diff options
Diffstat (limited to 'arch/arm/kernel/kprobes.h')
| -rw-r--r-- | arch/arm/kernel/kprobes.h | 400 |
1 files changed, 12 insertions, 388 deletions
diff --git a/arch/arm/kernel/kprobes.h b/arch/arm/kernel/kprobes.h index 38945f78f9f..9a2712ecefc 100644 --- a/arch/arm/kernel/kprobes.h +++ b/arch/arm/kernel/kprobes.h @@ -19,6 +19,8 @@ #ifndef _ARM_KERNEL_KPROBES_H #define _ARM_KERNEL_KPROBES_H +#include "probes.h" + /* * These undefined instructions must be unique and * reserved solely for kprobes' use. @@ -27,402 +29,24 @@ #define KPROBE_THUMB16_BREAKPOINT_INSTRUCTION 0xde18 #define KPROBE_THUMB32_BREAKPOINT_INSTRUCTION 0xf7f0a018 +enum probes_insn __kprobes +kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_probes_insn *asi, + const struct decode_header *h); -enum kprobe_insn { - INSN_REJECTED, - INSN_GOOD, - INSN_GOOD_NO_SLOT -}; - -typedef enum kprobe_insn (kprobe_decode_insn_t)(kprobe_opcode_t, - struct arch_specific_insn *); +typedef enum probes_insn (kprobe_decode_insn_t)(probes_opcode_t, + struct arch_probes_insn *, + bool, + const union decode_action *); #ifdef CONFIG_THUMB2_KERNEL -enum kprobe_insn thumb16_kprobe_decode_insn(kprobe_opcode_t, - struct arch_specific_insn *); -enum kprobe_insn thumb32_kprobe_decode_insn(kprobe_opcode_t, - struct arch_specific_insn *); +extern const union decode_action kprobes_t32_actions[]; +extern const union decode_action kprobes_t16_actions[]; #else /* !CONFIG_THUMB2_KERNEL */ -enum kprobe_insn arm_kprobe_decode_insn(kprobe_opcode_t, - struct arch_specific_insn *); -#endif - -void __init arm_kprobe_decode_init(void); - -extern kprobe_check_cc * const kprobe_condition_checks[16]; - - -#if __LINUX_ARM_ARCH__ >= 7 - -/* str_pc_offset is architecturally defined from ARMv7 onwards */ -#define str_pc_offset 8 -#define find_str_pc_offset() - -#else /* __LINUX_ARM_ARCH__ < 7 */ - -/* We need a run-time check to determine str_pc_offset */ -extern int str_pc_offset; -void __init find_str_pc_offset(void); +extern const union decode_action kprobes_arm_actions[]; #endif - -/* - * Update ITSTATE after normal execution of an IT block instruction. - * - * The 8 IT state bits are split into two parts in CPSR: - * ITSTATE<1:0> are in CPSR<26:25> - * ITSTATE<7:2> are in CPSR<15:10> - */ -static inline unsigned long it_advance(unsigned long cpsr) - { - if ((cpsr & 0x06000400) == 0) { - /* ITSTATE<2:0> == 0 means end of IT block, so clear IT state */ - cpsr &= ~PSR_IT_MASK; - } else { - /* We need to shift left ITSTATE<4:0> */ - const unsigned long mask = 0x06001c00; /* Mask ITSTATE<4:0> */ - unsigned long it = cpsr & mask; - it <<= 1; - it |= it >> (27 - 10); /* Carry ITSTATE<2> to correct place */ - it &= mask; - cpsr &= ~mask; - cpsr |= it; - } - return cpsr; -} - -static inline void __kprobes bx_write_pc(long pcv, struct pt_regs *regs) -{ - long cpsr = regs->ARM_cpsr; - if (pcv & 0x1) { - cpsr |= PSR_T_BIT; - pcv &= ~0x1; - } else { - cpsr &= ~PSR_T_BIT; - pcv &= ~0x2; /* Avoid UNPREDICTABLE address allignment */ - } - regs->ARM_cpsr = cpsr; - regs->ARM_pc = pcv; -} - - -#if __LINUX_ARM_ARCH__ >= 6 - -/* Kernels built for >= ARMv6 should never run on <= ARMv5 hardware, so... */ -#define load_write_pc_interworks true -#define test_load_write_pc_interworking() - -#else /* __LINUX_ARM_ARCH__ < 6 */ - -/* We need run-time testing to determine if load_write_pc() should interwork. */ -extern bool load_write_pc_interworks; -void __init test_load_write_pc_interworking(void); - -#endif - -static inline void __kprobes load_write_pc(long pcv, struct pt_regs *regs) -{ - if (load_write_pc_interworks) - bx_write_pc(pcv, regs); - else - regs->ARM_pc = pcv; -} - - -#if __LINUX_ARM_ARCH__ >= 7 - -#define alu_write_pc_interworks true -#define test_alu_write_pc_interworking() - -#elif __LINUX_ARM_ARCH__ <= 5 - -/* Kernels built for <= ARMv5 should never run on >= ARMv6 hardware, so... */ -#define alu_write_pc_interworks false -#define test_alu_write_pc_interworking() - -#else /* __LINUX_ARM_ARCH__ == 6 */ - -/* We could be an ARMv6 binary on ARMv7 hardware so we need a run-time check. */ -extern bool alu_write_pc_interworks; -void __init test_alu_write_pc_interworking(void); - -#endif /* __LINUX_ARM_ARCH__ == 6 */ - -static inline void __kprobes alu_write_pc(long pcv, struct pt_regs *regs) -{ - if (alu_write_pc_interworks) - bx_write_pc(pcv, regs); - else - regs->ARM_pc = pcv; -} - - -void __kprobes kprobe_simulate_nop(struct kprobe *p, struct pt_regs *regs); -void __kprobes kprobe_emulate_none(struct kprobe *p, struct pt_regs *regs); - -enum kprobe_insn __kprobes -kprobe_decode_ldmstm(kprobe_opcode_t insn, struct arch_specific_insn *asi); - -/* - * Test if load/store instructions writeback the address register. - * if P (bit 24) == 0 or W (bit 21) == 1 - */ -#define is_writeback(insn) ((insn ^ 0x01000000) & 0x01200000) - -/* - * The following definitions and macros are used to build instruction - * decoding tables for use by kprobe_decode_insn. - * - * These tables are a concatenation of entries each of which consist of one of - * the decode_* structs. All of the fields in every type of decode structure - * are of the union type decode_item, therefore the entire decode table can be - * viewed as an array of these and declared like: - * - * static const union decode_item table_name[] = {}; - * - * In order to construct each entry in the table, macros are used to - * initialise a number of sequential decode_item values in a layout which - * matches the relevant struct. E.g. DECODE_SIMULATE initialise a struct - * decode_simulate by initialising four decode_item objects like this... - * - * {.bits = _type}, - * {.bits = _mask}, - * {.bits = _value}, - * {.handler = _handler}, - * - * Initialising a specified member of the union means that the compiler - * will produce a warning if the argument is of an incorrect type. - * - * Below is a list of each of the macros used to initialise entries and a - * description of the action performed when that entry is matched to an - * instruction. A match is found when (instruction & mask) == value. - * - * DECODE_TABLE(mask, value, table) - * Instruction decoding jumps to parsing the new sub-table 'table'. - * - * DECODE_CUSTOM(mask, value, decoder) - * The custom function 'decoder' is called to the complete decoding - * of an instruction. - * - * DECODE_SIMULATE(mask, value, handler) - * Set the probes instruction handler to 'handler', this will be used - * to simulate the instruction when the probe is hit. Decoding returns - * with INSN_GOOD_NO_SLOT. - * - * DECODE_EMULATE(mask, value, handler) - * Set the probes instruction handler to 'handler', this will be used - * to emulate the instruction when the probe is hit. The modified - * instruction (see below) is placed in the probes instruction slot so it - * may be called by the emulation code. Decoding returns with INSN_GOOD. - * - * DECODE_REJECT(mask, value) - * Instruction decoding fails with INSN_REJECTED - * - * DECODE_OR(mask, value) - * This allows the mask/value test of multiple table entries to be - * logically ORed. Once an 'or' entry is matched the decoding action to - * be performed is that of the next entry which isn't an 'or'. E.g. - * - * DECODE_OR (mask1, value1) - * DECODE_OR (mask2, value2) - * DECODE_SIMULATE (mask3, value3, simulation_handler) - * - * This means that if any of the three mask/value pairs match the - * instruction being decoded, then 'simulation_handler' will be used - * for it. - * - * Both the SIMULATE and EMULATE macros have a second form which take an - * additional 'regs' argument. - * - * DECODE_SIMULATEX(mask, value, handler, regs) - * DECODE_EMULATEX (mask, value, handler, regs) - * - * These are used to specify what kind of CPU register is encoded in each of the - * least significant 5 nibbles of the instruction being decoded. The regs value - * is specified using the REGS macro, this takes any of the REG_TYPE_* values - * from enum decode_reg_type as arguments; only the '*' part of the name is - * given. E.g. - * - * REGS(0, ANY, NOPC, 0, ANY) - * - * This indicates an instruction is encoded like: - * - * bits 19..16 ignore - * bits 15..12 any register allowed here - * bits 11.. 8 any register except PC allowed here - * bits 7.. 4 ignore - * bits 3.. 0 any register allowed here - * - * This register specification is checked after a decode table entry is found to - * match an instruction (through the mask/value test). Any invalid register then - * found in the instruction will cause decoding to fail with INSN_REJECTED. In - * the above example this would happen if bits 11..8 of the instruction were - * 1111, indicating R15 or PC. - * - * As well as checking for legal combinations of registers, this data is also - * used to modify the registers encoded in the instructions so that an - * emulation routines can use it. (See decode_regs() and INSN_NEW_BITS.) - * - * Here is a real example which matches ARM instructions of the form - * "AND <Rd>,<Rn>,<Rm>,<shift> <Rs>" - * - * DECODE_EMULATEX (0x0e000090, 0x00000010, emulate_rd12rn16rm0rs8_rwflags, - * REGS(ANY, ANY, NOPC, 0, ANY)), - * ^ ^ ^ ^ - * Rn Rd Rs Rm - * - * Decoding the instruction "AND R4, R5, R6, ASL R15" will be rejected because - * Rs == R15 - * - * Decoding the instruction "AND R4, R5, R6, ASL R7" will be accepted and the - * instruction will be modified to "AND R0, R2, R3, ASL R1" and then placed into - * the kprobes instruction slot. This can then be called later by the handler - * function emulate_rd12rn16rm0rs8_rwflags in order to simulate the instruction. - */ - -enum decode_type { - DECODE_TYPE_END, - DECODE_TYPE_TABLE, - DECODE_TYPE_CUSTOM, - DECODE_TYPE_SIMULATE, - DECODE_TYPE_EMULATE, - DECODE_TYPE_OR, - DECODE_TYPE_REJECT, - NUM_DECODE_TYPES /* Must be last enum */ -}; - -#define DECODE_TYPE_BITS 4 -#define DECODE_TYPE_MASK ((1 << DECODE_TYPE_BITS) - 1) - -enum decode_reg_type { - REG_TYPE_NONE = 0, /* Not a register, ignore */ - REG_TYPE_ANY, /* Any register allowed */ - REG_TYPE_SAMEAS16, /* Register should be same as that at bits 19..16 */ - REG_TYPE_SP, /* Register must be SP */ - REG_TYPE_PC, /* Register must be PC */ - REG_TYPE_NOSP, /* Register must not be SP */ - REG_TYPE_NOSPPC, /* Register must not be SP or PC */ - REG_TYPE_NOPC, /* Register must not be PC */ - REG_TYPE_NOPCWB, /* No PC if load/store write-back flag also set */ - - /* The following types are used when the encoding for PC indicates - * another instruction form. This distiction only matters for test - * case coverage checks. - */ - REG_TYPE_NOPCX, /* Register must not be PC */ - REG_TYPE_NOSPPCX, /* Register must not be SP or PC */ - - /* Alias to allow '0' arg to be used in REGS macro. */ - REG_TYPE_0 = REG_TYPE_NONE -}; - -#define REGS(r16, r12, r8, r4, r0) \ - ((REG_TYPE_##r16) << 16) + \ - ((REG_TYPE_##r12) << 12) + \ - ((REG_TYPE_##r8) << 8) + \ - ((REG_TYPE_##r4) << 4) + \ - (REG_TYPE_##r0) - -union decode_item { - u32 bits; - const union decode_item *table; - kprobe_insn_handler_t *handler; - kprobe_decode_insn_t *decoder; -}; - - -#define DECODE_END \ - {.bits = DECODE_TYPE_END} - - -struct decode_header { - union decode_item type_regs; - union decode_item mask; - union decode_item value; -}; - -#define DECODE_HEADER(_type, _mask, _value, _regs) \ - {.bits = (_type) | ((_regs) << DECODE_TYPE_BITS)}, \ - {.bits = (_mask)}, \ - {.bits = (_value)} - - -struct decode_table { - struct decode_header header; - union decode_item table; -}; - -#define DECODE_TABLE(_mask, _value, _table) \ - DECODE_HEADER(DECODE_TYPE_TABLE, _mask, _value, 0), \ - {.table = (_table)} - - -struct decode_custom { - struct decode_header header; - union decode_item decoder; -}; - -#define DECODE_CUSTOM(_mask, _value, _decoder) \ - DECODE_HEADER(DECODE_TYPE_CUSTOM, _mask, _value, 0), \ - {.decoder = (_decoder)} - - -struct decode_simulate { - struct decode_header header; - union decode_item handler; -}; - -#define DECODE_SIMULATEX(_mask, _value, _handler, _regs) \ - DECODE_HEADER(DECODE_TYPE_SIMULATE, _mask, _value, _regs), \ - {.handler = (_handler)} - -#define DECODE_SIMULATE(_mask, _value, _handler) \ - DECODE_SIMULATEX(_mask, _value, _handler, 0) - - -struct decode_emulate { - struct decode_header header; - union decode_item handler; -}; - -#define DECODE_EMULATEX(_mask, _value, _handler, _regs) \ - DECODE_HEADER(DECODE_TYPE_EMULATE, _mask, _value, _regs), \ - {.handler = (_handler)} - -#define DECODE_EMULATE(_mask, _value, _handler) \ - DECODE_EMULATEX(_mask, _value, _handler, 0) - - -struct decode_or { - struct decode_header header; -}; - -#define DECODE_OR(_mask, _value) \ - DECODE_HEADER(DECODE_TYPE_OR, _mask, _value, 0) - - -struct decode_reject { - struct decode_header header; -}; - -#define DECODE_REJECT(_mask, _value) \ - DECODE_HEADER(DECODE_TYPE_REJECT, _mask, _value, 0) - - -#ifdef CONFIG_THUMB2_KERNEL -extern const union decode_item kprobe_decode_thumb16_table[]; -extern const union decode_item kprobe_decode_thumb32_table[]; -#else -extern const union decode_item kprobe_decode_arm_table[]; -#endif - - -int kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi, - const union decode_item *table, bool thumb16); - - #endif /* _ARM_KERNEL_KPROBES_H */ |