diff options
| -rw-r--r-- | arch/arm64/include/asm/insn.h | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/insn.c | 81 |
2 files changed, 66 insertions, 16 deletions
diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index d2f49423c5dc..f81b328d9cf4 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -285,6 +285,7 @@ bool aarch64_insn_is_nop(u32 insn); int aarch64_insn_read(void *addr, u32 *insnp); int aarch64_insn_write(void *addr, u32 insn); enum aarch64_insn_encoding_class aarch64_get_insn_class(u32 insn); +u64 aarch64_insn_decode_immediate(enum aarch64_insn_imm_type type, u32 insn); u32 aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type, u32 insn, u64 imm); u32 aarch64_insn_gen_branch_imm(unsigned long pc, unsigned long addr, diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index c8eca88f12e6..924902083e47 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -265,23 +265,13 @@ int __kprobes aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt) return aarch64_insn_patch_text_sync(addrs, insns, cnt); } -u32 __kprobes aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type, - u32 insn, u64 imm) +static int __kprobes aarch64_get_imm_shift_mask(enum aarch64_insn_imm_type type, + u32 *maskp, int *shiftp) { - u32 immlo, immhi, lomask, himask, mask; + u32 mask; int shift; switch (type) { - case AARCH64_INSN_IMM_ADR: - lomask = 0x3; - himask = 0x7ffff; - immlo = imm & lomask; - imm >>= 2; - immhi = imm & himask; - imm = (immlo << 24) | (immhi); - mask = (lomask << 24) | (himask); - shift = 5; - break; case AARCH64_INSN_IMM_26: mask = BIT(26) - 1; shift = 0; @@ -320,9 +310,68 @@ u32 __kprobes aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type, shift = 16; break; default: - pr_err("aarch64_insn_encode_immediate: unknown immediate encoding %d\n", - type); - return 0; + return -EINVAL; + } + + *maskp = mask; + *shiftp = shift; + + return 0; +} + +#define ADR_IMM_HILOSPLIT 2 +#define ADR_IMM_SIZE SZ_2M +#define ADR_IMM_LOMASK ((1 << ADR_IMM_HILOSPLIT) - 1) +#define ADR_IMM_HIMASK ((ADR_IMM_SIZE >> ADR_IMM_HILOSPLIT) - 1) +#define ADR_IMM_LOSHIFT 29 +#define ADR_IMM_HISHIFT 5 + +u64 aarch64_insn_decode_immediate(enum aarch64_insn_imm_type type, u32 insn) +{ + u32 immlo, immhi, mask; + int shift; + + switch (type) { + case AARCH64_INSN_IMM_ADR: + shift = 0; + immlo = (insn >> ADR_IMM_LOSHIFT) & ADR_IMM_LOMASK; + immhi = (insn >> ADR_IMM_HISHIFT) & ADR_IMM_HIMASK; + insn = (immhi << ADR_IMM_HILOSPLIT) | immlo; + mask = ADR_IMM_SIZE - 1; + break; + default: + if (aarch64_get_imm_shift_mask(type, &mask, &shift) < 0) { + pr_err("aarch64_insn_decode_immediate: unknown immediate encoding %d\n", + type); + return 0; + } + } + + return (insn >> shift) & mask; +} + +u32 __kprobes aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type, + u32 insn, u64 imm) +{ + u32 immlo, immhi, mask; + int shift; + + switch (type) { + case AARCH64_INSN_IMM_ADR: + shift = 0; + immlo = (imm & ADR_IMM_LOMASK) << ADR_IMM_LOSHIFT; + imm >>= ADR_IMM_HILOSPLIT; + immhi = (imm & ADR_IMM_HIMASK) << ADR_IMM_HISHIFT; + imm = immlo | immhi; + mask = ((ADR_IMM_LOMASK << ADR_IMM_LOSHIFT) | + (ADR_IMM_HIMASK << ADR_IMM_HISHIFT)); + break; + default: + if (aarch64_get_imm_shift_mask(type, &mask, &shift) < 0) { + pr_err("aarch64_insn_encode_immediate: unknown immediate encoding %d\n", + type); + return 0; + } } /* Update the immediate field. */ |