From c0cafbae20d2878883ec3c06d6ea30ff38a6bf92 Mon Sep 17 00:00:00 2001 From: Zi Shen Lim Date: Wed, 27 Aug 2014 05:15:18 +0100 Subject: [PATCH] arm64: introduce aarch64_insn_gen_branch_reg() Introduce function to generate unconditional branch (register) instructions. Signed-off-by: Zi Shen Lim Acked-by: Will Deacon Signed-off-by: Will Deacon --- arch/arm64/include/asm/insn.h | 7 +++++++ arch/arm64/kernel/insn.c | 35 +++++++++++++++++++++++++++++++++-- 2 files changed, 40 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index a98c4954b380..5080962058b0 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -71,6 +71,7 @@ enum aarch64_insn_imm_type { enum aarch64_insn_register_type { AARCH64_INSN_REGTYPE_RT, + AARCH64_INSN_REGTYPE_RN, }; enum aarch64_insn_register { @@ -119,6 +120,7 @@ enum aarch64_insn_variant { enum aarch64_insn_branch_type { AARCH64_INSN_BRANCH_NOLINK, AARCH64_INSN_BRANCH_LINK, + AARCH64_INSN_BRANCH_RETURN, AARCH64_INSN_BRANCH_COMP_ZERO, AARCH64_INSN_BRANCH_COMP_NONZERO, }; @@ -138,6 +140,9 @@ __AARCH64_INSN_FUNCS(hvc, 0xFFE0001F, 0xD4000002) __AARCH64_INSN_FUNCS(smc, 0xFFE0001F, 0xD4000003) __AARCH64_INSN_FUNCS(brk, 0xFFE0001F, 0xD4200000) __AARCH64_INSN_FUNCS(hint, 0xFFFFF01F, 0xD503201F) +__AARCH64_INSN_FUNCS(br, 0xFFFFFC1F, 0xD61F0000) +__AARCH64_INSN_FUNCS(blr, 0xFFFFFC1F, 0xD63F0000) +__AARCH64_INSN_FUNCS(ret, 0xFFFFFC1F, 0xD65F0000) #undef __AARCH64_INSN_FUNCS @@ -156,6 +161,8 @@ u32 aarch64_insn_gen_comp_branch_imm(unsigned long pc, unsigned long addr, enum aarch64_insn_branch_type type); u32 aarch64_insn_gen_hint(enum aarch64_insn_hint_op op); u32 aarch64_insn_gen_nop(void); +u32 aarch64_insn_gen_branch_reg(enum aarch64_insn_register reg, + enum aarch64_insn_branch_type type); bool aarch64_insn_hotpatch_safe(u32 old_insn, u32 new_insn); diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index d9f7827c5058..67979364daf6 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -283,6 +283,9 @@ static u32 aarch64_insn_encode_register(enum aarch64_insn_register_type type, case AARCH64_INSN_REGTYPE_RT: shift = 0; break; + case AARCH64_INSN_REGTYPE_RN: + shift = 5; + break; default: pr_err("%s: unknown register type encoding %d\n", __func__, type); @@ -325,10 +328,16 @@ u32 __kprobes aarch64_insn_gen_branch_imm(unsigned long pc, unsigned long addr, */ offset = branch_imm_common(pc, addr, SZ_128M); - if (type == AARCH64_INSN_BRANCH_LINK) + switch (type) { + case AARCH64_INSN_BRANCH_LINK: insn = aarch64_insn_get_bl_value(); - else + break; + case AARCH64_INSN_BRANCH_NOLINK: insn = aarch64_insn_get_b_value(); + break; + default: + BUG_ON(1); + } return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_26, insn, offset >> 2); @@ -380,3 +389,25 @@ u32 __kprobes aarch64_insn_gen_nop(void) { return aarch64_insn_gen_hint(AARCH64_INSN_HINT_NOP); } + +u32 aarch64_insn_gen_branch_reg(enum aarch64_insn_register reg, + enum aarch64_insn_branch_type type) +{ + u32 insn; + + switch (type) { + case AARCH64_INSN_BRANCH_NOLINK: + insn = aarch64_insn_get_br_value(); + break; + case AARCH64_INSN_BRANCH_LINK: + insn = aarch64_insn_get_blr_value(); + break; + case AARCH64_INSN_BRANCH_RETURN: + insn = aarch64_insn_get_ret_value(); + break; + default: + BUG_ON(1); + } + + return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, reg); +}