From 45fe57e7a5219717fc4ced85617f81aa10195e28 Mon Sep 17 00:00:00 2001 From: Andreas Tobler Date: Fri, 1 Feb 2013 20:59:08 +0000 Subject: [PATCH] Add missing file from the previous commit. --- gdb/ppc64-tdep.c | 363 +++++++++++++++++++++++++++++++++++++++++++++++ gdb/ppc64-tdep.h | 34 +++++ 2 files changed, 397 insertions(+) create mode 100644 gdb/ppc64-tdep.c create mode 100644 gdb/ppc64-tdep.h diff --git a/gdb/ppc64-tdep.c b/gdb/ppc64-tdep.c new file mode 100644 index 00000000000..9c3616a1a27 --- /dev/null +++ b/gdb/ppc64-tdep.c @@ -0,0 +1,363 @@ +/* Common target-dependent code for ppc64 GDB, the GNU debugger. + + Copyright (C) 1986-2013 Free Software Foundation, Inc. + + This file is part of GDB. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#include "defs.h" +#include "frame.h" +#include "gdbcore.h" +#include "ppc-tdep.h" +#include "ppc64-tdep.h" + +/* Macros for matching instructions. Note that, since all the + operands are masked off before they're or-ed into the instruction, + you can use -1 to make masks. */ + +#define insn_d(opcd, rts, ra, d) \ + ((((opcd) & 0x3f) << 26) \ + | (((rts) & 0x1f) << 21) \ + | (((ra) & 0x1f) << 16) \ + | ((d) & 0xffff)) + +#define insn_ds(opcd, rts, ra, d, xo) \ + ((((opcd) & 0x3f) << 26) \ + | (((rts) & 0x1f) << 21) \ + | (((ra) & 0x1f) << 16) \ + | ((d) & 0xfffc) \ + | ((xo) & 0x3)) + +#define insn_xfx(opcd, rts, spr, xo) \ + ((((opcd) & 0x3f) << 26) \ + | (((rts) & 0x1f) << 21) \ + | (((spr) & 0x1f) << 16) \ + | (((spr) & 0x3e0) << 6) \ + | (((xo) & 0x3ff) << 1)) + +/* If DESC is the address of a 64-bit PowerPC FreeBSD function + descriptor, return the descriptor's entry point. */ + +static CORE_ADDR +ppc64_desc_entry_point (struct gdbarch *gdbarch, CORE_ADDR desc) +{ + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + /* The first word of the descriptor is the entry point. */ + return (CORE_ADDR) read_memory_unsigned_integer (desc, 8, byte_order); +} + +/* 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 ppc_insn_pattern ppc64_standard_linkage1[] = + { + /* addis r12, r2, */ + { 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, (r12) */ + { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 }, + + /* addis r12, r12, 1 */ + { insn_d (-1, -1, -1, -1), insn_d (15, 12, 12, 1), 1 }, + + /* ld r2, (r12) */ + { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 12, 0, 0), 0 }, + + /* addis r12, r12, 1 */ + { insn_d (-1, -1, -1, -1), insn_d (15, 12, 12, 1), 1 }, + + /* mtctr r11 */ + { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), 0 }, + + /* ld r11, (r12) */ + { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 1 }, + + /* bctr */ + { -1, 0x4e800420, 0 }, + + { 0, 0, 0 } + }; + +#define PPC64_STANDARD_LINKAGE1_LEN ARRAY_SIZE (ppc64_standard_linkage1) + +static struct ppc_insn_pattern ppc64_standard_linkage2[] = + { + /* addis r12, r2, */ + { 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, (r12) */ + { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 }, + + /* addi r12, r12, */ + { insn_d (-1, -1, -1, 0), insn_d (14, 12, 12, 0), 1 }, + + /* mtctr r11 */ + { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), 0 }, + + /* ld r2, (r12) */ + { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 12, 0, 0), 0 }, + + /* ld r11, (r12) */ + { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 1 }, + + /* bctr */ + { -1, 0x4e800420, 0 }, + + { 0, 0, 0 } + }; + +#define PPC64_STANDARD_LINKAGE2_LEN ARRAY_SIZE (ppc64_standard_linkage2) + +static struct ppc_insn_pattern ppc64_standard_linkage3[] = + { + /* std r2, 40(r1) */ + { -1, insn_ds (62, 2, 1, 40, 0), 0 }, + + /* ld r11, (r2) */ + { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 2, 0, 0), 0 }, + + /* addi r2, r2, */ + { insn_d (-1, -1, -1, 0), insn_d (14, 2, 2, 0), 1 }, + + /* mtctr r11 */ + { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), 0 }, + + /* ld r11, (r2) */ + { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 2, 0, 0), 1 }, + + /* ld r2, (r2) */ + { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 2, 0, 0), 0 }, + + /* bctr */ + { -1, 0x4e800420, 0 }, + + { 0, 0, 0 } + }; + +#define PPC64_STANDARD_LINKAGE3_LEN ARRAY_SIZE (ppc64_standard_linkage3) + +/* 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_linkage1_target (struct frame_info *frame, + CORE_ADDR pc, unsigned int *insn) +{ + struct gdbarch *gdbarch = get_frame_arch (frame); + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + /* 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) + + (ppc_insn_d_field (insn[0]) << 16) + + ppc_insn_ds_field (insn[2])); + + /* The first word of the descriptor is the entry point. Return that. */ + return ppc64_desc_entry_point (gdbarch, desc); +} + +static CORE_ADDR +ppc64_standard_linkage2_target (struct frame_info *frame, + CORE_ADDR pc, unsigned int *insn) +{ + struct gdbarch *gdbarch = get_frame_arch (frame); + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + /* 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) + + (ppc_insn_d_field (insn[0]) << 16) + + ppc_insn_ds_field (insn[2])); + + /* The first word of the descriptor is the entry point. Return that. */ + return ppc64_desc_entry_point (gdbarch, desc); +} + +static CORE_ADDR +ppc64_standard_linkage3_target (struct frame_info *frame, + CORE_ADDR pc, unsigned int *insn) +{ + struct gdbarch *gdbarch = get_frame_arch (frame); + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + /* 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) + + ppc_insn_ds_field (insn[1])); + + /* The first word of the descriptor is the entry point. Return that. */ + return ppc64_desc_entry_point (gdbarch, desc); +} + + +/* Given that we've begun executing a call trampoline at PC, return + the entry point of the function the trampoline will go to. */ + +CORE_ADDR +ppc64_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc) +{ + unsigned int ppc64_standard_linkage1_insn[PPC64_STANDARD_LINKAGE1_LEN]; + unsigned int ppc64_standard_linkage2_insn[PPC64_STANDARD_LINKAGE2_LEN]; + unsigned int ppc64_standard_linkage3_insn[PPC64_STANDARD_LINKAGE3_LEN]; + CORE_ADDR target; + + if (ppc_insns_match_pattern (pc, ppc64_standard_linkage1, + ppc64_standard_linkage1_insn)) + pc = ppc64_standard_linkage1_target (frame, pc, + ppc64_standard_linkage1_insn); + else if (ppc_insns_match_pattern (pc, ppc64_standard_linkage2, + ppc64_standard_linkage2_insn)) + pc = ppc64_standard_linkage2_target (frame, pc, + ppc64_standard_linkage2_insn); + else if (ppc_insns_match_pattern (pc, ppc64_standard_linkage3, + ppc64_standard_linkage3_insn)) + pc = ppc64_standard_linkage3_target (frame, pc, + ppc64_standard_linkage3_insn); + else + return 0; + + /* The PLT descriptor will either point to the already resolved target + address, or else to a glink stub. As the latter carry synthetic @plt + symbols, find_solib_trampoline_target should be able to resolve them. */ + target = find_solib_trampoline_target (frame, pc); + return target ? target : pc; +} + +/* Support for convert_from_func_ptr_addr (ARCH, ADDR, TARG) on PPC64 + 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. + + 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. */ + +CORE_ADDR +ppc64_convert_from_func_ptr_addr (struct gdbarch *gdbarch, + CORE_ADDR addr, + struct target_ops *targ) +{ + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + struct target_section *s = target_section_by_addr (targ, addr); + + /* Check if ADDR points to a function descriptor. */ + if (s && strcmp (s->the_bfd_section->name, ".opd") == 0) + { + /* There may be relocations that need to be applied to the .opd + section. Unfortunately, this function may be called at a time + where these relocations have not yet been performed -- this can + happen for example shortly after a library has been loaded with + dlopen, but ld.so has not yet applied the relocations. + + To cope with both the case where the relocation has been applied, + and the case where it has not yet been applied, we do *not* read + the (maybe) relocated value from target memory, but we instead + read the non-relocated value from the BFD, and apply the relocation + offset manually. + + This makes the assumption that all .opd entries are always relocated + by the same offset the section itself was relocated. This should + always be the case for GNU/Linux executables and shared libraries. + Note that other kind of object files (e.g. those added via + add-symbol-files) will currently never end up here anyway, as this + function accesses *target* sections only; only the main exec and + shared libraries are ever added to the target. */ + + gdb_byte buf[8]; + int res; + + res = bfd_get_section_contents (s->bfd, s->the_bfd_section, + &buf, addr - s->addr, 8); + if (res != 0) + return extract_unsigned_integer (buf, 8, byte_order) + - bfd_section_vma (s->bfd, s->the_bfd_section) + s->addr; + } + + return addr; +} diff --git a/gdb/ppc64-tdep.h b/gdb/ppc64-tdep.h new file mode 100644 index 00000000000..c4c9d99455a --- /dev/null +++ b/gdb/ppc64-tdep.h @@ -0,0 +1,34 @@ +/* Common target-dependent code for ppc64. + + Copyright (C) 1986-2013 Free Software Foundation, Inc. + + This file is part of GDB. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#ifndef PPC64_TDEP_H +#define PPC64_TDEP_H + +struct gdbarch; +struct frame_info; +struct target_ops; + +extern CORE_ADDR ppc64_skip_trampoline_code (struct frame_info *frame, + CORE_ADDR pc); + +extern CORE_ADDR ppc64_convert_from_func_ptr_addr (struct gdbarch *gdbarch, + CORE_ADDR addr, + struct target_ops *targ); + +#endif /* PPC64_TDEP_H */ -- 2.30.2