| /* Target-dependent code for the MDEBUG MIPS architecture, for GDB, |
| the GNU Debugger. |
| |
| Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, |
| 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2006 |
| 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 2 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, write to the Free Software |
| Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| Boston, MA 02110-1301, USA. */ |
| |
| #include "defs.h" |
| #include "frame.h" |
| #include "mips-tdep.h" |
| #include "trad-frame.h" |
| #include "block.h" |
| #include "symtab.h" |
| #include "objfiles.h" |
| #include "elf/mips.h" |
| #include "elf-bfd.h" |
| #include "gdb_assert.h" |
| #include "frame-unwind.h" |
| #include "frame-base.h" |
| #include "mips-mdebug-tdep.h" |
| #include "mdebugread.h" |
| |
| #define PROC_LOW_ADDR(proc) ((proc)->pdr.adr) /* least address */ |
| #define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset) |
| #define PROC_FRAME_REG(proc) ((proc)->pdr.framereg) |
| #define PROC_REG_MASK(proc) ((proc)->pdr.regmask) |
| #define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask) |
| #define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset) |
| #define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset) |
| #define PROC_PC_REG(proc) ((proc)->pdr.pcreg) |
| /* FIXME drow/2002-06-10: If a pointer on the host is bigger than a long, |
| this will corrupt pdr.iline. Fortunately we don't use it. */ |
| #define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym) |
| #define _PROC_MAGIC_ 0x0F0F0F0F |
| |
| struct mips_objfile_private |
| { |
| bfd_size_type size; |
| char *contents; |
| }; |
| |
| /* Global used to communicate between non_heuristic_proc_desc and |
| compare_pdr_entries within qsort (). */ |
| static bfd *the_bfd; |
| |
| static int |
| compare_pdr_entries (const void *a, const void *b) |
| { |
| CORE_ADDR lhs = bfd_get_signed_32 (the_bfd, (bfd_byte *) a); |
| CORE_ADDR rhs = bfd_get_signed_32 (the_bfd, (bfd_byte *) b); |
| |
| if (lhs < rhs) |
| return -1; |
| else if (lhs == rhs) |
| return 0; |
| else |
| return 1; |
| } |
| |
| static const struct objfile_data *mips_pdr_data; |
| |
| static struct mdebug_extra_func_info * |
| non_heuristic_proc_desc (CORE_ADDR pc, CORE_ADDR *addrptr) |
| { |
| CORE_ADDR startaddr; |
| struct mdebug_extra_func_info *proc_desc; |
| struct block *b = block_for_pc (pc); |
| struct symbol *sym; |
| struct obj_section *sec; |
| struct mips_objfile_private *priv; |
| |
| find_pc_partial_function (pc, NULL, &startaddr, NULL); |
| if (addrptr) |
| *addrptr = startaddr; |
| |
| priv = NULL; |
| |
| sec = find_pc_section (pc); |
| if (sec != NULL) |
| { |
| priv = (struct mips_objfile_private *) objfile_data (sec->objfile, mips_pdr_data); |
| |
| /* Search the ".pdr" section generated by GAS. This includes most of |
| the information normally found in ECOFF PDRs. */ |
| |
| the_bfd = sec->objfile->obfd; |
| if (priv == NULL |
| && (the_bfd->format == bfd_object |
| && bfd_get_flavour (the_bfd) == bfd_target_elf_flavour |
| && elf_elfheader (the_bfd)->e_ident[EI_CLASS] == ELFCLASS64)) |
| { |
| /* Right now GAS only outputs the address as a four-byte sequence. |
| This means that we should not bother with this method on 64-bit |
| targets (until that is fixed). */ |
| |
| priv = obstack_alloc (&sec->objfile->objfile_obstack, |
| sizeof (struct mips_objfile_private)); |
| priv->size = 0; |
| set_objfile_data (sec->objfile, mips_pdr_data, priv); |
| } |
| else if (priv == NULL) |
| { |
| asection *bfdsec; |
| |
| priv = obstack_alloc (&sec->objfile->objfile_obstack, |
| sizeof (struct mips_objfile_private)); |
| |
| bfdsec = bfd_get_section_by_name (sec->objfile->obfd, ".pdr"); |
| if (bfdsec != NULL) |
| { |
| priv->size = bfd_section_size (sec->objfile->obfd, bfdsec); |
| priv->contents = obstack_alloc (&sec->objfile->objfile_obstack, |
| priv->size); |
| bfd_get_section_contents (sec->objfile->obfd, bfdsec, |
| priv->contents, 0, priv->size); |
| |
| /* In general, the .pdr section is sorted. However, in the |
| presence of multiple code sections (and other corner cases) |
| it can become unsorted. Sort it so that we can use a faster |
| binary search. */ |
| qsort (priv->contents, priv->size / 32, 32, |
| compare_pdr_entries); |
| } |
| else |
| priv->size = 0; |
| |
| set_objfile_data (sec->objfile, mips_pdr_data, priv); |
| } |
| the_bfd = NULL; |
| |
| if (priv->size != 0) |
| { |
| int low, mid, high; |
| char *ptr; |
| CORE_ADDR pdr_pc; |
| |
| low = 0; |
| high = priv->size / 32; |
| |
| /* We've found a .pdr section describing this objfile. We want to |
| find the entry which describes this code address. The .pdr |
| information is not very descriptive; we have only a function |
| start address. We have to look for the closest entry, because |
| the local symbol at the beginning of this function may have |
| been stripped - so if we ask the symbol table for the start |
| address we may get a preceding global function. */ |
| |
| /* First, find the last .pdr entry starting at or before PC. */ |
| do |
| { |
| mid = (low + high) / 2; |
| |
| ptr = priv->contents + mid * 32; |
| pdr_pc = bfd_get_signed_32 (sec->objfile->obfd, ptr); |
| pdr_pc += ANOFFSET (sec->objfile->section_offsets, |
| SECT_OFF_TEXT (sec->objfile)); |
| |
| if (pdr_pc > pc) |
| high = mid; |
| else |
| low = mid + 1; |
| } |
| while (low != high); |
| |
| /* Both low and high point one past the PDR of interest. If |
| both are zero, that means this PC is before any region |
| covered by a PDR, i.e. pdr_pc for the first PDR entry is |
| greater than PC. */ |
| if (low > 0) |
| { |
| ptr = priv->contents + (low - 1) * 32; |
| pdr_pc = bfd_get_signed_32 (sec->objfile->obfd, ptr); |
| pdr_pc += ANOFFSET (sec->objfile->section_offsets, |
| SECT_OFF_TEXT (sec->objfile)); |
| } |
| |
| /* We don't have a range, so we have no way to know for sure |
| whether we're in the correct PDR or a PDR for a preceding |
| function and the current function was a stripped local |
| symbol. But if the PDR's PC is at least as great as the |
| best guess from the symbol table, assume that it does cover |
| the right area; if a .pdr section is present at all then |
| nearly every function will have an entry. The biggest exception |
| will be the dynamic linker stubs; conveniently these are |
| placed before .text instead of after. */ |
| |
| if (pc >= pdr_pc && pdr_pc >= startaddr) |
| { |
| struct symbol *sym = find_pc_function (pc); |
| |
| if (addrptr) |
| *addrptr = pdr_pc; |
| |
| /* Fill in what we need of the proc_desc. */ |
| proc_desc = (struct mdebug_extra_func_info *) |
| obstack_alloc (&sec->objfile->objfile_obstack, |
| sizeof (struct mdebug_extra_func_info)); |
| PROC_LOW_ADDR (proc_desc) = pdr_pc; |
| |
| PROC_FRAME_OFFSET (proc_desc) |
| = bfd_get_signed_32 (sec->objfile->obfd, ptr + 20); |
| PROC_FRAME_REG (proc_desc) = bfd_get_32 (sec->objfile->obfd, |
| ptr + 24); |
| PROC_REG_MASK (proc_desc) = bfd_get_32 (sec->objfile->obfd, |
| ptr + 4); |
| PROC_FREG_MASK (proc_desc) = bfd_get_32 (sec->objfile->obfd, |
| ptr + 12); |
| PROC_REG_OFFSET (proc_desc) |
| = bfd_get_signed_32 (sec->objfile->obfd, ptr + 8); |
| PROC_FREG_OFFSET (proc_desc) |
| = bfd_get_signed_32 (sec->objfile->obfd, ptr + 16); |
| PROC_PC_REG (proc_desc) = bfd_get_32 (sec->objfile->obfd, |
| ptr + 28); |
| proc_desc->pdr.isym = (long) sym; |
| |
| return proc_desc; |
| } |
| } |
| } |
| |
| if (b == NULL) |
| return NULL; |
| |
| if (startaddr > BLOCK_START (b)) |
| { |
| /* This is the "pathological" case referred to in a comment in |
| print_frame_info. It might be better to move this check into |
| symbol reading. */ |
| return NULL; |
| } |
| |
| sym = lookup_symbol (MDEBUG_EFI_SYMBOL_NAME, b, LABEL_DOMAIN, 0, NULL); |
| |
| /* If we never found a PDR for this function in symbol reading, then |
| examine prologues to find the information. */ |
| if (sym) |
| { |
| proc_desc = (struct mdebug_extra_func_info *) SYMBOL_VALUE (sym); |
| if (PROC_FRAME_REG (proc_desc) == -1) |
| return NULL; |
| else |
| return proc_desc; |
| } |
| else |
| return NULL; |
| } |
| |
| struct mips_frame_cache |
| { |
| CORE_ADDR base; |
| struct trad_frame_saved_reg *saved_regs; |
| }; |
| |
| static struct mips_frame_cache * |
| mips_mdebug_frame_cache (struct frame_info *next_frame, void **this_cache) |
| { |
| CORE_ADDR startaddr = 0; |
| struct mdebug_extra_func_info *proc_desc; |
| struct mips_frame_cache *cache; |
| struct gdbarch *gdbarch = get_frame_arch (next_frame); |
| struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| /* r0 bit means kernel trap */ |
| int kernel_trap; |
| /* What registers have been saved? Bitmasks. */ |
| unsigned long gen_mask, float_mask; |
| |
| if ((*this_cache) != NULL) |
| return (*this_cache); |
| cache = FRAME_OBSTACK_ZALLOC (struct mips_frame_cache); |
| (*this_cache) = cache; |
| cache->saved_regs = trad_frame_alloc_saved_regs (next_frame); |
| |
| /* Get the mdebug proc descriptor. */ |
| proc_desc = non_heuristic_proc_desc (frame_pc_unwind (next_frame), |
| &startaddr); |
| /* Must be true. This is only called when the sniffer detected a |
| proc descriptor. */ |
| gdb_assert (proc_desc != NULL); |
| |
| /* Extract the frame's base. */ |
| cache->base = (frame_unwind_register_signed (next_frame, NUM_REGS + PROC_FRAME_REG (proc_desc)) |
| + PROC_FRAME_OFFSET (proc_desc)); |
| |
| kernel_trap = PROC_REG_MASK (proc_desc) & 1; |
| gen_mask = kernel_trap ? 0xFFFFFFFF : PROC_REG_MASK (proc_desc); |
| float_mask = kernel_trap ? 0xFFFFFFFF : PROC_FREG_MASK (proc_desc); |
| |
| /* Must be true. The in_prologue case is left for the heuristic |
| unwinder. This is always used on kernel traps. */ |
| gdb_assert (!in_prologue (frame_pc_unwind (next_frame), PROC_LOW_ADDR (proc_desc)) |
| || kernel_trap); |
| |
| /* Fill in the offsets for the registers which gen_mask says were |
| saved. */ |
| { |
| CORE_ADDR reg_position = (cache->base + PROC_REG_OFFSET (proc_desc)); |
| int ireg; |
| |
| for (ireg = MIPS_NUMREGS - 1; gen_mask; --ireg, gen_mask <<= 1) |
| if (gen_mask & 0x80000000) |
| { |
| cache->saved_regs[NUM_REGS + ireg].addr = reg_position; |
| reg_position -= mips_abi_regsize (gdbarch); |
| } |
| } |
| |
| /* Fill in the offsets for the registers which float_mask says were |
| saved. */ |
| { |
| CORE_ADDR reg_position = (cache->base |
| + PROC_FREG_OFFSET (proc_desc)); |
| int ireg; |
| /* Fill in the offsets for the float registers which float_mask |
| says were saved. */ |
| for (ireg = MIPS_NUMREGS - 1; float_mask; --ireg, float_mask <<= 1) |
| if (float_mask & 0x80000000) |
| { |
| if (mips_abi_regsize (gdbarch) == 4 |
| && TARGET_BYTE_ORDER == BFD_ENDIAN_BIG) |
| { |
| /* On a big endian 32 bit ABI, floating point registers |
| are paired to form doubles such that the most |
| significant part is in $f[N+1] and the least |
| significant in $f[N] vis: $f[N+1] ||| $f[N]. The |
| registers are also spilled as a pair and stored as a |
| double. |
| |
| When little-endian the least significant part is |
| stored first leading to the memory order $f[N] and |
| then $f[N+1]. |
| |
| Unfortunately, when big-endian the most significant |
| part of the double is stored first, and the least |
| significant is stored second. This leads to the |
| registers being ordered in memory as firt $f[N+1] and |
| then $f[N]. |
| |
| For the big-endian case make certain that the |
| addresses point at the correct (swapped) locations |
| $f[N] and $f[N+1] pair (keep in mind that |
| reg_position is decremented each time through the |
| loop). */ |
| if ((ireg & 1)) |
| cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->fp0 + ireg] |
| .addr = reg_position - mips_abi_regsize (gdbarch); |
| else |
| cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->fp0 + ireg] |
| .addr = reg_position + mips_abi_regsize (gdbarch); |
| } |
| else |
| cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->fp0 + ireg] |
| .addr = reg_position; |
| reg_position -= mips_abi_regsize (gdbarch); |
| } |
| |
| cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->pc] |
| = cache->saved_regs[NUM_REGS + MIPS_RA_REGNUM]; |
| } |
| |
| /* SP_REGNUM, contains the value and not the address. */ |
| trad_frame_set_value (cache->saved_regs, NUM_REGS + MIPS_SP_REGNUM, cache->base); |
| |
| return (*this_cache); |
| } |
| |
| static void |
| mips_mdebug_frame_this_id (struct frame_info *next_frame, void **this_cache, |
| struct frame_id *this_id) |
| { |
| struct mips_frame_cache *info = mips_mdebug_frame_cache (next_frame, |
| this_cache); |
| (*this_id) = frame_id_build (info->base, frame_func_unwind (next_frame)); |
| } |
| |
| static void |
| mips_mdebug_frame_prev_register (struct frame_info *next_frame, |
| void **this_cache, |
| int regnum, int *optimizedp, |
| enum lval_type *lvalp, CORE_ADDR *addrp, |
| int *realnump, void *valuep) |
| { |
| struct mips_frame_cache *info = mips_mdebug_frame_cache (next_frame, |
| this_cache); |
| trad_frame_get_prev_register (next_frame, info->saved_regs, regnum, |
| optimizedp, lvalp, addrp, realnump, valuep); |
| } |
| |
| static const struct frame_unwind mips_mdebug_frame_unwind = |
| { |
| NORMAL_FRAME, |
| mips_mdebug_frame_this_id, |
| mips_mdebug_frame_prev_register |
| }; |
| |
| static const struct frame_unwind * |
| mips_mdebug_frame_sniffer (struct frame_info *next_frame) |
| { |
| CORE_ADDR pc = frame_pc_unwind (next_frame); |
| CORE_ADDR startaddr = 0; |
| struct mdebug_extra_func_info *proc_desc; |
| int kernel_trap; |
| |
| /* Don't use this on MIPS16. */ |
| if (mips_pc_is_mips16 (pc)) |
| return NULL; |
| |
| /* Only use the mdebug frame unwinder on mdebug frames where all the |
| registers have been saved. Leave hard cases such as no mdebug or |
| in prologue for the heuristic unwinders. */ |
| |
| proc_desc = non_heuristic_proc_desc (pc, &startaddr); |
| if (proc_desc == NULL) |
| return NULL; |
| |
| /* Not sure exactly what kernel_trap means, but if it means the |
| kernel saves the registers without a prologue doing it, we better |
| not examine the prologue to see whether registers have been saved |
| yet. */ |
| kernel_trap = PROC_REG_MASK (proc_desc) & 1; |
| if (kernel_trap) |
| return &mips_mdebug_frame_unwind; |
| |
| /* In any frame other than the innermost or a frame interrupted by a |
| signal, we assume that all registers have been saved. This |
| assumes that all register saves in a function happen before the |
| first function call. */ |
| if (!in_prologue (pc, PROC_LOW_ADDR (proc_desc))) |
| return &mips_mdebug_frame_unwind; |
| |
| return NULL; |
| } |
| |
| static CORE_ADDR |
| mips_mdebug_frame_base_address (struct frame_info *next_frame, |
| void **this_cache) |
| { |
| struct mips_frame_cache *info = mips_mdebug_frame_cache (next_frame, |
| this_cache); |
| return info->base; |
| } |
| |
| static const struct frame_base mips_mdebug_frame_base = { |
| &mips_mdebug_frame_unwind, |
| mips_mdebug_frame_base_address, |
| mips_mdebug_frame_base_address, |
| mips_mdebug_frame_base_address |
| }; |
| |
| static const struct frame_base * |
| mips_mdebug_frame_base_sniffer (struct frame_info *next_frame) |
| { |
| if (mips_mdebug_frame_sniffer (next_frame) != NULL) |
| return &mips_mdebug_frame_base; |
| else |
| return NULL; |
| } |
| |
| void |
| mips_mdebug_append_sniffers (struct gdbarch *gdbarch) |
| { |
| frame_unwind_append_sniffer (gdbarch, mips_mdebug_frame_sniffer); |
| frame_base_append_sniffer (gdbarch, mips_mdebug_frame_base_sniffer); |
| } |
| |
| |
| extern void _initialize_mips_mdebug_tdep (void); |
| void |
| _initialize_mips_mdebug_tdep (void) |
| { |
| mips_pdr_data = register_objfile_data (); |
| } |