From b6542f81d0894d69e7f12a73b94bf4adead75a5c Mon Sep 17 00:00:00 2001 From: Yao Qi Date: Mon, 12 Oct 2015 11:28:38 +0100 Subject: Support displaced stepping in aarch64-linux This patch is to support displaced stepping in aarch64-linux. A visitor is implemented for displaced stepping, and used to record information to fixup pc after displaced stepping if needed. Some emit_* functions are converted to macros, and moved to arch/aarch64-insn.{c,h} so that they can be shared. gdb: 2015-10-12 Yao Qi * aarch64-linux-tdep.c: Include arch-utils.h. (aarch64_linux_init_abi): Call set_gdbarch_max_insn_length, set_gdbarch_displaced_step_copy_insn, set_gdbarch_displaced_step_fixup, set_gdbarch_displaced_step_free_closure, set_gdbarch_displaced_step_location, and set_gdbarch_displaced_step_hw_singlestep. * aarch64-tdep.c (struct displaced_step_closure): New. (struct aarch64_displaced_step_data): New. (aarch64_displaced_step_b): New function. (aarch64_displaced_step_b_cond): Likewise. (aarch64_register): Likewise. (aarch64_displaced_step_cb): Likewise. (aarch64_displaced_step_tb): Likewise. (aarch64_displaced_step_adr): Likewise. (aarch64_displaced_step_ldr_literal): Likewise. (aarch64_displaced_step_others): Likewise. (aarch64_displaced_step_copy_insn): Likewise. (aarch64_displaced_step_fixup): Likewise. (aarch64_displaced_step_hw_singlestep): Likewise. * aarch64-tdep.h (DISPLACED_MODIFIED_INSNS): New macro. (aarch64_displaced_step_copy_insn): Declare. (aarch64_displaced_step_fixup): Declare. (aarch64_displaced_step_hw_singlestep): Declare. * arch/aarch64-insn.c (emit_insn): Moved from gdbserver/linux-aarch64-low.c. (emit_load_store): Likewise. * arch/aarch64-insn.h (enum aarch64_opcodes): Moved from gdbserver/linux-aarch64-low.c. (struct aarch64_register): Likewise. (struct aarch64_memory_operand): Likewise. (ENCODE): Likewise. (can_encode_int32): New macro. (emit_b, emit_bcond, emit_cb, emit_ldr, emit_ldrsw): Likewise. (emit_tb, emit_nop): Likewise. (emit_insn): Declare. (emit_load_store): Declare. gdb/gdbserver: 2015-10-12 Yao Qi * linux-aarch64-low.c (enum aarch64_opcodes): Move to arch/aarch64-insn.h. (struct aarch64_memory_operand): Likewise. (ENCODE): Likewise. (emit_insn): Move to arch/aarch64-insn.c. (emit_b, emit_bcond, emit_cb, emit_tb): Remove. (emit_load_store): Move to arch/aarch64-insn.c. (emit_ldr, emit_ldrb, emit_ldrsw, emit_nop): Remove. (can_encode_int32): Remove. --- gdb/ChangeLog | 40 +++++ gdb/aarch64-linux-tdep.c | 12 ++ gdb/aarch64-tdep.c | 337 ++++++++++++++++++++++++++++++++++++++ gdb/aarch64-tdep.h | 17 ++ gdb/arch/aarch64-insn.c | 58 +++++++ gdb/arch/aarch64-insn.h | 232 ++++++++++++++++++++++++++ gdb/gdbserver/ChangeLog | 12 ++ gdb/gdbserver/linux-aarch64-low.c | 323 +----------------------------------- 8 files changed, 711 insertions(+), 320 deletions(-) (limited to 'gdb') diff --git a/gdb/ChangeLog b/gdb/ChangeLog index f79c93d..45a85e5 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,45 @@ 2015-10-12 Yao Qi + * aarch64-linux-tdep.c: Include arch-utils.h. + (aarch64_linux_init_abi): Call set_gdbarch_max_insn_length, + set_gdbarch_displaced_step_copy_insn, + set_gdbarch_displaced_step_fixup, + set_gdbarch_displaced_step_free_closure, + set_gdbarch_displaced_step_location, + and set_gdbarch_displaced_step_hw_singlestep. + * aarch64-tdep.c (struct displaced_step_closure): New. + (struct aarch64_displaced_step_data): New. + (aarch64_displaced_step_b): New function. + (aarch64_displaced_step_b_cond): Likewise. + (aarch64_register): Likewise. + (aarch64_displaced_step_cb): Likewise. + (aarch64_displaced_step_tb): Likewise. + (aarch64_displaced_step_adr): Likewise. + (aarch64_displaced_step_ldr_literal): Likewise. + (aarch64_displaced_step_others): Likewise. + (aarch64_displaced_step_copy_insn): Likewise. + (aarch64_displaced_step_fixup): Likewise. + (aarch64_displaced_step_hw_singlestep): Likewise. + * aarch64-tdep.h (DISPLACED_MODIFIED_INSNS): New macro. + (aarch64_displaced_step_copy_insn): Declare. + (aarch64_displaced_step_fixup): Declare. + (aarch64_displaced_step_hw_singlestep): Declare. + * arch/aarch64-insn.c (emit_insn): Moved from + gdbserver/linux-aarch64-low.c. + (emit_load_store): Likewise. + * arch/aarch64-insn.h (enum aarch64_opcodes): Moved from + gdbserver/linux-aarch64-low.c. + (struct aarch64_register): Likewise. + (struct aarch64_memory_operand): Likewise. + (ENCODE): Likewise. + (can_encode_int32): New macro. + (emit_b, emit_bcond, emit_cb, emit_ldr, emit_ldrsw): Likewise. + (emit_tb, emit_nop): Likewise. + (emit_insn): Declare. + (emit_load_store): Declare. + +2015-10-12 Yao Qi + * arch/aarch64-insn.c (aarch64_decode_ldr_literal): Moved from gdbserver/linux-aarch64-low.c. (aarch64_relocate_instruction): Likewise. diff --git a/gdb/aarch64-linux-tdep.c b/gdb/aarch64-linux-tdep.c index aaf6608..272aafe 100644 --- a/gdb/aarch64-linux-tdep.c +++ b/gdb/aarch64-linux-tdep.c @@ -21,6 +21,7 @@ #include "defs.h" #include "gdbarch.h" +#include "arch-utils.h" #include "glibc-tdep.h" #include "linux-tdep.h" #include "aarch64-tdep.h" @@ -1151,6 +1152,17 @@ aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) /* `catch syscall' */ set_xml_syscall_file_name (gdbarch, "syscalls/aarch64-linux.xml"); set_gdbarch_get_syscall_number (gdbarch, aarch64_linux_get_syscall_number); + + /* Displaced stepping. */ + set_gdbarch_max_insn_length (gdbarch, 4 * DISPLACED_MODIFIED_INSNS); + set_gdbarch_displaced_step_copy_insn (gdbarch, + aarch64_displaced_step_copy_insn); + set_gdbarch_displaced_step_fixup (gdbarch, aarch64_displaced_step_fixup); + set_gdbarch_displaced_step_free_closure (gdbarch, + simple_displaced_step_free_closure); + set_gdbarch_displaced_step_location (gdbarch, linux_displaced_step_location); + set_gdbarch_displaced_step_hw_singlestep (gdbarch, + aarch64_displaced_step_hw_singlestep); } /* Provide a prototype to silence -Wmissing-prototypes. */ diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index 90ee204..8426063 100644 --- a/gdb/aarch64-tdep.c +++ b/gdb/aarch64-tdep.c @@ -2559,6 +2559,343 @@ aarch64_software_single_step (struct frame_info *frame) return 1; } +struct displaced_step_closure +{ + /* It is true when condition instruction, such as B.CON, TBZ, etc, + is being displaced stepping. */ + int cond; + + /* PC adjustment offset after displaced stepping. */ + int32_t pc_adjust; +}; + +/* Data when visiting instructions for displaced stepping. */ + +struct aarch64_displaced_step_data +{ + struct aarch64_insn_data base; + + /* The address where the instruction will be executed at. */ + CORE_ADDR new_addr; + /* Buffer of instructions to be copied to NEW_ADDR to execute. */ + uint32_t insn_buf[DISPLACED_MODIFIED_INSNS]; + /* Number of instructions in INSN_BUF. */ + unsigned insn_count; + /* Registers when doing displaced stepping. */ + struct regcache *regs; + + struct displaced_step_closure *dsc; +}; + +/* Implementation of aarch64_insn_visitor method "b". */ + +static void +aarch64_displaced_step_b (const int is_bl, const int32_t offset, + struct aarch64_insn_data *data) +{ + struct aarch64_displaced_step_data *dsd + = (struct aarch64_displaced_step_data *) data; + int32_t new_offset = data->insn_addr - dsd->new_addr + offset; + + if (can_encode_int32 (new_offset, 28)) + { + /* Emit B rather than BL, because executing BL on a new address + will get the wrong address into LR. In order to avoid this, + we emit B, and update LR if the instruction is BL. */ + emit_b (dsd->insn_buf, 0, new_offset); + dsd->insn_count++; + } + else + { + /* Write NOP. */ + emit_nop (dsd->insn_buf); + dsd->insn_count++; + dsd->dsc->pc_adjust = offset; + } + + if (is_bl) + { + /* Update LR. */ + regcache_cooked_write_unsigned (dsd->regs, AARCH64_LR_REGNUM, + data->insn_addr + 4); + } +} + +/* Implementation of aarch64_insn_visitor method "b_cond". */ + +static void +aarch64_displaced_step_b_cond (const unsigned cond, const int32_t offset, + struct aarch64_insn_data *data) +{ + struct aarch64_displaced_step_data *dsd + = (struct aarch64_displaced_step_data *) data; + int32_t new_offset = data->insn_addr - dsd->new_addr + offset; + + /* GDB has to fix up PC after displaced step this instruction + differently according to the condition is true or false. Instead + of checking COND against conditional flags, we can use + the following instructions, and GDB can tell how to fix up PC + according to the PC value. + + B.COND TAKEN ; If cond is true, then jump to TAKEN. + INSN1 ; + TAKEN: + INSN2 + */ + + emit_bcond (dsd->insn_buf, cond, 8); + dsd->dsc->cond = 1; + dsd->dsc->pc_adjust = offset; + dsd->insn_count = 1; +} + +/* Dynamically allocate a new register. If we know the register + statically, we should make it a global as above instead of using this + helper function. */ + +static struct aarch64_register +aarch64_register (unsigned num, int is64) +{ + return (struct aarch64_register) { num, is64 }; +} + +/* Implementation of aarch64_insn_visitor method "cb". */ + +static void +aarch64_displaced_step_cb (const int32_t offset, const int is_cbnz, + const unsigned rn, int is64, + struct aarch64_insn_data *data) +{ + struct aarch64_displaced_step_data *dsd + = (struct aarch64_displaced_step_data *) data; + int32_t new_offset = data->insn_addr - dsd->new_addr + offset; + + /* The offset is out of range for a compare and branch + instruction. We can use the following instructions instead: + + CBZ xn, TAKEN ; xn == 0, then jump to TAKEN. + INSN1 ; + TAKEN: + INSN2 + */ + emit_cb (dsd->insn_buf, is_cbnz, aarch64_register (rn, is64), 8); + dsd->insn_count = 1; + dsd->dsc->cond = 1; + dsd->dsc->pc_adjust = offset; +} + +/* Implementation of aarch64_insn_visitor method "tb". */ + +static void +aarch64_displaced_step_tb (const int32_t offset, int is_tbnz, + const unsigned rt, unsigned bit, + struct aarch64_insn_data *data) +{ + struct aarch64_displaced_step_data *dsd + = (struct aarch64_displaced_step_data *) data; + int32_t new_offset = data->insn_addr - dsd->new_addr + offset; + + /* The offset is out of range for a test bit and branch + instruction We can use the following instructions instead: + + TBZ xn, #bit, TAKEN ; xn[bit] == 0, then jump to TAKEN. + INSN1 ; + TAKEN: + INSN2 + + */ + emit_tb (dsd->insn_buf, is_tbnz, bit, aarch64_register (rt, 1), 8); + dsd->insn_count = 1; + dsd->dsc->cond = 1; + dsd->dsc->pc_adjust = offset; +} + +/* Implementation of aarch64_insn_visitor method "adr". */ + +static void +aarch64_displaced_step_adr (const int32_t offset, const unsigned rd, + const int is_adrp, struct aarch64_insn_data *data) +{ + struct aarch64_displaced_step_data *dsd + = (struct aarch64_displaced_step_data *) data; + /* We know exactly the address the ADR{P,} instruction will compute. + We can just write it to the destination register. */ + CORE_ADDR address = data->insn_addr + offset; + + if (is_adrp) + { + /* Clear the lower 12 bits of the offset to get the 4K page. */ + regcache_cooked_write_unsigned (dsd->regs, AARCH64_X0_REGNUM + rd, + address & ~0xfff); + } + else + regcache_cooked_write_unsigned (dsd->regs, AARCH64_X0_REGNUM + rd, + address); + + dsd->dsc->pc_adjust = 4; + emit_nop (dsd->insn_buf); + dsd->insn_count = 1; +} + +/* Implementation of aarch64_insn_visitor method "ldr_literal". */ + +static void +aarch64_displaced_step_ldr_literal (const int32_t offset, const int is_sw, + const unsigned rt, const int is64, + struct aarch64_insn_data *data) +{ + struct aarch64_displaced_step_data *dsd + = (struct aarch64_displaced_step_data *) data; + CORE_ADDR address = data->insn_addr + offset; + struct aarch64_memory_operand zero = { MEMORY_OPERAND_OFFSET, 0 }; + + regcache_cooked_write_unsigned (dsd->regs, AARCH64_X0_REGNUM + rt, + address); + + if (is_sw) + dsd->insn_count = emit_ldrsw (dsd->insn_buf, aarch64_register (rt, 1), + aarch64_register (rt, 1), zero); + else + dsd->insn_count = emit_ldr (dsd->insn_buf, aarch64_register (rt, is64), + aarch64_register (rt, 1), zero); + + dsd->dsc->pc_adjust = 4; +} + +/* Implementation of aarch64_insn_visitor method "others". */ + +static void +aarch64_displaced_step_others (const uint32_t insn, + struct aarch64_insn_data *data) +{ + struct aarch64_displaced_step_data *dsd + = (struct aarch64_displaced_step_data *) data; + + emit_insn (dsd->insn_buf, insn); + dsd->insn_count = 1; + + if ((insn & 0xfffffc1f) == 0xd65f0000) + { + /* RET */ + dsd->dsc->pc_adjust = 0; + } + else + dsd->dsc->pc_adjust = 4; +} + +static const struct aarch64_insn_visitor visitor = +{ + aarch64_displaced_step_b, + aarch64_displaced_step_b_cond, + aarch64_displaced_step_cb, + aarch64_displaced_step_tb, + aarch64_displaced_step_adr, + aarch64_displaced_step_ldr_literal, + aarch64_displaced_step_others, +}; + +/* Implement the "displaced_step_copy_insn" gdbarch method. */ + +struct displaced_step_closure * +aarch64_displaced_step_copy_insn (struct gdbarch *gdbarch, + CORE_ADDR from, CORE_ADDR to, + struct regcache *regs) +{ + struct displaced_step_closure *dsc = NULL; + enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); + uint32_t insn = read_memory_unsigned_integer (from, 4, byte_order_for_code); + struct aarch64_displaced_step_data dsd; + + /* Look for a Load Exclusive instruction which begins the sequence. */ + if (decode_masked_match (insn, 0x3fc00000, 0x08400000)) + { + /* We can't displaced step atomic sequences. */ + return NULL; + } + + dsc = XCNEW (struct displaced_step_closure); + dsd.base.insn_addr = from; + dsd.new_addr = to; + dsd.regs = regs; + dsd.dsc = dsc; + aarch64_relocate_instruction (insn, &visitor, + (struct aarch64_insn_data *) &dsd); + gdb_assert (dsd.insn_count <= DISPLACED_MODIFIED_INSNS); + + if (dsd.insn_count != 0) + { + int i; + + /* Instruction can be relocated to scratch pad. Copy + relocated instruction(s) there. */ + for (i = 0; i < dsd.insn_count; i++) + { + if (debug_displaced) + { + debug_printf ("displaced: writing insn "); + debug_printf ("%.8x", dsd.insn_buf[i]); + debug_printf (" at %s\n", paddress (gdbarch, to + i * 4)); + } + write_memory_unsigned_integer (to + i * 4, 4, byte_order_for_code, + (ULONGEST) dsd.insn_buf[i]); + } + } + else + { + xfree (dsc); + dsc = NULL; + } + + return dsc; +} + +/* Implement the "displaced_step_fixup" gdbarch method. */ + +void +aarch64_displaced_step_fixup (struct gdbarch *gdbarch, + struct displaced_step_closure *dsc, + CORE_ADDR from, CORE_ADDR to, + struct regcache *regs) +{ + if (dsc->cond) + { + ULONGEST pc; + + regcache_cooked_read_unsigned (regs, AARCH64_PC_REGNUM, &pc); + if (pc - to == 8) + { + /* Condition is true. */ + } + else if (pc - to == 4) + { + /* Condition is false. */ + dsc->pc_adjust = 4; + } + else + gdb_assert_not_reached ("Unexpected PC value after displaced stepping"); + } + + if (dsc->pc_adjust != 0) + { + if (debug_displaced) + { + debug_printf ("displaced: fixup: set PC to %s:%d\n", + paddress (gdbarch, from), dsc->pc_adjust); + } + regcache_cooked_write_unsigned (regs, AARCH64_PC_REGNUM, + from + dsc->pc_adjust); + } +} + +/* Implement the "displaced_step_hw_singlestep" gdbarch method. */ + +int +aarch64_displaced_step_hw_singlestep (struct gdbarch *gdbarch, + struct displaced_step_closure *closure) +{ + return 1; +} + /* Initialize the current architecture based on INFO. If possible, re-use an architecture from ARCHES, which is a list of architectures already created during this debugging session. diff --git a/gdb/aarch64-tdep.h b/gdb/aarch64-tdep.h index af209a9..6297170 100644 --- a/gdb/aarch64-tdep.h +++ b/gdb/aarch64-tdep.h @@ -69,6 +69,10 @@ enum aarch64_regnum /* Total number of general (X) registers. */ #define AARCH64_X_REGISTER_COUNT 32 +/* The maximum number of modified instructions generated for one + single-stepped instruction. */ +#define DISPLACED_MODIFIED_INSNS 1 + /* Target-dependent structure in gdbarch. */ struct gdbarch_tdep { @@ -98,4 +102,17 @@ extern struct target_desc *tdesc_aarch64; extern int aarch64_process_record (struct gdbarch *gdbarch, struct regcache *regcache, CORE_ADDR addr); +struct displaced_step_closure * + aarch64_displaced_step_copy_insn (struct gdbarch *gdbarch, + CORE_ADDR from, CORE_ADDR to, + struct regcache *regs); + +void aarch64_displaced_step_fixup (struct gdbarch *gdbarch, + struct displaced_step_closure *dsc, + CORE_ADDR from, CORE_ADDR to, + struct regcache *regs); + +int aarch64_displaced_step_hw_singlestep (struct gdbarch *gdbarch, + struct displaced_step_closure *closure); + #endif /* aarch64-tdep.h */ diff --git a/gdb/arch/aarch64-insn.c b/gdb/arch/aarch64-insn.c index d0e88fa..3bc0117 100644 --- a/gdb/arch/aarch64-insn.c +++ b/gdb/arch/aarch64-insn.c @@ -328,3 +328,61 @@ aarch64_relocate_instruction (uint32_t insn, else visitor->others (insn, data); } + +/* Write a 32-bit unsigned integer INSN info *BUF. Return the number of + instructions written (aka. 1). */ + +int +emit_insn (uint32_t *buf, uint32_t insn) +{ + *buf = insn; + return 1; +} + +/* Helper function emitting a load or store instruction. */ + +int +emit_load_store (uint32_t *buf, uint32_t size, + enum aarch64_opcodes opcode, + struct aarch64_register rt, + struct aarch64_register rn, + struct aarch64_memory_operand operand) +{ + uint32_t op; + + switch (operand.type) + { + case MEMORY_OPERAND_OFFSET: + { + op = ENCODE (1, 1, 24); + + return emit_insn (buf, opcode | ENCODE (size, 2, 30) | op + | ENCODE (operand.index >> 3, 12, 10) + | ENCODE (rn.num, 5, 5) + | ENCODE (rt.num, 5, 0)); + } + case MEMORY_OPERAND_POSTINDEX: + { + uint32_t post_index = ENCODE (1, 2, 10); + + op = ENCODE (0, 1, 24); + + return emit_insn (buf, opcode | ENCODE (size, 2, 30) | op + | post_index | ENCODE (operand.index, 9, 12) + | ENCODE (rn.num, 5, 5) | ENCODE (rt.num, 5, 0)); + } + case MEMORY_OPERAND_PREINDEX: + { + uint32_t pre_index = ENCODE (3, 2, 10); + + op = ENCODE (0, 1, 24); + + return emit_insn (buf, opcode | ENCODE (size, 2, 30) | op + | pre_index | ENCODE (operand.index, 9, 12) + | ENCODE (rn.num, 5, 5) + | ENCODE (rt.num, 5, 0)); + } + default: + return 0; + } +} diff --git a/gdb/arch/aarch64-insn.h b/gdb/arch/aarch64-insn.h index 47f6715..01a5d73 100644 --- a/gdb/arch/aarch64-insn.h +++ b/gdb/arch/aarch64-insn.h @@ -21,6 +21,129 @@ extern int aarch64_debug; +/* List of opcodes that we need for building the jump pad and relocating + an instruction. */ + +enum aarch64_opcodes +{ + /* B 0001 01ii iiii iiii iiii iiii iiii iiii */ + /* BL 1001 01ii iiii iiii iiii iiii iiii iiii */ + /* B.COND 0101 0100 iiii iiii iiii iiii iii0 cccc */ + /* CBZ s011 0100 iiii iiii iiii iiii iiir rrrr */ + /* CBNZ s011 0101 iiii iiii iiii iiii iiir rrrr */ + /* TBZ b011 0110 bbbb biii iiii iiii iiir rrrr */ + /* TBNZ b011 0111 bbbb biii iiii iiii iiir rrrr */ + B = 0x14000000, + BL = 0x80000000 | B, + BCOND = 0x40000000 | B, + CBZ = 0x20000000 | B, + CBNZ = 0x21000000 | B, + TBZ = 0x36000000 | B, + TBNZ = 0x37000000 | B, + /* BLR 1101 0110 0011 1111 0000 00rr rrr0 0000 */ + BLR = 0xd63f0000, + /* RET 1101 0110 0101 1111 0000 00rr rrr0 0000 */ + RET = 0xd65f0000, + /* STP s010 100o o0ii iiii irrr rrrr rrrr rrrr */ + /* LDP s010 100o o1ii iiii irrr rrrr rrrr rrrr */ + /* STP (SIMD&VFP) ss10 110o o0ii iiii irrr rrrr rrrr rrrr */ + /* LDP (SIMD&VFP) ss10 110o o1ii iiii irrr rrrr rrrr rrrr */ + STP = 0x28000000, + LDP = 0x28400000, + STP_SIMD_VFP = 0x04000000 | STP, + LDP_SIMD_VFP = 0x04000000 | LDP, + /* STR ss11 100o 00xi iiii iiii xxrr rrrr rrrr */ + /* LDR ss11 100o 01xi iiii iiii xxrr rrrr rrrr */ + /* LDRSW 1011 100o 10xi iiii iiii xxrr rrrr rrrr */ + STR = 0x38000000, + LDR = 0x00400000 | STR, + LDRSW = 0x80800000 | STR, + /* LDAXR ss00 1000 0101 1111 1111 11rr rrrr rrrr */ + LDAXR = 0x085ffc00, + /* STXR ss00 1000 000r rrrr 0111 11rr rrrr rrrr */ + STXR = 0x08007c00, + /* STLR ss00 1000 1001 1111 1111 11rr rrrr rrrr */ + STLR = 0x089ffc00, + /* MOV s101 0010 1xxi iiii iiii iiii iiir rrrr */ + /* MOVK s111 0010 1xxi iiii iiii iiii iiir rrrr */ + MOV = 0x52800000, + MOVK = 0x20000000 | MOV, + /* ADD s00o ooo1 xxxx xxxx xxxx xxxx xxxx xxxx */ + /* SUB s10o ooo1 xxxx xxxx xxxx xxxx xxxx xxxx */ + /* SUBS s11o ooo1 xxxx xxxx xxxx xxxx xxxx xxxx */ + ADD = 0x01000000, + SUB = 0x40000000 | ADD, + SUBS = 0x20000000 | SUB, + /* AND s000 1010 xx0x xxxx xxxx xxxx xxxx xxxx */ + /* ORR s010 1010 xx0x xxxx xxxx xxxx xxxx xxxx */ + /* ORN s010 1010 xx1x xxxx xxxx xxxx xxxx xxxx */ + /* EOR s100 1010 xx0x xxxx xxxx xxxx xxxx xxxx */ + AND = 0x0a000000, + ORR = 0x20000000 | AND, + ORN = 0x00200000 | ORR, + EOR = 0x40000000 | AND, + /* LSLV s001 1010 110r rrrr 0010 00rr rrrr rrrr */ + /* LSRV s001 1010 110r rrrr 0010 01rr rrrr rrrr */ + /* ASRV s001 1010 110r rrrr 0010 10rr rrrr rrrr */ + LSLV = 0x1ac02000, + LSRV = 0x00000400 | LSLV, + ASRV = 0x00000800 | LSLV, + /* SBFM s001 0011 0nii iiii iiii iirr rrrr rrrr */ + SBFM = 0x13000000, + /* UBFM s101 0011 0nii iiii iiii iirr rrrr rrrr */ + UBFM = 0x40000000 | SBFM, + /* CSINC s001 1010 100r rrrr cccc 01rr rrrr rrrr */ + CSINC = 0x9a800400, + /* MUL s001 1011 000r rrrr 0111 11rr rrrr rrrr */ + MUL = 0x1b007c00, + /* MSR (register) 1101 0101 0001 oooo oooo oooo ooor rrrr */ + /* MRS 1101 0101 0011 oooo oooo oooo ooor rrrr */ + MSR = 0xd5100000, + MRS = 0x00200000 | MSR, + /* HINT 1101 0101 0000 0011 0010 oooo ooo1 1111 */ + HINT = 0xd503201f, + SEVL = (5 << 5) | HINT, + WFE = (2 << 5) | HINT, + NOP = (0 << 5) | HINT, +}; + +/* Representation of a general purpose register of the form xN or wN. + + This type is used by emitting functions that take registers as operands. */ + +struct aarch64_register +{ + unsigned num; + int is64; +}; + +/* Representation of a memory operand, used for load and store + instructions. + + The types correspond to the following variants: + + MEMORY_OPERAND_OFFSET: LDR rt, [rn, #offset] + MEMORY_OPERAND_PREINDEX: LDR rt, [rn, #index]! + MEMORY_OPERAND_POSTINDEX: LDR rt, [rn], #index */ + +struct aarch64_memory_operand +{ + /* Type of the operand. */ + enum + { + MEMORY_OPERAND_OFFSET, + MEMORY_OPERAND_PREINDEX, + MEMORY_OPERAND_POSTINDEX, + } type; + /* Index from the base register. */ + int32_t index; +}; + +/* Helper macro to mask and shift a value into a bitfield. */ + +#define ENCODE(val, size, offset) \ + ((uint32_t) ((val & ((1ULL << size) - 1)) << offset)) + int aarch64_decode_adr (CORE_ADDR addr, uint32_t insn, int *is_adrp, unsigned *rd, int32_t *offset); @@ -86,4 +209,113 @@ void aarch64_relocate_instruction (uint32_t insn, const struct aarch64_insn_visitor *visitor, struct aarch64_insn_data *data); +#define can_encode_int32(val, bits) \ + (((val) >> (bits)) == 0 || ((val) >> (bits)) == -1) + +/* Write a B or BL instruction into *BUF. + + B #offset + BL #offset + + IS_BL specifies if the link register should be updated. + OFFSET is the immediate offset from the current PC. It is + byte-addressed but should be 4 bytes aligned. It has a limited range of + +/- 128MB (26 bits << 2). */ + +#define emit_b(buf, is_bl, offset) \ + emit_insn (buf, ((is_bl) ? BL : B) | (ENCODE ((offset) >> 2, 26, 0))) + +/* Write a BCOND instruction into *BUF. + + B.COND #offset + + COND specifies the condition field. + OFFSET is the immediate offset from the current PC. It is + byte-addressed but should be 4 bytes aligned. It has a limited range of + +/- 1MB (19 bits << 2). */ + +#define emit_bcond(buf, cond, offset) \ + emit_insn (buf, \ + BCOND | ENCODE ((offset) >> 2, 19, 5) \ + | ENCODE ((cond), 4, 0)) + +/* Write a CBZ or CBNZ instruction into *BUF. + + CBZ rt, #offset + CBNZ rt, #offset + + IS_CBNZ distinguishes between CBZ and CBNZ instructions. + RN is the register to test. + OFFSET is the immediate offset from the current PC. It is + byte-addressed but should be 4 bytes aligned. It has a limited range of + +/- 1MB (19 bits << 2). */ + +#define emit_cb(buf, is_cbnz, rt, offset) \ + emit_insn (buf, \ + ((is_cbnz) ? CBNZ : CBZ) \ + | ENCODE (rt.is64, 1, 31) /* sf */ \ + | ENCODE (offset >> 2, 19, 5) /* imm19 */ \ + | ENCODE (rt.num, 5, 0)) + +/* Write a LDR instruction into *BUF. + + LDR rt, [rn, #offset] + LDR rt, [rn, #index]! + LDR rt, [rn], #index + + RT is the register to store. + RN is the base address register. + OFFSET is the immediate to add to the base address. It is limited to + 0 .. 32760 range (12 bits << 3). */ + +#define emit_ldr(buf, rt, rn, operand) \ + emit_load_store (buf, rt.is64 ? 3 : 2, LDR, rt, rn, operand) + +/* Write a LDRSW instruction into *BUF. The register size is 64-bit. + + LDRSW xt, [rn, #offset] + LDRSW xt, [rn, #index]! + LDRSW xt, [rn], #index + + RT is the register to store. + RN is the base address register. + OFFSET is the immediate to add to the base address. It is limited to + 0 .. 16380 range (12 bits << 2). */ + +#define emit_ldrsw(buf, rt, rn, operand) \ + emit_load_store (buf, 3, LDRSW, rt, rn, operand) + + +/* Write a TBZ or TBNZ instruction into *BUF. + + TBZ rt, #bit, #offset + TBNZ rt, #bit, #offset + + IS_TBNZ distinguishes between TBZ and TBNZ instructions. + RT is the register to test. + BIT is the index of the bit to test in register RT. + OFFSET is the immediate offset from the current PC. It is + byte-addressed but should be 4 bytes aligned. It has a limited range of + +/- 32KB (14 bits << 2). */ + +#define emit_tb(buf, is_tbnz, bit, rt, offset) \ + emit_insn (buf, \ + ((is_tbnz) ? TBNZ: TBZ) \ + | ENCODE (bit >> 5, 1, 31) /* b5 */ \ + | ENCODE (bit, 5, 19) /* b40 */ \ + | ENCODE (offset >> 2, 14, 5) /* imm14 */ \ + | ENCODE (rt.num, 5, 0)) + +/* Write a NOP instruction into *BUF. */ + +#define emit_nop(buf) emit_insn (buf, NOP) + +int emit_insn (uint32_t *buf, uint32_t insn); + +int emit_load_store (uint32_t *buf, uint32_t size, + enum aarch64_opcodes opcode, + struct aarch64_register rt, + struct aarch64_register rn, + struct aarch64_memory_operand operand); + #endif diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index 6d3d66d..3281026 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,5 +1,17 @@ 2015-10-12 Yao Qi + * linux-aarch64-low.c (enum aarch64_opcodes): Move to + arch/aarch64-insn.h. + (struct aarch64_memory_operand): Likewise. + (ENCODE): Likewise. + (emit_insn): Move to arch/aarch64-insn.c. + (emit_b, emit_bcond, emit_cb, emit_tb): Remove. + (emit_load_store): Move to arch/aarch64-insn.c. + (emit_ldr, emit_ldrb, emit_ldrsw, emit_nop): Remove. + (can_encode_int32): Remove. + +2015-10-12 Yao Qi + * linux-aarch64-low.c (extract_signed_bitfield): Remove. (aarch64_decode_ldr_literal): Move to gdb/arch/aarch64-insn.c. (aarch64_relocate_instruction): Likewise. diff --git a/gdb/gdbserver/linux-aarch64-low.c b/gdb/gdbserver/linux-aarch64-low.c index 1241434..9450449 100644 --- a/gdb/gdbserver/linux-aarch64-low.c +++ b/gdb/gdbserver/linux-aarch64-low.c @@ -584,92 +584,6 @@ aarch64_get_thread_area (int lwpid, CORE_ADDR *addrp) return 0; } -/* List of opcodes that we need for building the jump pad and relocating - an instruction. */ - -enum aarch64_opcodes -{ - /* B 0001 01ii iiii iiii iiii iiii iiii iiii */ - /* BL 1001 01ii iiii iiii iiii iiii iiii iiii */ - /* B.COND 0101 0100 iiii iiii iiii iiii iii0 cccc */ - /* CBZ s011 0100 iiii iiii iiii iiii iiir rrrr */ - /* CBNZ s011 0101 iiii iiii iiii iiii iiir rrrr */ - /* TBZ b011 0110 bbbb biii iiii iiii iiir rrrr */ - /* TBNZ b011 0111 bbbb biii iiii iiii iiir rrrr */ - B = 0x14000000, - BL = 0x80000000 | B, - BCOND = 0x40000000 | B, - CBZ = 0x20000000 | B, - CBNZ = 0x21000000 | B, - TBZ = 0x36000000 | B, - TBNZ = 0x37000000 | B, - /* BLR 1101 0110 0011 1111 0000 00rr rrr0 0000 */ - BLR = 0xd63f0000, - /* RET 1101 0110 0101 1111 0000 00rr rrr0 0000 */ - RET = 0xd65f0000, - /* STP s010 100o o0ii iiii irrr rrrr rrrr rrrr */ - /* LDP s010 100o o1ii iiii irrr rrrr rrrr rrrr */ - /* STP (SIMD&VFP) ss10 110o o0ii iiii irrr rrrr rrrr rrrr */ - /* LDP (SIMD&VFP) ss10 110o o1ii iiii irrr rrrr rrrr rrrr */ - STP = 0x28000000, - LDP = 0x28400000, - STP_SIMD_VFP = 0x04000000 | STP, - LDP_SIMD_VFP = 0x04000000 | LDP, - /* STR ss11 100o 00xi iiii iiii xxrr rrrr rrrr */ - /* LDR ss11 100o 01xi iiii iiii xxrr rrrr rrrr */ - /* LDRSW 1011 100o 10xi iiii iiii xxrr rrrr rrrr */ - STR = 0x38000000, - LDR = 0x00400000 | STR, - LDRSW = 0x80800000 | STR, - /* LDAXR ss00 1000 0101 1111 1111 11rr rrrr rrrr */ - LDAXR = 0x085ffc00, - /* STXR ss00 1000 000r rrrr 0111 11rr rrrr rrrr */ - STXR = 0x08007c00, - /* STLR ss00 1000 1001 1111 1111 11rr rrrr rrrr */ - STLR = 0x089ffc00, - /* MOV s101 0010 1xxi iiii iiii iiii iiir rrrr */ - /* MOVK s111 0010 1xxi iiii iiii iiii iiir rrrr */ - MOV = 0x52800000, - MOVK = 0x20000000 | MOV, - /* ADD s00o ooo1 xxxx xxxx xxxx xxxx xxxx xxxx */ - /* SUB s10o ooo1 xxxx xxxx xxxx xxxx xxxx xxxx */ - /* SUBS s11o ooo1 xxxx xxxx xxxx xxxx xxxx xxxx */ - ADD = 0x01000000, - SUB = 0x40000000 | ADD, - SUBS = 0x20000000 | SUB, - /* AND s000 1010 xx0x xxxx xxxx xxxx xxxx xxxx */ - /* ORR s010 1010 xx0x xxxx xxxx xxxx xxxx xxxx */ - /* ORN s010 1010 xx1x xxxx xxxx xxxx xxxx xxxx */ - /* EOR s100 1010 xx0x xxxx xxxx xxxx xxxx xxxx */ - AND = 0x0a000000, - ORR = 0x20000000 | AND, - ORN = 0x00200000 | ORR, - EOR = 0x40000000 | AND, - /* LSLV s001 1010 110r rrrr 0010 00rr rrrr rrrr */ - /* LSRV s001 1010 110r rrrr 0010 01rr rrrr rrrr */ - /* ASRV s001 1010 110r rrrr 0010 10rr rrrr rrrr */ - LSLV = 0x1ac02000, - LSRV = 0x00000400 | LSLV, - ASRV = 0x00000800 | LSLV, - /* SBFM s001 0011 0nii iiii iiii iirr rrrr rrrr */ - SBFM = 0x13000000, - /* UBFM s101 0011 0nii iiii iiii iirr rrrr rrrr */ - UBFM = 0x40000000 | SBFM, - /* CSINC s001 1010 100r rrrr cccc 01rr rrrr rrrr */ - CSINC = 0x9a800400, - /* MUL s001 1011 000r rrrr 0111 11rr rrrr rrrr */ - MUL = 0x1b007c00, - /* MSR (register) 1101 0101 0001 oooo oooo oooo ooor rrrr */ - /* MRS 1101 0101 0011 oooo oooo oooo ooor rrrr */ - MSR = 0xd5100000, - MRS = 0x00200000 | MSR, - /* HINT 1101 0101 0000 0011 0010 oooo ooo1 1111 */ - HINT = 0xd503201f, - SEVL = (5 << 5) | HINT, - WFE = (2 << 5) | HINT, - NOP = (0 << 5) | HINT, -}; - /* List of condition codes that we need. */ enum aarch64_condition_codes @@ -683,16 +597,6 @@ enum aarch64_condition_codes LE = 0xd, }; -/* Representation of a general purpose register of the form xN or wN. - - This type is used by emitting functions that take registers as operands. */ - -struct aarch64_register -{ - unsigned num; - int is64; -}; - /* Representation of an operand. At this time, it only supports register and immediate types. */ @@ -779,28 +683,6 @@ immediate_operand (uint32_t imm) return operand; } -/* Representation of a memory operand, used for load and store - instructions. - - The types correspond to the following variants: - - MEMORY_OPERAND_OFFSET: LDR rt, [rn, #offset] - MEMORY_OPERAND_PREINDEX: LDR rt, [rn, #index]! - MEMORY_OPERAND_POSTINDEX: LDR rt, [rn], #index */ - -struct aarch64_memory_operand -{ - /* Type of the operand. */ - enum - { - MEMORY_OPERAND_OFFSET, - MEMORY_OPERAND_PREINDEX, - MEMORY_OPERAND_POSTINDEX, - } type; - /* Index from the base register. */ - int32_t index; -}; - /* Helper function to create an offset memory operand. For example: @@ -852,108 +734,6 @@ enum aarch64_system_control_registers TPIDR_EL0 = (0x1 << 14) | (0x3 << 11) | (0xd << 7) | (0x0 << 3) | 0x2 }; -/* Helper macro to mask and shift a value into a bitfield. */ - -#define ENCODE(val, size, offset) \ - ((uint32_t) ((val & ((1ULL << size) - 1)) << offset)) - -/* Write a 32-bit unsigned integer INSN info *BUF. Return the number of - instructions written (aka. 1). */ - -static int -emit_insn (uint32_t *buf, uint32_t insn) -{ - *buf = insn; - return 1; -} - -/* Write a B or BL instruction into *BUF. - - B #offset - BL #offset - - IS_BL specifies if the link register should be updated. - OFFSET is the immediate offset from the current PC. It is - byte-addressed but should be 4 bytes aligned. It has a limited range of - +/- 128MB (26 bits << 2). */ - -static int -emit_b (uint32_t *buf, int is_bl, int32_t offset) -{ - uint32_t imm26 = ENCODE (offset >> 2, 26, 0); - - if (is_bl) - return emit_insn (buf, BL | imm26); - else - return emit_insn (buf, B | imm26); -} - -/* Write a BCOND instruction into *BUF. - - B.COND #offset - - COND specifies the condition field. - OFFSET is the immediate offset from the current PC. It is - byte-addressed but should be 4 bytes aligned. It has a limited range of - +/- 1MB (19 bits << 2). */ - -static int -emit_bcond (uint32_t *buf, unsigned cond, int32_t offset) -{ - return emit_insn (buf, BCOND | ENCODE (offset >> 2, 19, 5) - | ENCODE (cond, 4, 0)); -} - -/* Write a CBZ or CBNZ instruction into *BUF. - - CBZ rt, #offset - CBNZ rt, #offset - - IS_CBNZ distinguishes between CBZ and CBNZ instructions. - RN is the register to test. - OFFSET is the immediate offset from the current PC. It is - byte-addressed but should be 4 bytes aligned. It has a limited range of - +/- 1MB (19 bits << 2). */ - -static int -emit_cb (uint32_t *buf, int is_cbnz, struct aarch64_register rt, - int32_t offset) -{ - uint32_t imm19 = ENCODE (offset >> 2, 19, 5); - uint32_t sf = ENCODE (rt.is64, 1, 31); - - if (is_cbnz) - return emit_insn (buf, CBNZ | sf | imm19 | ENCODE (rt.num, 5, 0)); - else - return emit_insn (buf, CBZ | sf | imm19 | ENCODE (rt.num, 5, 0)); -} - -/* Write a TBZ or TBNZ instruction into *BUF. - - TBZ rt, #bit, #offset - TBNZ rt, #bit, #offset - - IS_TBNZ distinguishes between TBZ and TBNZ instructions. - RT is the register to test. - BIT is the index of the bit to test in register RT. - OFFSET is the immediate offset from the current PC. It is - byte-addressed but should be 4 bytes aligned. It has a limited range of - +/- 32KB (14 bits << 2). */ - -static int -emit_tb (uint32_t *buf, int is_tbnz, unsigned bit, - struct aarch64_register rt, int32_t offset) -{ - uint32_t imm14 = ENCODE (offset >> 2, 14, 5); - uint32_t b40 = ENCODE (bit, 5, 19); - uint32_t b5 = ENCODE (bit >> 5, 1, 31); - - if (is_tbnz) - return emit_insn (buf, TBNZ | b5 | b40 | imm14 | ENCODE (rt.num, 5, 0)); - else - return emit_insn (buf, TBZ | b5 | b40 | imm14 | ENCODE (rt.num, 5, 0)); -} - /* Write a BLR instruction into *BUF. BLR rn @@ -1100,70 +880,9 @@ emit_stp_q_offset (uint32_t *buf, unsigned rt, unsigned rt2, uint32_t pre_index = ENCODE (1, 1, 24); return emit_insn (buf, STP_SIMD_VFP | opc | pre_index - | ENCODE (offset >> 4, 7, 15) | ENCODE (rt2, 5, 10) - | ENCODE (rn.num, 5, 5) | ENCODE (rt, 5, 0)); -} - -/* Helper function emitting a load or store instruction. */ - -static int -emit_load_store (uint32_t *buf, uint32_t size, enum aarch64_opcodes opcode, - struct aarch64_register rt, struct aarch64_register rn, - struct aarch64_memory_operand operand) -{ - uint32_t op; - - switch (operand.type) - { - case MEMORY_OPERAND_OFFSET: - { - op = ENCODE (1, 1, 24); - - return emit_insn (buf, opcode | ENCODE (size, 2, 30) | op - | ENCODE (operand.index >> 3, 12, 10) - | ENCODE (rn.num, 5, 5) | ENCODE (rt.num, 5, 0)); - } - case MEMORY_OPERAND_POSTINDEX: - { - uint32_t post_index = ENCODE (1, 2, 10); - - op = ENCODE (0, 1, 24); - - return emit_insn (buf, opcode | ENCODE (size, 2, 30) | op - | post_index | ENCODE (operand.index, 9, 12) - | ENCODE (rn.num, 5, 5) | ENCODE (rt.num, 5, 0)); - } - case MEMORY_OPERAND_PREINDEX: - { - uint32_t pre_index = ENCODE (3, 2, 10); - - op = ENCODE (0, 1, 24); - - return emit_insn (buf, opcode | ENCODE (size, 2, 30) | op - | pre_index | ENCODE (operand.index, 9, 12) - | ENCODE (rn.num, 5, 5) | ENCODE (rt.num, 5, 0)); - } - default: - return 0; - } -} - -/* Write a LDR instruction into *BUF. - - LDR rt, [rn, #offset] - LDR rt, [rn, #index]! - LDR rt, [rn], #index - - RT is the register to store. - RN is the base address register. - OFFSET is the immediate to add to the base address. It is limited to - 0 .. 32760 range (12 bits << 3). */ - -static int -emit_ldr (uint32_t *buf, struct aarch64_register rt, - struct aarch64_register rn, struct aarch64_memory_operand operand) -{ - return emit_load_store (buf, rt.is64 ? 3 : 2, LDR, rt, rn, operand); + | ENCODE (offset >> 4, 7, 15) + | ENCODE (rt2, 5, 10) + | ENCODE (rn.num, 5, 5) | ENCODE (rt, 5, 0)); } /* Write a LDRH instruction into *BUF. @@ -1204,24 +923,7 @@ emit_ldrb (uint32_t *buf, struct aarch64_register rt, return emit_load_store (buf, 0, LDR, rt, rn, operand); } -/* Write a LDRSW instruction into *BUF. The register size is 64-bit. - LDRSW xt, [rn, #offset] - LDRSW xt, [rn, #index]! - LDRSW xt, [rn], #index - - RT is the register to store. - RN is the base address register. - OFFSET is the immediate to add to the base address. It is limited to - 0 .. 16380 range (12 bits << 2). */ - -static int -emit_ldrsw (uint32_t *buf, struct aarch64_register rt, - struct aarch64_register rn, - struct aarch64_memory_operand operand) -{ - return emit_load_store (buf, 3, LDRSW, rt, rn, operand); -} /* Write a STR instruction into *BUF. @@ -1816,14 +1518,6 @@ emit_cset (uint32_t *buf, struct aarch64_register rd, unsigned cond) return emit_csinc (buf, rd, xzr, xzr, cond ^ 0x1); } -/* Write a NOP instruction into *BUF. */ - -static int -emit_nop (uint32_t *buf) -{ - return emit_insn (buf, NOP); -} - /* Write LEN instructions from BUF into the inferior memory at *TO. Note instructions are always little endian on AArch64, unlike data. */ @@ -1849,17 +1543,6 @@ append_insns (CORE_ADDR *to, size_t len, const uint32_t *buf) *to += byte_len; } -/* Helper function. Return 1 if VAL can be encoded in BITS bits. */ - -static int -can_encode_int32 (int32_t val, unsigned bits) -{ - /* This must be an arithemic shift. */ - int32_t rest = val >> bits; - - return rest == 0 || rest == -1; -} - /* Sub-class of struct aarch64_insn_data, store information of instruction relocation for fast tracepoint. Visitor can relocate an instruction from BASE.INSN_ADDR to NEW_ADDR and save -- cgit v1.1