^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * arch/arm/probes/kprobes/checkers-thumb.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2014 Huawei Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include "../decode.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include "../decode-thumb.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include "checkers.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) static enum probes_insn __kprobes t32_check_stack(probes_opcode_t insn,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) struct arch_probes_insn *asi,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) const struct decode_header *h)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * PROBES_T32_LDMSTM, PROBES_T32_LDRDSTRD and PROBES_T32_LDRSTR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * may get here. Simply mark all normal insns as STACK_USE_NONE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) static const union decode_item table[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * First, filter out all ldr insns to make our life easier.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * Following load insns may come here:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * LDM, LDRD, LDR.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * In T32 encoding, bit 20 is enough for distinguishing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * load and store. All load insns have this bit set, when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * all store insns have this bit clear.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) DECODE_CUSTOM (0x00100000, 0x00100000, STACK_USE_NONE),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * Mark all 'STR{,B,H}, Rt, [Rn, Rm]' as STACK_USE_UNKNOWN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) * if Rn or Rm is SP. T32 doesn't encode STRD.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) /* xx | Rn | Rt | | Rm |*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) /* STR (register) 1111 1000 0100 xxxx xxxx 0000 00xx xxxx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) /* STRB (register) 1111 1000 0000 xxxx xxxx 0000 00xx xxxx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) /* STRH (register) 1111 1000 0010 xxxx xxxx 0000 00xx xxxx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) /* INVALID INSN 1111 1000 0110 xxxx xxxx 0000 00xx xxxx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) /* By Introducing INVALID INSN, bit 21 and 22 can be ignored. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) DECODE_OR (0xff9f0fc0, 0xf80d0000),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) DECODE_CUSTOM (0xff900fcf, 0xf800000d, STACK_USE_UNKNOWN),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) /* xx | Rn | Rt | PUW| imm8 |*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) /* STR (imm 8) 1111 1000 0100 1101 xxxx 110x xxxx xxxx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) /* STRB (imm 8) 1111 1000 0000 1101 xxxx 110x xxxx xxxx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) /* STRH (imm 8) 1111 1000 0010 1101 xxxx 110x xxxx xxxx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) /* INVALID INSN 1111 1000 0110 1101 xxxx 110x xxxx xxxx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) /* Only consider U == 0 and P == 1: strx rx, [sp, #-<imm>] */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) DECODE_CUSTOM (0xff9f0e00, 0xf80d0c00, STACK_USE_FIXED_0XX),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) /* For STR{,B,H} (imm 12), offset is always positive, so ignore them. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) /* P U W | Rn | Rt | Rt2| imm8 |*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) /* STRD (immediate) 1110 1001 01x0 1101 xxxx xxxx xxxx xxxx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * Only consider U == 0 and P == 1.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * Also note that STRD in T32 encoding is special:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * imm = ZeroExtend(imm8:'00', 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) DECODE_CUSTOM (0xffdf0000, 0xe94d0000, STACK_USE_T32STRD),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) /* | Rn | */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) /* STMDB 1110 1001 00x0 1101 xxxx xxxx xxxx xxxx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) DECODE_CUSTOM (0xffdf0000, 0xe90d0000, STACK_USE_STMDX),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) /* fall through */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) DECODE_CUSTOM (0, 0, STACK_USE_NONE),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) DECODE_END
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) return probes_decode_insn(insn, asi, table, false, false, stack_check_actions, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) const struct decode_checker t32_stack_checker[NUM_PROBES_T32_ACTIONS] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) [PROBES_T32_LDMSTM] = {.checker = t32_check_stack},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) [PROBES_T32_LDRDSTRD] = {.checker = t32_check_stack},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) [PROBES_T32_LDRSTR] = {.checker = t32_check_stack},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * See following comments. This insn must be 'push'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) static enum probes_insn __kprobes t16_check_stack(probes_opcode_t insn,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) struct arch_probes_insn *asi,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) const struct decode_header *h)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) unsigned int reglist = insn & 0x1ff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) asi->stack_space = hweight32(reglist) * 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) return INSN_GOOD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * T16 encoding is simple: only the 'push' insn can need extra stack space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) * Other insns, like str, can only use r0-r7 as Rn.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) const struct decode_checker t16_stack_checker[NUM_PROBES_T16_ACTIONS] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) [PROBES_T16_PUSH] = {.checker = t16_check_stack},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) };
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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