diff options
| -rw-r--r-- | arch/arm64/include/asm/insn.h | 10 | ||||
| -rw-r--r-- | arch/arm64/kernel/insn.c | 40 |
2 files changed, 50 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index fb4466022bd0..c44ad39ed310 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -66,6 +66,11 @@ enum aarch64_insn_imm_type { AARCH64_INSN_IMM_MAX }; +enum aarch64_insn_branch_type { + AARCH64_INSN_BRANCH_NOLINK, + AARCH64_INSN_BRANCH_LINK, +}; + #define __AARCH64_INSN_FUNCS(abbr, mask, val) \ static __always_inline bool aarch64_insn_is_##abbr(u32 code) \ { return (code & (mask)) == (val); } \ @@ -89,6 +94,11 @@ int aarch64_insn_write(void *addr, u32 insn); enum aarch64_insn_encoding_class aarch64_get_insn_class(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, + enum aarch64_insn_branch_type type); +u32 aarch64_insn_gen_hint(enum aarch64_insn_hint_op op); +u32 aarch64_insn_gen_nop(void); + bool aarch64_insn_hotpatch_safe(u32 old_insn, u32 new_insn); int aarch64_insn_patch_text_nosync(void *addr, u32 insn); diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index 7df08075fc7a..92f36835486b 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -14,6 +14,7 @@ * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include <linux/bitops.h> #include <linux/compiler.h> #include <linux/kernel.h> #include <linux/smp.h> @@ -262,3 +263,42 @@ u32 __kprobes aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type, return insn; } + +u32 __kprobes aarch64_insn_gen_branch_imm(unsigned long pc, unsigned long addr, + enum aarch64_insn_branch_type type) +{ + u32 insn; + long offset; + + /* + * PC: A 64-bit Program Counter holding the address of the current + * instruction. A64 instructions must be word-aligned. + */ + BUG_ON((pc & 0x3) || (addr & 0x3)); + + /* + * B/BL support [-128M, 128M) offset + * ARM64 virtual address arrangement guarantees all kernel and module + * texts are within +/-128M. + */ + offset = ((long)addr - (long)pc); + BUG_ON(offset < -SZ_128M || offset >= SZ_128M); + + if (type == AARCH64_INSN_BRANCH_LINK) + insn = aarch64_insn_get_bl_value(); + else + insn = aarch64_insn_get_b_value(); + + return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_26, insn, + offset >> 2); +} + +u32 __kprobes aarch64_insn_gen_hint(enum aarch64_insn_hint_op op) +{ + return aarch64_insn_get_hint_value() | op; +} + +u32 __kprobes aarch64_insn_gen_nop(void) +{ + return aarch64_insn_gen_hint(AARCH64_INSN_HINT_NOP); +} |