diff options
Diffstat (limited to 'arch/arm64/kernel/alternative.c')
-rw-r--r-- | arch/arm64/kernel/alternative.c | 53 |
1 files changed, 1 insertions, 52 deletions
diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c index 21033bba9390..28f8365edc4c 100644 --- a/arch/arm64/kernel/alternative.c +++ b/arch/arm64/kernel/alternative.c @@ -24,7 +24,6 @@ #include <asm/cacheflush.h> #include <asm/alternative.h> #include <asm/cpufeature.h> -#include <asm/insn.h> #include <linux/stop_machine.h> extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; @@ -34,48 +33,6 @@ struct alt_region { struct alt_instr *end; }; -/* - * Decode the imm field of a b/bl instruction, and return the byte - * offset as a signed value (so it can be used when computing a new - * branch target). - */ -static s32 get_branch_offset(u32 insn) -{ - s32 imm = aarch64_insn_decode_immediate(AARCH64_INSN_IMM_26, insn); - - /* sign-extend the immediate before turning it into a byte offset */ - return (imm << 6) >> 4; -} - -static u32 get_alt_insn(u8 *insnptr, u8 *altinsnptr) -{ - u32 insn; - - aarch64_insn_read(altinsnptr, &insn); - - /* Stop the world on instructions we don't support... */ - BUG_ON(aarch64_insn_is_cbz(insn)); - BUG_ON(aarch64_insn_is_cbnz(insn)); - BUG_ON(aarch64_insn_is_bcond(insn)); - /* ... and there is probably more. */ - - if (aarch64_insn_is_b(insn) || aarch64_insn_is_bl(insn)) { - enum aarch64_insn_branch_type type; - unsigned long target; - - if (aarch64_insn_is_b(insn)) - type = AARCH64_INSN_BRANCH_NOLINK; - else - type = AARCH64_INSN_BRANCH_LINK; - - target = (unsigned long)altinsnptr + get_branch_offset(insn); - insn = aarch64_insn_gen_branch_imm((unsigned long)insnptr, - target, type); - } - - return insn; -} - static int __apply_alternatives(void *alt_region) { struct alt_instr *alt; @@ -83,9 +40,6 @@ static int __apply_alternatives(void *alt_region) u8 *origptr, *replptr; for (alt = region->begin; alt < region->end; alt++) { - u32 insn; - int i; - if (!cpus_have_cap(alt->cpufeature)) continue; @@ -95,12 +49,7 @@ static int __apply_alternatives(void *alt_region) origptr = (u8 *)&alt->orig_offset + alt->orig_offset; replptr = (u8 *)&alt->alt_offset + alt->alt_offset; - - for (i = 0; i < alt->alt_len; i += sizeof(insn)) { - insn = get_alt_insn(origptr + i, replptr + i); - aarch64_insn_write(origptr + i, insn); - } - + memcpy(origptr, replptr, alt->alt_len); flush_icache_range((uintptr_t)origptr, (uintptr_t)(origptr + alt->alt_len)); } |