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Diffstat (limited to 'gdb/s390-tdep.c')
| -rw-r--r-- | gdb/s390-tdep.c | 3352 |
1 files changed, 3352 insertions, 0 deletions
diff --git a/gdb/s390-tdep.c b/gdb/s390-tdep.c new file mode 100644 index 0000000..8c49b06 --- /dev/null +++ b/gdb/s390-tdep.c @@ -0,0 +1,3352 @@ +/* Target-dependent code for S390. + Copyright (C) 2017 Free Software Foundation, Inc. + + This file is part of GDB. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + 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 "defs.h" + +#include "arch-utils.h" +#include "auxv.h" +#include "ax-gdb.h" +#include "dis-asm.h" +#include "dwarf2-frame.h" +#include "elf/common.h" +#include "elf/s390.h" +#include "elf-bfd.h" +#include "frame.h" +#include "frame-base.h" +#include "frame-unwind.h" +#include "gdbarch.h" +#include "gdbcore.h" +#include "infrun.h" +#include "linux-tdep.h" +#include "objfiles.h" +#include "osabi.h" +#include "prologue-value.h" +#include "record-full.h" +#include "reggroups.h" +#include "regset.h" +#include "s390-linux-tdep.h" +#include "s390-tdep.h" +#include "target-descriptions.h" +#include "trad-frame.h" +#include "value.h" + +/* Decoding S/390 instructions. */ + +/* Read a single instruction from address AT. */ + +static int +s390_readinstruction (bfd_byte instr[], CORE_ADDR at) +{ + static int s390_instrlen[] = { 2, 4, 4, 6 }; + int instrlen; + + if (target_read_memory (at, &instr[0], 2)) + return -1; + instrlen = s390_instrlen[instr[0] >> 6]; + if (instrlen > 2) + { + if (target_read_memory (at + 2, &instr[2], instrlen - 2)) + return -1; + } + return instrlen; +} + +/* The functions below are for recognizing and decoding S/390 + instructions of various formats. Each of them checks whether INSN + is an instruction of the given format, with the specified opcodes. + If it is, it sets the remaining arguments to the values of the + instruction's fields, and returns a non-zero value; otherwise, it + returns zero. + + These functions' arguments appear in the order they appear in the + instruction, not in the machine-language form. So, opcodes always + come first, even though they're sometimes scattered around the + instructions. And displacements appear before base and extension + registers, as they do in the assembly syntax, not at the end, as + they do in the machine language. */ + +static int +is_ri (bfd_byte *insn, int op1, int op2, unsigned int *r1, int *i2) +{ + if (insn[0] == op1 && (insn[1] & 0xf) == op2) + { + *r1 = (insn[1] >> 4) & 0xf; + /* i2 is a 16-bit signed quantity. */ + *i2 = (((insn[2] << 8) | insn[3]) ^ 0x8000) - 0x8000; + return 1; + } + else + return 0; +} + + +static int +is_ril (bfd_byte *insn, int op1, int op2, + unsigned int *r1, int *i2) +{ + if (insn[0] == op1 && (insn[1] & 0xf) == op2) + { + *r1 = (insn[1] >> 4) & 0xf; + /* i2 is a signed quantity. If the host 'int' is 32 bits long, + no sign extension is necessary, but we don't want to assume + that. */ + *i2 = (((insn[2] << 24) + | (insn[3] << 16) + | (insn[4] << 8) + | (insn[5])) ^ 0x80000000) - 0x80000000; + return 1; + } + else + return 0; +} + + +static int +is_rr (bfd_byte *insn, int op, unsigned int *r1, unsigned int *r2) +{ + if (insn[0] == op) + { + *r1 = (insn[1] >> 4) & 0xf; + *r2 = insn[1] & 0xf; + return 1; + } + else + return 0; +} + + +static int +is_rre (bfd_byte *insn, int op, unsigned int *r1, unsigned int *r2) +{ + if (((insn[0] << 8) | insn[1]) == op) + { + /* Yes, insn[3]. insn[2] is unused in RRE format. */ + *r1 = (insn[3] >> 4) & 0xf; + *r2 = insn[3] & 0xf; + return 1; + } + else + return 0; +} + + +static int +is_rs (bfd_byte *insn, int op, + unsigned int *r1, unsigned int *r3, int *d2, unsigned int *b2) +{ + if (insn[0] == op) + { + *r1 = (insn[1] >> 4) & 0xf; + *r3 = insn[1] & 0xf; + *b2 = (insn[2] >> 4) & 0xf; + *d2 = ((insn[2] & 0xf) << 8) | insn[3]; + return 1; + } + else + return 0; +} + + +static int +is_rsy (bfd_byte *insn, int op1, int op2, + unsigned int *r1, unsigned int *r3, int *d2, unsigned int *b2) +{ + if (insn[0] == op1 + && insn[5] == op2) + { + *r1 = (insn[1] >> 4) & 0xf; + *r3 = insn[1] & 0xf; + *b2 = (insn[2] >> 4) & 0xf; + /* The 'long displacement' is a 20-bit signed integer. */ + *d2 = ((((insn[2] & 0xf) << 8) | insn[3] | (insn[4] << 12)) + ^ 0x80000) - 0x80000; + return 1; + } + else + return 0; +} + + +static int +is_rsi (bfd_byte *insn, int op, + unsigned int *r1, unsigned int *r3, int *i2) +{ + if (insn[0] == op) + { + *r1 = (insn[1] >> 4) & 0xf; + *r3 = insn[1] & 0xf; + /* i2 is a 16-bit signed quantity. */ + *i2 = (((insn[2] << 8) | insn[3]) ^ 0x8000) - 0x8000; + return 1; + } + else + return 0; +} + + +static int +is_rie (bfd_byte *insn, int op1, int op2, + unsigned int *r1, unsigned int *r3, int *i2) +{ + if (insn[0] == op1 + && insn[5] == op2) + { + *r1 = (insn[1] >> 4) & 0xf; + *r3 = insn[1] & 0xf; + /* i2 is a 16-bit signed quantity. */ + *i2 = (((insn[2] << 8) | insn[3]) ^ 0x8000) - 0x8000; + return 1; + } + else + return 0; +} + + +static int +is_rx (bfd_byte *insn, int op, + unsigned int *r1, int *d2, unsigned int *x2, unsigned int *b2) +{ + if (insn[0] == op) + { + *r1 = (insn[1] >> 4) & 0xf; + *x2 = insn[1] & 0xf; + *b2 = (insn[2] >> 4) & 0xf; + *d2 = ((insn[2] & 0xf) << 8) | insn[3]; + return 1; + } + else + return 0; +} + + +static int +is_rxy (bfd_byte *insn, int op1, int op2, + unsigned int *r1, int *d2, unsigned int *x2, unsigned int *b2) +{ + if (insn[0] == op1 + && insn[5] == op2) + { + *r1 = (insn[1] >> 4) & 0xf; + *x2 = insn[1] & 0xf; + *b2 = (insn[2] >> 4) & 0xf; + /* The 'long displacement' is a 20-bit signed integer. */ + *d2 = ((((insn[2] & 0xf) << 8) | insn[3] | (insn[4] << 12)) + ^ 0x80000) - 0x80000; + return 1; + } + else + return 0; +} + +/* Breakpoints. */ + +constexpr gdb_byte s390_break_insn[] = { 0x0, 0x1 }; + +typedef BP_MANIPULATION (s390_break_insn) s390_breakpoint; + +/* A helper for s390_software_single_step, decides if an instruction + is a partial-execution instruction that needs to be executed until + completion when in record mode. If it is, returns 1 and writes + instruction length to a pointer. */ + +static int +s390_is_partial_instruction (struct gdbarch *gdbarch, CORE_ADDR loc, int *len) +{ + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + uint16_t insn; + + insn = read_memory_integer (loc, 2, byte_order); + + switch (insn >> 8) + { + case 0xa8: /* MVCLE */ + *len = 4; + return 1; + + case 0xeb: + { + insn = read_memory_integer (loc + 4, 2, byte_order); + if ((insn & 0xff) == 0x8e) + { + /* MVCLU */ + *len = 6; + return 1; + } + } + break; + } + + switch (insn) + { + case 0xb255: /* MVST */ + case 0xb263: /* CMPSC */ + case 0xb2a5: /* TRE */ + case 0xb2a6: /* CU21 */ + case 0xb2a7: /* CU12 */ + case 0xb9b0: /* CU14 */ + case 0xb9b1: /* CU24 */ + case 0xb9b2: /* CU41 */ + case 0xb9b3: /* CU42 */ + case 0xb92a: /* KMF */ + case 0xb92b: /* KMO */ + case 0xb92f: /* KMC */ + case 0xb92d: /* KMCTR */ + case 0xb92e: /* KM */ + case 0xb93c: /* PPNO */ + case 0xb990: /* TRTT */ + case 0xb991: /* TRTO */ + case 0xb992: /* TROT */ + case 0xb993: /* TROO */ + *len = 4; + return 1; + } + + return 0; +} + +/* Implement the "software_single_step" gdbarch method, needed to single step + through instructions like MVCLE in record mode, to make sure they are + executed to completion. Without that, record will save the full length + of destination buffer on every iteration, even though the CPU will only + process about 4kiB of it each time, leading to O(n**2) memory and time + complexity. */ + +static VEC (CORE_ADDR) * +s390_software_single_step (struct regcache *regcache) +{ + struct gdbarch *gdbarch = get_regcache_arch (regcache); + CORE_ADDR loc = regcache_read_pc (regcache); + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + int len; + uint16_t insn; + VEC (CORE_ADDR) *next_pcs = NULL; + + /* Special handling only if recording. */ + if (!record_full_is_used ()) + return NULL; + + /* First, match a partial instruction. */ + if (!s390_is_partial_instruction (gdbarch, loc, &len)) + return NULL; + + loc += len; + + /* Second, look for a branch back to it. */ + insn = read_memory_integer (loc, 2, byte_order); + if (insn != 0xa714) /* BRC with mask 1 */ + return NULL; + + insn = read_memory_integer (loc + 2, 2, byte_order); + if (insn != (uint16_t) -(len / 2)) + return NULL; + + loc += 4; + + /* Found it, step past the whole thing. */ + VEC_safe_push (CORE_ADDR, next_pcs, loc); + + return next_pcs; +} + + +/* Prologue analysis. */ + +struct s390_prologue_data { + + /* The stack. */ + struct pv_area *stack; + + /* The size and byte-order of a GPR or FPR. */ + int gpr_size; + int fpr_size; + enum bfd_endian byte_order; + + /* The general-purpose registers. */ + pv_t gpr[S390_NUM_GPRS]; + + /* The floating-point registers. */ + pv_t fpr[S390_NUM_FPRS]; + + /* The offset relative to the CFA where the incoming GPR N was saved + by the function prologue. 0 if not saved or unknown. */ + int gpr_slot[S390_NUM_GPRS]; + + /* Likewise for FPRs. */ + int fpr_slot[S390_NUM_FPRS]; + + /* Nonzero if the backchain was saved. This is assumed to be the + case when the incoming SP is saved at the current SP location. */ + int back_chain_saved_p; +}; + +/* Return the effective address for an X-style instruction, like: + + L R1, D2(X2, B2) + + Here, X2 and B2 are registers, and D2 is a signed 20-bit + constant; the effective address is the sum of all three. If either + X2 or B2 are zero, then it doesn't contribute to the sum --- this + means that r0 can't be used as either X2 or B2. */ + +static pv_t +s390_addr (struct s390_prologue_data *data, + int d2, unsigned int x2, unsigned int b2) +{ + pv_t result; + + result = pv_constant (d2); + if (x2) + result = pv_add (result, data->gpr[x2]); + if (b2) + result = pv_add (result, data->gpr[b2]); + + return result; +} + +/* Do a SIZE-byte store of VALUE to D2(X2,B2). Helper for + s390_analyze_prologue. */ + +static void +s390_store (struct s390_prologue_data *data, + int d2, unsigned int x2, unsigned int b2, CORE_ADDR size, + pv_t value) +{ + pv_t addr = s390_addr (data, d2, x2, b2); + pv_t offset; + + /* Check whether we are storing the backchain. */ + offset = pv_subtract (data->gpr[S390_SP_REGNUM - S390_R0_REGNUM], addr); + + if (pv_is_constant (offset) && offset.k == 0) + if (size == data->gpr_size + && pv_is_register_k (value, S390_SP_REGNUM, 0)) + { + data->back_chain_saved_p = 1; + return; + } + + + /* Check whether we are storing a register into the stack. */ + if (!pv_area_store_would_trash (data->stack, addr)) + pv_area_store (data->stack, addr, size, value); + + + /* Note: If this is some store we cannot identify, you might think we + should forget our cached values, as any of those might have been hit. + + However, we make the assumption that the register save areas are only + ever stored to once in any given function, and we do recognize these + stores. Thus every store we cannot recognize does not hit our data. */ +} + +/* Do a SIZE-byte load from D2(X2,B2). Helper for s390_analyze_prologue. */ + +static pv_t +s390_load (struct s390_prologue_data *data, + int d2, unsigned int x2, unsigned int b2, CORE_ADDR size) + +{ + pv_t addr = s390_addr (data, d2, x2, b2); + + /* If it's a load from an in-line constant pool, then we can + simulate that, under the assumption that the code isn't + going to change between the time the processor actually + executed it creating the current frame, and the time when + we're analyzing the code to unwind past that frame. */ + if (pv_is_constant (addr)) + { + struct target_section *secp; + secp = target_section_by_addr (¤t_target, addr.k); + if (secp != NULL + && (bfd_get_section_flags (secp->the_bfd_section->owner, + secp->the_bfd_section) + & SEC_READONLY)) + return pv_constant (read_memory_integer (addr.k, size, + data->byte_order)); + } + + /* Check whether we are accessing one of our save slots. */ + return pv_area_fetch (data->stack, addr, size); +} + +/* Function for finding saved registers in a 'struct pv_area'; we pass + this to pv_area_scan. + + If VALUE is a saved register, ADDR says it was saved at a constant + offset from the frame base, and SIZE indicates that the whole + register was saved, record its offset in the reg_offset table in + PROLOGUE_UNTYPED. */ + +static void +s390_check_for_saved (void *data_untyped, pv_t addr, + CORE_ADDR size, pv_t value) +{ + struct s390_prologue_data *data = (struct s390_prologue_data *) data_untyped; + int i, offset; + + if (!pv_is_register (addr, S390_SP_REGNUM)) + return; + + offset = 16 * data->gpr_size + 32 - addr.k; + + /* If we are storing the original value of a register, we want to + record the CFA offset. If the same register is stored multiple + times, the stack slot with the highest address counts. */ + + for (i = 0; i < S390_NUM_GPRS; i++) + if (size == data->gpr_size + && pv_is_register_k (value, S390_R0_REGNUM + i, 0)) + if (data->gpr_slot[i] == 0 + || data->gpr_slot[i] > offset) + { + data->gpr_slot[i] = offset; + return; + } + + for (i = 0; i < S390_NUM_FPRS; i++) + if (size == data->fpr_size + && pv_is_register_k (value, S390_F0_REGNUM + i, 0)) + if (data->fpr_slot[i] == 0 + || data->fpr_slot[i] > offset) + { + data->fpr_slot[i] = offset; + return; + } +} + +/* Analyze the prologue of the function starting at START_PC, + continuing at most until CURRENT_PC. Initialize DATA to + hold all information we find out about the state of the registers + and stack slots. Return the address of the instruction after + the last one that changed the SP, FP, or back chain; or zero + on error. */ + +static CORE_ADDR +s390_analyze_prologue (struct gdbarch *gdbarch, + CORE_ADDR start_pc, + CORE_ADDR current_pc, + struct s390_prologue_data *data) +{ + int word_size = gdbarch_ptr_bit (gdbarch) / 8; + + /* Our return value: + The address of the instruction after the last one that changed + the SP, FP, or back chain; zero if we got an error trying to + read memory. */ + CORE_ADDR result = start_pc; + + /* The current PC for our abstract interpretation. */ + CORE_ADDR pc; + + /* The address of the next instruction after that. */ + CORE_ADDR next_pc; + + /* Set up everything's initial value. */ + { + int i; + + data->stack = make_pv_area (S390_SP_REGNUM, gdbarch_addr_bit (gdbarch)); + + /* For the purpose of prologue tracking, we consider the GPR size to + be equal to the ABI word size, even if it is actually larger + (i.e. when running a 32-bit binary under a 64-bit kernel). */ + data->gpr_size = word_size; + data->fpr_size = 8; + data->byte_order = gdbarch_byte_order (gdbarch); + + for (i = 0; i < S390_NUM_GPRS; i++) + data->gpr[i] = pv_register (S390_R0_REGNUM + i, 0); + + for (i = 0; i < S390_NUM_FPRS; i++) + data->fpr[i] = pv_register (S390_F0_REGNUM + i, 0); + + for (i = 0; i < S390_NUM_GPRS; i++) + data->gpr_slot[i] = 0; + + for (i = 0; i < S390_NUM_FPRS; i++) + data->fpr_slot[i] = 0; + + data->back_chain_saved_p = 0; + } + + /* Start interpreting instructions, until we hit the frame's + current PC or the first branch instruction. */ + for (pc = start_pc; pc > 0 && pc < current_pc; pc = next_pc) + { + bfd_byte insn[S390_MAX_INSTR_SIZE]; + int insn_len = s390_readinstruction (insn, pc); + + bfd_byte dummy[S390_MAX_INSTR_SIZE] = { 0 }; + bfd_byte *insn32 = word_size == 4 ? insn : dummy; + bfd_byte *insn64 = word_size == 8 ? insn : dummy; + + /* Fields for various kinds of instructions. */ + unsigned int b2, r1, r2, x2, r3; + int i2, d2; + + /* The values of SP and FP before this instruction, + for detecting instructions that change them. */ + pv_t pre_insn_sp, pre_insn_fp; + /* Likewise for the flag whether the back chain was saved. */ + int pre_insn_back_chain_saved_p; + + /* If we got an error trying to read the instruction, report it. */ + if (insn_len < 0) + { + result = 0; + break; + } + + next_pc = pc + insn_len; + + pre_insn_sp = data->gpr[S390_SP_REGNUM - S390_R0_REGNUM]; + pre_insn_fp = data->gpr[S390_FRAME_REGNUM - S390_R0_REGNUM]; + pre_insn_back_chain_saved_p = data->back_chain_saved_p; + + + /* LHI r1, i2 --- load halfword immediate. */ + /* LGHI r1, i2 --- load halfword immediate (64-bit version). */ + /* LGFI r1, i2 --- load fullword immediate. */ + if (is_ri (insn32, op1_lhi, op2_lhi, &r1, &i2) + || is_ri (insn64, op1_lghi, op2_lghi, &r1, &i2) + || is_ril (insn, op1_lgfi, op2_lgfi, &r1, &i2)) + data->gpr[r1] = pv_constant (i2); + + /* LR r1, r2 --- load from register. */ + /* LGR r1, r2 --- load from register (64-bit version). */ + else if (is_rr (insn32, op_lr, &r1, &r2) + || is_rre (insn64, op_lgr, &r1, &r2)) + data->gpr[r1] = data->gpr[r2]; + + /* L r1, d2(x2, b2) --- load. */ + /* LY r1, d2(x2, b2) --- load (long-displacement version). */ + /* LG r1, d2(x2, b2) --- load (64-bit version). */ + else if (is_rx (insn32, op_l, &r1, &d2, &x2, &b2) + || is_rxy (insn32, op1_ly, op2_ly, &r1, &d2, &x2, &b2) + || is_rxy (insn64, op1_lg, op2_lg, &r1, &d2, &x2, &b2)) + data->gpr[r1] = s390_load (data, d2, x2, b2, data->gpr_size); + + /* ST r1, d2(x2, b2) --- store. */ + /* STY r1, d2(x2, b2) --- store (long-displacement version). */ + /* STG r1, d2(x2, b2) --- store (64-bit version). */ + else if (is_rx (insn32, op_st, &r1, &d2, &x2, &b2) + || is_rxy (insn32, op1_sty, op2_sty, &r1, &d2, &x2, &b2) + || is_rxy (insn64, op1_stg, op2_stg, &r1, &d2, &x2, &b2)) + s390_store (data, d2, x2, b2, data->gpr_size, data->gpr[r1]); + + /* STD r1, d2(x2,b2) --- store floating-point register. */ + else if (is_rx (insn, op_std, &r1, &d2, &x2, &b2)) + s390_store (data, d2, x2, b2, data->fpr_size, data->fpr[r1]); + + /* STM r1, r3, d2(b2) --- store multiple. */ + /* STMY r1, r3, d2(b2) --- store multiple (long-displacement + version). */ + /* STMG r1, r3, d2(b2) --- store multiple (64-bit version). */ + else if (is_rs (insn32, op_stm, &r1, &r3, &d2, &b2) + || is_rsy (insn32, op1_stmy, op2_stmy, &r1, &r3, &d2, &b2) + || is_rsy (insn64, op1_stmg, op2_stmg, &r1, &r3, &d2, &b2)) + { + for (; r1 <= r3; r1++, d2 += data->gpr_size) + s390_store (data, d2, 0, b2, data->gpr_size, data->gpr[r1]); + } + + /* AHI r1, i2 --- add halfword immediate. */ + /* AGHI r1, i2 --- add halfword immediate (64-bit version). */ + /* AFI r1, i2 --- add fullword immediate. */ + /* AGFI r1, i2 --- add fullword immediate (64-bit version). */ + else if (is_ri (insn32, op1_ahi, op2_ahi, &r1, &i2) + || is_ri (insn64, op1_aghi, op2_aghi, &r1, &i2) + || is_ril (insn32, op1_afi, op2_afi, &r1, &i2) + || is_ril (insn64, op1_agfi, op2_agfi, &r1, &i2)) + data->gpr[r1] = pv_add_constant (data->gpr[r1], i2); + + /* ALFI r1, i2 --- add logical immediate. */ + /* ALGFI r1, i2 --- add logical immediate (64-bit version). */ + else if (is_ril (insn32, op1_alfi, op2_alfi, &r1, &i2) + || is_ril (insn64, op1_algfi, op2_algfi, &r1, &i2)) + data->gpr[r1] = pv_add_constant (data->gpr[r1], + (CORE_ADDR)i2 & 0xffffffff); + + /* AR r1, r2 -- add register. */ + /* AGR r1, r2 -- add register (64-bit version). */ + else if (is_rr (insn32, op_ar, &r1, &r2) + || is_rre (insn64, op_agr, &r1, &r2)) + data->gpr[r1] = pv_add (data->gpr[r1], data->gpr[r2]); + + /* A r1, d2(x2, b2) -- add. */ + /* AY r1, d2(x2, b2) -- add (long-displacement version). */ + /* AG r1, d2(x2, b2) -- add (64-bit version). */ + else if (is_rx (insn32, op_a, &r1, &d2, &x2, &b2) + || is_rxy (insn32, op1_ay, op2_ay, &r1, &d2, &x2, &b2) + || is_rxy (insn64, op1_ag, op2_ag, &r1, &d2, &x2, &b2)) + data->gpr[r1] = pv_add (data->gpr[r1], + s390_load (data, d2, x2, b2, data->gpr_size)); + + /* SLFI r1, i2 --- subtract logical immediate. */ + /* SLGFI r1, i2 --- subtract logical immediate (64-bit version). */ + else if (is_ril (insn32, op1_slfi, op2_slfi, &r1, &i2) + || is_ril (insn64, op1_slgfi, op2_slgfi, &r1, &i2)) + data->gpr[r1] = pv_add_constant (data->gpr[r1], + -((CORE_ADDR)i2 & 0xffffffff)); + + /* SR r1, r2 -- subtract register. */ + /* SGR r1, r2 -- subtract register (64-bit version). */ + else if (is_rr (insn32, op_sr, &r1, &r2) + || is_rre (insn64, op_sgr, &r1, &r2)) + data->gpr[r1] = pv_subtract (data->gpr[r1], data->gpr[r2]); + + /* S r1, d2(x2, b2) -- subtract. */ + /* SY r1, d2(x2, b2) -- subtract (long-displacement version). */ + /* SG r1, d2(x2, b2) -- subtract (64-bit version). */ + else if (is_rx (insn32, op_s, &r1, &d2, &x2, &b2) + || is_rxy (insn32, op1_sy, op2_sy, &r1, &d2, &x2, &b2) + || is_rxy (insn64, op1_sg, op2_sg, &r1, &d2, &x2, &b2)) + data->gpr[r1] = pv_subtract (data->gpr[r1], + s390_load (data, d2, x2, b2, data->gpr_size)); + + /* LA r1, d2(x2, b2) --- load address. */ + /* LAY r1, d2(x2, b2) --- load address (long-displacement version). */ + else if (is_rx (insn, op_la, &r1, &d2, &x2, &b2) + || is_rxy (insn, op1_lay, op2_lay, &r1, &d2, &x2, &b2)) + data->gpr[r1] = s390_addr (data, d2, x2, b2); + + /* LARL r1, i2 --- load address relative long. */ + else if (is_ril (insn, op1_larl, op2_larl, &r1, &i2)) + data->gpr[r1] = pv_constant (pc + i2 * 2); + + /* BASR r1, 0 --- branch and save. + Since r2 is zero, this saves the PC in r1, but doesn't branch. */ + else if (is_rr (insn, op_basr, &r1, &r2) + && r2 == 0) + data->gpr[r1] = pv_constant (next_pc); + + /* BRAS r1, i2 --- branch relative and save. */ + else if (is_ri (insn, op1_bras, op2_bras, &r1, &i2)) + { + data->gpr[r1] = pv_constant (next_pc); + next_pc = pc + i2 * 2; + + /* We'd better not interpret any backward branches. We'll + never terminate. */ + if (next_pc <= pc) + break; + } + + /* BRC/BRCL -- branch relative on condition. Ignore "branch + never", branch to following instruction, and "conditional + trap" (BRC +2). Otherwise terminate search. */ + else if (is_ri (insn, op1_brc, op2_brc, &r1, &i2)) + { + if (r1 != 0 && i2 != 1 && i2 != 2) + break; + } + else if (is_ril (insn, op1_brcl, op2_brcl, &r1, &i2)) + { + if (r1 != 0 && i2 != 3) + break; + } + + /* Terminate search when hitting any other branch instruction. */ + else if (is_rr (insn, op_basr, &r1, &r2) + || is_rx (insn, op_bas, &r1, &d2, &x2, &b2) + || is_rr (insn, op_bcr, &r1, &r2) + || is_rx (insn, op_bc, &r1, &d2, &x2, &b2) + || is_ril (insn, op1_brasl, op2_brasl, &r2, &i2)) + break; + + else + { + /* An instruction we don't know how to simulate. The only + safe thing to do would be to set every value we're tracking + to 'unknown'. Instead, we'll be optimistic: we assume that + we *can* interpret every instruction that the compiler uses + to manipulate any of the data we're interested in here -- + then we can just ignore anything else. */ + } + + /* Record the address after the last instruction that changed + the FP, SP, or backlink. Ignore instructions that changed + them back to their original values --- those are probably + restore instructions. (The back chain is never restored, + just popped.) */ + { + pv_t sp = data->gpr[S390_SP_REGNUM - S390_R0_REGNUM]; + pv_t fp = data->gpr[S390_FRAME_REGNUM - S390_R0_REGNUM]; + + if ((! pv_is_identical (pre_insn_sp, sp) + && ! pv_is_register_k (sp, S390_SP_REGNUM, 0) + && sp.kind != pvk_unknown) + || (! pv_is_identical (pre_insn_fp, fp) + && ! pv_is_register_k (fp, S390_FRAME_REGNUM, 0) + && fp.kind != pvk_unknown) + || pre_insn_back_chain_saved_p != data->back_chain_saved_p) + result = next_pc; + } + } + + /* Record where all the registers were saved. */ + pv_area_scan (data->stack, s390_check_for_saved, data); + + free_pv_area (data->stack); + data->stack = NULL; + + return result; +} + +/* Advance PC across any function entry prologue instructions to reach + some "real" code. */ + +static CORE_ADDR +s390_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc) +{ + struct s390_prologue_data data; + CORE_ADDR skip_pc, func_addr; + + if (find_pc_partial_function (pc, NULL, &func_addr, NULL)) + { + CORE_ADDR post_prologue_pc + = skip_prologue_using_sal (gdbarch, func_addr); + if (post_prologue_pc != 0) + return std::max (pc, post_prologue_pc); + } + + skip_pc = s390_analyze_prologue (gdbarch, pc, (CORE_ADDR)-1, &data); + return skip_pc ? skip_pc : pc; +} + + +/* Registers. */ + +/* ABI call-saved register information. */ + +static int +s390_register_call_saved (struct gdbarch *gdbarch, int regnum) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + switch (tdep->abi) + { + case ABI_LINUX_S390: + if ((regnum >= S390_R6_REGNUM && regnum <= S390_R15_REGNUM) + || regnum == S390_F4_REGNUM || regnum == S390_F6_REGNUM + || regnum == S390_A0_REGNUM) + return 1; + + break; + + case ABI_LINUX_ZSERIES: + if ((regnum >= S390_R6_REGNUM && regnum <= S390_R15_REGNUM) + || (regnum >= S390_F8_REGNUM && regnum <= S390_F15_REGNUM) + || (regnum >= S390_A0_REGNUM && regnum <= S390_A1_REGNUM)) + return 1; + + break; + } + + return 0; +} + +/* Return the name of register REGNO. Return the empty string for + registers that shouldn't be visible. */ + +static const char * +s390_register_name (struct gdbarch *gdbarch, int regnum) +{ + if (regnum >= S390_V0_LOWER_REGNUM + && regnum <= S390_V15_LOWER_REGNUM) + return ""; + return tdesc_register_name (gdbarch, regnum); +} + +static int +s390_cannot_store_register (struct gdbarch *gdbarch, int regnum) +{ + /* The last-break address is read-only. */ + return regnum == S390_LAST_BREAK_REGNUM; +} + +static void +s390_write_pc (struct regcache *regcache, CORE_ADDR pc) +{ + struct gdbarch *gdbarch = get_regcache_arch (regcache); + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + regcache_cooked_write_unsigned (regcache, tdep->pc_regnum, pc); + + /* Set special SYSTEM_CALL register to 0 to prevent the kernel from + messing with the PC we just installed, if we happen to be within + an interrupted system call that the kernel wants to restart. + + Note that after we return from the dummy call, the SYSTEM_CALL and + ORIG_R2 registers will be automatically restored, and the kernel + continues to restart the system call at this point. */ + if (register_size (gdbarch, S390_SYSTEM_CALL_REGNUM) > 0) + regcache_cooked_write_unsigned (regcache, S390_SYSTEM_CALL_REGNUM, 0); +} + +/* DWARF Register Mapping. */ + +static const short s390_dwarf_regmap[] = +{ + /* 0-15: General Purpose Registers. */ + S390_R0_REGNUM, S390_R1_REGNUM, S390_R2_REGNUM, S390_R3_REGNUM, + S390_R4_REGNUM, S390_R5_REGNUM, S390_R6_REGNUM, S390_R7_REGNUM, + S390_R8_REGNUM, S390_R9_REGNUM, S390_R10_REGNUM, S390_R11_REGNUM, + S390_R12_REGNUM, S390_R13_REGNUM, S390_R14_REGNUM, S390_R15_REGNUM, + + /* 16-31: Floating Point Registers / Vector Registers 0-15. */ + S390_F0_REGNUM, S390_F2_REGNUM, S390_F4_REGNUM, S390_F6_REGNUM, + S390_F1_REGNUM, S390_F3_REGNUM, S390_F5_REGNUM, S390_F7_REGNUM, + S390_F8_REGNUM, S390_F10_REGNUM, S390_F12_REGNUM, S390_F14_REGNUM, + S390_F9_REGNUM, S390_F11_REGNUM, S390_F13_REGNUM, S390_F15_REGNUM, + + /* 32-47: Control Registers (not mapped). */ + -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, + + /* 48-63: Access Registers. */ + S390_A0_REGNUM, S390_A1_REGNUM, S390_A2_REGNUM, S390_A3_REGNUM, + S390_A4_REGNUM, S390_A5_REGNUM, S390_A6_REGNUM, S390_A7_REGNUM, + S390_A8_REGNUM, S390_A9_REGNUM, S390_A10_REGNUM, S390_A11_REGNUM, + S390_A12_REGNUM, S390_A13_REGNUM, S390_A14_REGNUM, S390_A15_REGNUM, + + /* 64-65: Program Status Word. */ + S390_PSWM_REGNUM, + S390_PSWA_REGNUM, + + /* 66-67: Reserved. */ + -1, -1, + + /* 68-83: Vector Registers 16-31. */ + S390_V16_REGNUM, S390_V18_REGNUM, S390_V20_REGNUM, S390_V22_REGNUM, + S390_V17_REGNUM, S390_V19_REGNUM, S390_V21_REGNUM, S390_V23_REGNUM, + S390_V24_REGNUM, S390_V26_REGNUM, S390_V28_REGNUM, S390_V30_REGNUM, + S390_V25_REGNUM, S390_V27_REGNUM, S390_V29_REGNUM, S390_V31_REGNUM, + + /* End of "official" DWARF registers. The remainder of the map is + for GDB internal use only. */ + + /* GPR Lower Half Access. */ + S390_R0_REGNUM, S390_R1_REGNUM, S390_R2_REGNUM, S390_R3_REGNUM, + S390_R4_REGNUM, S390_R5_REGNUM, S390_R6_REGNUM, S390_R7_REGNUM, + S390_R8_REGNUM, S390_R9_REGNUM, S390_R10_REGNUM, S390_R11_REGNUM, + S390_R12_REGNUM, S390_R13_REGNUM, S390_R14_REGNUM, S390_R15_REGNUM, +}; + +enum { s390_dwarf_reg_r0l = ARRAY_SIZE (s390_dwarf_regmap) - 16 }; + +/* Convert DWARF register number REG to the appropriate register + number used by GDB. */ + +static int +s390_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + int gdb_reg = -1; + + /* In a 32-on-64 debug scenario, debug info refers to the full + 64-bit GPRs. Note that call frame information still refers to + the 32-bit lower halves, because s390_adjust_frame_regnum uses + special register numbers to access GPRs. */ + if (tdep->gpr_full_regnum != -1 && reg >= 0 && reg < 16) + return tdep->gpr_full_regnum + reg; + + if (reg >= 0 && reg < ARRAY_SIZE (s390_dwarf_regmap)) + gdb_reg = s390_dwarf_regmap[reg]; + + if (tdep->v0_full_regnum == -1) + { + if (gdb_reg >= S390_V16_REGNUM && gdb_reg <= S390_V31_REGNUM) + gdb_reg = -1; + } + else + { + if (gdb_reg >= S390_F0_REGNUM && gdb_reg <= S390_F15_REGNUM) + gdb_reg = gdb_reg - S390_F0_REGNUM + tdep->v0_full_regnum; + } + + return gdb_reg; +} + +static int +regnum_is_gpr_full (struct gdbarch_tdep *tdep, int regnum) +{ + return (tdep->gpr_full_regnum != -1 + && regnum >= tdep->gpr_full_regnum + && regnum <= tdep->gpr_full_regnum + 15); +} + +/* Check whether REGNUM indicates a full vector register (v0-v15). + These pseudo-registers are composed of f0-f15 and v0l-v15l. */ + +static int +regnum_is_vxr_full (struct gdbarch_tdep *tdep, int regnum) +{ + return (tdep->v0_full_regnum != -1 + && regnum >= tdep->v0_full_regnum + && regnum <= tdep->v0_full_regnum + 15); +} + +/* 'float' values are stored in the upper half of floating-point + registers, even though we are otherwise a big-endian platform. The + same applies to a 'float' value within a vector. */ + +static struct value * +s390_value_from_register (struct gdbarch *gdbarch, struct type *type, + int regnum, struct frame_id frame_id) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + struct value *value = default_value_from_register (gdbarch, type, + regnum, frame_id); + check_typedef (type); + + if ((regnum >= S390_F0_REGNUM && regnum <= S390_F15_REGNUM + && TYPE_LENGTH (type) < 8) + || regnum_is_vxr_full (tdep, regnum) + || (regnum >= S390_V16_REGNUM && regnum <= S390_V31_REGNUM)) + set_value_offset (value, 0); + + return value; +} + +static const struct target_desc * +s390_core_read_description (struct gdbarch *gdbarch, + struct target_ops *target, bfd *abfd) +{ + asection *section = bfd_get_section_by_name (abfd, ".reg"); + CORE_ADDR hwcap = 0; + int high_gprs, v1, v2, te, vx; + + target_auxv_search (target, AT_HWCAP, &hwcap); + if (!section) + return NULL; + + high_gprs = (bfd_get_section_by_name (abfd, ".reg-s390-high-gprs") + != NULL); + v1 = (bfd_get_section_by_name (abfd, ".reg-s390-last-break") != NULL); + v2 = (bfd_get_section_by_name (abfd, ".reg-s390-system-call") != NULL); + vx = (hwcap & HWCAP_S390_VX); + te = (hwcap & HWCAP_S390_TE); + + switch (bfd_section_size (abfd, section)) + { + case s390_sizeof_gregset: + if (high_gprs) + return (te && vx ? tdesc_s390_tevx_linux64 : + vx ? tdesc_s390_vx_linux64 : + te ? tdesc_s390_te_linux64 : + v2 ? tdesc_s390_linux64v2 : + v1 ? tdesc_s390_linux64v1 : tdesc_s390_linux64); + else + return (v2 ? tdesc_s390_linux32v2 : + v1 ? tdesc_s390_linux32v1 : tdesc_s390_linux32); + + case s390x_sizeof_gregset: + return (te && vx ? tdesc_s390x_tevx_linux64 : + vx ? tdesc_s390x_vx_linux64 : + te ? tdesc_s390x_te_linux64 : + v2 ? tdesc_s390x_linux64v2 : + v1 ? tdesc_s390x_linux64v1 : tdesc_s390x_linux64); + + default: + return NULL; + } +} + +/* Iterate over supported core file register note sections. */ + +static void +s390_iterate_over_regset_sections (struct gdbarch *gdbarch, + iterate_over_regset_sections_cb *cb, + void *cb_data, + const struct regcache *regcache) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + const int gregset_size = (tdep->abi == ABI_LINUX_S390 ? + s390_sizeof_gregset : s390x_sizeof_gregset); + + cb (".reg", gregset_size, &s390_gregset, NULL, cb_data); + cb (".reg2", s390_sizeof_fpregset, &s390_fpregset, NULL, cb_data); + + if (tdep->abi == ABI_LINUX_S390 && tdep->gpr_full_regnum != -1) + cb (".reg-s390-high-gprs", 16 * 4, &s390_upper_regset, + "s390 GPR upper halves", cb_data); + + if (tdep->have_linux_v1) + cb (".reg-s390-last-break", 8, + (gdbarch_ptr_bit (gdbarch) == 32 + ? &s390_last_break_regset : &s390x_last_break_regset), + "s390 last-break address", cb_data); + + if (tdep->have_linux_v2) + cb (".reg-s390-system-call", 4, &s390_system_call_regset, + "s390 system-call", cb_data); + + /* If regcache is set, we are in "write" (gcore) mode. In this + case, don't iterate over the TDB unless its registers are + available. */ + if (tdep->have_tdb + && (regcache == NULL + || REG_VALID == regcache_register_status (regcache, + S390_TDB_DWORD0_REGNUM))) + cb (".reg-s390-tdb", s390_sizeof_tdbregset, &s390_tdb_regset, + "s390 TDB", cb_data); + + if (tdep->v0_full_regnum != -1) + { + cb (".reg-s390-vxrs-low", 16 * 8, &s390_vxrs_low_regset, + "s390 vector registers 0-15 lower half", cb_data); + cb (".reg-s390-vxrs-high", 16 * 16, &s390_vxrs_high_regset, + "s390 vector registers 16-31", cb_data); + } +} + + +/* Pseudo registers. */ + +static const char * +s390_pseudo_register_name (struct gdbarch *gdbarch, int regnum) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + if (regnum == tdep->pc_regnum) + return "pc"; + + if (regnum == tdep->cc_regnum) + return "cc"; + + if (regnum_is_gpr_full (tdep, regnum)) + { + static const char *full_name[] = { + "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", + "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15" + }; + return full_name[regnum - tdep->gpr_full_regnum]; + } + + if (regnum_is_vxr_full (tdep, regnum)) + { + static const char *full_name[] = { + "v0", "v1", "v2", "v3", "v4", "v5", "v6", "v7", + "v8", "v9", "v10", "v11", "v12", "v13", "v14", "v15" + }; + return full_name[regnum - tdep->v0_full_regnum]; + } + + internal_error (__FILE__, __LINE__, _("invalid regnum")); +} + +static enum register_status +s390_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache, + int regnum, gdb_byte *buf) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + int regsize = register_size (gdbarch, regnum); + ULONGEST val; + + if (regnum == tdep->pc_regnum) + { + enum register_status status; + + status = regcache_raw_read_unsigned (regcache, S390_PSWA_REGNUM, &val); + if (status == REG_VALID) + { + if (register_size (gdbarch, S390_PSWA_REGNUM) == 4) + val &= 0x7fffffff; + store_unsigned_integer (buf, regsize, byte_order, val); + } + return status; + } + + if (regnum == tdep->cc_regnum) + { + enum register_status status; + + status = regcache_raw_read_unsigned (regcache, S390_PSWM_REGNUM, &val); + if (status == REG_VALID) + { + if (register_size (gdbarch, S390_PSWA_REGNUM) == 4) + val = (val >> 12) & 3; + else + val = (val >> 44) & 3; + store_unsigned_integer (buf, regsize, byte_order, val); + } + return status; + } + + if (regnum_is_gpr_full (tdep, regnum)) + { + enum register_status status; + ULONGEST val_upper; + + regnum -= tdep->gpr_full_regnum; + + status = regcache_raw_read_unsigned (regcache, + S390_R0_REGNUM + regnum, &val); + if (status == REG_VALID) + status = regcache_raw_read_unsigned (regcache, + S390_R0_UPPER_REGNUM + regnum, + &val_upper); + if (status == REG_VALID) + { + val |= val_upper << 32; + store_unsigned_integer (buf, regsize, byte_order, val); + } + return status; + } + + if (regnum_is_vxr_full (tdep, regnum)) + { + enum register_status status; + + regnum -= tdep->v0_full_regnum; + + status = regcache_raw_read (regcache, S390_F0_REGNUM + regnum, buf); + if (status == REG_VALID) + status = regcache_raw_read (regcache, + S390_V0_LOWER_REGNUM + regnum, buf + 8); + return status; + } + + internal_error (__FILE__, __LINE__, _("invalid regnum")); +} + +static void +s390_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache, + int regnum, const gdb_byte *buf) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + int regsize = register_size (gdbarch, regnum); + ULONGEST val, psw; + + if (regnum == tdep->pc_regnum) + { + val = extract_unsigned_integer (buf, regsize, byte_order); + if (register_size (gdbarch, S390_PSWA_REGNUM) == 4) + { + regcache_raw_read_unsigned (regcache, S390_PSWA_REGNUM, &psw); + val = (psw & 0x80000000) | (val & 0x7fffffff); + } + regcache_raw_write_unsigned (regcache, S390_PSWA_REGNUM, val); + return; + } + + if (regnum == tdep->cc_regnum) + { + val = extract_unsigned_integer (buf, regsize, byte_order); + regcache_raw_read_unsigned (regcache, S390_PSWM_REGNUM, &psw); + if (register_size (gdbarch, S390_PSWA_REGNUM) == 4) + val = (psw & ~((ULONGEST)3 << 12)) | ((val & 3) << 12); + else + val = (psw & ~((ULONGEST)3 << 44)) | ((val & 3) << 44); + regcache_raw_write_unsigned (regcache, S390_PSWM_REGNUM, val); + return; + } + + if (regnum_is_gpr_full (tdep, regnum)) + { + regnum -= tdep->gpr_full_regnum; + val = extract_unsigned_integer (buf, regsize, byte_order); + regcache_raw_write_unsigned (regcache, S390_R0_REGNUM + regnum, + val & 0xffffffff); + regcache_raw_write_unsigned (regcache, S390_R0_UPPER_REGNUM + regnum, + val >> 32); + return; + } + + if (regnum_is_vxr_full (tdep, regnum)) + { + regnum -= tdep->v0_full_regnum; + regcache_raw_write (regcache, S390_F0_REGNUM + regnum, buf); + regcache_raw_write (regcache, S390_V0_LOWER_REGNUM + regnum, buf + 8); + return; + } + + internal_error (__FILE__, __LINE__, _("invalid regnum")); +} + +static struct type * +s390_pseudo_register_type (struct gdbarch *gdbarch, int regnum) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + if (regnum == tdep->pc_regnum) + return builtin_type (gdbarch)->builtin_func_ptr; + + if (regnum == tdep->cc_regnum) + return builtin_type (gdbarch)->builtin_int; + + if (regnum_is_gpr_full (tdep, regnum)) + return builtin_type (gdbarch)->builtin_uint64; + + if (regnum_is_vxr_full (tdep, regnum)) + return tdesc_find_type (gdbarch, "vec128"); + + internal_error (__FILE__, __LINE__, _("invalid regnum")); +} + +/* Register groups. */ + +static int +s390_pseudo_register_reggroup_p (struct gdbarch *gdbarch, int regnum, + struct reggroup *group) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + /* We usually save/restore the whole PSW, which includes PC and CC. + However, some older gdbservers may not support saving/restoring + the whole PSW yet, and will return an XML register description + excluding those from the save/restore register groups. In those + cases, we still need to explicitly save/restore PC and CC in order + to push or pop frames. Since this doesn't hurt anything if we + already save/restore the whole PSW (it's just redundant), we add + PC and CC at this point unconditionally. */ + if (group == save_reggroup || group == restore_reggroup) + return regnum == tdep->pc_regnum || regnum == tdep->cc_regnum; + + if (group == vector_reggroup) + return regnum_is_vxr_full (tdep, regnum); + + if (group == general_reggroup && regnum_is_vxr_full (tdep, regnum)) + return 0; + + return default_register_reggroup_p (gdbarch, regnum, group); +} + +/* The "ax_pseudo_register_collect" gdbarch method. */ + +static int +s390_ax_pseudo_register_collect (struct gdbarch *gdbarch, + struct agent_expr *ax, int regnum) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + if (regnum == tdep->pc_regnum) + { + ax_reg_mask (ax, S390_PSWA_REGNUM); + } + else if (regnum == tdep->cc_regnum) + { + ax_reg_mask (ax, S390_PSWM_REGNUM); + } + else if (regnum_is_gpr_full (tdep, regnum)) + { + regnum -= tdep->gpr_full_regnum; + ax_reg_mask (ax, S390_R0_REGNUM + regnum); + ax_reg_mask (ax, S390_R0_UPPER_REGNUM + regnum); + } + else if (regnum_is_vxr_full (tdep, regnum)) + { + regnum -= tdep->v0_full_regnum; + ax_reg_mask (ax, S390_F0_REGNUM + regnum); + ax_reg_mask (ax, S390_V0_LOWER_REGNUM + regnum); + } + else + { + internal_error (__FILE__, __LINE__, _("invalid regnum")); + } + return 0; +} + +/* The "ax_pseudo_register_push_stack" gdbarch method. */ + +static int +s390_ax_pseudo_register_push_stack (struct gdbarch *gdbarch, + struct agent_expr *ax, int regnum) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + if (regnum == tdep->pc_regnum) + { + ax_reg (ax, S390_PSWA_REGNUM); + if (register_size (gdbarch, S390_PSWA_REGNUM) == 4) + { + ax_zero_ext (ax, 31); + } + } + else if (regnum == tdep->cc_regnum) + { + ax_reg (ax, S390_PSWM_REGNUM); + if (register_size (gdbarch, S390_PSWA_REGNUM) == 4) + ax_const_l (ax, 12); + else + ax_const_l (ax, 44); + ax_simple (ax, aop_rsh_unsigned); + ax_zero_ext (ax, 2); + } + else if (regnum_is_gpr_full (tdep, regnum)) + { + regnum -= tdep->gpr_full_regnum; + ax_reg (ax, S390_R0_REGNUM + regnum); + ax_reg (ax, S390_R0_UPPER_REGNUM + regnum); + ax_const_l (ax, 32); + ax_simple (ax, aop_lsh); + ax_simple (ax, aop_bit_or); + } + else if (regnum_is_vxr_full (tdep, regnum)) + { + /* Too large to stuff on the stack. */ + return 1; + } + else + { + internal_error (__FILE__, __LINE__, _("invalid regnum")); + } + return 0; +} + +/* The "gen_return_address" gdbarch method. Since this is supposed to be + just a best-effort method, and we don't really have the means to run + the full unwinder here, just collect the link register. */ + +static void +s390_gen_return_address (struct gdbarch *gdbarch, + struct agent_expr *ax, struct axs_value *value, + CORE_ADDR scope) +{ + value->type = register_type (gdbarch, S390_R14_REGNUM); + value->kind = axs_lvalue_register; + value->u.reg = S390_R14_REGNUM; +} + +/* Helper routine to unwind pseudo registers. */ + +static struct value * +s390_unwind_pseudo_register (struct frame_info *this_frame, int regnum) +{ + struct gdbarch *gdbarch = get_frame_arch (this_frame); + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + struct type *type = register_type (gdbarch, regnum); + + /* Unwind PC via PSW address. */ + if (regnum == tdep->pc_regnum) + { + struct value *val; + + val = frame_unwind_register_value (this_frame, S390_PSWA_REGNUM); + if (!value_optimized_out (val)) + { + LONGEST pswa = value_as_long (val); + + if (TYPE_LENGTH (type) == 4) + return value_from_pointer (type, pswa & 0x7fffffff); + else + return value_from_pointer (type, pswa); + } + } + + /* Unwind CC via PSW mask. */ + if (regnum == tdep->cc_regnum) + { + struct value *val; + + val = frame_unwind_register_value (this_frame, S390_PSWM_REGNUM); + if (!value_optimized_out (val)) + { + LONGEST pswm = value_as_long (val); + + if (TYPE_LENGTH (type) == 4) + return value_from_longest (type, (pswm >> 12) & 3); + else + return value_from_longest (type, (pswm >> 44) & 3); + } + } + + /* Unwind full GPRs to show at least the lower halves (as the + upper halves are undefined). */ + if (regnum_is_gpr_full (tdep, regnum)) + { + int reg = regnum - tdep->gpr_full_regnum; + struct value *val; + + val = frame_unwind_register_value (this_frame, S390_R0_REGNUM + reg); + if (!value_optimized_out (val)) + return value_cast (type, val); + } + + return allocate_optimized_out_value (type); +} + + +/* Inferior function calls. */ + +/* Dummy function calls. */ + +/* Unwrap any single-field structs in TYPE and return the effective + "inner" type. E.g., yield "float" for all these cases: + + float x; + struct { float x }; + struct { struct { float x; } x; }; + struct { struct { struct { float x; } x; } x; }; + + However, if an inner type is smaller than MIN_SIZE, abort the + unwrapping. */ + +static struct type * +s390_effective_inner_type (struct type *type, unsigned int min_size) +{ + while (TYPE_CODE (type) == TYPE_CODE_STRUCT + && TYPE_NFIELDS (type) == 1) + { + struct type *inner = check_typedef (TYPE_FIELD_TYPE (type, 0)); + + if (TYPE_LENGTH (inner) < min_size) + break; + type = inner; + } + + return type; +} + +/* Return non-zero if TYPE should be passed like "float" or + "double". */ + +static int +s390_function_arg_float (struct type *type) +{ + /* Note that long double as well as complex types are intentionally + excluded. */ + if (TYPE_LENGTH (type) > 8) + return 0; + + /* A struct containing just a float or double is passed like a float + or double. */ + type = s390_effective_inner_type (type, 0); + + return (TYPE_CODE (type) == TYPE_CODE_FLT + || TYPE_CODE (type) == TYPE_CODE_DECFLOAT); +} + +/* Return non-zero if TYPE should be passed like a vector. */ + +static int +s390_function_arg_vector (struct type *type) +{ + if (TYPE_LENGTH (type) > 16) + return 0; + + /* Structs containing just a vector are passed like a vector. */ + type = s390_effective_inner_type (type, TYPE_LENGTH (type)); + + return TYPE_CODE (type) == TYPE_CODE_ARRAY && TYPE_VECTOR (type); +} + +/* Determine whether N is a power of two. */ + +static int +is_power_of_two (unsigned int n) +{ + return n && ((n & (n - 1)) == 0); +} + +/* For an argument whose type is TYPE and which is not passed like a + float or vector, return non-zero if it should be passed like "int" + or "long long". */ + +static int +s390_function_arg_integer (struct type *type) +{ + enum type_code code = TYPE_CODE (type); + + if (TYPE_LENGTH (type) > 8) + return 0; + + if (code == TYPE_CODE_INT + || code == TYPE_CODE_ENUM + || code == TYPE_CODE_RANGE + || code == TYPE_CODE_CHAR + || code == TYPE_CODE_BOOL + || code == TYPE_CODE_PTR + || code == TYPE_CODE_REF) + return 1; + + return ((code == TYPE_CODE_UNION || code == TYPE_CODE_STRUCT) + && is_power_of_two (TYPE_LENGTH (type))); +} + +/* Argument passing state: Internal data structure passed to helper + routines of s390_push_dummy_call. */ + +struct s390_arg_state + { + /* Register cache, or NULL, if we are in "preparation mode". */ + struct regcache *regcache; + /* Next available general/floating-point/vector register for + argument passing. */ + int gr, fr, vr; + /* Current pointer to copy area (grows downwards). */ + CORE_ADDR copy; + /* Current pointer to parameter area (grows upwards). */ + CORE_ADDR argp; + }; + +/* Prepare one argument ARG for a dummy call and update the argument + passing state AS accordingly. If the regcache field in AS is set, + operate in "write mode" and write ARG into the inferior. Otherwise + run "preparation mode" and skip all updates to the inferior. */ + +static void +s390_handle_arg (struct s390_arg_state *as, struct value *arg, + struct gdbarch_tdep *tdep, int word_size, + enum bfd_endian byte_order, int is_unnamed) +{ + struct type *type = check_typedef (value_type (arg)); + unsigned int length = TYPE_LENGTH (type); + int write_mode = as->regcache != NULL; + + if (s390_function_arg_float (type)) + { + /* The GNU/Linux for S/390 ABI uses FPRs 0 and 2 to pass + arguments. The GNU/Linux for zSeries ABI uses 0, 2, 4, and + 6. */ + if (as->fr <= (tdep->abi == ABI_LINUX_S390 ? 2 : 6)) + { + /* When we store a single-precision value in an FP register, + it occupies the leftmost bits. */ + if (write_mode) + regcache_cooked_write_part (as->regcache, + S390_F0_REGNUM + as->fr, + 0, length, + value_contents (arg)); + as->fr += 2; + } + else + { + /* When we store a single-precision value in a stack slot, + it occupies the rightmost bits. */ + as->argp = align_up (as->argp + length, word_size); + if (write_mode) + write_memory (as->argp - length, value_contents (arg), + length); + } + } + else if (tdep->vector_abi == S390_VECTOR_ABI_128 + && s390_function_arg_vector (type)) + { + static const char use_vr[] = {24, 26, 28, 30, 25, 27, 29, 31}; + + if (!is_unnamed && as->vr < ARRAY_SIZE (use_vr)) + { + int regnum = S390_V24_REGNUM + use_vr[as->vr] - 24; + + if (write_mode) + regcache_cooked_write_part (as->regcache, regnum, + 0, length, + value_contents (arg)); + as->vr++; + } + else + { + if (write_mode) + write_memory (as->argp, value_contents (arg), length); + as->argp = align_up (as->argp + length, word_size); + } + } + else if (s390_function_arg_integer (type) && length <= word_size) + { + /* Initialize it just to avoid a GCC false warning. */ + ULONGEST val = 0; + + if (write_mode) + { + /* Place value in least significant bits of the register or + memory word and sign- or zero-extend to full word size. + This also applies to a struct or union. */ + val = TYPE_UNSIGNED (type) + ? extract_unsigned_integer (value_contents (arg), + length, byte_order) + : extract_signed_integer (value_contents (arg), + length, byte_order); + } + + if (as->gr <= 6) + { + if (write_mode) + regcache_cooked_write_unsigned (as->regcache, + S390_R0_REGNUM + as->gr, + val); + as->gr++; + } + else + { + if (write_mode) + write_memory_unsigned_integer (as->argp, word_size, + byte_order, val); + as->argp += word_size; + } + } + else if (s390_function_arg_integer (type) && length == 8) + { + if (as->gr <= 5) + { + if (write_mode) + { + regcache_cooked_write (as->regcache, + S390_R0_REGNUM + as->gr, + value_contents (arg)); + regcache_cooked_write (as->regcache, + S390_R0_REGNUM + as->gr + 1, + value_contents (arg) + word_size); + } + as->gr += 2; + } + else + { + /* If we skipped r6 because we couldn't fit a DOUBLE_ARG + in it, then don't go back and use it again later. */ + as->gr = 7; + + if (write_mode) + write_memory (as->argp, value_contents (arg), length); + as->argp += length; + } + } + else + { + /* This argument type is never passed in registers. Place the + value in the copy area and pass a pointer to it. Use 8-byte + alignment as a conservative assumption. */ + as->copy = align_down (as->copy - length, 8); + if (write_mode) + write_memory (as->copy, value_contents (arg), length); + + if (as->gr <= 6) + { + if (write_mode) + regcache_cooked_write_unsigned (as->regcache, + S390_R0_REGNUM + as->gr, + as->copy); + as->gr++; + } + else + { + if (write_mode) + write_memory_unsigned_integer (as->argp, word_size, + byte_order, as->copy); + as->argp += word_size; + } + } +} + +/* Put the actual parameter values pointed to by ARGS[0..NARGS-1] in + place to be passed to a function, as specified by the "GNU/Linux + for S/390 ELF Application Binary Interface Supplement". + + SP is the current stack pointer. We must put arguments, links, + padding, etc. whereever they belong, and return the new stack + pointer value. + + If STRUCT_RETURN is non-zero, then the function we're calling is + going to return a structure by value; STRUCT_ADDR is the address of + a block we've allocated for it on the stack. + + Our caller has taken care of any type promotions needed to satisfy + prototypes or the old K&R argument-passing rules. */ + +static CORE_ADDR +s390_push_dummy_call (struct gdbarch *gdbarch, struct value *function, + struct regcache *regcache, CORE_ADDR bp_addr, + int nargs, struct value **args, CORE_ADDR sp, + int struct_return, CORE_ADDR struct_addr) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + int word_size = gdbarch_ptr_bit (gdbarch) / 8; + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + int i; + struct s390_arg_state arg_state, arg_prep; + CORE_ADDR param_area_start, new_sp; + struct type *ftype = check_typedef (value_type (function)); + + if (TYPE_CODE (ftype) == TYPE_CODE_PTR) + ftype = check_typedef (TYPE_TARGET_TYPE (ftype)); + + arg_prep.copy = sp; + arg_prep.gr = struct_return ? 3 : 2; + arg_prep.fr = 0; + arg_prep.vr = 0; + arg_prep.argp = 0; + arg_prep.regcache = NULL; + + /* Initialize arg_state for "preparation mode". */ + arg_state = arg_prep; + + /* Update arg_state.copy with the start of the reference-to-copy area + and arg_state.argp with the size of the parameter area. */ + for (i = 0; i < nargs; i++) + s390_handle_arg (&arg_state, args[i], tdep, word_size, byte_order, + TYPE_VARARGS (ftype) && i >= TYPE_NFIELDS (ftype)); + + param_area_start = align_down (arg_state.copy - arg_state.argp, 8); + + /* Allocate the standard frame areas: the register save area, the + word reserved for the compiler, and the back chain pointer. */ + new_sp = param_area_start - (16 * word_size + 32); + + /* Now we have the final stack pointer. Make sure we didn't + underflow; on 31-bit, this would result in addresses with the + high bit set, which causes confusion elsewhere. Note that if we + error out here, stack and registers remain untouched. */ + if (gdbarch_addr_bits_remove (gdbarch, new_sp) != new_sp) + error (_("Stack overflow")); + + /* Pass the structure return address in general register 2. */ + if (struct_return) + regcache_cooked_write_unsigned (regcache, S390_R2_REGNUM, struct_addr); + + /* Initialize arg_state for "write mode". */ + arg_state = arg_prep; + arg_state.argp = param_area_start; + arg_state.regcache = regcache; + + /* Write all parameters. */ + for (i = 0; i < nargs; i++) + s390_handle_arg (&arg_state, args[i], tdep, word_size, byte_order, + TYPE_VARARGS (ftype) && i >= TYPE_NFIELDS (ftype)); + + /* Store return PSWA. In 31-bit mode, keep addressing mode bit. */ + if (word_size == 4) + { + ULONGEST pswa; + regcache_cooked_read_unsigned (regcache, S390_PSWA_REGNUM, &pswa); + bp_addr = (bp_addr & 0x7fffffff) | (pswa & 0x80000000); + } + regcache_cooked_write_unsigned (regcache, S390_RETADDR_REGNUM, bp_addr); + + /* Store updated stack pointer. */ + regcache_cooked_write_unsigned (regcache, S390_SP_REGNUM, new_sp); + + /* We need to return the 'stack part' of the frame ID, + which is actually the top of the register save area. */ + return param_area_start; +} + +/* Assuming THIS_FRAME is a dummy, return the frame ID of that + dummy frame. The frame ID's base needs to match the TOS value + returned by push_dummy_call, and the PC match the dummy frame's + breakpoint. */ + +static struct frame_id +s390_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame) +{ + int word_size = gdbarch_ptr_bit (gdbarch) / 8; + CORE_ADDR sp = get_frame_register_unsigned (this_frame, S390_SP_REGNUM); + sp = gdbarch_addr_bits_remove (gdbarch, sp); + + return frame_id_build (sp + 16*word_size + 32, + get_frame_pc (this_frame)); +} + +static CORE_ADDR +s390_frame_align (struct gdbarch *gdbarch, CORE_ADDR addr) +{ + /* Both the 32- and 64-bit ABI's say that the stack pointer should + always be aligned on an eight-byte boundary. */ + return (addr & -8); +} + +/* Helper for s390_return_value: Set or retrieve a function return + value if it resides in a register. */ + +static void +s390_register_return_value (struct gdbarch *gdbarch, struct type *type, + struct regcache *regcache, + gdb_byte *out, const gdb_byte *in) +{ + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + int word_size = gdbarch_ptr_bit (gdbarch) / 8; + int length = TYPE_LENGTH (type); + int code = TYPE_CODE (type); + + if (code == TYPE_CODE_FLT || code == TYPE_CODE_DECFLOAT) + { + /* Float-like value: left-aligned in f0. */ + if (in != NULL) + regcache_cooked_write_part (regcache, S390_F0_REGNUM, + 0, length, in); + else + regcache_cooked_read_part (regcache, S390_F0_REGNUM, + 0, length, out); + } + else if (code == TYPE_CODE_ARRAY) + { + /* Vector: left-aligned in v24. */ + if (in != NULL) + regcache_cooked_write_part (regcache, S390_V24_REGNUM, + 0, length, in); + else + regcache_cooked_read_part (regcache, S390_V24_REGNUM, + 0, length, out); + } + else if (length <= word_size) + { + /* Integer: zero- or sign-extended in r2. */ + if (out != NULL) + regcache_cooked_read_part (regcache, S390_R2_REGNUM, + word_size - length, length, out); + else if (TYPE_UNSIGNED (type)) + regcache_cooked_write_unsigned + (regcache, S390_R2_REGNUM, + extract_unsigned_integer (in, length, byte_order)); + else + regcache_cooked_write_signed + (regcache, S390_R2_REGNUM, + extract_signed_integer (in, length, byte_order)); + } + else if (length == 2 * word_size) + { + /* Double word: in r2 and r3. */ + if (in != NULL) + { + regcache_cooked_write (regcache, S390_R2_REGNUM, in); + regcache_cooked_write (regcache, S390_R3_REGNUM, + in + word_size); + } + else + { + regcache_cooked_read (regcache, S390_R2_REGNUM, out); + regcache_cooked_read (regcache, S390_R3_REGNUM, + out + word_size); + } + } + else + internal_error (__FILE__, __LINE__, _("invalid return type")); +} + +/* Implement the 'return_value' gdbarch method. */ + +static enum return_value_convention +s390_return_value (struct gdbarch *gdbarch, struct value *function, + struct type *type, struct regcache *regcache, + gdb_byte *out, const gdb_byte *in) +{ + enum return_value_convention rvc; + + type = check_typedef (type); + + switch (TYPE_CODE (type)) + { + case TYPE_CODE_STRUCT: + case TYPE_CODE_UNION: + case TYPE_CODE_COMPLEX: + rvc = RETURN_VALUE_STRUCT_CONVENTION; + break; + case TYPE_CODE_ARRAY: + rvc = (gdbarch_tdep (gdbarch)->vector_abi == S390_VECTOR_ABI_128 + && TYPE_LENGTH (type) <= 16 && TYPE_VECTOR (type)) + ? RETURN_VALUE_REGISTER_CONVENTION + : RETURN_VALUE_STRUCT_CONVENTION; + break; + default: + rvc = TYPE_LENGTH (type) <= 8 + ? RETURN_VALUE_REGISTER_CONVENTION + : RETURN_VALUE_STRUCT_CONVENTION; + } + + if (in != NULL || out != NULL) + { + if (rvc == RETURN_VALUE_REGISTER_CONVENTION) + s390_register_return_value (gdbarch, type, regcache, out, in); + else if (in != NULL) + error (_("Cannot set function return value.")); + else + error (_("Function return value unknown.")); + } + + return rvc; +} + + +/* Frame handling. */ + +/* Implmement the stack_frame_destroyed_p gdbarch method. */ + +static int +s390_stack_frame_destroyed_p (struct gdbarch *gdbarch, CORE_ADDR pc) +{ + int word_size = gdbarch_ptr_bit (gdbarch) / 8; + + /* In frameless functions, there's not frame to destroy and thus + we don't care about the epilogue. + + In functions with frame, the epilogue sequence is a pair of + a LM-type instruction that restores (amongst others) the + return register %r14 and the stack pointer %r15, followed + by a branch 'br %r14' --or equivalent-- that effects the + actual return. + + In that situation, this function needs to return 'true' in + exactly one case: when pc points to that branch instruction. + + Thus we try to disassemble the one instructions immediately + preceding pc and check whether it is an LM-type instruction + modifying the stack pointer. + + Note that disassembling backwards is not reliable, so there + is a slight chance of false positives here ... */ + + bfd_byte insn[6]; + unsigned int r1, r3, b2; + int d2; + + if (word_size == 4 + && !target_read_memory (pc - 4, insn, 4) + && is_rs (insn, op_lm, &r1, &r3, &d2, &b2) + && r3 == S390_SP_REGNUM - S390_R0_REGNUM) + return 1; + + if (word_size == 4 + && !target_read_memory (pc - 6, insn, 6) + && is_rsy (insn, op1_lmy, op2_lmy, &r1, &r3, &d2, &b2) + && r3 == S390_SP_REGNUM - S390_R0_REGNUM) + return 1; + + if (word_size == 8 + && !target_read_memory (pc - 6, insn, 6) + && is_rsy (insn, op1_lmg, op2_lmg, &r1, &r3, &d2, &b2) + && r3 == S390_SP_REGNUM - S390_R0_REGNUM) + return 1; + + return 0; +} + +/* DWARF-2 frame support. */ + +static struct value * +s390_dwarf2_prev_register (struct frame_info *this_frame, void **this_cache, + int regnum) +{ + return s390_unwind_pseudo_register (this_frame, regnum); +} + +static void +s390_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum, + struct dwarf2_frame_state_reg *reg, + struct frame_info *this_frame) +{ + /* The condition code (and thus PSW mask) is call-clobbered. */ + if (regnum == S390_PSWM_REGNUM) + reg->how = DWARF2_FRAME_REG_UNDEFINED; + + /* The PSW address unwinds to the return address. */ + else if (regnum == S390_PSWA_REGNUM) + reg->how = DWARF2_FRAME_REG_RA; + + /* Fixed registers are call-saved or call-clobbered + depending on the ABI in use. */ + else if (regnum < S390_NUM_REGS) + { + if (s390_register_call_saved (gdbarch, regnum)) + reg->how = DWARF2_FRAME_REG_SAME_VALUE; + else + reg->how = DWARF2_FRAME_REG_UNDEFINED; + } + + /* We install a special function to unwind pseudos. */ + else + { + reg->how = DWARF2_FRAME_REG_FN; + reg->loc.fn = s390_dwarf2_prev_register; + } +} + +/* Translate a .eh_frame register to DWARF register, or adjust a + .debug_frame register. */ + +static int +s390_adjust_frame_regnum (struct gdbarch *gdbarch, int num, int eh_frame_p) +{ + /* See s390_dwarf_reg_to_regnum for comments. */ + return (num >= 0 && num < 16) ? num + s390_dwarf_reg_r0l : num; +} + +/* Normal stack frames. */ + +struct s390_unwind_cache { + + CORE_ADDR func; + CORE_ADDR frame_base; + CORE_ADDR local_base; + + struct trad_frame_saved_reg *saved_regs; +}; + +static int +s390_prologue_frame_unwind_cache (struct frame_info *this_frame, + struct s390_unwind_cache *info) +{ + struct gdbarch *gdbarch = get_frame_arch (this_frame); + int word_size = gdbarch_ptr_bit (gdbarch) / 8; + struct s390_prologue_data data; + pv_t *fp = &data.gpr[S390_FRAME_REGNUM - S390_R0_REGNUM]; + pv_t *sp = &data.gpr[S390_SP_REGNUM - S390_R0_REGNUM]; + int i; + CORE_ADDR cfa; + CORE_ADDR func; + CORE_ADDR result; + ULONGEST reg; + CORE_ADDR prev_sp; + int frame_pointer; + int size; + struct frame_info *next_frame; + + /* Try to find the function start address. If we can't find it, we don't + bother searching for it -- with modern compilers this would be mostly + pointless anyway. Trust that we'll either have valid DWARF-2 CFI data + or else a valid backchain ... */ + if (!get_frame_func_if_available (this_frame, &info->func)) + { + info->func = -1; + return 0; + } + func = info->func; + + /* Try to analyze the prologue. */ + result = s390_analyze_prologue (gdbarch, func, + get_frame_pc (this_frame), &data); + if (!result) + return 0; + + /* If this was successful, we should have found the instruction that + sets the stack pointer register to the previous value of the stack + pointer minus the frame size. */ + if (!pv_is_register (*sp, S390_SP_REGNUM)) + return 0; + + /* A frame size of zero at this point can mean either a real + frameless function, or else a failure to find the prologue. + Perform some sanity checks to verify we really have a + frameless function. */ + if (sp->k == 0) + { + /* If the next frame is a NORMAL_FRAME, this frame *cannot* have frame + size zero. This is only possible if the next frame is a sentinel + frame, a dummy frame, or a signal trampoline frame. */ + /* FIXME: cagney/2004-05-01: This sanity check shouldn't be + needed, instead the code should simpliy rely on its + analysis. */ + next_frame = get_next_frame (this_frame); + while (next_frame && get_frame_type (next_frame) == INLINE_FRAME) + next_frame = get_next_frame (next_frame); + if (next_frame + && get_frame_type (get_next_frame (this_frame)) == NORMAL_FRAME) + return 0; + + /* If we really have a frameless function, %r14 must be valid + -- in particular, it must point to a different function. */ + reg = get_frame_register_unsigned (this_frame, S390_RETADDR_REGNUM); + reg = gdbarch_addr_bits_remove (gdbarch, reg) - 1; + if (get_pc_function_start (reg) == func) + { + /* However, there is one case where it *is* valid for %r14 + to point to the same function -- if this is a recursive + call, and we have stopped in the prologue *before* the + stack frame was allocated. + + Recognize this case by looking ahead a bit ... */ + + struct s390_prologue_data data2; + pv_t *sp = &data2.gpr[S390_SP_REGNUM - S390_R0_REGNUM]; + + if (!(s390_analyze_prologue (gdbarch, func, (CORE_ADDR)-1, &data2) + && pv_is_register (*sp, S390_SP_REGNUM) + && sp->k != 0)) + return 0; + } + } + + + /* OK, we've found valid prologue data. */ + size = -sp->k; + + /* If the frame pointer originally also holds the same value + as the stack pointer, we're probably using it. If it holds + some other value -- even a constant offset -- it is most + likely used as temp register. */ + if (pv_is_identical (*sp, *fp)) + frame_pointer = S390_FRAME_REGNUM; + else + frame_pointer = S390_SP_REGNUM; + + /* If we've detected a function with stack frame, we'll still have to + treat it as frameless if we're currently within the function epilog + code at a point where the frame pointer has already been restored. + This can only happen in an innermost frame. */ + /* FIXME: cagney/2004-05-01: This sanity check shouldn't be needed, + instead the code should simpliy rely on its analysis. */ + next_frame = get_next_frame (this_frame); + while (next_frame && get_frame_type (next_frame) == INLINE_FRAME) + next_frame = get_next_frame (next_frame); + if (size > 0 + && (next_frame == NULL + || get_frame_type (get_next_frame (this_frame)) != NORMAL_FRAME)) + { + /* See the comment in s390_stack_frame_destroyed_p on why this is + not completely reliable ... */ + if (s390_stack_frame_destroyed_p (gdbarch, get_frame_pc (this_frame))) + { + memset (&data, 0, sizeof (data)); + size = 0; + frame_pointer = S390_SP_REGNUM; + } + } + + /* Once we know the frame register and the frame size, we can unwind + the current value of the frame register from the next frame, and + add back the frame size to arrive that the previous frame's + stack pointer value. */ + prev_sp = get_frame_register_unsigned (this_frame, frame_pointer) + size; + cfa = prev_sp + 16*word_size + 32; + + /* Set up ABI call-saved/call-clobbered registers. */ + for (i = 0; i < S390_NUM_REGS; i++) + if (!s390_register_call_saved (gdbarch, i)) + trad_frame_set_unknown (info->saved_regs, i); + + /* CC is always call-clobbered. */ + trad_frame_set_unknown (info->saved_regs, S390_PSWM_REGNUM); + + /* Record the addresses of all register spill slots the prologue parser + has recognized. Consider only registers defined as call-saved by the + ABI; for call-clobbered registers the parser may have recognized + spurious stores. */ + + for (i = 0; i < 16; i++) + if (s390_register_call_saved (gdbarch, S390_R0_REGNUM + i) + && data.gpr_slot[i] != 0) + info->saved_regs[S390_R0_REGNUM + i].addr = cfa - data.gpr_slot[i]; + + for (i = 0; i < 16; i++) + if (s390_register_call_saved (gdbarch, S390_F0_REGNUM + i) + && data.fpr_slot[i] != 0) + info->saved_regs[S390_F0_REGNUM + i].addr = cfa - data.fpr_slot[i]; + + /* Function return will set PC to %r14. */ + info->saved_regs[S390_PSWA_REGNUM] = info->saved_regs[S390_RETADDR_REGNUM]; + + /* In frameless functions, we unwind simply by moving the return + address to the PC. However, if we actually stored to the + save area, use that -- we might only think the function frameless + because we're in the middle of the prologue ... */ + if (size == 0 + && !trad_frame_addr_p (info->saved_regs, S390_PSWA_REGNUM)) + { + info->saved_regs[S390_PSWA_REGNUM].realreg = S390_RETADDR_REGNUM; + } + + /* Another sanity check: unless this is a frameless function, + we should have found spill slots for SP and PC. + If not, we cannot unwind further -- this happens e.g. in + libc's thread_start routine. */ + if (size > 0) + { + if (!trad_frame_addr_p (info->saved_regs, S390_SP_REGNUM) + || !trad_frame_addr_p (info->saved_regs, S390_PSWA_REGNUM)) + prev_sp = -1; + } + + /* We use the current value of the frame register as local_base, + and the top of the register save area as frame_base. */ + if (prev_sp != -1) + { + info->frame_base = prev_sp + 16*word_size + 32; + info->local_base = prev_sp - size; + } + + return 1; +} + + +/* Code stubs and their stack frames. For things like PLTs and NULL + function calls (where there is no true frame and the return address + is in the RETADDR register). */ + +struct s390_stub_unwind_cache +{ + CORE_ADDR frame_base; + struct trad_frame_saved_reg *saved_regs; +}; + +static struct s390_stub_unwind_cache * +s390_stub_frame_unwind_cache (struct frame_info *this_frame, + void **this_prologue_cache) +{ + struct gdbarch *gdbarch = get_frame_arch (this_frame); + int word_size = gdbarch_ptr_bit (gdbarch) / 8; + struct s390_stub_unwind_cache *info; + ULONGEST reg; + + if (*this_prologue_cache) + return (struct s390_stub_unwind_cache *) *this_prologue_cache; + + info = FRAME_OBSTACK_ZALLOC (struct s390_stub_unwind_cache); + *this_prologue_cache = info; + info->saved_regs = trad_frame_alloc_saved_regs (this_frame); + + /* The return address is in register %r14. */ + info->saved_regs[S390_PSWA_REGNUM].realreg = S390_RETADDR_REGNUM; + + /* Retrieve stack pointer and determine our frame base. */ + reg = get_frame_register_unsigned (this_frame, S390_SP_REGNUM); + info->frame_base = reg + 16*word_size + 32; + + return info; +} + +static void +s390_stub_frame_this_id (struct frame_info *this_frame, + void **this_prologue_cache, + struct frame_id *this_id) +{ + struct s390_stub_unwind_cache *info + = s390_stub_frame_unwind_cache (this_frame, this_prologue_cache); + *this_id = frame_id_build (info->frame_base, get_frame_pc (this_frame)); +} + +static struct value * +s390_trad_frame_prev_register (struct frame_info *this_frame, + struct trad_frame_saved_reg saved_regs[], + int regnum) +{ + if (regnum < S390_NUM_REGS) + return trad_frame_get_prev_register (this_frame, saved_regs, regnum); + else + return s390_unwind_pseudo_register (this_frame, regnum); +} + +static struct value * +s390_stub_frame_prev_register (struct frame_info *this_frame, + void **this_prologue_cache, int regnum) +{ + struct s390_stub_unwind_cache *info + = s390_stub_frame_unwind_cache (this_frame, this_prologue_cache); + return s390_trad_frame_prev_register (this_frame, info->saved_regs, regnum); +} + +static int +s390_stub_frame_sniffer (const struct frame_unwind *self, + struct frame_info *this_frame, + void **this_prologue_cache) +{ + CORE_ADDR addr_in_block; + bfd_byte insn[S390_MAX_INSTR_SIZE]; + + /* If the current PC points to non-readable memory, we assume we + have trapped due to an invalid function pointer call. We handle + the non-existing current function like a PLT stub. */ + addr_in_block = get_frame_address_in_block (this_frame); + if (in_plt_section (addr_in_block) + || s390_readinstruction (insn, get_frame_pc (this_frame)) < 0) + return 1; + return 0; +} + +static const struct frame_unwind s390_stub_frame_unwind = { + NORMAL_FRAME, + default_frame_unwind_stop_reason, + s390_stub_frame_this_id, + s390_stub_frame_prev_register, + NULL, + s390_stub_frame_sniffer +}; + +/* Signal trampoline stack frames. */ + +struct s390_sigtramp_unwind_cache { + CORE_ADDR frame_base; + struct trad_frame_saved_reg *saved_regs; +}; + +static struct s390_sigtramp_unwind_cache * +s390_sigtramp_frame_unwind_cache (struct frame_info *this_frame, + void **this_prologue_cache) +{ + struct gdbarch *gdbarch = get_frame_arch (this_frame); + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + int word_size = gdbarch_ptr_bit (gdbarch) / 8; + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + struct s390_sigtramp_unwind_cache *info; + ULONGEST this_sp, prev_sp; + CORE_ADDR next_ra, next_cfa, sigreg_ptr, sigreg_high_off; + int i; + + if (*this_prologue_cache) + return (struct s390_sigtramp_unwind_cache *) *this_prologue_cache; + + info = FRAME_OBSTACK_ZALLOC (struct s390_sigtramp_unwind_cache); + *this_prologue_cache = info; + info->saved_regs = trad_frame_alloc_saved_regs (this_frame); + + this_sp = get_frame_register_unsigned (this_frame, S390_SP_REGNUM); + next_ra = get_frame_pc (this_frame); + next_cfa = this_sp + 16*word_size + 32; + + /* New-style RT frame: + retcode + alignment (8 bytes) + siginfo (128 bytes) + ucontext (contains sigregs at offset 5 words). */ + if (next_ra == next_cfa) + { + sigreg_ptr = next_cfa + 8 + 128 + align_up (5*word_size, 8); + /* sigregs are followed by uc_sigmask (8 bytes), then by the + upper GPR halves if present. */ + sigreg_high_off = 8; + } + + /* Old-style RT frame and all non-RT frames: + old signal mask (8 bytes) + pointer to sigregs. */ + else + { + sigreg_ptr = read_memory_unsigned_integer (next_cfa + 8, + word_size, byte_order); + /* sigregs are followed by signo (4 bytes), then by the + upper GPR halves if present. */ + sigreg_high_off = 4; + } + + /* The sigregs structure looks like this: + long psw_mask; + long psw_addr; + long gprs[16]; + int acrs[16]; + int fpc; + int __pad; + double fprs[16]; */ + + /* PSW mask and address. */ + info->saved_regs[S390_PSWM_REGNUM].addr = sigreg_ptr; + sigreg_ptr += word_size; + info->saved_regs[S390_PSWA_REGNUM].addr = sigreg_ptr; + sigreg_ptr += word_size; + + /* Then the GPRs. */ + for (i = 0; i < 16; i++) + { + info->saved_regs[S390_R0_REGNUM + i].addr = sigreg_ptr; + sigreg_ptr += word_size; + } + + /* Then the ACRs. */ + for (i = 0; i < 16; i++) + { + info->saved_regs[S390_A0_REGNUM + i].addr = sigreg_ptr; + sigreg_ptr += 4; + } + + /* The floating-point control word. */ + info->saved_regs[S390_FPC_REGNUM].addr = sigreg_ptr; + sigreg_ptr += 8; + + /* And finally the FPRs. */ + for (i = 0; i < 16; i++) + { + info->saved_regs[S390_F0_REGNUM + i].addr = sigreg_ptr; + sigreg_ptr += 8; + } + + /* If we have them, the GPR upper halves are appended at the end. */ + sigreg_ptr += sigreg_high_off; + if (tdep->gpr_full_regnum != -1) + for (i = 0; i < 16; i++) + { + info->saved_regs[S390_R0_UPPER_REGNUM + i].addr = sigreg_ptr; + sigreg_ptr += 4; + } + + /* Restore the previous frame's SP. */ + prev_sp = read_memory_unsigned_integer ( + info->saved_regs[S390_SP_REGNUM].addr, + word_size, byte_order); + + /* Determine our frame base. */ + info->frame_base = prev_sp + 16*word_size + 32; + + return info; +} + +static void +s390_sigtramp_frame_this_id (struct frame_info *this_frame, + void **this_prologue_cache, + struct frame_id *this_id) +{ + struct s390_sigtramp_unwind_cache *info + = s390_sigtramp_frame_unwind_cache (this_frame, this_prologue_cache); + *this_id = frame_id_build (info->frame_base, get_frame_pc (this_frame)); +} + +static struct value * +s390_sigtramp_frame_prev_register (struct frame_info *this_frame, + void **this_prologue_cache, int regnum) +{ + struct s390_sigtramp_unwind_cache *info + = s390_sigtramp_frame_unwind_cache (this_frame, this_prologue_cache); + return s390_trad_frame_prev_register (this_frame, info->saved_regs, regnum); +} + +static int +s390_sigtramp_frame_sniffer (const struct frame_unwind *self, + struct frame_info *this_frame, + void **this_prologue_cache) +{ + CORE_ADDR pc = get_frame_pc (this_frame); + bfd_byte sigreturn[2]; + + if (target_read_memory (pc, sigreturn, 2)) + return 0; + + if (sigreturn[0] != op_svc) + return 0; + + if (sigreturn[1] != 119 /* sigreturn */ + && sigreturn[1] != 173 /* rt_sigreturn */) + return 0; + + return 1; +} + +static const struct frame_unwind s390_sigtramp_frame_unwind = { + SIGTRAMP_FRAME, + default_frame_unwind_stop_reason, + s390_sigtramp_frame_this_id, + s390_sigtramp_frame_prev_register, + NULL, + s390_sigtramp_frame_sniffer +}; + +/* Frame unwind. */ + +static void +s390_backchain_frame_unwind_cache (struct frame_info *this_frame, + struct s390_unwind_cache *info) +{ + struct gdbarch *gdbarch = get_frame_arch (this_frame); + int word_size = gdbarch_ptr_bit (gdbarch) / 8; + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + CORE_ADDR backchain; + ULONGEST reg; + LONGEST sp, tmp; + int i; + + /* Set up ABI call-saved/call-clobbered registers. */ + for (i = 0; i < S390_NUM_REGS; i++) + if (!s390_register_call_saved (gdbarch, i)) + trad_frame_set_unknown (info->saved_regs, i); + + /* CC is always call-clobbered. */ + trad_frame_set_unknown (info->saved_regs, S390_PSWM_REGNUM); + + /* Get the backchain. */ + reg = get_frame_register_unsigned (this_frame, S390_SP_REGNUM); + if (!safe_read_memory_integer (reg, word_size, byte_order, &tmp)) + tmp = 0; + backchain = (CORE_ADDR) tmp; + + /* A zero backchain terminates the frame chain. As additional + sanity check, let's verify that the spill slot for SP in the + save area pointed to by the backchain in fact links back to + the save area. */ + if (backchain != 0 + && safe_read_memory_integer (backchain + 15*word_size, + word_size, byte_order, &sp) + && (CORE_ADDR)sp == backchain) + { + /* We don't know which registers were saved, but it will have + to be at least %r14 and %r15. This will allow us to continue + unwinding, but other prev-frame registers may be incorrect ... */ + info->saved_regs[S390_SP_REGNUM].addr = backchain + 15*word_size; + info->saved_regs[S390_RETADDR_REGNUM].addr = backchain + 14*word_size; + + /* Function return will set PC to %r14. */ + info->saved_regs[S390_PSWA_REGNUM] + = info->saved_regs[S390_RETADDR_REGNUM]; + + /* We use the current value of the frame register as local_base, + and the top of the register save area as frame_base. */ + info->frame_base = backchain + 16*word_size + 32; + info->local_base = reg; + } + + info->func = get_frame_pc (this_frame); +} + +static struct s390_unwind_cache * +s390_frame_unwind_cache (struct frame_info *this_frame, + void **this_prologue_cache) +{ + struct s390_unwind_cache *info; + + if (*this_prologue_cache) + return (struct s390_unwind_cache *) *this_prologue_cache; + + info = FRAME_OBSTACK_ZALLOC (struct s390_unwind_cache); + *this_prologue_cache = info; + info->saved_regs = trad_frame_alloc_saved_regs (this_frame); + info->func = -1; + info->frame_base = -1; + info->local_base = -1; + + TRY + { + /* Try to use prologue analysis to fill the unwind cache. + If this fails, fall back to reading the stack backchain. */ + if (!s390_prologue_frame_unwind_cache (this_frame, info)) + s390_backchain_frame_unwind_cache (this_frame, info); + } + CATCH (ex, RETURN_MASK_ERROR) + { + if (ex.error != NOT_AVAILABLE_ERROR) + throw_exception (ex); + } + END_CATCH + + return info; +} + +static void +s390_frame_this_id (struct frame_info *this_frame, + void **this_prologue_cache, + struct frame_id *this_id) +{ + struct s390_unwind_cache *info + = s390_frame_unwind_cache (this_frame, this_prologue_cache); + + if (info->frame_base == -1) + { + if (info->func != -1) + *this_id = frame_id_build_unavailable_stack (info->func); + return; + } + + *this_id = frame_id_build (info->frame_base, info->func); +} + +static struct value * +s390_frame_prev_register (struct frame_info *this_frame, + void **this_prologue_cache, int regnum) +{ + struct s390_unwind_cache *info + = s390_frame_unwind_cache (this_frame, this_prologue_cache); + + return s390_trad_frame_prev_register (this_frame, info->saved_regs, regnum); +} + +static const struct frame_unwind s390_frame_unwind = { + NORMAL_FRAME, + default_frame_unwind_stop_reason, + s390_frame_this_id, + s390_frame_prev_register, + NULL, + default_frame_sniffer +}; + +/* Frame base handling. */ + +static CORE_ADDR +s390_frame_base_address (struct frame_info *this_frame, void **this_cache) +{ + struct s390_unwind_cache *info + = s390_frame_unwind_cache (this_frame, this_cache); + return info->frame_base; +} + +static CORE_ADDR +s390_local_base_address (struct frame_info *this_frame, void **this_cache) +{ + struct s390_unwind_cache *info + = s390_frame_unwind_cache (this_frame, this_cache); + return info->local_base; +} + +static const struct frame_base s390_frame_base = { + &s390_frame_unwind, + s390_frame_base_address, + s390_local_base_address, + s390_local_base_address +}; + +static CORE_ADDR +s390_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + ULONGEST pc; + pc = frame_unwind_register_unsigned (next_frame, tdep->pc_regnum); + return gdbarch_addr_bits_remove (gdbarch, pc); +} + +static CORE_ADDR +s390_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame) +{ + ULONGEST sp; + sp = frame_unwind_register_unsigned (next_frame, S390_SP_REGNUM); + return gdbarch_addr_bits_remove (gdbarch, sp); +} + + +/* Displaced stepping. */ + +/* Return true if INSN is a non-branch RIL-b or RIL-c format + instruction. */ + +static int +is_non_branch_ril (gdb_byte *insn) +{ + gdb_byte op1 = insn[0]; + + if (op1 == 0xc4) + { + gdb_byte op2 = insn[1] & 0x0f; + + switch (op2) + { + case 0x02: /* llhrl */ + case 0x04: /* lghrl */ + case 0x05: /* lhrl */ + case 0x06: /* llghrl */ + case 0x07: /* sthrl */ + case 0x08: /* lgrl */ + case 0x0b: /* stgrl */ + case 0x0c: /* lgfrl */ + case 0x0d: /* lrl */ + case 0x0e: /* llgfrl */ + case 0x0f: /* strl */ + return 1; + } + } + else if (op1 == 0xc6) + { + gdb_byte op2 = insn[1] & 0x0f; + + switch (op2) + { + case 0x00: /* exrl */ + case 0x02: /* pfdrl */ + case 0x04: /* cghrl */ + case 0x05: /* chrl */ + case 0x06: /* clghrl */ + case 0x07: /* clhrl */ + case 0x08: /* cgrl */ + case 0x0a: /* clgrl */ + case 0x0c: /* cgfrl */ + case 0x0d: /* crl */ + case 0x0e: /* clgfrl */ + case 0x0f: /* clrl */ + return 1; + } + } + + return 0; +} + +/* Implementation of gdbarch_displaced_step_copy_insn. */ + +static struct displaced_step_closure * +s390_displaced_step_copy_insn (struct gdbarch *gdbarch, + CORE_ADDR from, CORE_ADDR to, + struct regcache *regs) +{ + size_t len = gdbarch_max_insn_length (gdbarch); + gdb_byte *buf = (gdb_byte *) xmalloc (len); + struct cleanup *old_chain = make_cleanup (xfree, buf); + + read_memory (from, buf, len); + + /* Adjust the displacement field of PC-relative RIL instructions, + except branches. The latter are handled in the fixup hook. */ + if (is_non_branch_ril (buf)) + { + LONGEST offset; + + offset = extract_signed_integer (buf + 2, 4, BFD_ENDIAN_BIG); + offset = (from - to + offset * 2) / 2; + + /* If the instruction is too far from the jump pad, punt. This + will usually happen with instructions in shared libraries. + We could probably support these by rewriting them to be + absolute or fully emulating them. */ + if (offset < INT32_MIN || offset > INT32_MAX) + { + /* Let the core fall back to stepping over the breakpoint + in-line. */ + if (debug_displaced) + { + fprintf_unfiltered (gdb_stdlog, + "displaced: can't displaced step " + "RIL instruction: offset %s out of range\n", + plongest (offset)); + } + do_cleanups (old_chain); + return NULL; + } + + store_signed_integer (buf + 2, 4, BFD_ENDIAN_BIG, offset); + } + + write_memory (to, buf, len); + + if (debug_displaced) + { + fprintf_unfiltered (gdb_stdlog, "displaced: copy %s->%s: ", + paddress (gdbarch, from), paddress (gdbarch, to)); + displaced_step_dump_bytes (gdb_stdlog, buf, len); + } + + discard_cleanups (old_chain); + return (struct displaced_step_closure *) buf; +} + +/* Fix up the state of registers and memory after having single-stepped + a displaced instruction. */ + +static void +s390_displaced_step_fixup (struct gdbarch *gdbarch, + struct displaced_step_closure *closure, + CORE_ADDR from, CORE_ADDR to, + struct regcache *regs) +{ + /* Our closure is a copy of the instruction. */ + gdb_byte *insn = (gdb_byte *) closure; + static int s390_instrlen[] = { 2, 4, 4, 6 }; + int insnlen = s390_instrlen[insn[0] >> 6]; + + /* Fields for various kinds of instructions. */ + unsigned int b2, r1, r2, x2, r3; + int i2, d2; + + /* Get current PC and addressing mode bit. */ + CORE_ADDR pc = regcache_read_pc (regs); + ULONGEST amode = 0; + + if (register_size (gdbarch, S390_PSWA_REGNUM) == 4) + { + regcache_cooked_read_unsigned (regs, S390_PSWA_REGNUM, &amode); + amode &= 0x80000000; + } + + if (debug_displaced) + fprintf_unfiltered (gdb_stdlog, + "displaced: (s390) fixup (%s, %s) pc %s len %d amode 0x%x\n", + paddress (gdbarch, from), paddress (gdbarch, to), + paddress (gdbarch, pc), insnlen, (int) amode); + + /* Handle absolute branch and save instructions. */ + if (is_rr (insn, op_basr, &r1, &r2) + || is_rx (insn, op_bas, &r1, &d2, &x2, &b2)) + { + /* Recompute saved return address in R1. */ + regcache_cooked_write_unsigned (regs, S390_R0_REGNUM + r1, + amode | (from + insnlen)); + } + + /* Handle absolute branch instructions. */ + else if (is_rr (insn, op_bcr, &r1, &r2) + || is_rx (insn, op_bc, &r1, &d2, &x2, &b2) + || is_rr (insn, op_bctr, &r1, &r2) + || is_rre (insn, op_bctgr, &r1, &r2) + || is_rx (insn, op_bct, &r1, &d2, &x2, &b2) + || is_rxy (insn, op1_bctg, op2_brctg, &r1, &d2, &x2, &b2) + || is_rs (insn, op_bxh, &r1, &r3, &d2, &b2) + || is_rsy (insn, op1_bxhg, op2_bxhg, &r1, &r3, &d2, &b2) + || is_rs (insn, op_bxle, &r1, &r3, &d2, &b2) + || is_rsy (insn, op1_bxleg, op2_bxleg, &r1, &r3, &d2, &b2)) + { + /* Update PC iff branch was *not* taken. */ + if (pc == to + insnlen) + regcache_write_pc (regs, from + insnlen); + } + + /* Handle PC-relative branch and save instructions. */ + else if (is_ri (insn, op1_bras, op2_bras, &r1, &i2) + || is_ril (insn, op1_brasl, op2_brasl, &r1, &i2)) + { + /* Update PC. */ + regcache_write_pc (regs, pc - to + from); + /* Recompute saved return address in R1. */ + regcache_cooked_write_unsigned (regs, S390_R0_REGNUM + r1, + amode | (from + insnlen)); + } + + /* Handle PC-relative branch instructions. */ + else if (is_ri (insn, op1_brc, op2_brc, &r1, &i2) + || is_ril (insn, op1_brcl, op2_brcl, &r1, &i2) + || is_ri (insn, op1_brct, op2_brct, &r1, &i2) + || is_ri (insn, op1_brctg, op2_brctg, &r1, &i2) + || is_rsi (insn, op_brxh, &r1, &r3, &i2) + || is_rie (insn, op1_brxhg, op2_brxhg, &r1, &r3, &i2) + || is_rsi (insn, op_brxle, &r1, &r3, &i2) + || is_rie (insn, op1_brxlg, op2_brxlg, &r1, &r3, &i2)) + { + /* Update PC. */ + regcache_write_pc (regs, pc - to + from); + } + + /* Handle LOAD ADDRESS RELATIVE LONG. */ + else if (is_ril (insn, op1_larl, op2_larl, &r1, &i2)) + { + /* Update PC. */ + regcache_write_pc (regs, from + insnlen); + /* Recompute output address in R1. */ + regcache_cooked_write_unsigned (regs, S390_R0_REGNUM + r1, + amode | (from + i2 * 2)); + } + + /* If we executed a breakpoint instruction, point PC right back at it. */ + else if (insn[0] == 0x0 && insn[1] == 0x1) + regcache_write_pc (regs, from); + + /* For any other insn, PC points right after the original instruction. */ + else + regcache_write_pc (regs, from + insnlen); + + if (debug_displaced) + fprintf_unfiltered (gdb_stdlog, + "displaced: (s390) pc is now %s\n", + paddress (gdbarch, regcache_read_pc (regs))); +} + +static int +s390_displaced_step_hw_singlestep (struct gdbarch *gdbarch, + struct displaced_step_closure *closure) +{ + return 1; +} + + +/* Address handling. */ + +static CORE_ADDR +s390_addr_bits_remove (struct gdbarch *gdbarch, CORE_ADDR addr) +{ + return addr & 0x7fffffff; +} + +static int +s390_address_class_type_flags (int byte_size, int dwarf2_addr_class) +{ + if (byte_size == 4) + return TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1; + else + return 0; +} + +static const char * +s390_address_class_type_flags_to_name (struct gdbarch *gdbarch, int type_flags) +{ + if (type_flags & TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1) + return "mode32"; + else + return NULL; +} + +static int +s390_address_class_name_to_type_flags (struct gdbarch *gdbarch, + const char *name, + int *type_flags_ptr) +{ + if (strcmp (name, "mode32") == 0) + { + *type_flags_ptr = TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1; + return 1; + } + else + return 0; +} + + +/* Set up gdbarch struct. */ + +static struct gdbarch * +s390_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) +{ + const struct target_desc *tdesc = info.target_desc; + struct tdesc_arch_data *tdesc_data = NULL; + struct gdbarch *gdbarch; + struct gdbarch_tdep *tdep; + enum s390_abi_kind tdep_abi; + enum s390_vector_abi_kind vector_abi; + int have_upper = 0; + int have_linux_v1 = 0; + int have_linux_v2 = 0; + int have_tdb = 0; + int have_vx = 0; + int first_pseudo_reg, last_pseudo_reg; + static const char *const stap_register_prefixes[] = { "%", NULL }; + static const char *const stap_register_indirection_prefixes[] = { "(", + NULL }; + static const char *const stap_register_indirection_suffixes[] = { ")", + NULL }; + + /* Default ABI and register size. */ + switch (info.bfd_arch_info->mach) + { + case bfd_mach_s390_31: + tdep_abi = ABI_LINUX_S390; + break; + + case bfd_mach_s390_64: + tdep_abi = ABI_LINUX_ZSERIES; + break; + + default: + return NULL; + } + + /* Use default target description if none provided by the target. */ + if (!tdesc_has_registers (tdesc)) + { + if (tdep_abi == ABI_LINUX_S390) + tdesc = tdesc_s390_linux32; + else + tdesc = tdesc_s390x_linux64; + } + + /* Check any target description for validity. */ + if (tdesc_has_registers (tdesc)) + { + static const char *const gprs[] = { + "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", + "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15" + }; + static const char *const fprs[] = { + "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", + "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15" + }; + static const char *const acrs[] = { + "acr0", "acr1", "acr2", "acr3", "acr4", "acr5", "acr6", "acr7", + "acr8", "acr9", "acr10", "acr11", "acr12", "acr13", "acr14", "acr15" + }; + static const char *const gprs_lower[] = { + "r0l", "r1l", "r2l", "r3l", "r4l", "r5l", "r6l", "r7l", + "r8l", "r9l", "r10l", "r11l", "r12l", "r13l", "r14l", "r15l" + }; + static const char *const gprs_upper[] = { + "r0h", "r1h", "r2h", "r3h", "r4h", "r5h", "r6h", "r7h", + "r8h", "r9h", "r10h", "r11h", "r12h", "r13h", "r14h", "r15h" + }; + static const char *const tdb_regs[] = { + "tdb0", "tac", "tct", "atia", + "tr0", "tr1", "tr2", "tr3", "tr4", "tr5", "tr6", "tr7", + "tr8", "tr9", "tr10", "tr11", "tr12", "tr13", "tr14", "tr15" + }; + static const char *const vxrs_low[] = { + "v0l", "v1l", "v2l", "v3l", "v4l", "v5l", "v6l", "v7l", "v8l", + "v9l", "v10l", "v11l", "v12l", "v13l", "v14l", "v15l", + }; + static const char *const vxrs_high[] = { + "v16", "v17", "v18", "v19", "v20", "v21", "v22", "v23", "v24", + "v25", "v26", "v27", "v28", "v29", "v30", "v31", + }; + static const char *const cr[] = { + "cr0", "cr1", "cr2", "cr3", "cr4", "cr5", "cr6", "cr7", + "cr8", "cr9", "cr10", "cr11", "cr12", "cr13", "cr14", "cr15" + }; + const struct tdesc_feature *feature; + int i, valid_p = 1; + + feature = tdesc_find_feature (tdesc, "org.gnu.gdb.s390.core"); + if (feature == NULL) + return NULL; + + tdesc_data = tdesc_data_alloc (); + + valid_p &= tdesc_numbered_register (feature, tdesc_data, + S390_PSWM_REGNUM, "pswm"); + valid_p &= tdesc_numbered_register (feature, tdesc_data, + S390_PSWA_REGNUM, "pswa"); + + if (tdesc_unnumbered_register (feature, "r0")) + { + for (i = 0; i < 16; i++) + valid_p &= tdesc_numbered_register (feature, tdesc_data, + S390_R0_REGNUM + i, gprs[i]); + } + else + { + have_upper = 1; + + for (i = 0; i < 16; i++) + valid_p &= tdesc_numbered_register (feature, tdesc_data, + S390_R0_REGNUM + i, + gprs_lower[i]); + for (i = 0; i < 16; i++) + valid_p &= tdesc_numbered_register (feature, tdesc_data, + S390_R0_UPPER_REGNUM + i, + gprs_upper[i]); + } + + feature = tdesc_find_feature (tdesc, "org.gnu.gdb.s390.fpr"); + if (feature == NULL) + { + tdesc_data_cleanup (tdesc_data); + return NULL; + } + + valid_p &= tdesc_numbered_register (feature, tdesc_data, + S390_FPC_REGNUM, "fpc"); + for (i = 0; i < 16; i++) + valid_p &= tdesc_numbered_register (feature, tdesc_data, + S390_F0_REGNUM + i, fprs[i]); + + feature = tdesc_find_feature (tdesc, "org.gnu.gdb.s390.acr"); + if (feature == NULL) + { + tdesc_data_cleanup (tdesc_data); + return NULL; + } + + for (i = 0; i < 16; i++) + valid_p &= tdesc_numbered_register (feature, tdesc_data, + S390_A0_REGNUM + i, acrs[i]); + + /* Optional GNU/Linux-specific "registers". */ + feature = tdesc_find_feature (tdesc, "org.gnu.gdb.s390.linux"); + if (feature) + { + tdesc_numbered_register (feature, tdesc_data, + S390_ORIG_R2_REGNUM, "orig_r2"); + + if (tdesc_numbered_register (feature, tdesc_data, + S390_LAST_BREAK_REGNUM, "last_break")) + have_linux_v1 = 1; + + if (tdesc_numbered_register (feature, tdesc_data, + S390_SYSTEM_CALL_REGNUM, "system_call")) + have_linux_v2 = 1; + + if (have_linux_v2 > have_linux_v1) + valid_p = 0; + } + + /* Transaction diagnostic block. */ + feature = tdesc_find_feature (tdesc, "org.gnu.gdb.s390.tdb"); + if (feature) + { + for (i = 0; i < ARRAY_SIZE (tdb_regs); i++) + valid_p &= tdesc_numbered_register (feature, tdesc_data, + S390_TDB_DWORD0_REGNUM + i, + tdb_regs[i]); + have_tdb = 1; + } + + /* Vector registers. */ + feature = tdesc_find_feature (tdesc, "org.gnu.gdb.s390.vx"); + if (feature) + { + for (i = 0; i < 16; i++) + valid_p &= tdesc_numbered_register (feature, tdesc_data, + S390_V0_LOWER_REGNUM + i, + vxrs_low[i]); + for (i = 0; i < 16; i++) + valid_p &= tdesc_numbered_register (feature, tdesc_data, + S390_V16_REGNUM + i, + vxrs_high[i]); + have_vx = 1; + } + + if (!valid_p) + { + tdesc_data_cleanup (tdesc_data); + return NULL; + } + } + + /* Determine vector ABI. */ + vector_abi = S390_VECTOR_ABI_NONE; +#ifdef HAVE_ELF + if (have_vx + && info.abfd != NULL + && info.abfd->format == bfd_object + && bfd_get_flavour (info.abfd) == bfd_target_elf_flavour + && bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_GNU, + Tag_GNU_S390_ABI_Vector) == 2) + vector_abi = S390_VECTOR_ABI_128; +#endif + + /* Find a candidate among extant architectures. */ + for (arches = gdbarch_list_lookup_by_info (arches, &info); + arches != NULL; + arches = gdbarch_list_lookup_by_info (arches->next, &info)) + { + tdep = gdbarch_tdep (arches->gdbarch); + if (!tdep) + continue; + if (tdep->abi != tdep_abi) + continue; + if (tdep->vector_abi != vector_abi) + continue; + if ((tdep->gpr_full_regnum != -1) != have_upper) + continue; + if (tdesc_data != NULL) + tdesc_data_cleanup (tdesc_data); + + return arches->gdbarch; + } + + /* Otherwise create a new gdbarch for the specified machine type. */ + tdep = XCNEW (struct gdbarch_tdep); + tdep->abi = tdep_abi; + tdep->vector_abi = vector_abi; + tdep->have_linux_v1 = have_linux_v1; + tdep->have_linux_v2 = have_linux_v2; + tdep->have_tdb = have_tdb; + gdbarch = gdbarch_alloc (&info, tdep); + + set_gdbarch_believe_pcc_promotion (gdbarch, 0); + set_gdbarch_char_signed (gdbarch, 0); + + /* S/390 GNU/Linux uses either 64-bit or 128-bit long doubles. + We can safely let them default to 128-bit, since the debug info + will give the size of type actually used in each case. */ + set_gdbarch_long_double_bit (gdbarch, 128); + set_gdbarch_long_double_format (gdbarch, floatformats_ia64_quad); + + /* Amount PC must be decremented by after a breakpoint. This is + often the number of bytes returned by gdbarch_breakpoint_from_pc but not + always. */ + set_gdbarch_decr_pc_after_break (gdbarch, 2); + + /* Breakpoints. */ + set_gdbarch_breakpoint_kind_from_pc (gdbarch, s390_breakpoint::kind_from_pc); + set_gdbarch_sw_breakpoint_from_kind (gdbarch, s390_breakpoint::bp_from_kind); + set_gdbarch_software_single_step (gdbarch, s390_software_single_step); + set_gdbarch_skip_prologue (gdbarch, s390_skip_prologue); + + /* Registers. */ + set_gdbarch_num_regs (gdbarch, S390_NUM_REGS); + set_gdbarch_sp_regnum (gdbarch, S390_SP_REGNUM); + set_gdbarch_fp0_regnum (gdbarch, S390_F0_REGNUM); + set_gdbarch_register_name (gdbarch, s390_register_name); + set_gdbarch_cannot_store_register (gdbarch, s390_cannot_store_register); + set_gdbarch_write_pc (gdbarch, s390_write_pc); + set_gdbarch_stab_reg_to_regnum (gdbarch, s390_dwarf_reg_to_regnum); + set_gdbarch_dwarf2_reg_to_regnum (gdbarch, s390_dwarf_reg_to_regnum); + set_gdbarch_value_from_register (gdbarch, s390_value_from_register); + set_gdbarch_core_read_description (gdbarch, s390_core_read_description); + set_gdbarch_iterate_over_regset_sections (gdbarch, + s390_iterate_over_regset_sections); + + /* Pseudo registers. */ + set_tdesc_pseudo_register_name (gdbarch, s390_pseudo_register_name); + set_gdbarch_pseudo_register_read (gdbarch, s390_pseudo_register_read); + set_gdbarch_pseudo_register_write (gdbarch, s390_pseudo_register_write); + set_tdesc_pseudo_register_type (gdbarch, s390_pseudo_register_type); + set_tdesc_pseudo_register_reggroup_p (gdbarch, + s390_pseudo_register_reggroup_p); + set_gdbarch_ax_pseudo_register_collect (gdbarch, + s390_ax_pseudo_register_collect); + set_gdbarch_ax_pseudo_register_push_stack (gdbarch, + s390_ax_pseudo_register_push_stack); + set_gdbarch_gen_return_address (gdbarch, s390_gen_return_address); + tdesc_use_registers (gdbarch, tdesc, tdesc_data); + + /* Assign pseudo register numbers. */ + first_pseudo_reg = gdbarch_num_regs (gdbarch); + last_pseudo_reg = first_pseudo_reg; + tdep->gpr_full_regnum = -1; + if (have_upper) + { + tdep->gpr_full_regnum = last_pseudo_reg; + last_pseudo_reg += 16; + } + tdep->v0_full_regnum = -1; + if (have_vx) + { + tdep->v0_full_regnum = last_pseudo_reg; + last_pseudo_reg += 16; + } + tdep->pc_regnum = last_pseudo_reg++; + tdep->cc_regnum = last_pseudo_reg++; + set_gdbarch_pc_regnum (gdbarch, tdep->pc_regnum); + set_gdbarch_num_pseudo_regs (gdbarch, last_pseudo_reg - first_pseudo_reg); + + /* Inferior function calls. */ + set_gdbarch_push_dummy_call (gdbarch, s390_push_dummy_call); + set_gdbarch_dummy_id (gdbarch, s390_dummy_id); + set_gdbarch_frame_align (gdbarch, s390_frame_align); + set_gdbarch_return_value (gdbarch, s390_return_value); + + /* Frame handling. */ + /* Stack grows downward. */ + set_gdbarch_inner_than (gdbarch, core_addr_lessthan); + set_gdbarch_stack_frame_destroyed_p (gdbarch, s390_stack_frame_destroyed_p); + dwarf2_frame_set_init_reg (gdbarch, s390_dwarf2_frame_init_reg); + dwarf2_frame_set_adjust_regnum (gdbarch, s390_adjust_frame_regnum); + dwarf2_append_unwinders (gdbarch); + frame_base_append_sniffer (gdbarch, dwarf2_frame_base_sniffer); + frame_unwind_append_unwinder (gdbarch, &s390_stub_frame_unwind); + frame_unwind_append_unwinder (gdbarch, &s390_sigtramp_frame_unwind); + frame_unwind_append_unwinder (gdbarch, &s390_frame_unwind); + frame_base_set_default (gdbarch, &s390_frame_base); + set_gdbarch_unwind_pc (gdbarch, s390_unwind_pc); + set_gdbarch_unwind_sp (gdbarch, s390_unwind_sp); + + /* Displaced stepping. */ + set_gdbarch_displaced_step_copy_insn (gdbarch, + s390_displaced_step_copy_insn); + set_gdbarch_displaced_step_fixup (gdbarch, s390_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, + s390_displaced_step_hw_singlestep); + set_gdbarch_max_insn_length (gdbarch, S390_MAX_INSTR_SIZE); + + switch (tdep->abi) + { + case ABI_LINUX_S390: + set_gdbarch_addr_bits_remove (gdbarch, s390_addr_bits_remove); + break; + + case ABI_LINUX_ZSERIES: + set_gdbarch_long_bit (gdbarch, 64); + set_gdbarch_long_long_bit (gdbarch, 64); + set_gdbarch_ptr_bit (gdbarch, 64); + set_gdbarch_address_class_type_flags (gdbarch, + s390_address_class_type_flags); + set_gdbarch_address_class_type_flags_to_name (gdbarch, + s390_address_class_type_flags_to_name); + set_gdbarch_address_class_name_to_type_flags (gdbarch, + s390_address_class_name_to_type_flags); + break; + } + + set_gdbarch_print_insn (gdbarch, print_insn_s390); + + /* SystemTap functions. */ + set_gdbarch_stap_register_prefixes (gdbarch, stap_register_prefixes); + set_gdbarch_stap_register_indirection_prefixes (gdbarch, + stap_register_indirection_prefixes); + set_gdbarch_stap_register_indirection_suffixes (gdbarch, + stap_register_indirection_suffixes); + + + /* Note that GNU/Linux is the only OS supported on this platform. */ + s390_gdbarch_linux_init (info, gdbarch); + + return gdbarch; +} + + +extern initialize_file_ftype _initialize_s390_tdep; /* -Wmissing-prototypes */ + +void +_initialize_s390_tdep (void) +{ + /* Hook us into the gdbarch mechanism. */ + register_gdbarch_init (bfd_arch_s390, s390_gdbarch_init); +} |