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- /* Native support code for PPC AIX, for GDB the GNU debugger.
- Copyright (C) 2006-2022 Free Software Foundation, Inc.
- 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 "osabi.h"
- #include "regcache.h"
- #include "regset.h"
- #include "gdbtypes.h"
- #include "gdbcore.h"
- #include "target.h"
- #include "value.h"
- #include "infcall.h"
- #include "objfiles.h"
- #include "breakpoint.h"
- #include "ppc-tdep.h"
- #include "rs6000-aix-tdep.h"
- #include "xcoffread.h"
- #include "solib.h"
- #include "solib-aix.h"
- #include "target-float.h"
- #include "gdbsupport/xml-utils.h"
- #include "trad-frame.h"
- #include "frame-unwind.h"
- /* If the kernel has to deliver a signal, it pushes a sigcontext
- structure on the stack and then calls the signal handler, passing
- the address of the sigcontext in an argument register. Usually
- the signal handler doesn't save this register, so we have to
- access the sigcontext structure via an offset from the signal handler
- frame.
- The following constants were determined by experimentation on AIX 3.2.
- sigcontext structure have the mstsave saved under the
- sc_jmpbuf.jmp_context. STKMIN(minimum stack size) is 56 for 32-bit
- processes, and iar offset under sc_jmpbuf.jmp_context is 40.
- ie offsetof(struct sigcontext, sc_jmpbuf.jmp_context.iar).
- so PC offset in this case is STKMIN+iar offset, which is 96. */
- #define SIG_FRAME_PC_OFFSET 96
- #define SIG_FRAME_LR_OFFSET 108
- /* STKMIN+grp1 offset, which is 56+228=284 */
- #define SIG_FRAME_FP_OFFSET 284
- /* 64 bit process.
- STKMIN64 is 112 and iar offset is 312. So 112+312=424 */
- #define SIG_FRAME_LR_OFFSET64 424
- /* STKMIN64+grp1 offset. 112+56=168 */
- #define SIG_FRAME_FP_OFFSET64 168
- /* Minimum possible text address in AIX. */
- #define AIX_TEXT_SEGMENT_BASE 0x10000000
- static struct trad_frame_cache *
- aix_sighandle_frame_cache (struct frame_info *this_frame,
- void **this_cache)
- {
- LONGEST backchain;
- CORE_ADDR base, base_orig, func;
- struct gdbarch *gdbarch = get_frame_arch (this_frame);
- ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- struct trad_frame_cache *this_trad_cache;
- if ((*this_cache) != NULL)
- return (struct trad_frame_cache *) (*this_cache);
- this_trad_cache = trad_frame_cache_zalloc (this_frame);
- (*this_cache) = this_trad_cache;
- base = get_frame_register_unsigned (this_frame,
- gdbarch_sp_regnum (gdbarch));
- base_orig = base;
- if (tdep->wordsize == 4)
- {
- func = read_memory_unsigned_integer (base_orig +
- SIG_FRAME_PC_OFFSET + 8,
- tdep->wordsize, byte_order);
- safe_read_memory_integer (base_orig + SIG_FRAME_FP_OFFSET + 8,
- tdep->wordsize, byte_order, &backchain);
- base = (CORE_ADDR)backchain;
- }
- else
- {
- func = read_memory_unsigned_integer (base_orig +
- SIG_FRAME_LR_OFFSET64,
- tdep->wordsize, byte_order);
- safe_read_memory_integer (base_orig + SIG_FRAME_FP_OFFSET64,
- tdep->wordsize, byte_order, &backchain);
- base = (CORE_ADDR)backchain;
- }
- trad_frame_set_reg_value (this_trad_cache, gdbarch_pc_regnum (gdbarch), func);
- trad_frame_set_reg_value (this_trad_cache, gdbarch_sp_regnum (gdbarch), base);
- if (tdep->wordsize == 4)
- trad_frame_set_reg_addr (this_trad_cache, tdep->ppc_lr_regnum,
- base_orig + 0x38 + 52 + 8);
- else
- trad_frame_set_reg_addr (this_trad_cache, tdep->ppc_lr_regnum,
- base_orig + 0x70 + 320);
- trad_frame_set_id (this_trad_cache, frame_id_build (base, func));
- trad_frame_set_this_base (this_trad_cache, base);
- return this_trad_cache;
- }
- static void
- aix_sighandle_frame_this_id (struct frame_info *this_frame,
- void **this_prologue_cache,
- struct frame_id *this_id)
- {
- struct trad_frame_cache *this_trad_cache
- = aix_sighandle_frame_cache (this_frame, this_prologue_cache);
- trad_frame_get_id (this_trad_cache, this_id);
- }
- static struct value *
- aix_sighandle_frame_prev_register (struct frame_info *this_frame,
- void **this_prologue_cache, int regnum)
- {
- struct trad_frame_cache *this_trad_cache
- = aix_sighandle_frame_cache (this_frame, this_prologue_cache);
- return trad_frame_get_register (this_trad_cache, this_frame, regnum);
- }
- static int
- aix_sighandle_frame_sniffer (const struct frame_unwind *self,
- struct frame_info *this_frame,
- void **this_prologue_cache)
- {
- CORE_ADDR pc = get_frame_pc (this_frame);
- if (pc && pc < AIX_TEXT_SEGMENT_BASE)
- return 1;
- return 0;
- }
- /* AIX signal handler frame unwinder */
- static const struct frame_unwind aix_sighandle_frame_unwind = {
- "rs6000 aix sighandle",
- SIGTRAMP_FRAME,
- default_frame_unwind_stop_reason,
- aix_sighandle_frame_this_id,
- aix_sighandle_frame_prev_register,
- NULL,
- aix_sighandle_frame_sniffer
- };
- /* Core file support. */
- static struct ppc_reg_offsets rs6000_aix32_reg_offsets =
- {
- /* General-purpose registers. */
- 208, /* r0_offset */
- 4, /* gpr_size */
- 4, /* xr_size */
- 24, /* pc_offset */
- 28, /* ps_offset */
- 32, /* cr_offset */
- 36, /* lr_offset */
- 40, /* ctr_offset */
- 44, /* xer_offset */
- 48, /* mq_offset */
- /* Floating-point registers. */
- 336, /* f0_offset */
- 56, /* fpscr_offset */
- 4 /* fpscr_size */
- };
- static struct ppc_reg_offsets rs6000_aix64_reg_offsets =
- {
- /* General-purpose registers. */
- 0, /* r0_offset */
- 8, /* gpr_size */
- 4, /* xr_size */
- 264, /* pc_offset */
- 256, /* ps_offset */
- 288, /* cr_offset */
- 272, /* lr_offset */
- 280, /* ctr_offset */
- 292, /* xer_offset */
- -1, /* mq_offset */
- /* Floating-point registers. */
- 312, /* f0_offset */
- 296, /* fpscr_offset */
- 4 /* fpscr_size */
- };
- /* Supply register REGNUM in the general-purpose register set REGSET
- from the buffer specified by GREGS and LEN to register cache
- REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
- static void
- rs6000_aix_supply_regset (const struct regset *regset,
- struct regcache *regcache, int regnum,
- const void *gregs, size_t len)
- {
- ppc_supply_gregset (regset, regcache, regnum, gregs, len);
- ppc_supply_fpregset (regset, regcache, regnum, gregs, len);
- }
- /* Collect register REGNUM in the general-purpose register set
- REGSET, from register cache REGCACHE into the buffer specified by
- GREGS and LEN. If REGNUM is -1, do this for all registers in
- REGSET. */
- static void
- rs6000_aix_collect_regset (const struct regset *regset,
- const struct regcache *regcache, int regnum,
- void *gregs, size_t len)
- {
- ppc_collect_gregset (regset, regcache, regnum, gregs, len);
- ppc_collect_fpregset (regset, regcache, regnum, gregs, len);
- }
- /* AIX register set. */
- static const struct regset rs6000_aix32_regset =
- {
- &rs6000_aix32_reg_offsets,
- rs6000_aix_supply_regset,
- rs6000_aix_collect_regset,
- };
- static const struct regset rs6000_aix64_regset =
- {
- &rs6000_aix64_reg_offsets,
- rs6000_aix_supply_regset,
- rs6000_aix_collect_regset,
- };
- /* Iterate over core file register note sections. */
- static void
- rs6000_aix_iterate_over_regset_sections (struct gdbarch *gdbarch,
- iterate_over_regset_sections_cb *cb,
- void *cb_data,
- const struct regcache *regcache)
- {
- ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- if (tdep->wordsize == 4)
- cb (".reg", 592, 592, &rs6000_aix32_regset, NULL, cb_data);
- else
- cb (".reg", 576, 576, &rs6000_aix64_regset, NULL, cb_data);
- }
- /* Pass the arguments in either registers, or in the stack. In RS/6000,
- the first eight words of the argument list (that might be less than
- eight parameters if some parameters occupy more than one word) are
- passed in r3..r10 registers. Float and double parameters are
- passed in fpr's, in addition to that. Rest of the parameters if any
- are passed in user stack. There might be cases in which half of the
- parameter is copied into registers, the other half is pushed into
- stack.
- Stack must be aligned on 64-bit boundaries when synthesizing
- function calls.
- If the function is returning a structure, then the return address is passed
- in r3, then the first 7 words of the parameters can be passed in registers,
- starting from r4. */
- static CORE_ADDR
- rs6000_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
- struct regcache *regcache, CORE_ADDR bp_addr,
- int nargs, struct value **args, CORE_ADDR sp,
- function_call_return_method return_method,
- CORE_ADDR struct_addr)
- {
- ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- int ii;
- int len = 0;
- int argno; /* current argument number */
- int argbytes; /* current argument byte */
- gdb_byte tmp_buffer[50];
- int f_argno = 0; /* current floating point argno */
- int wordsize = tdep->wordsize;
- CORE_ADDR func_addr = find_function_addr (function, NULL);
- struct value *arg = 0;
- struct type *type;
- ULONGEST saved_sp;
- /* The calling convention this function implements assumes the
- processor has floating-point registers. We shouldn't be using it
- on PPC variants that lack them. */
- gdb_assert (ppc_floating_point_unit_p (gdbarch));
- /* The first eight words of ther arguments are passed in registers.
- Copy them appropriately. */
- ii = 0;
- /* If the function is returning a `struct', then the first word
- (which will be passed in r3) is used for struct return address.
- In that case we should advance one word and start from r4
- register to copy parameters. */
- if (return_method == return_method_struct)
- {
- regcache_raw_write_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
- struct_addr);
- ii++;
- }
- /* effectively indirect call... gcc does...
- return_val example( float, int);
- eabi:
- float in fp0, int in r3
- offset of stack on overflow 8/16
- for varargs, must go by type.
- power open:
- float in r3&r4, int in r5
- offset of stack on overflow different
- both:
- return in r3 or f0. If no float, must study how gcc emulates floats;
- pay attention to arg promotion.
- User may have to cast\args to handle promotion correctly
- since gdb won't know if prototype supplied or not. */
- for (argno = 0, argbytes = 0; argno < nargs && ii < 8; ++ii)
- {
- int reg_size = register_size (gdbarch, ii + 3);
- arg = args[argno];
- type = check_typedef (value_type (arg));
- len = TYPE_LENGTH (type);
- if (type->code () == TYPE_CODE_FLT)
- {
- /* Floating point arguments are passed in fpr's, as well as gpr's.
- There are 13 fpr's reserved for passing parameters. At this point
- there is no way we would run out of them.
- Always store the floating point value using the register's
- floating-point format. */
- const int fp_regnum = tdep->ppc_fp0_regnum + 1 + f_argno;
- gdb_byte reg_val[PPC_MAX_REGISTER_SIZE];
- struct type *reg_type = register_type (gdbarch, fp_regnum);
- gdb_assert (len <= 8);
- target_float_convert (value_contents (arg).data (), type, reg_val,
- reg_type);
- regcache->cooked_write (fp_regnum, reg_val);
- ++f_argno;
- }
- if (len > reg_size)
- {
- /* Argument takes more than one register. */
- while (argbytes < len)
- {
- gdb_byte word[PPC_MAX_REGISTER_SIZE];
- memset (word, 0, reg_size);
- memcpy (word,
- ((char *) value_contents (arg).data ()) + argbytes,
- (len - argbytes) > reg_size
- ? reg_size : len - argbytes);
- regcache->cooked_write (tdep->ppc_gp0_regnum + 3 + ii, word);
- ++ii, argbytes += reg_size;
- if (ii >= 8)
- goto ran_out_of_registers_for_arguments;
- }
- argbytes = 0;
- --ii;
- }
- else
- {
- /* Argument can fit in one register. No problem. */
- gdb_byte word[PPC_MAX_REGISTER_SIZE];
- memset (word, 0, reg_size);
- memcpy (word, value_contents (arg).data (), len);
- regcache->cooked_write (tdep->ppc_gp0_regnum + 3 +ii, word);
- }
- ++argno;
- }
- ran_out_of_registers_for_arguments:
- regcache_cooked_read_unsigned (regcache,
- gdbarch_sp_regnum (gdbarch),
- &saved_sp);
- /* Location for 8 parameters are always reserved. */
- sp -= wordsize * 8;
- /* Another six words for back chain, TOC register, link register, etc. */
- sp -= wordsize * 6;
- /* Stack pointer must be quadword aligned. */
- sp &= -16;
- /* If there are more arguments, allocate space for them in
- the stack, then push them starting from the ninth one. */
- if ((argno < nargs) || argbytes)
- {
- int space = 0, jj;
- if (argbytes)
- {
- space += ((len - argbytes + 3) & -4);
- jj = argno + 1;
- }
- else
- jj = argno;
- for (; jj < nargs; ++jj)
- {
- struct value *val = args[jj];
- space += ((TYPE_LENGTH (value_type (val))) + 3) & -4;
- }
- /* Add location required for the rest of the parameters. */
- space = (space + 15) & -16;
- sp -= space;
- /* This is another instance we need to be concerned about
- securing our stack space. If we write anything underneath %sp
- (r1), we might conflict with the kernel who thinks he is free
- to use this area. So, update %sp first before doing anything
- else. */
- regcache_raw_write_signed (regcache,
- gdbarch_sp_regnum (gdbarch), sp);
- /* If the last argument copied into the registers didn't fit there
- completely, push the rest of it into stack. */
- if (argbytes)
- {
- write_memory (sp + 24 + (ii * 4),
- value_contents (arg).data () + argbytes,
- len - argbytes);
- ++argno;
- ii += ((len - argbytes + 3) & -4) / 4;
- }
- /* Push the rest of the arguments into stack. */
- for (; argno < nargs; ++argno)
- {
- arg = args[argno];
- type = check_typedef (value_type (arg));
- len = TYPE_LENGTH (type);
- /* Float types should be passed in fpr's, as well as in the
- stack. */
- if (type->code () == TYPE_CODE_FLT && f_argno < 13)
- {
- gdb_assert (len <= 8);
- regcache->cooked_write (tdep->ppc_fp0_regnum + 1 + f_argno,
- value_contents (arg).data ());
- ++f_argno;
- }
- write_memory (sp + 24 + (ii * 4), value_contents (arg).data (), len);
- ii += ((len + 3) & -4) / 4;
- }
- }
- /* Set the stack pointer. According to the ABI, the SP is meant to
- be set _before_ the corresponding stack space is used. On AIX,
- this even applies when the target has been completely stopped!
- Not doing this can lead to conflicts with the kernel which thinks
- that it still has control over this not-yet-allocated stack
- region. */
- regcache_raw_write_signed (regcache, gdbarch_sp_regnum (gdbarch), sp);
- /* Set back chain properly. */
- store_unsigned_integer (tmp_buffer, wordsize, byte_order, saved_sp);
- write_memory (sp, tmp_buffer, wordsize);
- /* Point the inferior function call's return address at the dummy's
- breakpoint. */
- regcache_raw_write_signed (regcache, tdep->ppc_lr_regnum, bp_addr);
- /* Set the TOC register value. */
- regcache_raw_write_signed (regcache, tdep->ppc_toc_regnum,
- solib_aix_get_toc_value (func_addr));
- target_store_registers (regcache, -1);
- return sp;
- }
- static enum return_value_convention
- rs6000_return_value (struct gdbarch *gdbarch, struct value *function,
- struct type *valtype, struct regcache *regcache,
- gdb_byte *readbuf, const gdb_byte *writebuf)
- {
- ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- /* The calling convention this function implements assumes the
- processor has floating-point registers. We shouldn't be using it
- on PowerPC variants that lack them. */
- gdb_assert (ppc_floating_point_unit_p (gdbarch));
- /* AltiVec extension: Functions that declare a vector data type as a
- return value place that return value in VR2. */
- if (valtype->code () == TYPE_CODE_ARRAY && valtype->is_vector ()
- && TYPE_LENGTH (valtype) == 16)
- {
- if (readbuf)
- regcache->cooked_read (tdep->ppc_vr0_regnum + 2, readbuf);
- if (writebuf)
- regcache->cooked_write (tdep->ppc_vr0_regnum + 2, writebuf);
- return RETURN_VALUE_REGISTER_CONVENTION;
- }
- /* If the called subprogram returns an aggregate, there exists an
- implicit first argument, whose value is the address of a caller-
- allocated buffer into which the callee is assumed to store its
- return value. All explicit parameters are appropriately
- relabeled. */
- if (valtype->code () == TYPE_CODE_STRUCT
- || valtype->code () == TYPE_CODE_UNION
- || valtype->code () == TYPE_CODE_ARRAY)
- return RETURN_VALUE_STRUCT_CONVENTION;
- /* Scalar floating-point values are returned in FPR1 for float or
- double, and in FPR1:FPR2 for quadword precision. Fortran
- complex*8 and complex*16 are returned in FPR1:FPR2, and
- complex*32 is returned in FPR1:FPR4. */
- if (valtype->code () == TYPE_CODE_FLT
- && (TYPE_LENGTH (valtype) == 4 || TYPE_LENGTH (valtype) == 8))
- {
- struct type *regtype = register_type (gdbarch, tdep->ppc_fp0_regnum);
- gdb_byte regval[8];
- /* FIXME: kettenis/2007-01-01: Add support for quadword
- precision and complex. */
- if (readbuf)
- {
- regcache->cooked_read (tdep->ppc_fp0_regnum + 1, regval);
- target_float_convert (regval, regtype, readbuf, valtype);
- }
- if (writebuf)
- {
- target_float_convert (writebuf, valtype, regval, regtype);
- regcache->cooked_write (tdep->ppc_fp0_regnum + 1, regval);
- }
- return RETURN_VALUE_REGISTER_CONVENTION;
- }
- /* Values of the types int, long, short, pointer, and char (length
- is less than or equal to four bytes), as well as bit values of
- lengths less than or equal to 32 bits, must be returned right
- justified in GPR3 with signed values sign extended and unsigned
- values zero extended, as necessary. */
- if (TYPE_LENGTH (valtype) <= tdep->wordsize)
- {
- if (readbuf)
- {
- ULONGEST regval;
- /* For reading we don't have to worry about sign extension. */
- regcache_cooked_read_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
- ®val);
- store_unsigned_integer (readbuf, TYPE_LENGTH (valtype), byte_order,
- regval);
- }
- if (writebuf)
- {
- /* For writing, use unpack_long since that should handle any
- required sign extension. */
- regcache_cooked_write_unsigned (regcache, tdep->ppc_gp0_regnum + 3,
- unpack_long (valtype, writebuf));
- }
- return RETURN_VALUE_REGISTER_CONVENTION;
- }
- /* Eight-byte non-floating-point scalar values must be returned in
- GPR3:GPR4. */
- if (TYPE_LENGTH (valtype) == 8)
- {
- gdb_assert (valtype->code () != TYPE_CODE_FLT);
- gdb_assert (tdep->wordsize == 4);
- if (readbuf)
- {
- gdb_byte regval[8];
- regcache->cooked_read (tdep->ppc_gp0_regnum + 3, regval);
- regcache->cooked_read (tdep->ppc_gp0_regnum + 4, regval + 4);
- memcpy (readbuf, regval, 8);
- }
- if (writebuf)
- {
- regcache->cooked_write (tdep->ppc_gp0_regnum + 3, writebuf);
- regcache->cooked_write (tdep->ppc_gp0_regnum + 4, writebuf + 4);
- }
- return RETURN_VALUE_REGISTER_CONVENTION;
- }
- return RETURN_VALUE_STRUCT_CONVENTION;
- }
- /* Support for CONVERT_FROM_FUNC_PTR_ADDR (ARCH, ADDR, TARG).
- Usually a function pointer's representation is simply the address
- of the function. On the RS/6000 however, a function pointer is
- represented by a pointer to an OPD entry. This OPD entry contains
- three words, the first word is the address of the function, the
- second word is the TOC pointer (r2), and the third word is the
- static chain value. Throughout GDB it is currently assumed that a
- function pointer contains the address of the function, which is not
- easy to fix. In addition, the conversion of a function address to
- a function pointer would require allocation of an OPD entry in the
- inferior's memory space, with all its drawbacks. To be able to
- call C++ virtual methods in the inferior (which are called via
- function pointers), find_function_addr uses this function to get the
- function address from a function pointer. */
- /* Return real function address if ADDR (a function pointer) is in the data
- space and is therefore a special function pointer. */
- static CORE_ADDR
- rs6000_convert_from_func_ptr_addr (struct gdbarch *gdbarch,
- CORE_ADDR addr,
- struct target_ops *targ)
- {
- ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- struct obj_section *s;
- s = find_pc_section (addr);
- /* Normally, functions live inside a section that is executable.
- So, if ADDR points to a non-executable section, then treat it
- as a function descriptor and return the target address iff
- the target address itself points to a section that is executable. */
- if (s && (s->the_bfd_section->flags & SEC_CODE) == 0)
- {
- CORE_ADDR pc = 0;
- struct obj_section *pc_section;
- try
- {
- pc = read_memory_unsigned_integer (addr, tdep->wordsize, byte_order);
- }
- catch (const gdb_exception_error &e)
- {
- /* An error occured during reading. Probably a memory error
- due to the section not being loaded yet. This address
- cannot be a function descriptor. */
- return addr;
- }
- pc_section = find_pc_section (pc);
- if (pc_section && (pc_section->the_bfd_section->flags & SEC_CODE))
- return pc;
- }
- return addr;
- }
- /* Calculate the destination of a branch/jump. Return -1 if not a branch. */
- static CORE_ADDR
- branch_dest (struct regcache *regcache, int opcode, int instr,
- CORE_ADDR pc, CORE_ADDR safety)
- {
- struct gdbarch *gdbarch = regcache->arch ();
- ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- CORE_ADDR dest;
- int immediate;
- int absolute;
- int ext_op;
- absolute = (int) ((instr >> 1) & 1);
- switch (opcode)
- {
- case 18:
- immediate = ((instr & ~3) << 6) >> 6; /* br unconditional */
- if (absolute)
- dest = immediate;
- else
- dest = pc + immediate;
- break;
- case 16:
- immediate = ((instr & ~3) << 16) >> 16; /* br conditional */
- if (absolute)
- dest = immediate;
- else
- dest = pc + immediate;
- break;
- case 19:
- ext_op = (instr >> 1) & 0x3ff;
- if (ext_op == 16) /* br conditional register */
- {
- dest = regcache_raw_get_unsigned (regcache, tdep->ppc_lr_regnum) & ~3;
- /* If we are about to return from a signal handler, dest is
- something like 0x3c90. The current frame is a signal handler
- caller frame, upon completion of the sigreturn system call
- execution will return to the saved PC in the frame. */
- if (dest < AIX_TEXT_SEGMENT_BASE)
- {
- struct frame_info *frame = get_current_frame ();
- dest = read_memory_unsigned_integer
- (get_frame_base (frame) + SIG_FRAME_PC_OFFSET,
- tdep->wordsize, byte_order);
- }
- }
- else if (ext_op == 528) /* br cond to count reg */
- {
- dest = regcache_raw_get_unsigned (regcache,
- tdep->ppc_ctr_regnum) & ~3;
- /* If we are about to execute a system call, dest is something
- like 0x22fc or 0x3b00. Upon completion the system call
- will return to the address in the link register. */
- if (dest < AIX_TEXT_SEGMENT_BASE)
- dest = regcache_raw_get_unsigned (regcache,
- tdep->ppc_lr_regnum) & ~3;
- }
- else
- return -1;
- break;
- default:
- return -1;
- }
- return (dest < AIX_TEXT_SEGMENT_BASE) ? safety : dest;
- }
- /* AIX does not support PT_STEP. Simulate it. */
- static std::vector<CORE_ADDR>
- rs6000_software_single_step (struct regcache *regcache)
- {
- struct gdbarch *gdbarch = regcache->arch ();
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- int ii, insn;
- CORE_ADDR loc;
- CORE_ADDR breaks[2];
- int opcode;
- loc = regcache_read_pc (regcache);
- insn = read_memory_integer (loc, 4, byte_order);
- std::vector<CORE_ADDR> next_pcs = ppc_deal_with_atomic_sequence (regcache);
- if (!next_pcs.empty ())
- return next_pcs;
-
- breaks[0] = loc + PPC_INSN_SIZE;
- opcode = insn >> 26;
- breaks[1] = branch_dest (regcache, opcode, insn, loc, breaks[0]);
- /* Don't put two breakpoints on the same address. */
- if (breaks[1] == breaks[0])
- breaks[1] = -1;
- for (ii = 0; ii < 2; ++ii)
- {
- /* ignore invalid breakpoint. */
- if (breaks[ii] == -1)
- continue;
- next_pcs.push_back (breaks[ii]);
- }
- errno = 0; /* FIXME, don't ignore errors! */
- /* What errors? {read,write}_memory call error(). */
- return next_pcs;
- }
- /* Implement the "auto_wide_charset" gdbarch method for this platform. */
- static const char *
- rs6000_aix_auto_wide_charset (void)
- {
- return "UTF-16";
- }
- /* Implement an osabi sniffer for RS6000/AIX.
- This function assumes that ABFD's flavour is XCOFF. In other words,
- it should be registered as a sniffer for bfd_target_xcoff_flavour
- objfiles only. A failed assertion will be raised if this condition
- is not met. */
- static enum gdb_osabi
- rs6000_aix_osabi_sniffer (bfd *abfd)
- {
- gdb_assert (bfd_get_flavour (abfd) == bfd_target_xcoff_flavour);
- /* The only noticeable difference between Lynx178 XCOFF files and
- AIX XCOFF files comes from the fact that there are no shared
- libraries on Lynx178. On AIX, we are betting that an executable
- linked with no shared library will never exist. */
- if (xcoff_get_n_import_files (abfd) <= 0)
- return GDB_OSABI_UNKNOWN;
- return GDB_OSABI_AIX;
- }
- /* A structure encoding the offset and size of a field within
- a struct. */
- struct field_info
- {
- int offset;
- int size;
- };
- /* A structure describing the layout of all the fields of interest
- in AIX's struct ld_info. Each field in this struct corresponds
- to the field of the same name in struct ld_info. */
- struct ld_info_desc
- {
- struct field_info ldinfo_next;
- struct field_info ldinfo_fd;
- struct field_info ldinfo_textorg;
- struct field_info ldinfo_textsize;
- struct field_info ldinfo_dataorg;
- struct field_info ldinfo_datasize;
- struct field_info ldinfo_filename;
- };
- /* The following data has been generated by compiling and running
- the following program on AIX 5.3. */
- #if 0
- #include <stddef.h>
- #include <stdio.h>
- #define __LDINFO_PTRACE32__
- #define __LDINFO_PTRACE64__
- #include <sys/ldr.h>
- #define pinfo(type,member) \
- { \
- struct type ldi = {0}; \
- \
- printf (" {%d, %d},\t/* %s */\n", \
- offsetof (struct type, member), \
- sizeof (ldi.member), \
- #member); \
- } \
- while (0)
- int
- main (void)
- {
- printf ("static const struct ld_info_desc ld_info32_desc =\n{\n");
- pinfo (__ld_info32, ldinfo_next);
- pinfo (__ld_info32, ldinfo_fd);
- pinfo (__ld_info32, ldinfo_textorg);
- pinfo (__ld_info32, ldinfo_textsize);
- pinfo (__ld_info32, ldinfo_dataorg);
- pinfo (__ld_info32, ldinfo_datasize);
- pinfo (__ld_info32, ldinfo_filename);
- printf ("};\n");
- printf ("\n");
- printf ("static const struct ld_info_desc ld_info64_desc =\n{\n");
- pinfo (__ld_info64, ldinfo_next);
- pinfo (__ld_info64, ldinfo_fd);
- pinfo (__ld_info64, ldinfo_textorg);
- pinfo (__ld_info64, ldinfo_textsize);
- pinfo (__ld_info64, ldinfo_dataorg);
- pinfo (__ld_info64, ldinfo_datasize);
- pinfo (__ld_info64, ldinfo_filename);
- printf ("};\n");
- return 0;
- }
- #endif /* 0 */
- /* Layout of the 32bit version of struct ld_info. */
- static const struct ld_info_desc ld_info32_desc =
- {
- {0, 4}, /* ldinfo_next */
- {4, 4}, /* ldinfo_fd */
- {8, 4}, /* ldinfo_textorg */
- {12, 4}, /* ldinfo_textsize */
- {16, 4}, /* ldinfo_dataorg */
- {20, 4}, /* ldinfo_datasize */
- {24, 2}, /* ldinfo_filename */
- };
- /* Layout of the 64bit version of struct ld_info. */
- static const struct ld_info_desc ld_info64_desc =
- {
- {0, 4}, /* ldinfo_next */
- {8, 4}, /* ldinfo_fd */
- {16, 8}, /* ldinfo_textorg */
- {24, 8}, /* ldinfo_textsize */
- {32, 8}, /* ldinfo_dataorg */
- {40, 8}, /* ldinfo_datasize */
- {48, 2}, /* ldinfo_filename */
- };
- /* A structured representation of one entry read from the ld_info
- binary data provided by the AIX loader. */
- struct ld_info
- {
- ULONGEST next;
- int fd;
- CORE_ADDR textorg;
- ULONGEST textsize;
- CORE_ADDR dataorg;
- ULONGEST datasize;
- char *filename;
- char *member_name;
- };
- /* Return a struct ld_info object corresponding to the entry at
- LDI_BUF.
- Note that the filename and member_name strings still point
- to the data in LDI_BUF. So LDI_BUF must not be deallocated
- while the struct ld_info object returned is in use. */
- static struct ld_info
- rs6000_aix_extract_ld_info (struct gdbarch *gdbarch,
- const gdb_byte *ldi_buf)
- {
- ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
- const struct ld_info_desc desc
- = tdep->wordsize == 8 ? ld_info64_desc : ld_info32_desc;
- struct ld_info info;
- info.next = extract_unsigned_integer (ldi_buf + desc.ldinfo_next.offset,
- desc.ldinfo_next.size,
- byte_order);
- info.fd = extract_signed_integer (ldi_buf + desc.ldinfo_fd.offset,
- desc.ldinfo_fd.size,
- byte_order);
- info.textorg = extract_typed_address (ldi_buf + desc.ldinfo_textorg.offset,
- ptr_type);
- info.textsize
- = extract_unsigned_integer (ldi_buf + desc.ldinfo_textsize.offset,
- desc.ldinfo_textsize.size,
- byte_order);
- info.dataorg = extract_typed_address (ldi_buf + desc.ldinfo_dataorg.offset,
- ptr_type);
- info.datasize
- = extract_unsigned_integer (ldi_buf + desc.ldinfo_datasize.offset,
- desc.ldinfo_datasize.size,
- byte_order);
- info.filename = (char *) ldi_buf + desc.ldinfo_filename.offset;
- info.member_name = info.filename + strlen (info.filename) + 1;
- return info;
- }
- /* Append to OBJSTACK an XML string description of the shared library
- corresponding to LDI, following the TARGET_OBJECT_LIBRARIES_AIX
- format. */
- static void
- rs6000_aix_shared_library_to_xml (struct ld_info *ldi,
- struct obstack *obstack)
- {
- obstack_grow_str (obstack, "<library name=\"");
- std::string p = xml_escape_text (ldi->filename);
- obstack_grow_str (obstack, p.c_str ());
- obstack_grow_str (obstack, "\"");
- if (ldi->member_name[0] != '\0')
- {
- obstack_grow_str (obstack, " member=\"");
- p = xml_escape_text (ldi->member_name);
- obstack_grow_str (obstack, p.c_str ());
- obstack_grow_str (obstack, "\"");
- }
- obstack_grow_str (obstack, " text_addr=\"");
- obstack_grow_str (obstack, core_addr_to_string (ldi->textorg));
- obstack_grow_str (obstack, "\"");
- obstack_grow_str (obstack, " text_size=\"");
- obstack_grow_str (obstack, pulongest (ldi->textsize));
- obstack_grow_str (obstack, "\"");
- obstack_grow_str (obstack, " data_addr=\"");
- obstack_grow_str (obstack, core_addr_to_string (ldi->dataorg));
- obstack_grow_str (obstack, "\"");
- obstack_grow_str (obstack, " data_size=\"");
- obstack_grow_str (obstack, pulongest (ldi->datasize));
- obstack_grow_str (obstack, "\"");
- obstack_grow_str (obstack, "></library>");
- }
- /* Convert the ld_info binary data provided by the AIX loader into
- an XML representation following the TARGET_OBJECT_LIBRARIES_AIX
- format.
- LDI_BUF is a buffer containing the ld_info data.
- READBUF, OFFSET and LEN follow the same semantics as target_ops'
- to_xfer_partial target_ops method.
- If CLOSE_LDINFO_FD is nonzero, then this routine also closes
- the ldinfo_fd file descriptor. This is useful when the ldinfo
- data is obtained via ptrace, as ptrace opens a file descriptor
- for each and every entry; but we cannot use this descriptor
- as the consumer of the XML library list might live in a different
- process. */
- ULONGEST
- rs6000_aix_ld_info_to_xml (struct gdbarch *gdbarch, const gdb_byte *ldi_buf,
- gdb_byte *readbuf, ULONGEST offset, ULONGEST len,
- int close_ldinfo_fd)
- {
- struct obstack obstack;
- const char *buf;
- ULONGEST len_avail;
- obstack_init (&obstack);
- obstack_grow_str (&obstack, "<library-list-aix version=\"1.0\">\n");
- while (1)
- {
- struct ld_info ldi = rs6000_aix_extract_ld_info (gdbarch, ldi_buf);
- rs6000_aix_shared_library_to_xml (&ldi, &obstack);
- if (close_ldinfo_fd)
- close (ldi.fd);
- if (!ldi.next)
- break;
- ldi_buf = ldi_buf + ldi.next;
- }
- obstack_grow_str0 (&obstack, "</library-list-aix>\n");
- buf = (const char *) obstack_finish (&obstack);
- len_avail = strlen (buf);
- if (offset >= len_avail)
- len= 0;
- else
- {
- if (len > len_avail - offset)
- len = len_avail - offset;
- memcpy (readbuf, buf + offset, len);
- }
- obstack_free (&obstack, NULL);
- return len;
- }
- /* Implement the core_xfer_shared_libraries_aix gdbarch method. */
- static ULONGEST
- rs6000_aix_core_xfer_shared_libraries_aix (struct gdbarch *gdbarch,
- gdb_byte *readbuf,
- ULONGEST offset,
- ULONGEST len)
- {
- struct bfd_section *ldinfo_sec;
- int ldinfo_size;
- ldinfo_sec = bfd_get_section_by_name (core_bfd, ".ldinfo");
- if (ldinfo_sec == NULL)
- error (_("cannot find .ldinfo section from core file: %s"),
- bfd_errmsg (bfd_get_error ()));
- ldinfo_size = bfd_section_size (ldinfo_sec);
- gdb::byte_vector ldinfo_buf (ldinfo_size);
- if (! bfd_get_section_contents (core_bfd, ldinfo_sec,
- ldinfo_buf.data (), 0, ldinfo_size))
- error (_("unable to read .ldinfo section from core file: %s"),
- bfd_errmsg (bfd_get_error ()));
- return rs6000_aix_ld_info_to_xml (gdbarch, ldinfo_buf.data (), readbuf,
- offset, len, 0);
- }
- static void
- rs6000_aix_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
- {
- ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- /* RS6000/AIX does not support PT_STEP. Has to be simulated. */
- set_gdbarch_software_single_step (gdbarch, rs6000_software_single_step);
- /* Displaced stepping is currently not supported in combination with
- software single-stepping. These override the values set by
- rs6000_gdbarch_init. */
- set_gdbarch_displaced_step_copy_insn (gdbarch, NULL);
- set_gdbarch_displaced_step_fixup (gdbarch, NULL);
- set_gdbarch_displaced_step_prepare (gdbarch, NULL);
- set_gdbarch_displaced_step_finish (gdbarch, NULL);
- set_gdbarch_push_dummy_call (gdbarch, rs6000_push_dummy_call);
- set_gdbarch_return_value (gdbarch, rs6000_return_value);
- set_gdbarch_long_double_bit (gdbarch, 8 * TARGET_CHAR_BIT);
- /* Handle RS/6000 function pointers (which are really function
- descriptors). */
- set_gdbarch_convert_from_func_ptr_addr
- (gdbarch, rs6000_convert_from_func_ptr_addr);
- /* Core file support. */
- set_gdbarch_iterate_over_regset_sections
- (gdbarch, rs6000_aix_iterate_over_regset_sections);
- set_gdbarch_core_xfer_shared_libraries_aix
- (gdbarch, rs6000_aix_core_xfer_shared_libraries_aix);
- if (tdep->wordsize == 8)
- tdep->lr_frame_offset = 16;
- else
- tdep->lr_frame_offset = 8;
- if (tdep->wordsize == 4)
- /* PowerOpen / AIX 32 bit. The saved area or red zone consists of
- 19 4 byte GPRS + 18 8 byte FPRs giving a total of 220 bytes.
- Problem is, 220 isn't frame (16 byte) aligned. Round it up to
- 224. */
- set_gdbarch_frame_red_zone_size (gdbarch, 224);
- else
- set_gdbarch_frame_red_zone_size (gdbarch, 0);
- if (tdep->wordsize == 8)
- set_gdbarch_wchar_bit (gdbarch, 32);
- else
- set_gdbarch_wchar_bit (gdbarch, 16);
- set_gdbarch_wchar_signed (gdbarch, 0);
- set_gdbarch_auto_wide_charset (gdbarch, rs6000_aix_auto_wide_charset);
- set_solib_ops (gdbarch, &solib_aix_so_ops);
- frame_unwind_append_unwinder (gdbarch, &aix_sighandle_frame_unwind);
- }
- void _initialize_rs6000_aix_tdep ();
- void
- _initialize_rs6000_aix_tdep ()
- {
- gdbarch_register_osabi_sniffer (bfd_arch_rs6000,
- bfd_target_xcoff_flavour,
- rs6000_aix_osabi_sniffer);
- gdbarch_register_osabi_sniffer (bfd_arch_powerpc,
- bfd_target_xcoff_flavour,
- rs6000_aix_osabi_sniffer);
- gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_AIX,
- rs6000_aix_init_osabi);
- gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_AIX,
- rs6000_aix_init_osabi);
- }
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