/* Target-dependent code for HP-UX on PA-RISC. Copyright (C) 2002, 2003, 2004, 2005, 2007 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 "arch-utils.h" #include "gdbcore.h" #include "osabi.h" #include "frame.h" #include "frame-unwind.h" #include "trad-frame.h" #include "symtab.h" #include "objfiles.h" #include "inferior.h" #include "infcall.h" #include "observer.h" #include "hppa-tdep.h" #include "solib-som.h" #include "solib-pa64.h" #include "regset.h" #include "regcache.h" #include "exceptions.h" #include "gdb_string.h" #define IS_32BIT_TARGET(_gdbarch) \ ((gdbarch_tdep (_gdbarch))->bytes_per_address == 4) /* Bit in the `ss_flag' member of `struct save_state' that indicates that the 64-bit register values are live. From . */ #define HPPA_HPUX_SS_WIDEREGS 0x40 /* Offsets of various parts of `struct save_state'. From . */ #define HPPA_HPUX_SS_FLAGS_OFFSET 0 #define HPPA_HPUX_SS_NARROW_OFFSET 4 #define HPPA_HPUX_SS_FPBLOCK_OFFSET 256 #define HPPA_HPUX_SS_WIDE_OFFSET 640 /* The size of `struct save_state. */ #define HPPA_HPUX_SAVE_STATE_SIZE 1152 /* The size of `struct pa89_save_state', which corresponds to PA-RISC 1.1, the lowest common denominator that we support. */ #define HPPA_HPUX_PA89_SAVE_STATE_SIZE 512 /* Forward declarations. */ extern void _initialize_hppa_hpux_tdep (void); extern initialize_file_ftype _initialize_hppa_hpux_tdep; static int in_opd_section (CORE_ADDR pc) { struct obj_section *s; int retval = 0; s = find_pc_section (pc); retval = (s != NULL && s->the_bfd_section->name != NULL && strcmp (s->the_bfd_section->name, ".opd") == 0); return (retval); } /* Return one if PC is in the call path of a trampoline, else return zero. Note we return one for *any* call trampoline (long-call, arg-reloc), not just shared library trampolines (import, export). */ static int hppa32_hpux_in_solib_call_trampoline (CORE_ADDR pc, char *name) { struct minimal_symbol *minsym; struct unwind_table_entry *u; /* First see if PC is in one of the two C-library trampolines. */ if (pc == hppa_symbol_address("$$dyncall") || pc == hppa_symbol_address("_sr4export")) return 1; minsym = lookup_minimal_symbol_by_pc (pc); if (minsym && strcmp (DEPRECATED_SYMBOL_NAME (minsym), ".stub") == 0) return 1; /* Get the unwind descriptor corresponding to PC, return zero if no unwind was found. */ u = find_unwind_entry (pc); if (!u) return 0; /* If this isn't a linker stub, then return now. */ if (u->stub_unwind.stub_type == 0) return 0; /* By definition a long-branch stub is a call stub. */ if (u->stub_unwind.stub_type == LONG_BRANCH) return 1; /* The call and return path execute the same instructions within an IMPORT stub! So an IMPORT stub is both a call and return trampoline. */ if (u->stub_unwind.stub_type == IMPORT) return 1; /* Parameter relocation stubs always have a call path and may have a return path. */ if (u->stub_unwind.stub_type == PARAMETER_RELOCATION || u->stub_unwind.stub_type == EXPORT) { CORE_ADDR addr; /* Search forward from the current PC until we hit a branch or the end of the stub. */ for (addr = pc; addr <= u->region_end; addr += 4) { unsigned long insn; insn = read_memory_integer (addr, 4); /* Does it look like a bl? If so then it's the call path, if we find a bv or be first, then we're on the return path. */ if ((insn & 0xfc00e000) == 0xe8000000) return 1; else if ((insn & 0xfc00e001) == 0xe800c000 || (insn & 0xfc000000) == 0xe0000000) return 0; } /* Should never happen. */ warning (_("Unable to find branch in parameter relocation stub.")); return 0; } /* Unknown stub type. For now, just return zero. */ return 0; } static int hppa64_hpux_in_solib_call_trampoline (CORE_ADDR pc, char *name) { /* PA64 has a completely different stub/trampoline scheme. Is it better? Maybe. It's certainly harder to determine with any certainty that we are in a stub because we can not refer to the unwinders to help. The heuristic is simple. Try to lookup the current PC value in th minimal symbol table. If that fails, then assume we are not in a stub and return. Then see if the PC value falls within the section bounds for the section containing the minimal symbol we found in the first step. If it does, then assume we are not in a stub and return. Finally peek at the instructions to see if they look like a stub. */ struct minimal_symbol *minsym; asection *sec; CORE_ADDR addr; int insn, i; minsym = lookup_minimal_symbol_by_pc (pc); if (! minsym) return 0; sec = SYMBOL_BFD_SECTION (minsym); if (bfd_get_section_vma (sec->owner, sec) <= pc && pc < (bfd_get_section_vma (sec->owner, sec) + bfd_section_size (sec->owner, sec))) return 0; /* We might be in a stub. Peek at the instructions. Stubs are 3 instructions long. */ insn = read_memory_integer (pc, 4); /* Find out where we think we are within the stub. */ if ((insn & 0xffffc00e) == 0x53610000) addr = pc; else if ((insn & 0xffffffff) == 0xe820d000) addr = pc - 4; else if ((insn & 0xffffc00e) == 0x537b0000) addr = pc - 8; else return 0; /* Now verify each insn in the range looks like a stub instruction. */ insn = read_memory_integer (addr, 4); if ((insn & 0xffffc00e) != 0x53610000) return 0; /* Now verify each insn in the range looks like a stub instruction. */ insn = read_memory_integer (addr + 4, 4); if ((insn & 0xffffffff) != 0xe820d000) return 0; /* Now verify each insn in the range looks like a stub instruction. */ insn = read_memory_integer (addr + 8, 4); if ((insn & 0xffffc00e) != 0x537b0000) return 0; /* Looks like a stub. */ return 1; } /* Return one if PC is in the return path of a trampoline, else return zero. Note we return one for *any* call trampoline (long-call, arg-reloc), not just shared library trampolines (import, export). */ static int hppa_hpux_in_solib_return_trampoline (CORE_ADDR pc, char *name) { struct unwind_table_entry *u; /* Get the unwind descriptor corresponding to PC, return zero if no unwind was found. */ u = find_unwind_entry (pc); if (!u) return 0; /* If this isn't a linker stub or it's just a long branch stub, then return zero. */ if (u->stub_unwind.stub_type == 0 || u->stub_unwind.stub_type == LONG_BRANCH) return 0; /* The call and return path execute the same instructions within an IMPORT stub! So an IMPORT stub is both a call and return trampoline. */ if (u->stub_unwind.stub_type == IMPORT) return 1; /* Parameter relocation stubs always have a call path and may have a return path. */ if (u->stub_unwind.stub_type == PARAMETER_RELOCATION || u->stub_unwind.stub_type == EXPORT) { CORE_ADDR addr; /* Search forward from the current PC until we hit a branch or the end of the stub. */ for (addr = pc; addr <= u->region_end; addr += 4) { unsigned long insn; insn = read_memory_integer (addr, 4); /* Does it look like a bl? If so then it's the call path, if we find a bv or be first, then we're on the return path. */ if ((insn & 0xfc00e000) == 0xe8000000) return 0; else if ((insn & 0xfc00e001) == 0xe800c000 || (insn & 0xfc000000) == 0xe0000000) return 1; } /* Should never happen. */ warning (_("Unable to find branch in parameter relocation stub.")); return 0; } /* Unknown stub type. For now, just return zero. */ return 0; } /* Figure out if PC is in a trampoline, and if so find out where the trampoline will jump to. If not in a trampoline, return zero. Simple code examination probably is not a good idea since the code sequences in trampolines can also appear in user code. We use unwinds and information from the minimal symbol table to determine when we're in a trampoline. This won't work for ELF (yet) since it doesn't create stub unwind entries. Whether or not ELF will create stub unwinds or normal unwinds for linker stubs is still being debated. This should handle simple calls through dyncall or sr4export, long calls, argument relocation stubs, and dyncall/sr4export calling an argument relocation stub. It even handles some stubs used in dynamic executables. */ static CORE_ADDR hppa_hpux_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc) { long orig_pc = pc; long prev_inst, curr_inst, loc; struct minimal_symbol *msym; struct unwind_table_entry *u; /* Addresses passed to dyncall may *NOT* be the actual address of the function. So we may have to do something special. */ if (pc == hppa_symbol_address("$$dyncall")) { pc = (CORE_ADDR) get_frame_register_unsigned (frame, 22); /* If bit 30 (counting from the left) is on, then pc is the address of the PLT entry for this function, not the address of the function itself. Bit 31 has meaning too, but only for MPE. */ if (pc & 0x2) pc = (CORE_ADDR) read_memory_integer (pc & ~0x3, gdbarch_ptr_bit (current_gdbarch) / 8); } if (pc == hppa_symbol_address("$$dyncall_external")) { pc = (CORE_ADDR) get_frame_register_unsigned (frame, 22); pc = (CORE_ADDR) read_memory_integer (pc & ~0x3, gdbarch_ptr_bit (current_gdbarch) / 8); } else if (pc == hppa_symbol_address("_sr4export")) pc = (CORE_ADDR) get_frame_register_unsigned (frame, 22); /* Get the unwind descriptor corresponding to PC, return zero if no unwind was found. */ u = find_unwind_entry (pc); if (!u) return 0; /* If this isn't a linker stub, then return now. */ /* elz: attention here! (FIXME) because of a compiler/linker error, some stubs which should have a non zero stub_unwind.stub_type have unfortunately a value of zero. So this function would return here as if we were not in a trampoline. To fix this, we go look at the partial symbol information, which reports this guy as a stub. (FIXME): Unfortunately, we are not that lucky: it turns out that the partial symbol information is also wrong sometimes. This is because when it is entered (somread.c::som_symtab_read()) it can happen that if the type of the symbol (from the som) is Entry, and the symbol is in a shared library, then it can also be a trampoline. This would be OK, except that I believe the way they decide if we are ina shared library does not work. SOOOO..., even if we have a regular function w/o trampolines its minimal symbol can be assigned type mst_solib_trampoline. Also, if we find that the symbol is a real stub, then we fix the unwind descriptor, and define the stub type to be EXPORT. Hopefully this is correct most of the times. */ if (u->stub_unwind.stub_type == 0) { /* elz: NOTE (FIXME!) once the problem with the unwind information is fixed we can delete all the code which appears between the lines */ /*--------------------------------------------------------------------------*/ msym = lookup_minimal_symbol_by_pc (pc); if (msym == NULL || MSYMBOL_TYPE (msym) != mst_solib_trampoline) return orig_pc == pc ? 0 : pc & ~0x3; else if (msym != NULL && MSYMBOL_TYPE (msym) == mst_solib_trampoline) { struct objfile *objfile; struct minimal_symbol *msymbol; int function_found = 0; /* go look if there is another minimal symbol with the same name as this one, but with type mst_text. This would happen if the msym is an actual trampoline, in which case there would be another symbol with the same name corresponding to the real function */ ALL_MSYMBOLS (objfile, msymbol) { if (MSYMBOL_TYPE (msymbol) == mst_text && DEPRECATED_STREQ (DEPRECATED_SYMBOL_NAME (msymbol), DEPRECATED_SYMBOL_NAME (msym))) { function_found = 1; break; } } if (function_found) /* the type of msym is correct (mst_solib_trampoline), but the unwind info is wrong, so set it to the correct value */ u->stub_unwind.stub_type = EXPORT; else /* the stub type info in the unwind is correct (this is not a trampoline), but the msym type information is wrong, it should be mst_text. So we need to fix the msym, and also get out of this function */ { MSYMBOL_TYPE (msym) = mst_text; return orig_pc == pc ? 0 : pc & ~0x3; } } /*--------------------------------------------------------------------------*/ } /* It's a stub. Search for a branch and figure out where it goes. Note we have to handle multi insn branch sequences like ldil;ble. Most (all?) other branches can be determined by examining the contents of certain registers and the stack. */ loc = pc; curr_inst = 0; prev_inst = 0; while (1) { /* Make sure we haven't walked outside the range of this stub. */ if (u != find_unwind_entry (loc)) { warning (_("Unable to find branch in linker stub")); return orig_pc == pc ? 0 : pc & ~0x3; } prev_inst = curr_inst; curr_inst = read_memory_integer (loc, 4); /* Does it look like a branch external using %r1? Then it's the branch from the stub to the actual function. */ if ((curr_inst & 0xffe0e000) == 0xe0202000) { /* Yup. See if the previous instruction loaded a value into %r1. If so compute and return the jump address. */ if ((prev_inst & 0xffe00000) == 0x20200000) return (hppa_extract_21 (prev_inst) + hppa_extract_17 (curr_inst)) & ~0x3; else { warning (_("Unable to find ldil X,%%r1 before ble Y(%%sr4,%%r1).")); return orig_pc == pc ? 0 : pc & ~0x3; } } /* Does it look like a be 0(sr0,%r21)? OR Does it look like a be, n 0(sr0,%r21)? OR Does it look like a bve (r21)? (this is on PA2.0) Does it look like a bve, n(r21)? (this is also on PA2.0) That's the branch from an import stub to an export stub. It is impossible to determine the target of the branch via simple examination of instructions and/or data (consider that the address in the plabel may be the address of the bind-on-reference routine in the dynamic loader). So we have try an alternative approach. Get the name of the symbol at our current location; it should be a stub symbol with the same name as the symbol in the shared library. Then lookup a minimal symbol with the same name; we should get the minimal symbol for the target routine in the shared library as those take precedence of import/export stubs. */ if ((curr_inst == 0xe2a00000) || (curr_inst == 0xe2a00002) || (curr_inst == 0xeaa0d000) || (curr_inst == 0xeaa0d002)) { struct minimal_symbol *stubsym, *libsym; stubsym = lookup_minimal_symbol_by_pc (loc); if (stubsym == NULL) { warning (_("Unable to find symbol for 0x%lx"), loc); return orig_pc == pc ? 0 : pc & ~0x3; } libsym = lookup_minimal_symbol (DEPRECATED_SYMBOL_NAME (stubsym), NULL, NULL); if (libsym == NULL) { warning (_("Unable to find library symbol for %s."), DEPRECATED_SYMBOL_NAME (stubsym)); return orig_pc == pc ? 0 : pc & ~0x3; } return SYMBOL_VALUE (libsym); } /* Does it look like bl X,%rp or bl X,%r0? Another way to do a branch from the stub to the actual function. */ /*elz */ else if ((curr_inst & 0xffe0e000) == 0xe8400000 || (curr_inst & 0xffe0e000) == 0xe8000000 || (curr_inst & 0xffe0e000) == 0xe800A000) return (loc + hppa_extract_17 (curr_inst) + 8) & ~0x3; /* Does it look like bv (rp)? Note this depends on the current stack pointer being the same as the stack pointer in the stub itself! This is a branch on from the stub back to the original caller. */ /*else if ((curr_inst & 0xffe0e000) == 0xe840c000) */ else if ((curr_inst & 0xffe0f000) == 0xe840c000) { /* Yup. See if the previous instruction loaded rp from sp - 8. */ if (prev_inst == 0x4bc23ff1) { CORE_ADDR sp; sp = get_frame_register_unsigned (frame, HPPA_SP_REGNUM); return read_memory_integer (sp - 8, 4) & ~0x3; } else { warning (_("Unable to find restore of %%rp before bv (%%rp).")); return orig_pc == pc ? 0 : pc & ~0x3; } } /* elz: added this case to capture the new instruction at the end of the return part of an export stub used by the PA2.0: BVE, n (rp) */ else if ((curr_inst & 0xffe0f000) == 0xe840d000) { return (read_memory_integer (get_frame_register_unsigned (frame, HPPA_SP_REGNUM) - 24, gdbarch_ptr_bit (current_gdbarch) / 8)) & ~0x3; } /* What about be,n 0(sr0,%rp)? It's just another way we return to the original caller from the stub. Used in dynamic executables. */ else if (curr_inst == 0xe0400002) { /* The value we jump to is sitting in sp - 24. But that's loaded several instructions before the be instruction. I guess we could check for the previous instruction being mtsp %r1,%sr0 if we want to do sanity checking. */ return (read_memory_integer (get_frame_register_unsigned (frame, HPPA_SP_REGNUM) - 24, gdbarch_ptr_bit (current_gdbarch) / 8)) & ~0x3; } /* Haven't found the branch yet, but we're still in the stub. Keep looking. */ loc += 4; } } static void hppa_skip_permanent_breakpoint (struct regcache *regcache) { /* To step over a breakpoint instruction on the PA takes some fiddling with the instruction address queue. When we stop at a breakpoint, the IA queue front (the instruction we're executing now) points at the breakpoint instruction, and the IA queue back (the next instruction to execute) points to whatever instruction we would execute after the breakpoint, if it were an ordinary instruction. This is the case even if the breakpoint is in the delay slot of a branch instruction. Clearly, to step past the breakpoint, we need to set the queue front to the back. But what do we put in the back? What instruction comes after that one? Because of the branch delay slot, the next insn is always at the back + 4. */ ULONGEST pcoq_tail, pcsq_tail; regcache_cooked_read_unsigned (regcache, HPPA_PCOQ_TAIL_REGNUM, &pcoq_tail); regcache_cooked_read_unsigned (regcache, HPPA_PCSQ_TAIL_REGNUM, &pcsq_tail); regcache_cooked_write_unsigned (regcache, HPPA_PCOQ_HEAD_REGNUM, pcoq_tail); regcache_cooked_write_unsigned (regcache, HPPA_PCSQ_HEAD_REGNUM, pcsq_tail); regcache_cooked_write_unsigned (regcache, HPPA_PCOQ_TAIL_REGNUM, pcoq_tail + 4); /* We can leave the tail's space the same, since there's no jump. */ } /* Signal frames. */ struct hppa_hpux_sigtramp_unwind_cache { CORE_ADDR base; struct trad_frame_saved_reg *saved_regs; }; static int hppa_hpux_tramp_reg[] = { HPPA_SAR_REGNUM, HPPA_PCOQ_HEAD_REGNUM, HPPA_PCSQ_HEAD_REGNUM, HPPA_PCOQ_TAIL_REGNUM, HPPA_PCSQ_TAIL_REGNUM, HPPA_EIEM_REGNUM, HPPA_IIR_REGNUM, HPPA_ISR_REGNUM, HPPA_IOR_REGNUM, HPPA_IPSW_REGNUM, -1, HPPA_SR4_REGNUM, HPPA_SR4_REGNUM + 1, HPPA_SR4_REGNUM + 2, HPPA_SR4_REGNUM + 3, HPPA_SR4_REGNUM + 4, HPPA_SR4_REGNUM + 5, HPPA_SR4_REGNUM + 6, HPPA_SR4_REGNUM + 7, HPPA_RCR_REGNUM, HPPA_PID0_REGNUM, HPPA_PID1_REGNUM, HPPA_CCR_REGNUM, HPPA_PID2_REGNUM, HPPA_PID3_REGNUM, HPPA_TR0_REGNUM, HPPA_TR0_REGNUM + 1, HPPA_TR0_REGNUM + 2, HPPA_CR27_REGNUM }; static struct hppa_hpux_sigtramp_unwind_cache * hppa_hpux_sigtramp_frame_unwind_cache (struct frame_info *next_frame, void **this_cache) { struct gdbarch *gdbarch = get_frame_arch (next_frame); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); struct hppa_hpux_sigtramp_unwind_cache *info; unsigned int flag; CORE_ADDR sp, scptr, off; int i, incr, szoff; if (*this_cache) return *this_cache; info = FRAME_OBSTACK_ZALLOC (struct hppa_hpux_sigtramp_unwind_cache); *this_cache = info; info->saved_regs = trad_frame_alloc_saved_regs (next_frame); sp = frame_unwind_register_unsigned (next_frame, HPPA_SP_REGNUM); if (IS_32BIT_TARGET (gdbarch)) scptr = sp - 1352; else scptr = sp - 1520; off = scptr; /* See /usr/include/machine/save_state.h for the structure of the save_state_t structure. */ flag = read_memory_unsigned_integer(scptr + HPPA_HPUX_SS_FLAGS_OFFSET, 4); if (!(flag & HPPA_HPUX_SS_WIDEREGS)) { /* Narrow registers. */ off = scptr + HPPA_HPUX_SS_NARROW_OFFSET; incr = 4; szoff = 0; } else { /* Wide registers. */ off = scptr + HPPA_HPUX_SS_WIDE_OFFSET + 8; incr = 8; szoff = (tdep->bytes_per_address == 4 ? 4 : 0); } for (i = 1; i < 32; i++) { info->saved_regs[HPPA_R0_REGNUM + i].addr = off + szoff; off += incr; } for (i = 0; i < ARRAY_SIZE (hppa_hpux_tramp_reg); i++) { if (hppa_hpux_tramp_reg[i] > 0) info->saved_regs[hppa_hpux_tramp_reg[i]].addr = off + szoff; off += incr; } /* TODO: fp regs */ info->base = frame_unwind_register_unsigned (next_frame, HPPA_SP_REGNUM); return info; } static void hppa_hpux_sigtramp_frame_this_id (struct frame_info *next_frame, void **this_prologue_cache, struct frame_id *this_id) { struct hppa_hpux_sigtramp_unwind_cache *info = hppa_hpux_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache); *this_id = frame_id_build (info->base, frame_pc_unwind (next_frame)); } static void hppa_hpux_sigtramp_frame_prev_register (struct frame_info *next_frame, void **this_prologue_cache, int regnum, int *optimizedp, enum lval_type *lvalp, CORE_ADDR *addrp, int *realnump, gdb_byte *valuep) { struct hppa_hpux_sigtramp_unwind_cache *info = hppa_hpux_sigtramp_frame_unwind_cache (next_frame, this_prologue_cache); hppa_frame_prev_register_helper (next_frame, info->saved_regs, regnum, optimizedp, lvalp, addrp, realnump, valuep); } static const struct frame_unwind hppa_hpux_sigtramp_frame_unwind = { SIGTRAMP_FRAME, hppa_hpux_sigtramp_frame_this_id, hppa_hpux_sigtramp_frame_prev_register }; static const struct frame_unwind * hppa_hpux_sigtramp_unwind_sniffer (struct frame_info *next_frame) { struct unwind_table_entry *u; CORE_ADDR pc = frame_pc_unwind (next_frame); u = find_unwind_entry (pc); /* If this is an export stub, try to get the unwind descriptor for the actual function itself. */ if (u && u->stub_unwind.stub_type == EXPORT) { gdb_byte buf[HPPA_INSN_SIZE]; unsigned long insn; if (!safe_frame_unwind_memory (next_frame, u->region_start, buf, sizeof buf)) return NULL; insn = extract_unsigned_integer (buf, sizeof buf); if ((insn & 0xffe0e000) == 0xe8400000) u = find_unwind_entry(u->region_start + hppa_extract_17 (insn) + 8); } if (u && u->HP_UX_interrupt_marker) return &hppa_hpux_sigtramp_frame_unwind; return NULL; } static CORE_ADDR hppa32_hpux_find_global_pointer (struct value *function) { CORE_ADDR faddr; faddr = value_as_address (function); /* Is this a plabel? If so, dereference it to get the gp value. */ if (faddr & 2) { int status; char buf[4]; faddr &= ~3; status = target_read_memory (faddr + 4, buf, sizeof (buf)); if (status == 0) return extract_unsigned_integer (buf, sizeof (buf)); } return gdbarch_tdep (current_gdbarch)->solib_get_got_by_pc (faddr); } static CORE_ADDR hppa64_hpux_find_global_pointer (struct value *function) { CORE_ADDR faddr; char buf[32]; faddr = value_as_address (function); if (in_opd_section (faddr)) { target_read_memory (faddr, buf, sizeof (buf)); return extract_unsigned_integer (&buf[24], 8); } else { return gdbarch_tdep (current_gdbarch)->solib_get_got_by_pc (faddr); } } static unsigned int ldsid_pattern[] = { 0x000010a0, /* ldsid (rX),rY */ 0x00001820, /* mtsp rY,sr0 */ 0xe0000000 /* be,n (sr0,rX) */ }; static CORE_ADDR hppa_hpux_search_pattern (CORE_ADDR start, CORE_ADDR end, unsigned int *patterns, int count) { int num_insns = (end - start + HPPA_INSN_SIZE) / HPPA_INSN_SIZE; unsigned int *insns; gdb_byte *buf; int offset, i; buf = alloca (num_insns * HPPA_INSN_SIZE); insns = alloca (num_insns * sizeof (unsigned int)); read_memory (start, buf, num_insns * HPPA_INSN_SIZE); for (i = 0; i < num_insns; i++, buf += HPPA_INSN_SIZE) insns[i] = extract_unsigned_integer (buf, HPPA_INSN_SIZE); for (offset = 0; offset <= num_insns - count; offset++) { for (i = 0; i < count; i++) { if ((insns[offset + i] & patterns[i]) != patterns[i]) break; } if (i == count) break; } if (offset <= num_insns - count) return start + offset * HPPA_INSN_SIZE; else return 0; } static CORE_ADDR hppa32_hpux_search_dummy_call_sequence (struct gdbarch *gdbarch, CORE_ADDR pc, int *argreg) { struct objfile *obj; struct obj_section *sec; struct hppa_objfile_private *priv; struct frame_info *frame; struct unwind_table_entry *u; CORE_ADDR addr, rp; char buf[4]; unsigned int insn; sec = find_pc_section (pc); obj = sec->objfile; priv = objfile_data (obj, hppa_objfile_priv_data); if (!priv) priv = hppa_init_objfile_priv_data (obj); if (!priv) error (_("Internal error creating objfile private data.")); /* Use the cached value if we have one. */ if (priv->dummy_call_sequence_addr != 0) { *argreg = priv->dummy_call_sequence_reg; return priv->dummy_call_sequence_addr; } /* First try a heuristic; if we are in a shared library call, our return pointer is likely to point at an export stub. */ frame = get_current_frame (); rp = frame_unwind_register_unsigned (frame, 2); u = find_unwind_entry (rp); if (u && u->stub_unwind.stub_type == EXPORT) { addr = hppa_hpux_search_pattern (u->region_start, u->region_end, ldsid_pattern, ARRAY_SIZE (ldsid_pattern)); if (addr) goto found_pattern; } /* Next thing to try is to look for an export stub. */ if (priv->unwind_info) { int i; for (i = 0; i < priv->unwind_info->last; i++) { struct unwind_table_entry *u; u = &priv->unwind_info->table[i]; if (u->stub_unwind.stub_type == EXPORT) { addr = hppa_hpux_search_pattern (u->region_start, u->region_end, ldsid_pattern, ARRAY_SIZE (ldsid_pattern)); if (addr) { goto found_pattern; } } } } /* Finally, if this is the main executable, try to locate a sequence from noshlibs */ addr = hppa_symbol_address ("noshlibs"); sec = find_pc_section (addr); if (sec && sec->objfile == obj) { CORE_ADDR start, end; find_pc_partial_function (addr, NULL, &start, &end); if (start != 0 && end != 0) { addr = hppa_hpux_search_pattern (start, end, ldsid_pattern, ARRAY_SIZE (ldsid_pattern)); if (addr) goto found_pattern; } } /* Can't find a suitable sequence. */ return 0; found_pattern: target_read_memory (addr, buf, sizeof (buf)); insn = extract_unsigned_integer (buf, sizeof (buf)); priv->dummy_call_sequence_addr = addr; priv->dummy_call_sequence_reg = (insn >> 21) & 0x1f; *argreg = priv->dummy_call_sequence_reg; return priv->dummy_call_sequence_addr; } static CORE_ADDR hppa64_hpux_search_dummy_call_sequence (struct gdbarch *gdbarch, CORE_ADDR pc, int *argreg) { struct objfile *obj; struct obj_section *sec; struct hppa_objfile_private *priv; CORE_ADDR addr; struct minimal_symbol *msym; int i; sec = find_pc_section (pc); obj = sec->objfile; priv = objfile_data (obj, hppa_objfile_priv_data); if (!priv) priv = hppa_init_objfile_priv_data (obj); if (!priv) error (_("Internal error creating objfile private data.")); /* Use the cached value if we have one. */ if (priv->dummy_call_sequence_addr != 0) { *argreg = priv->dummy_call_sequence_reg; return priv->dummy_call_sequence_addr; } /* FIXME: Without stub unwind information, locating a suitable sequence is fairly difficult. For now, we implement a very naive and inefficient scheme; try to read in blocks of code, and look for a "bve,n (rp)" instruction. These are likely to occur at the end of functions, so we only look at the last two instructions of each function. */ for (i = 0, msym = obj->msymbols; i < obj->minimal_symbol_count; i++, msym++) { CORE_ADDR begin, end; char *name; gdb_byte buf[2 * HPPA_INSN_SIZE]; int offset; find_pc_partial_function (SYMBOL_VALUE_ADDRESS (msym), &name, &begin, &end); if (name == NULL || begin == 0 || end == 0) continue; if (target_read_memory (end - sizeof (buf), buf, sizeof (buf)) == 0) { for (offset = 0; offset < sizeof (buf); offset++) { unsigned int insn; insn = extract_unsigned_integer (buf + offset, HPPA_INSN_SIZE); if (insn == 0xe840d002) /* bve,n (rp) */ { addr = (end - sizeof (buf)) + offset; goto found_pattern; } } } } /* Can't find a suitable sequence. */ return 0; found_pattern: priv->dummy_call_sequence_addr = addr; /* Right now we only look for a "bve,l (rp)" sequence, so the register is always HPPA_RP_REGNUM. */ priv->dummy_call_sequence_reg = HPPA_RP_REGNUM; *argreg = priv->dummy_call_sequence_reg; return priv->dummy_call_sequence_addr; } static CORE_ADDR hppa_hpux_find_import_stub_for_addr (CORE_ADDR funcaddr) { struct objfile *objfile; struct minimal_symbol *funsym, *stubsym; CORE_ADDR stubaddr; funsym = lookup_minimal_symbol_by_pc (funcaddr); stubaddr = 0; ALL_OBJFILES (objfile) { stubsym = lookup_minimal_symbol_solib_trampoline (SYMBOL_LINKAGE_NAME (funsym), objfile); if (stubsym) { struct unwind_table_entry *u; u = find_unwind_entry (SYMBOL_VALUE (stubsym)); if (u == NULL || (u->stub_unwind.stub_type != IMPORT && u->stub_unwind.stub_type != IMPORT_SHLIB)) continue; stubaddr = SYMBOL_VALUE (stubsym); /* If we found an IMPORT stub, then we can stop searching; if we found an IMPORT_SHLIB, we want to continue the search in the hopes that we will find an IMPORT stub. */ if (u->stub_unwind.stub_type == IMPORT) break; } } return stubaddr; } static int hppa_hpux_sr_for_addr (CORE_ADDR addr) { int sr; /* The space register to use is encoded in the top 2 bits of the address. */ sr = addr >> (gdbarch_tdep (current_gdbarch)->bytes_per_address * 8 - 2); return sr + 4; } static CORE_ADDR hppa_hpux_find_dummy_bpaddr (CORE_ADDR addr) { /* In order for us to restore the space register to its starting state, we need the dummy trampoline to return to the an instruction address in the same space as where we started the call. We used to place the breakpoint near the current pc, however, this breaks nested dummy calls as the nested call will hit the breakpoint address and terminate prematurely. Instead, we try to look for an address in the same space to put the breakpoint. This is similar in spirit to putting the breakpoint at the "entry point" of an executable. */ struct obj_section *sec; struct unwind_table_entry *u; struct minimal_symbol *msym; CORE_ADDR func; int i; sec = find_pc_section (addr); if (sec) { /* First try the lowest address in the section; we can use it as long as it is "regular" code (i.e. not a stub) */ u = find_unwind_entry (sec->addr); if (!u || u->stub_unwind.stub_type == 0) return sec->addr; /* Otherwise, we need to find a symbol for a regular function. We do this by walking the list of msymbols in the objfile. The symbol we find should not be the same as the function that was passed in. */ /* FIXME: this is broken, because we can find a function that will be called by the dummy call target function, which will still not work. */ find_pc_partial_function (addr, NULL, &func, NULL); for (i = 0, msym = sec->objfile->msymbols; i < sec->objfile->minimal_symbol_count; i++, msym++) { u = find_unwind_entry (SYMBOL_VALUE_ADDRESS (msym)); if (func != SYMBOL_VALUE_ADDRESS (msym) && (!u || u->stub_unwind.stub_type == 0)) return SYMBOL_VALUE_ADDRESS (msym); } } warning (_("Cannot find suitable address to place dummy breakpoint; nested " "calls may fail.")); return addr - 4; } static CORE_ADDR hppa_hpux_push_dummy_code (struct gdbarch *gdbarch, CORE_ADDR sp, CORE_ADDR funcaddr, int using_gcc, struct value **args, int nargs, struct type *value_type, CORE_ADDR *real_pc, CORE_ADDR *bp_addr, struct regcache *regcache) { CORE_ADDR pc, stubaddr; int argreg = 0; pc = read_pc (); /* Note: we don't want to pass a function descriptor here; push_dummy_call fills in the PIC register for us. */ funcaddr = gdbarch_convert_from_func_ptr_addr (gdbarch, funcaddr, NULL); /* The simple case is where we call a function in the same space that we are currently in; in that case we don't really need to do anything. */ if (hppa_hpux_sr_for_addr (pc) == hppa_hpux_sr_for_addr (funcaddr)) { /* Intraspace call. */ *bp_addr = hppa_hpux_find_dummy_bpaddr (pc); *real_pc = funcaddr; regcache_cooked_write_unsigned (regcache, HPPA_RP_REGNUM, *bp_addr); return sp; } /* In order to make an interspace call, we need to go through a stub. gcc supplies an appropriate stub called "__gcc_plt_call", however, if an application is compiled with HP compilers then this stub is not available. We used to fallback to "__d_plt_call", however that stub is not entirely useful for us because it doesn't do an interspace return back to the caller. Also, on hppa64-hpux, there is no __gcc_plt_call available. In order to keep the code uniform, we instead don't use either of these stubs, but instead write our own onto the stack. A problem arises since the stack is located in a different space than code, so in order to branch to a stack stub, we will need to do an interspace branch. Previous versions of gdb did this by modifying code at the current pc and doing single-stepping to set the pcsq. Since this is highly undesirable, we use a different scheme: All we really need to do the branch to the stub is a short instruction sequence like this: PA1.1: ldsid (rX),r1 mtsp r1,sr0 be,n (sr0,rX) PA2.0: bve,n (sr0,rX) Instead of writing these sequences ourselves, we can find it in the instruction stream that belongs to the current space. While this seems difficult at first, we are actually guaranteed to find the sequences in several places: For 32-bit code: - in export stubs for shared libraries - in the "noshlibs" routine in the main module For 64-bit code: - at the end of each "regular" function We cache the address of these sequences in the objfile's private data since these operations can potentially be quite expensive. So, what we do is: - write a stack trampoline - look for a suitable instruction sequence in the current space - point the sequence at the trampoline - set the return address of the trampoline to the current space (see hppa_hpux_find_dummy_call_bpaddr) - set the continuing address of the "dummy code" as the sequence. */ if (IS_32BIT_TARGET (gdbarch)) { static unsigned int hppa32_tramp[] = { 0x0fdf1291, /* stw r31,-8(,sp) */ 0x02c010a1, /* ldsid (,r22),r1 */ 0x00011820, /* mtsp r1,sr0 */ 0xe6c00000, /* be,l 0(sr0,r22),%sr0,%r31 */ 0x081f0242, /* copy r31,rp */ 0x0fd11082, /* ldw -8(,sp),rp */ 0x004010a1, /* ldsid (,rp),r1 */ 0x00011820, /* mtsp r1,sr0 */ 0xe0400000, /* be 0(sr0,rp) */ 0x08000240 /* nop */ }; /* for hppa32, we must call the function through a stub so that on return it can return to the space of our trampoline. */ stubaddr = hppa_hpux_find_import_stub_for_addr (funcaddr); if (stubaddr == 0) error (_("Cannot call external function not referenced by application " "(no import stub).\n")); regcache_cooked_write_unsigned (regcache, 22, stubaddr); write_memory (sp, (char *)&hppa32_tramp, sizeof (hppa32_tramp)); *bp_addr = hppa_hpux_find_dummy_bpaddr (pc); regcache_cooked_write_unsigned (regcache, 31, *bp_addr); *real_pc = hppa32_hpux_search_dummy_call_sequence (gdbarch, pc, &argreg); if (*real_pc == 0) error (_("Cannot make interspace call from here.")); regcache_cooked_write_unsigned (regcache, argreg, sp); sp += sizeof (hppa32_tramp); } else { static unsigned int hppa64_tramp[] = { 0xeac0f000, /* bve,l (r22),%r2 */ 0x0fdf12d1, /* std r31,-8(,sp) */ 0x0fd110c2, /* ldd -8(,sp),rp */ 0xe840d002, /* bve,n (rp) */ 0x08000240 /* nop */ }; /* for hppa64, we don't need to call through a stub; all functions return via a bve. */ regcache_cooked_write_unsigned (regcache, 22, funcaddr); write_memory (sp, (char *)&hppa64_tramp, sizeof (hppa64_tramp)); *bp_addr = pc - 4; regcache_cooked_write_unsigned (regcache, 31, *bp_addr); *real_pc = hppa64_hpux_search_dummy_call_sequence (gdbarch, pc, &argreg); if (*real_pc == 0) error (_("Cannot make interspace call from here.")); regcache_cooked_write_unsigned (regcache, argreg, sp); sp += sizeof (hppa64_tramp); } sp = gdbarch_frame_align (gdbarch, sp); return sp; } static void hppa_hpux_supply_ss_narrow (struct regcache *regcache, int regnum, const char *save_state) { const char *ss_narrow = save_state + HPPA_HPUX_SS_NARROW_OFFSET; int i, offset = 0; for (i = HPPA_R1_REGNUM; i < HPPA_FP0_REGNUM; i++) { if (regnum == i || regnum == -1) regcache_raw_supply (regcache, i, ss_narrow + offset); offset += 4; } } static void hppa_hpux_supply_ss_fpblock (struct regcache *regcache, int regnum, const char *save_state) { const char *ss_fpblock = save_state + HPPA_HPUX_SS_FPBLOCK_OFFSET; int i, offset = 0; /* FIXME: We view the floating-point state as 64 single-precision registers for 32-bit code, and 32 double-precision register for 64-bit code. This distinction is artificial and should be eliminated. If that ever happens, we should remove the if-clause below. */ if (register_size (get_regcache_arch (regcache), HPPA_FP0_REGNUM) == 4) { for (i = HPPA_FP0_REGNUM; i < HPPA_FP0_REGNUM + 64; i++) { if (regnum == i || regnum == -1) regcache_raw_supply (regcache, i, ss_fpblock + offset); offset += 4; } } else { for (i = HPPA_FP0_REGNUM; i < HPPA_FP0_REGNUM + 32; i++) { if (regnum == i || regnum == -1) regcache_raw_supply (regcache, i, ss_fpblock + offset); offset += 8; } } } static void hppa_hpux_supply_ss_wide (struct regcache *regcache, int regnum, const char *save_state) { const char *ss_wide = save_state + HPPA_HPUX_SS_WIDE_OFFSET; int i, offset = 8; if (register_size (get_regcache_arch (regcache), HPPA_R1_REGNUM) == 4) offset += 4; for (i = HPPA_R1_REGNUM; i < HPPA_FP0_REGNUM; i++) { if (regnum == i || regnum == -1) regcache_raw_supply (regcache, i, ss_wide + offset); offset += 8; } } static void hppa_hpux_supply_save_state (const struct regset *regset, struct regcache *regcache, int regnum, const void *regs, size_t len) { const char *proc_info = regs; const char *save_state = proc_info + 8; ULONGEST flags; flags = extract_unsigned_integer (save_state + HPPA_HPUX_SS_FLAGS_OFFSET, 4); if (regnum == -1 || regnum == HPPA_FLAGS_REGNUM) { struct gdbarch *arch = get_regcache_arch (regcache); size_t size = register_size (arch, HPPA_FLAGS_REGNUM); char buf[8]; store_unsigned_integer (buf, size, flags); regcache_raw_supply (regcache, HPPA_FLAGS_REGNUM, buf); } /* If the SS_WIDEREGS flag is set, we really do need the full `struct save_state'. */ if (flags & HPPA_HPUX_SS_WIDEREGS && len < HPPA_HPUX_SAVE_STATE_SIZE) error (_("Register set contents too small")); if (flags & HPPA_HPUX_SS_WIDEREGS) hppa_hpux_supply_ss_wide (regcache, regnum, save_state); else hppa_hpux_supply_ss_narrow (regcache, regnum, save_state); hppa_hpux_supply_ss_fpblock (regcache, regnum, save_state); } /* HP-UX register set. */ static struct regset hppa_hpux_regset = { NULL, hppa_hpux_supply_save_state }; static const struct regset * hppa_hpux_regset_from_core_section (struct gdbarch *gdbarch, const char *sect_name, size_t sect_size) { if (strcmp (sect_name, ".reg") == 0 && sect_size >= HPPA_HPUX_PA89_SAVE_STATE_SIZE + 8) return &hppa_hpux_regset; return NULL; } /* Bit in the `ss_flag' member of `struct save_state' that indicates the state was saved from a system call. From . */ #define HPPA_HPUX_SS_INSYSCALL 0x02 static CORE_ADDR hppa_hpux_read_pc (ptid_t ptid) { ULONGEST flags; /* If we're currently in a system call return the contents of %r31. */ flags = read_register_pid (HPPA_FLAGS_REGNUM, ptid); if (flags & HPPA_HPUX_SS_INSYSCALL) return read_register_pid (HPPA_R31_REGNUM, ptid) & ~0x3; return hppa_read_pc (ptid); } static void hppa_hpux_write_pc (CORE_ADDR pc, ptid_t ptid) { ULONGEST flags; /* If we're currently in a system call also write PC into %r31. */ flags = read_register_pid (HPPA_FLAGS_REGNUM, ptid); if (flags & HPPA_HPUX_SS_INSYSCALL) write_register_pid (HPPA_R31_REGNUM, pc | 0x3, ptid); return hppa_write_pc (pc, ptid); } static CORE_ADDR hppa_hpux_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame) { ULONGEST flags; /* If we're currently in a system call return the contents of %r31. */ flags = frame_unwind_register_unsigned (next_frame, HPPA_FLAGS_REGNUM); if (flags & HPPA_HPUX_SS_INSYSCALL) return frame_unwind_register_unsigned (next_frame, HPPA_R31_REGNUM) & ~0x3; return hppa_unwind_pc (gdbarch, next_frame); } /* Given the current value of the pc, check to see if it is inside a stub, and if so, change the value of the pc to point to the caller of the stub. NEXT_FRAME is the next frame in the current list of frames. BASE contains to stack frame base of the current frame. SAVE_REGS is the register file stored in the frame cache. */ static void hppa_hpux_unwind_adjust_stub (struct frame_info *next_frame, CORE_ADDR base, struct trad_frame_saved_reg *saved_regs) { int optimized, realreg; enum lval_type lval; CORE_ADDR addr; char buffer[sizeof(ULONGEST)]; ULONGEST val; CORE_ADDR stubpc; struct unwind_table_entry *u; trad_frame_get_prev_register (next_frame, saved_regs, HPPA_PCOQ_HEAD_REGNUM, &optimized, &lval, &addr, &realreg, buffer); val = extract_unsigned_integer (buffer, register_size (get_frame_arch (next_frame), HPPA_PCOQ_HEAD_REGNUM)); u = find_unwind_entry (val); if (u && u->stub_unwind.stub_type == EXPORT) { stubpc = read_memory_integer (base - 24, gdbarch_ptr_bit (current_gdbarch) / 8); trad_frame_set_value (saved_regs, HPPA_PCOQ_HEAD_REGNUM, stubpc); } else if (hppa_symbol_address ("__gcc_plt_call") == get_pc_function_start (val)) { stubpc = read_memory_integer (base - 8, gdbarch_ptr_bit (current_gdbarch) / 8); trad_frame_set_value (saved_regs, HPPA_PCOQ_HEAD_REGNUM, stubpc); } } static void hppa_hpux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (IS_32BIT_TARGET (gdbarch)) tdep->in_solib_call_trampoline = hppa32_hpux_in_solib_call_trampoline; else tdep->in_solib_call_trampoline = hppa64_hpux_in_solib_call_trampoline; tdep->unwind_adjust_stub = hppa_hpux_unwind_adjust_stub; set_gdbarch_in_solib_return_trampoline (gdbarch, hppa_hpux_in_solib_return_trampoline); set_gdbarch_skip_trampoline_code (gdbarch, hppa_hpux_skip_trampoline_code); set_gdbarch_push_dummy_code (gdbarch, hppa_hpux_push_dummy_code); set_gdbarch_call_dummy_location (gdbarch, ON_STACK); set_gdbarch_read_pc (gdbarch, hppa_hpux_read_pc); set_gdbarch_write_pc (gdbarch, hppa_hpux_write_pc); set_gdbarch_unwind_pc (gdbarch, hppa_hpux_unwind_pc); set_gdbarch_skip_permanent_breakpoint (gdbarch, hppa_skip_permanent_breakpoint); set_gdbarch_regset_from_core_section (gdbarch, hppa_hpux_regset_from_core_section); frame_unwind_append_sniffer (gdbarch, hppa_hpux_sigtramp_unwind_sniffer); } static void hppa_hpux_som_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); tdep->is_elf = 0; tdep->find_global_pointer = hppa32_hpux_find_global_pointer; hppa_hpux_init_abi (info, gdbarch); som_solib_select (tdep); } static void hppa_hpux_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); tdep->is_elf = 1; tdep->find_global_pointer = hppa64_hpux_find_global_pointer; hppa_hpux_init_abi (info, gdbarch); pa64_solib_select (tdep); } static enum gdb_osabi hppa_hpux_core_osabi_sniffer (bfd *abfd) { if (strcmp (bfd_get_target (abfd), "hpux-core") == 0) return GDB_OSABI_HPUX_SOM; else if (strcmp (bfd_get_target (abfd), "elf64-hppa") == 0) { asection *section; section = bfd_get_section_by_name (abfd, ".kernel"); if (section) { bfd_size_type size; char *contents; size = bfd_section_size (abfd, section); contents = alloca (size); if (bfd_get_section_contents (abfd, section, contents, (file_ptr) 0, size) && strcmp (contents, "HP-UX") == 0) return GDB_OSABI_HPUX_ELF; } } return GDB_OSABI_UNKNOWN; } void _initialize_hppa_hpux_tdep (void) { /* BFD doesn't set a flavour for HP-UX style core files. It doesn't set the architecture either. */ gdbarch_register_osabi_sniffer (bfd_arch_unknown, bfd_target_unknown_flavour, hppa_hpux_core_osabi_sniffer); gdbarch_register_osabi_sniffer (bfd_arch_hppa, bfd_target_elf_flavour, hppa_hpux_core_osabi_sniffer); gdbarch_register_osabi (bfd_arch_hppa, 0, GDB_OSABI_HPUX_SOM, hppa_hpux_som_init_abi); gdbarch_register_osabi (bfd_arch_hppa, bfd_mach_hppa20w, GDB_OSABI_HPUX_ELF, hppa_hpux_elf_init_abi); }