diff options
| -rw-r--r-- | arch/arm/kernel/kprobes-decode.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/arm/kernel/kprobes-decode.c b/arch/arm/kernel/kprobes-decode.c index 4ab83f4c47cf..6d09db9c84ab 100644 --- a/arch/arm/kernel/kprobes-decode.c +++ b/arch/arm/kernel/kprobes-decode.c @@ -68,6 +68,8 @@ #define branch_displacement(insn) sign_extend(((insn) & 0xffffff) << 2, 25) +#define is_r15(insn, bitpos) (((insn) & (0xf << bitpos)) == (0xf << bitpos)) + #define PSR_fs (PSR_f|PSR_s) #define KPROBE_RETURN_INSTRUCTION 0xe1a0f00e /* mov pc, lr */ @@ -897,6 +899,9 @@ prep_emulate_ldr_str(kprobe_opcode_t insn, struct arch_specific_insn *asi) static enum kprobe_insn __kprobes prep_emulate_rd12rm0(kprobe_opcode_t insn, struct arch_specific_insn *asi) { + if (is_r15(insn, 12)) + return INSN_REJECTED; /* Rd is PC */ + insn &= 0xffff0ff0; /* Rd = r0, Rm = r0 */ asi->insn[0] = insn; asi->insn_handler = emulate_rd12rm0; @@ -907,6 +912,9 @@ static enum kprobe_insn __kprobes prep_emulate_rd12rn16rm0_wflags(kprobe_opcode_t insn, struct arch_specific_insn *asi) { + if (is_r15(insn, 12)) + return INSN_REJECTED; /* Rd is PC */ + insn &= 0xfff00ff0; /* Rd = r0, Rn = r0 */ insn |= 0x00000001; /* Rm = r1 */ asi->insn[0] = insn; @@ -918,6 +926,9 @@ static enum kprobe_insn __kprobes prep_emulate_rd16rs8rm0_wflags(kprobe_opcode_t insn, struct arch_specific_insn *asi) { + if (is_r15(insn, 16)) + return INSN_REJECTED; /* Rd is PC */ + insn &= 0xfff0f0f0; /* Rd = r0, Rs = r0 */ insn |= 0x00000001; /* Rm = r1 */ asi->insn[0] = insn; @@ -929,6 +940,9 @@ static enum kprobe_insn __kprobes prep_emulate_rd16rn12rs8rm0_wflags(kprobe_opcode_t insn, struct arch_specific_insn *asi) { + if (is_r15(insn, 16)) + return INSN_REJECTED; /* Rd is PC */ + insn &= 0xfff000f0; /* Rd = r0, Rn = r0 */ insn |= 0x00000102; /* Rs = r1, Rm = r2 */ asi->insn[0] = insn; @@ -940,6 +954,9 @@ static enum kprobe_insn __kprobes prep_emulate_rdhi16rdlo12rs8rm0_wflags(kprobe_opcode_t insn, struct arch_specific_insn *asi) { + if (is_r15(insn, 16) || is_r15(insn, 12)) + return INSN_REJECTED; /* RdHi or RdLo is PC */ + insn &= 0xfff000f0; /* RdHi = r0, RdLo = r1 */ insn |= 0x00001203; /* Rs = r2, Rm = r3 */ asi->insn[0] = insn; @@ -1035,6 +1052,8 @@ space_cccc_000x(kprobe_opcode_t insn, struct arch_specific_insn *asi) /* MRS cpsr : cccc 0001 0000 xxxx xxxx xxxx 0000 xxxx */ if ((insn & 0x0ff000f0) == 0x01000000) { + if (is_r15(insn, 12)) + return INSN_REJECTED; /* Rd is PC */ asi->insn_handler = simulate_mrs; return INSN_GOOD_NO_SLOT; } @@ -1065,6 +1084,8 @@ space_cccc_000x(kprobe_opcode_t insn, struct arch_specific_insn *asi) /* BLX(2) : cccc 0001 0010 xxxx xxxx xxxx 0011 xxxx */ /* BX : cccc 0001 0010 xxxx xxxx xxxx 0001 xxxx */ if ((insn & 0x0ff000d0) == 0x01200010) { + if ((insn & 0x0ff000ff) == 0x0120003f) + return INSN_REJECTED; /* BLX pc */ asi->insn_handler = simulate_blx2bx; return INSN_GOOD_NO_SLOT; } @@ -1234,6 +1255,8 @@ space_cccc_0110__1(kprobe_opcode_t insn, struct arch_specific_insn *asi) { /* SEL : cccc 0110 1000 xxxx xxxx xxxx 1011 xxxx GE: !!! */ if ((insn & 0x0ff000f0) == 0x068000b0) { + if (is_r15(insn, 12)) + return INSN_REJECTED; /* Rd is PC */ insn &= 0xfff00ff0; /* Rd = r0, Rn = r0 */ insn |= 0x00000001; /* Rm = r1 */ asi->insn[0] = insn; @@ -1247,6 +1270,8 @@ space_cccc_0110__1(kprobe_opcode_t insn, struct arch_specific_insn *asi) /* USAT16 : cccc 0110 1110 xxxx xxxx xxxx 0011 xxxx :Q */ if ((insn & 0x0fa00030) == 0x06a00010 || (insn & 0x0fb000f0) == 0x06a00030) { + if (is_r15(insn, 12)) + return INSN_REJECTED; /* Rd is PC */ insn &= 0xffff0ff0; /* Rd = r0, Rm = r0 */ asi->insn[0] = insn; asi->insn_handler = emulate_sat; @@ -1384,6 +1409,9 @@ space_cccc_1100_010x(kprobe_opcode_t insn, struct arch_specific_insn *asi) { /* MCRR : cccc 1100 0100 xxxx xxxx xxxx xxxx xxxx : (Rd!=Rn) */ /* MRRC : cccc 1100 0101 xxxx xxxx xxxx xxxx xxxx : (Rd!=Rn) */ + if (is_r15(insn, 16) || is_r15(insn, 12)) + return INSN_REJECTED; /* Rn or Rd is PC */ + insn &= 0xfff00fff; insn |= 0x00001000; /* Rn = r0, Rd = r1 */ asi->insn[0] = insn; |
