2bbe3cc107
Thiago Bauermann <bauerman@br.ibm.com> Joseph S. Myers <joseph@codesourcery.com> Daniel Jacobowitz <dan@codesourcery.com> gdb/ * remote.c (remote_check_symbols): Use gdbarch_convert_from_func_ptr_addr. * infcall.c (find_function_addr): Handle function descriptors without debugging information. * ppc-linux-tdep.c (ppc_linux_convert_from_func_ptr_addr): Renamed from ppc64_linux_convert_from_func_ptr_addr. Handle -msecure-plt. (ppc_linux_init_abi): Always set convert_from_func_ptr_addr. * solib-svr4.c (solib_break_names): Remove "._dl_debug_state". (bfd_lookup_symbol): Do not take a SECT_FLAGS argument. Always allow SEC_CODE and SEC_DATA. (enable_break): Update calls. Pass current_target to solib_add. Use gdbarch_convert_from_func_ptr_addr. gdb/gdbserver/ * remote-utils.c (look_up_one_symbol): Handle 'm' packets.
1004 lines
34 KiB
C
1004 lines
34 KiB
C
/* Target-dependent code for GDB, the GNU debugger.
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Copyright (C) 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
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2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
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Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor,
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Boston, MA 02110-1301, USA. */
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#include "defs.h"
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#include "frame.h"
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#include "inferior.h"
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#include "symtab.h"
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#include "target.h"
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#include "gdbcore.h"
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#include "gdbcmd.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include "regcache.h"
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#include "value.h"
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#include "osabi.h"
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#include "regset.h"
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#include "solib-svr4.h"
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#include "ppc-tdep.h"
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#include "trad-frame.h"
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#include "frame-unwind.h"
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#include "tramp-frame.h"
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/* From <asm/ptrace.h>, values for PT_NIP, PT_R1, and PT_LNK */
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#define PPC_LINUX_PT_R0 0
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#define PPC_LINUX_PT_R1 1
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#define PPC_LINUX_PT_R2 2
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#define PPC_LINUX_PT_R3 3
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#define PPC_LINUX_PT_R4 4
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#define PPC_LINUX_PT_R5 5
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#define PPC_LINUX_PT_R6 6
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#define PPC_LINUX_PT_R7 7
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#define PPC_LINUX_PT_R8 8
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#define PPC_LINUX_PT_R9 9
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#define PPC_LINUX_PT_R10 10
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#define PPC_LINUX_PT_R11 11
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#define PPC_LINUX_PT_R12 12
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#define PPC_LINUX_PT_R13 13
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#define PPC_LINUX_PT_R14 14
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#define PPC_LINUX_PT_R15 15
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#define PPC_LINUX_PT_R16 16
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#define PPC_LINUX_PT_R17 17
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#define PPC_LINUX_PT_R18 18
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#define PPC_LINUX_PT_R19 19
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#define PPC_LINUX_PT_R20 20
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#define PPC_LINUX_PT_R21 21
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#define PPC_LINUX_PT_R22 22
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#define PPC_LINUX_PT_R23 23
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#define PPC_LINUX_PT_R24 24
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#define PPC_LINUX_PT_R25 25
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#define PPC_LINUX_PT_R26 26
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#define PPC_LINUX_PT_R27 27
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#define PPC_LINUX_PT_R28 28
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#define PPC_LINUX_PT_R29 29
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#define PPC_LINUX_PT_R30 30
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#define PPC_LINUX_PT_R31 31
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#define PPC_LINUX_PT_NIP 32
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#define PPC_LINUX_PT_MSR 33
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#define PPC_LINUX_PT_CTR 35
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#define PPC_LINUX_PT_LNK 36
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#define PPC_LINUX_PT_XER 37
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#define PPC_LINUX_PT_CCR 38
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#define PPC_LINUX_PT_MQ 39
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#define PPC_LINUX_PT_FPR0 48 /* each FP reg occupies 2 slots in this space */
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#define PPC_LINUX_PT_FPR31 (PPC_LINUX_PT_FPR0 + 2*31)
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#define PPC_LINUX_PT_FPSCR (PPC_LINUX_PT_FPR0 + 2*32 + 1)
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static CORE_ADDR
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ppc_linux_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
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{
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gdb_byte buf[4];
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struct obj_section *sect;
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struct objfile *objfile;
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unsigned long insn;
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CORE_ADDR plt_start = 0;
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CORE_ADDR symtab = 0;
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CORE_ADDR strtab = 0;
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int num_slots = -1;
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int reloc_index = -1;
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CORE_ADDR plt_table;
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CORE_ADDR reloc;
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CORE_ADDR sym;
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long symidx;
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char symname[1024];
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struct minimal_symbol *msymbol;
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/* Find the section pc is in; return if not in .plt */
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sect = find_pc_section (pc);
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if (!sect || strcmp (sect->the_bfd_section->name, ".plt") != 0)
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return 0;
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objfile = sect->objfile;
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/* Pick up the instruction at pc. It had better be of the
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form
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li r11, IDX
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where IDX is an index into the plt_table. */
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if (target_read_memory (pc, buf, 4) != 0)
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return 0;
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insn = extract_unsigned_integer (buf, 4);
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if ((insn & 0xffff0000) != 0x39600000 /* li r11, VAL */ )
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return 0;
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reloc_index = (insn << 16) >> 16;
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/* Find the objfile that pc is in and obtain the information
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necessary for finding the symbol name. */
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for (sect = objfile->sections; sect < objfile->sections_end; ++sect)
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{
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const char *secname = sect->the_bfd_section->name;
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if (strcmp (secname, ".plt") == 0)
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plt_start = sect->addr;
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else if (strcmp (secname, ".rela.plt") == 0)
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num_slots = ((int) sect->endaddr - (int) sect->addr) / 12;
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else if (strcmp (secname, ".dynsym") == 0)
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symtab = sect->addr;
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else if (strcmp (secname, ".dynstr") == 0)
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strtab = sect->addr;
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}
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/* Make sure we have all the information we need. */
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if (plt_start == 0 || num_slots == -1 || symtab == 0 || strtab == 0)
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return 0;
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/* Compute the value of the plt table */
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plt_table = plt_start + 72 + 8 * num_slots;
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/* Get address of the relocation entry (Elf32_Rela) */
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if (target_read_memory (plt_table + reloc_index, buf, 4) != 0)
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return 0;
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reloc = extract_unsigned_integer (buf, 4);
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sect = find_pc_section (reloc);
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if (!sect)
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return 0;
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if (strcmp (sect->the_bfd_section->name, ".text") == 0)
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return reloc;
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/* Now get the r_info field which is the relocation type and symbol
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index. */
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if (target_read_memory (reloc + 4, buf, 4) != 0)
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return 0;
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symidx = extract_unsigned_integer (buf, 4);
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/* Shift out the relocation type leaving just the symbol index */
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/* symidx = ELF32_R_SYM(symidx); */
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symidx = symidx >> 8;
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/* compute the address of the symbol */
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sym = symtab + symidx * 4;
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/* Fetch the string table index */
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if (target_read_memory (sym, buf, 4) != 0)
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return 0;
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symidx = extract_unsigned_integer (buf, 4);
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/* Fetch the string; we don't know how long it is. Is it possible
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that the following will fail because we're trying to fetch too
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much? */
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if (target_read_memory (strtab + symidx, (gdb_byte *) symname,
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sizeof (symname)) != 0)
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return 0;
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/* This might not work right if we have multiple symbols with the
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same name; the only way to really get it right is to perform
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the same sort of lookup as the dynamic linker. */
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msymbol = lookup_minimal_symbol_text (symname, NULL);
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if (!msymbol)
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return 0;
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return SYMBOL_VALUE_ADDRESS (msymbol);
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}
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/* ppc_linux_memory_remove_breakpoints attempts to remove a breakpoint
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in much the same fashion as memory_remove_breakpoint in mem-break.c,
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but is careful not to write back the previous contents if the code
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in question has changed in between inserting the breakpoint and
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removing it.
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Here is the problem that we're trying to solve...
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Once upon a time, before introducing this function to remove
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breakpoints from the inferior, setting a breakpoint on a shared
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library function prior to running the program would not work
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properly. In order to understand the problem, it is first
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necessary to understand a little bit about dynamic linking on
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this platform.
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A call to a shared library function is accomplished via a bl
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(branch-and-link) instruction whose branch target is an entry
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in the procedure linkage table (PLT). The PLT in the object
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file is uninitialized. To gdb, prior to running the program, the
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entries in the PLT are all zeros.
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Once the program starts running, the shared libraries are loaded
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and the procedure linkage table is initialized, but the entries in
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the table are not (necessarily) resolved. Once a function is
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actually called, the code in the PLT is hit and the function is
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resolved. In order to better illustrate this, an example is in
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order; the following example is from the gdb testsuite.
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We start the program shmain.
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[kev@arroyo testsuite]$ ../gdb gdb.base/shmain
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[...]
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We place two breakpoints, one on shr1 and the other on main.
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(gdb) b shr1
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Breakpoint 1 at 0x100409d4
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(gdb) b main
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Breakpoint 2 at 0x100006a0: file gdb.base/shmain.c, line 44.
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Examine the instruction (and the immediatly following instruction)
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upon which the breakpoint was placed. Note that the PLT entry
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for shr1 contains zeros.
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(gdb) x/2i 0x100409d4
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0x100409d4 <shr1>: .long 0x0
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0x100409d8 <shr1+4>: .long 0x0
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Now run 'til main.
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(gdb) r
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Starting program: gdb.base/shmain
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Breakpoint 1 at 0xffaf790: file gdb.base/shr1.c, line 19.
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Breakpoint 2, main ()
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at gdb.base/shmain.c:44
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44 g = 1;
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Examine the PLT again. Note that the loading of the shared
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library has initialized the PLT to code which loads a constant
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(which I think is an index into the GOT) into r11 and then
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branchs a short distance to the code which actually does the
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resolving.
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(gdb) x/2i 0x100409d4
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0x100409d4 <shr1>: li r11,4
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0x100409d8 <shr1+4>: b 0x10040984 <sg+4>
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(gdb) c
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Continuing.
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Breakpoint 1, shr1 (x=1)
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at gdb.base/shr1.c:19
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19 l = 1;
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Now we've hit the breakpoint at shr1. (The breakpoint was
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reset from the PLT entry to the actual shr1 function after the
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shared library was loaded.) Note that the PLT entry has been
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resolved to contain a branch that takes us directly to shr1.
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(The real one, not the PLT entry.)
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(gdb) x/2i 0x100409d4
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0x100409d4 <shr1>: b 0xffaf76c <shr1>
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0x100409d8 <shr1+4>: b 0x10040984 <sg+4>
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The thing to note here is that the PLT entry for shr1 has been
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changed twice.
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Now the problem should be obvious. GDB places a breakpoint (a
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trap instruction) on the zero value of the PLT entry for shr1.
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Later on, after the shared library had been loaded and the PLT
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initialized, GDB gets a signal indicating this fact and attempts
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(as it always does when it stops) to remove all the breakpoints.
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The breakpoint removal was causing the former contents (a zero
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word) to be written back to the now initialized PLT entry thus
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destroying a portion of the initialization that had occurred only a
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short time ago. When execution continued, the zero word would be
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executed as an instruction an an illegal instruction trap was
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generated instead. (0 is not a legal instruction.)
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The fix for this problem was fairly straightforward. The function
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memory_remove_breakpoint from mem-break.c was copied to this file,
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modified slightly, and renamed to ppc_linux_memory_remove_breakpoint.
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In tm-linux.h, MEMORY_REMOVE_BREAKPOINT is defined to call this new
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function.
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The differences between ppc_linux_memory_remove_breakpoint () and
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memory_remove_breakpoint () are minor. All that the former does
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that the latter does not is check to make sure that the breakpoint
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location actually contains a breakpoint (trap instruction) prior
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to attempting to write back the old contents. If it does contain
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a trap instruction, we allow the old contents to be written back.
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Otherwise, we silently do nothing.
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The big question is whether memory_remove_breakpoint () should be
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changed to have the same functionality. The downside is that more
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traffic is generated for remote targets since we'll have an extra
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fetch of a memory word each time a breakpoint is removed.
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For the time being, we'll leave this self-modifying-code-friendly
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version in ppc-linux-tdep.c, but it ought to be migrated somewhere
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else in the event that some other platform has similar needs with
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regard to removing breakpoints in some potentially self modifying
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code. */
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int
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ppc_linux_memory_remove_breakpoint (struct bp_target_info *bp_tgt)
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{
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CORE_ADDR addr = bp_tgt->placed_address;
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const unsigned char *bp;
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int val;
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int bplen;
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gdb_byte old_contents[BREAKPOINT_MAX];
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/* Determine appropriate breakpoint contents and size for this address. */
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bp = gdbarch_breakpoint_from_pc (current_gdbarch, &addr, &bplen);
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if (bp == NULL)
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error (_("Software breakpoints not implemented for this target."));
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val = target_read_memory (addr, old_contents, bplen);
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/* If our breakpoint is no longer at the address, this means that the
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program modified the code on us, so it is wrong to put back the
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old value */
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if (val == 0 && memcmp (bp, old_contents, bplen) == 0)
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val = target_write_memory (addr, bp_tgt->shadow_contents, bplen);
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return val;
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}
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/* For historic reasons, PPC 32 GNU/Linux follows PowerOpen rather
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than the 32 bit SYSV R4 ABI structure return convention - all
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structures, no matter their size, are put in memory. Vectors,
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which were added later, do get returned in a register though. */
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static enum return_value_convention
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ppc_linux_return_value (struct gdbarch *gdbarch, struct type *valtype,
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struct regcache *regcache, gdb_byte *readbuf,
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const gdb_byte *writebuf)
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{
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if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
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|| TYPE_CODE (valtype) == TYPE_CODE_UNION)
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&& !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8)
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&& TYPE_VECTOR (valtype)))
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return RETURN_VALUE_STRUCT_CONVENTION;
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else
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return ppc_sysv_abi_return_value (gdbarch, valtype, regcache, readbuf,
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writebuf);
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}
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/* Macros for matching instructions. Note that, since all the
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operands are masked off before they're or-ed into the instruction,
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you can use -1 to make masks. */
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#define insn_d(opcd, rts, ra, d) \
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((((opcd) & 0x3f) << 26) \
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| (((rts) & 0x1f) << 21) \
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| (((ra) & 0x1f) << 16) \
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| ((d) & 0xffff))
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#define insn_ds(opcd, rts, ra, d, xo) \
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((((opcd) & 0x3f) << 26) \
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| (((rts) & 0x1f) << 21) \
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| (((ra) & 0x1f) << 16) \
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| ((d) & 0xfffc) \
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| ((xo) & 0x3))
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#define insn_xfx(opcd, rts, spr, xo) \
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((((opcd) & 0x3f) << 26) \
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| (((rts) & 0x1f) << 21) \
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| (((spr) & 0x1f) << 16) \
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| (((spr) & 0x3e0) << 6) \
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| (((xo) & 0x3ff) << 1))
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/* Read a PPC instruction from memory. PPC instructions are always
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big-endian, no matter what endianness the program is running in, so
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we can't use read_memory_integer or one of its friends here. */
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static unsigned int
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read_insn (CORE_ADDR pc)
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{
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unsigned char buf[4];
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read_memory (pc, buf, 4);
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return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
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}
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/* An instruction to match. */
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struct insn_pattern
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{
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unsigned int mask; /* mask the insn with this... */
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unsigned int data; /* ...and see if it matches this. */
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int optional; /* If non-zero, this insn may be absent. */
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};
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/* Return non-zero if the instructions at PC match the series
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described in PATTERN, or zero otherwise. PATTERN is an array of
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'struct insn_pattern' objects, terminated by an entry whose mask is
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zero.
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When the match is successful, fill INSN[i] with what PATTERN[i]
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matched. If PATTERN[i] is optional, and the instruction wasn't
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present, set INSN[i] to 0 (which is not a valid PPC instruction).
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INSN should have as many elements as PATTERN. Note that, if
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PATTERN contains optional instructions which aren't present in
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memory, then INSN will have holes, so INSN[i] isn't necessarily the
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i'th instruction in memory. */
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static int
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insns_match_pattern (CORE_ADDR pc,
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struct insn_pattern *pattern,
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unsigned int *insn)
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{
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int i;
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for (i = 0; pattern[i].mask; i++)
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{
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insn[i] = read_insn (pc);
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if ((insn[i] & pattern[i].mask) == pattern[i].data)
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pc += 4;
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else if (pattern[i].optional)
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insn[i] = 0;
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else
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return 0;
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}
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return 1;
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}
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/* Return the 'd' field of the d-form instruction INSN, properly
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sign-extended. */
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static CORE_ADDR
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insn_d_field (unsigned int insn)
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{
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return ((((CORE_ADDR) insn & 0xffff) ^ 0x8000) - 0x8000);
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}
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|
|
|
/* Return the 'ds' field of the ds-form instruction INSN, with the two
|
|
zero bits concatenated at the right, and properly
|
|
sign-extended. */
|
|
static CORE_ADDR
|
|
insn_ds_field (unsigned int insn)
|
|
{
|
|
return ((((CORE_ADDR) insn & 0xfffc) ^ 0x8000) - 0x8000);
|
|
}
|
|
|
|
|
|
/* If DESC is the address of a 64-bit PowerPC GNU/Linux function
|
|
descriptor, return the descriptor's entry point. */
|
|
static CORE_ADDR
|
|
ppc64_desc_entry_point (CORE_ADDR desc)
|
|
{
|
|
/* The first word of the descriptor is the entry point. */
|
|
return (CORE_ADDR) read_memory_unsigned_integer (desc, 8);
|
|
}
|
|
|
|
|
|
/* Pattern for the standard linkage function. These are built by
|
|
build_plt_stub in elf64-ppc.c, whose GLINK argument is always
|
|
zero. */
|
|
static struct insn_pattern ppc64_standard_linkage[] =
|
|
{
|
|
/* addis r12, r2, <any> */
|
|
{ insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 },
|
|
|
|
/* std r2, 40(r1) */
|
|
{ -1, insn_ds (62, 2, 1, 40, 0), 0 },
|
|
|
|
/* ld r11, <any>(r12) */
|
|
{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 },
|
|
|
|
/* addis r12, r12, 1 <optional> */
|
|
{ insn_d (-1, -1, -1, -1), insn_d (15, 12, 2, 1), 1 },
|
|
|
|
/* ld r2, <any>(r12) */
|
|
{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 12, 0, 0), 0 },
|
|
|
|
/* addis r12, r12, 1 <optional> */
|
|
{ insn_d (-1, -1, -1, -1), insn_d (15, 12, 2, 1), 1 },
|
|
|
|
/* mtctr r11 */
|
|
{ insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467),
|
|
0 },
|
|
|
|
/* ld r11, <any>(r12) */
|
|
{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 },
|
|
|
|
/* bctr */
|
|
{ -1, 0x4e800420, 0 },
|
|
|
|
{ 0, 0, 0 }
|
|
};
|
|
#define PPC64_STANDARD_LINKAGE_LEN \
|
|
(sizeof (ppc64_standard_linkage) / sizeof (ppc64_standard_linkage[0]))
|
|
|
|
/* When the dynamic linker is doing lazy symbol resolution, the first
|
|
call to a function in another object will go like this:
|
|
|
|
- The user's function calls the linkage function:
|
|
|
|
100007c4: 4b ff fc d5 bl 10000498
|
|
100007c8: e8 41 00 28 ld r2,40(r1)
|
|
|
|
- The linkage function loads the entry point (and other stuff) from
|
|
the function descriptor in the PLT, and jumps to it:
|
|
|
|
10000498: 3d 82 00 00 addis r12,r2,0
|
|
1000049c: f8 41 00 28 std r2,40(r1)
|
|
100004a0: e9 6c 80 98 ld r11,-32616(r12)
|
|
100004a4: e8 4c 80 a0 ld r2,-32608(r12)
|
|
100004a8: 7d 69 03 a6 mtctr r11
|
|
100004ac: e9 6c 80 a8 ld r11,-32600(r12)
|
|
100004b0: 4e 80 04 20 bctr
|
|
|
|
- But since this is the first time that PLT entry has been used, it
|
|
sends control to its glink entry. That loads the number of the
|
|
PLT entry and jumps to the common glink0 code:
|
|
|
|
10000c98: 38 00 00 00 li r0,0
|
|
10000c9c: 4b ff ff dc b 10000c78
|
|
|
|
- The common glink0 code then transfers control to the dynamic
|
|
linker's fixup code:
|
|
|
|
10000c78: e8 41 00 28 ld r2,40(r1)
|
|
10000c7c: 3d 82 00 00 addis r12,r2,0
|
|
10000c80: e9 6c 80 80 ld r11,-32640(r12)
|
|
10000c84: e8 4c 80 88 ld r2,-32632(r12)
|
|
10000c88: 7d 69 03 a6 mtctr r11
|
|
10000c8c: e9 6c 80 90 ld r11,-32624(r12)
|
|
10000c90: 4e 80 04 20 bctr
|
|
|
|
Eventually, this code will figure out how to skip all of this,
|
|
including the dynamic linker. At the moment, we just get through
|
|
the linkage function. */
|
|
|
|
/* If the current thread is about to execute a series of instructions
|
|
at PC matching the ppc64_standard_linkage pattern, and INSN is the result
|
|
from that pattern match, return the code address to which the
|
|
standard linkage function will send them. (This doesn't deal with
|
|
dynamic linker lazy symbol resolution stubs.) */
|
|
static CORE_ADDR
|
|
ppc64_standard_linkage_target (struct frame_info *frame,
|
|
CORE_ADDR pc, unsigned int *insn)
|
|
{
|
|
struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (frame));
|
|
|
|
/* The address of the function descriptor this linkage function
|
|
references. */
|
|
CORE_ADDR desc
|
|
= ((CORE_ADDR) get_frame_register_unsigned (frame,
|
|
tdep->ppc_gp0_regnum + 2)
|
|
+ (insn_d_field (insn[0]) << 16)
|
|
+ insn_ds_field (insn[2]));
|
|
|
|
/* The first word of the descriptor is the entry point. Return that. */
|
|
return ppc64_desc_entry_point (desc);
|
|
}
|
|
|
|
|
|
/* Given that we've begun executing a call trampoline at PC, return
|
|
the entry point of the function the trampoline will go to. */
|
|
static CORE_ADDR
|
|
ppc64_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
|
|
{
|
|
unsigned int ppc64_standard_linkage_insn[PPC64_STANDARD_LINKAGE_LEN];
|
|
|
|
if (insns_match_pattern (pc, ppc64_standard_linkage,
|
|
ppc64_standard_linkage_insn))
|
|
return ppc64_standard_linkage_target (frame, pc,
|
|
ppc64_standard_linkage_insn);
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* Support for convert_from_func_ptr_addr (ARCH, ADDR, TARG) on PPC
|
|
GNU/Linux.
|
|
|
|
Usually a function pointer's representation is simply the address
|
|
of the function. On GNU/Linux on the PowerPC however, a function
|
|
pointer may be a pointer to a function descriptor.
|
|
|
|
For PPC64, a function descriptor is a TOC entry, in a data section,
|
|
which 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.
|
|
|
|
For PPC32, there are two kinds of function pointers: non-secure and
|
|
secure. Non-secure function pointers point directly to the
|
|
function in a code section and thus need no translation. Secure
|
|
ones (from GCC's -msecure-plt option) are in a data section and
|
|
contain one word: the address of the function.
|
|
|
|
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 a TOC 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.
|
|
|
|
If ADDR points at what is clearly a function descriptor, transform
|
|
it into the address of the corresponding function, if needed. Be
|
|
conservative, otherwise GDB will do the transformation on any
|
|
random addresses such as occur when there is no symbol table. */
|
|
|
|
static CORE_ADDR
|
|
ppc_linux_convert_from_func_ptr_addr (struct gdbarch *gdbarch,
|
|
CORE_ADDR addr,
|
|
struct target_ops *targ)
|
|
{
|
|
struct gdbarch_tdep *tdep;
|
|
struct section_table *s = target_section_by_addr (targ, addr);
|
|
char *sect_name = NULL;
|
|
|
|
if (!s)
|
|
return addr;
|
|
|
|
tdep = gdbarch_tdep (gdbarch);
|
|
|
|
switch (tdep->wordsize)
|
|
{
|
|
case 4:
|
|
sect_name = ".plt";
|
|
break;
|
|
case 8:
|
|
sect_name = ".opd";
|
|
break;
|
|
default:
|
|
internal_error (__FILE__, __LINE__,
|
|
_("failed internal consistency check"));
|
|
}
|
|
|
|
/* Check if ADDR points to a function descriptor. */
|
|
|
|
/* NOTE: this depends on the coincidence that the address of a functions
|
|
entry point is contained in the first word of its function descriptor
|
|
for both PPC-64 and for PPC-32 with secure PLTs. */
|
|
if ((strcmp (s->the_bfd_section->name, sect_name) == 0)
|
|
&& s->the_bfd_section->flags & SEC_DATA)
|
|
return get_target_memory_unsigned (targ, addr, tdep->wordsize);
|
|
|
|
return addr;
|
|
}
|
|
|
|
static void
|
|
right_supply_register (struct regcache *regcache, int wordsize, int regnum,
|
|
const bfd_byte *buf)
|
|
{
|
|
regcache_raw_supply (regcache, regnum,
|
|
(buf + wordsize - register_size (current_gdbarch, regnum)));
|
|
}
|
|
|
|
/* Extract the register values found in the WORDSIZED ABI GREGSET,
|
|
storing their values in REGCACHE. Note that some are left-aligned,
|
|
while others are right aligned. */
|
|
|
|
void
|
|
ppc_linux_supply_gregset (struct regcache *regcache,
|
|
int regnum, const void *gregs, size_t size,
|
|
int wordsize)
|
|
{
|
|
int regi;
|
|
struct gdbarch *regcache_arch = get_regcache_arch (regcache);
|
|
struct gdbarch_tdep *regcache_tdep = gdbarch_tdep (regcache_arch);
|
|
const bfd_byte *buf = gregs;
|
|
|
|
for (regi = 0; regi < ppc_num_gprs; regi++)
|
|
right_supply_register (regcache, wordsize,
|
|
regcache_tdep->ppc_gp0_regnum + regi,
|
|
buf + wordsize * regi);
|
|
|
|
right_supply_register (regcache, wordsize, gdbarch_pc_regnum (regcache_arch),
|
|
buf + wordsize * PPC_LINUX_PT_NIP);
|
|
right_supply_register (regcache, wordsize, regcache_tdep->ppc_lr_regnum,
|
|
buf + wordsize * PPC_LINUX_PT_LNK);
|
|
regcache_raw_supply (regcache, regcache_tdep->ppc_cr_regnum,
|
|
buf + wordsize * PPC_LINUX_PT_CCR);
|
|
regcache_raw_supply (regcache, regcache_tdep->ppc_xer_regnum,
|
|
buf + wordsize * PPC_LINUX_PT_XER);
|
|
regcache_raw_supply (regcache, regcache_tdep->ppc_ctr_regnum,
|
|
buf + wordsize * PPC_LINUX_PT_CTR);
|
|
if (regcache_tdep->ppc_mq_regnum != -1)
|
|
right_supply_register (regcache, wordsize, regcache_tdep->ppc_mq_regnum,
|
|
buf + wordsize * PPC_LINUX_PT_MQ);
|
|
right_supply_register (regcache, wordsize, regcache_tdep->ppc_ps_regnum,
|
|
buf + wordsize * PPC_LINUX_PT_MSR);
|
|
}
|
|
|
|
static void
|
|
ppc32_linux_supply_gregset (const struct regset *regset,
|
|
struct regcache *regcache,
|
|
int regnum, const void *gregs, size_t size)
|
|
{
|
|
ppc_linux_supply_gregset (regcache, regnum, gregs, size, 4);
|
|
}
|
|
|
|
static struct regset ppc32_linux_gregset = {
|
|
NULL, ppc32_linux_supply_gregset
|
|
};
|
|
|
|
static void
|
|
ppc64_linux_supply_gregset (const struct regset *regset,
|
|
struct regcache * regcache,
|
|
int regnum, const void *gregs, size_t size)
|
|
{
|
|
ppc_linux_supply_gregset (regcache, regnum, gregs, size, 8);
|
|
}
|
|
|
|
static struct regset ppc64_linux_gregset = {
|
|
NULL, ppc64_linux_supply_gregset
|
|
};
|
|
|
|
void
|
|
ppc_linux_supply_fpregset (const struct regset *regset,
|
|
struct regcache * regcache,
|
|
int regnum, const void *fpset, size_t size)
|
|
{
|
|
int regi;
|
|
struct gdbarch *regcache_arch = get_regcache_arch (regcache);
|
|
struct gdbarch_tdep *regcache_tdep = gdbarch_tdep (regcache_arch);
|
|
const bfd_byte *buf = fpset;
|
|
|
|
if (! ppc_floating_point_unit_p (regcache_arch))
|
|
return;
|
|
|
|
for (regi = 0; regi < ppc_num_fprs; regi++)
|
|
regcache_raw_supply (regcache,
|
|
regcache_tdep->ppc_fp0_regnum + regi,
|
|
buf + 8 * regi);
|
|
|
|
/* The FPSCR is stored in the low order word of the last
|
|
doubleword in the fpregset. */
|
|
regcache_raw_supply (regcache, regcache_tdep->ppc_fpscr_regnum,
|
|
buf + 8 * 32 + 4);
|
|
}
|
|
|
|
static struct regset ppc_linux_fpregset = { NULL, ppc_linux_supply_fpregset };
|
|
|
|
static const struct regset *
|
|
ppc_linux_regset_from_core_section (struct gdbarch *core_arch,
|
|
const char *sect_name, size_t sect_size)
|
|
{
|
|
struct gdbarch_tdep *tdep = gdbarch_tdep (core_arch);
|
|
if (strcmp (sect_name, ".reg") == 0)
|
|
{
|
|
if (tdep->wordsize == 4)
|
|
return &ppc32_linux_gregset;
|
|
else
|
|
return &ppc64_linux_gregset;
|
|
}
|
|
if (strcmp (sect_name, ".reg2") == 0)
|
|
return &ppc_linux_fpregset;
|
|
return NULL;
|
|
}
|
|
|
|
static void
|
|
ppc_linux_sigtramp_cache (struct frame_info *next_frame,
|
|
struct trad_frame_cache *this_cache,
|
|
CORE_ADDR func, LONGEST offset,
|
|
int bias)
|
|
{
|
|
CORE_ADDR base;
|
|
CORE_ADDR regs;
|
|
CORE_ADDR gpregs;
|
|
CORE_ADDR fpregs;
|
|
int i;
|
|
struct gdbarch *gdbarch = get_frame_arch (next_frame);
|
|
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
|
|
|
base = frame_unwind_register_unsigned (next_frame,
|
|
gdbarch_sp_regnum (current_gdbarch));
|
|
if (bias > 0 && frame_pc_unwind (next_frame) != func)
|
|
/* See below, some signal trampolines increment the stack as their
|
|
first instruction, need to compensate for that. */
|
|
base -= bias;
|
|
|
|
/* Find the address of the register buffer pointer. */
|
|
regs = base + offset;
|
|
/* Use that to find the address of the corresponding register
|
|
buffers. */
|
|
gpregs = read_memory_unsigned_integer (regs, tdep->wordsize);
|
|
fpregs = gpregs + 48 * tdep->wordsize;
|
|
|
|
/* General purpose. */
|
|
for (i = 0; i < 32; i++)
|
|
{
|
|
int regnum = i + tdep->ppc_gp0_regnum;
|
|
trad_frame_set_reg_addr (this_cache, regnum, gpregs + i * tdep->wordsize);
|
|
}
|
|
trad_frame_set_reg_addr (this_cache,
|
|
gdbarch_pc_regnum (current_gdbarch),
|
|
gpregs + 32 * tdep->wordsize);
|
|
trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum,
|
|
gpregs + 35 * tdep->wordsize);
|
|
trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum,
|
|
gpregs + 36 * tdep->wordsize);
|
|
trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum,
|
|
gpregs + 37 * tdep->wordsize);
|
|
trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum,
|
|
gpregs + 38 * tdep->wordsize);
|
|
|
|
if (ppc_floating_point_unit_p (gdbarch))
|
|
{
|
|
/* Floating point registers. */
|
|
for (i = 0; i < 32; i++)
|
|
{
|
|
int regnum = i + gdbarch_fp0_regnum (current_gdbarch);
|
|
trad_frame_set_reg_addr (this_cache, regnum,
|
|
fpregs + i * tdep->wordsize);
|
|
}
|
|
trad_frame_set_reg_addr (this_cache, tdep->ppc_fpscr_regnum,
|
|
fpregs + 32 * tdep->wordsize);
|
|
}
|
|
trad_frame_set_id (this_cache, frame_id_build (base, func));
|
|
}
|
|
|
|
static void
|
|
ppc32_linux_sigaction_cache_init (const struct tramp_frame *self,
|
|
struct frame_info *next_frame,
|
|
struct trad_frame_cache *this_cache,
|
|
CORE_ADDR func)
|
|
{
|
|
ppc_linux_sigtramp_cache (next_frame, this_cache, func,
|
|
0xd0 /* Offset to ucontext_t. */
|
|
+ 0x30 /* Offset to .reg. */,
|
|
0);
|
|
}
|
|
|
|
static void
|
|
ppc64_linux_sigaction_cache_init (const struct tramp_frame *self,
|
|
struct frame_info *next_frame,
|
|
struct trad_frame_cache *this_cache,
|
|
CORE_ADDR func)
|
|
{
|
|
ppc_linux_sigtramp_cache (next_frame, this_cache, func,
|
|
0x80 /* Offset to ucontext_t. */
|
|
+ 0xe0 /* Offset to .reg. */,
|
|
128);
|
|
}
|
|
|
|
static void
|
|
ppc32_linux_sighandler_cache_init (const struct tramp_frame *self,
|
|
struct frame_info *next_frame,
|
|
struct trad_frame_cache *this_cache,
|
|
CORE_ADDR func)
|
|
{
|
|
ppc_linux_sigtramp_cache (next_frame, this_cache, func,
|
|
0x40 /* Offset to ucontext_t. */
|
|
+ 0x1c /* Offset to .reg. */,
|
|
0);
|
|
}
|
|
|
|
static void
|
|
ppc64_linux_sighandler_cache_init (const struct tramp_frame *self,
|
|
struct frame_info *next_frame,
|
|
struct trad_frame_cache *this_cache,
|
|
CORE_ADDR func)
|
|
{
|
|
ppc_linux_sigtramp_cache (next_frame, this_cache, func,
|
|
0x80 /* Offset to struct sigcontext. */
|
|
+ 0x38 /* Offset to .reg. */,
|
|
128);
|
|
}
|
|
|
|
static struct tramp_frame ppc32_linux_sigaction_tramp_frame = {
|
|
SIGTRAMP_FRAME,
|
|
4,
|
|
{
|
|
{ 0x380000ac, -1 }, /* li r0, 172 */
|
|
{ 0x44000002, -1 }, /* sc */
|
|
{ TRAMP_SENTINEL_INSN },
|
|
},
|
|
ppc32_linux_sigaction_cache_init
|
|
};
|
|
static struct tramp_frame ppc64_linux_sigaction_tramp_frame = {
|
|
SIGTRAMP_FRAME,
|
|
4,
|
|
{
|
|
{ 0x38210080, -1 }, /* addi r1,r1,128 */
|
|
{ 0x380000ac, -1 }, /* li r0, 172 */
|
|
{ 0x44000002, -1 }, /* sc */
|
|
{ TRAMP_SENTINEL_INSN },
|
|
},
|
|
ppc64_linux_sigaction_cache_init
|
|
};
|
|
static struct tramp_frame ppc32_linux_sighandler_tramp_frame = {
|
|
SIGTRAMP_FRAME,
|
|
4,
|
|
{
|
|
{ 0x38000077, -1 }, /* li r0,119 */
|
|
{ 0x44000002, -1 }, /* sc */
|
|
{ TRAMP_SENTINEL_INSN },
|
|
},
|
|
ppc32_linux_sighandler_cache_init
|
|
};
|
|
static struct tramp_frame ppc64_linux_sighandler_tramp_frame = {
|
|
SIGTRAMP_FRAME,
|
|
4,
|
|
{
|
|
{ 0x38210080, -1 }, /* addi r1,r1,128 */
|
|
{ 0x38000077, -1 }, /* li r0,119 */
|
|
{ 0x44000002, -1 }, /* sc */
|
|
{ TRAMP_SENTINEL_INSN },
|
|
},
|
|
ppc64_linux_sighandler_cache_init
|
|
};
|
|
|
|
static void
|
|
ppc_linux_init_abi (struct gdbarch_info info,
|
|
struct gdbarch *gdbarch)
|
|
{
|
|
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
|
|
|
/* NOTE: jimb/2004-03-26: The System V ABI PowerPC Processor
|
|
Supplement says that long doubles are sixteen bytes long.
|
|
However, as one of the known warts of its ABI, PPC GNU/Linux uses
|
|
eight-byte long doubles. GCC only recently got 128-bit long
|
|
double support on PPC, so it may be changing soon. The
|
|
Linux[sic] Standards Base says that programs that use 'long
|
|
double' on PPC GNU/Linux are non-conformant. */
|
|
/* NOTE: cagney/2005-01-25: True for both 32- and 64-bit. */
|
|
set_gdbarch_long_double_bit (gdbarch, 8 * TARGET_CHAR_BIT);
|
|
|
|
/* Handle PPC GNU/Linux 64-bit function pointers (which are really
|
|
function descriptors) and 32-bit secure PLT entries. */
|
|
set_gdbarch_convert_from_func_ptr_addr
|
|
(gdbarch, ppc_linux_convert_from_func_ptr_addr);
|
|
|
|
if (tdep->wordsize == 4)
|
|
{
|
|
/* Until November 2001, gcc did not comply with the 32 bit SysV
|
|
R4 ABI requirement that structures less than or equal to 8
|
|
bytes should be returned in registers. Instead GCC was using
|
|
the the AIX/PowerOpen ABI - everything returned in memory
|
|
(well ignoring vectors that is). When this was corrected, it
|
|
wasn't fixed for GNU/Linux native platform. Use the
|
|
PowerOpen struct convention. */
|
|
set_gdbarch_return_value (gdbarch, ppc_linux_return_value);
|
|
|
|
set_gdbarch_memory_remove_breakpoint (gdbarch,
|
|
ppc_linux_memory_remove_breakpoint);
|
|
|
|
/* Shared library handling. */
|
|
set_gdbarch_skip_trampoline_code (gdbarch,
|
|
ppc_linux_skip_trampoline_code);
|
|
set_solib_svr4_fetch_link_map_offsets
|
|
(gdbarch, svr4_ilp32_fetch_link_map_offsets);
|
|
|
|
/* Trampolines. */
|
|
tramp_frame_prepend_unwinder (gdbarch, &ppc32_linux_sigaction_tramp_frame);
|
|
tramp_frame_prepend_unwinder (gdbarch, &ppc32_linux_sighandler_tramp_frame);
|
|
}
|
|
|
|
if (tdep->wordsize == 8)
|
|
{
|
|
/* Shared library handling. */
|
|
set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code);
|
|
set_solib_svr4_fetch_link_map_offsets
|
|
(gdbarch, svr4_lp64_fetch_link_map_offsets);
|
|
|
|
/* Trampolines. */
|
|
tramp_frame_prepend_unwinder (gdbarch, &ppc64_linux_sigaction_tramp_frame);
|
|
tramp_frame_prepend_unwinder (gdbarch, &ppc64_linux_sighandler_tramp_frame);
|
|
}
|
|
set_gdbarch_regset_from_core_section (gdbarch, ppc_linux_regset_from_core_section);
|
|
|
|
/* Enable TLS support. */
|
|
set_gdbarch_fetch_tls_load_module_address (gdbarch,
|
|
svr4_fetch_objfile_link_map);
|
|
}
|
|
|
|
void
|
|
_initialize_ppc_linux_tdep (void)
|
|
{
|
|
/* Register for all sub-familes of the POWER/PowerPC: 32-bit and
|
|
64-bit PowerPC, and the older rs6k. */
|
|
gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc, GDB_OSABI_LINUX,
|
|
ppc_linux_init_abi);
|
|
gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc64, GDB_OSABI_LINUX,
|
|
ppc_linux_init_abi);
|
|
gdbarch_register_osabi (bfd_arch_rs6000, bfd_mach_rs6k, GDB_OSABI_LINUX,
|
|
ppc_linux_init_abi);
|
|
}
|