32(r1)
|
|
mtcr r10
|
|
|
|
addi r1,r1,PROM_FRAME_SIZE
|
|
ld r0,16(r1)
|
|
mtlr r0
|
|
blr
|
|
#endif
|