631 lines
21 KiB
C
631 lines
21 KiB
C
/* Common target-dependent code for ppc64 GDB, the GNU debugger.
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Copyright (C) 1986-2015 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 3 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, see <http://www.gnu.org/licenses/>. */
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#include "defs.h"
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#include "frame.h"
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#include "gdbcore.h"
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#include "infrun.h"
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#include "ppc-tdep.h"
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#include "ppc64-tdep.h"
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#include "elf-bfd.h"
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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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/* If PLT is the address of a 64-bit PowerPC PLT entry,
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return the function's entry point. */
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static CORE_ADDR
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ppc64_plt_entry_point (struct gdbarch *gdbarch, CORE_ADDR plt)
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{
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enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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/* The first word of the PLT entry is the function entry point. */
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return (CORE_ADDR) read_memory_unsigned_integer (plt, 8, byte_order);
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}
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/* Patterns for the standard linkage functions. These are built by
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build_plt_stub in bfd/elf64-ppc.c. */
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/* Old ELFv1 PLT call stub. */
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static struct ppc_insn_pattern ppc64_standard_linkage1[] =
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{
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/* addis r12, r2, <any> */
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{ insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 },
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/* std r2, 40(r1) */
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{ -1, insn_ds (62, 2, 1, 40, 0), 0 },
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/* ld r11, <any>(r12) */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 },
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/* addis r12, r12, 1 <optional> */
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{ insn_d (-1, -1, -1, -1), insn_d (15, 12, 12, 1), 1 },
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/* ld r2, <any>(r12) */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 12, 0, 0), 0 },
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/* addis r12, r12, 1 <optional> */
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{ insn_d (-1, -1, -1, -1), insn_d (15, 12, 12, 1), 1 },
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/* mtctr r11 */
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{ insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), 0 },
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/* ld r11, <any>(r12) <optional> */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 1 },
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/* bctr */
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{ -1, 0x4e800420, 0 },
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{ 0, 0, 0 }
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};
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/* ELFv1 PLT call stub to access PLT entries more than +/- 32k from r2.
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Also supports older stub with different placement of std 2,40(1),
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a stub that omits the std 2,40(1), and both versions of power7
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thread safety read barriers. Note that there are actually two more
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instructions following "cmpldi r2, 0", "bnectr+" and "b <glink_i>",
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but there isn't any need to match them. */
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static struct ppc_insn_pattern ppc64_standard_linkage2[] =
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{
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/* std r2, 40(r1) <optional> */
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{ -1, insn_ds (62, 2, 1, 40, 0), 1 },
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/* addis r12, r2, <any> */
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{ insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 },
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/* std r2, 40(r1) <optional> */
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{ -1, insn_ds (62, 2, 1, 40, 0), 1 },
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/* ld r11, <any>(r12) */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 },
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/* addi r12, r12, <any> <optional> */
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{ insn_d (-1, -1, -1, 0), insn_d (14, 12, 12, 0), 1 },
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/* mtctr r11 */
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{ insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), 0 },
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/* xor r11, r11, r11 <optional> */
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{ -1, 0x7d6b5a78, 1 },
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/* add r12, r12, r11 <optional> */
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{ -1, 0x7d8c5a14, 1 },
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/* ld r2, <any>(r12) */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 12, 0, 0), 0 },
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/* ld r11, <any>(r12) <optional> */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 1 },
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/* bctr <optional> */
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{ -1, 0x4e800420, 1 },
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/* cmpldi r2, 0 <optional> */
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{ -1, 0x28220000, 1 },
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{ 0, 0, 0 }
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};
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/* ELFv1 PLT call stub to access PLT entries within +/- 32k of r2. */
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static struct ppc_insn_pattern ppc64_standard_linkage3[] =
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{
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/* std r2, 40(r1) <optional> */
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{ -1, insn_ds (62, 2, 1, 40, 0), 1 },
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/* ld r11, <any>(r2) */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 2, 0, 0), 0 },
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/* addi r2, r2, <any> <optional> */
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{ insn_d (-1, -1, -1, 0), insn_d (14, 2, 2, 0), 1 },
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/* mtctr r11 */
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{ insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), 0 },
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/* xor r11, r11, r11 <optional> */
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{ -1, 0x7d6b5a78, 1 },
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/* add r2, r2, r11 <optional> */
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{ -1, 0x7c425a14, 1 },
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/* ld r11, <any>(r2) <optional> */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 2, 0, 0), 1 },
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/* ld r2, <any>(r2) */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 2, 0, 0), 0 },
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/* bctr <optional> */
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{ -1, 0x4e800420, 1 },
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/* cmpldi r2, 0 <optional> */
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{ -1, 0x28220000, 1 },
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{ 0, 0, 0 }
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};
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/* ELFv1 PLT call stub to access PLT entries more than +/- 32k from r2.
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A more modern variant of ppc64_standard_linkage2 differing in
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register usage. */
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static struct ppc_insn_pattern ppc64_standard_linkage4[] =
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{
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/* std r2, 40(r1) <optional> */
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{ -1, insn_ds (62, 2, 1, 40, 0), 1 },
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/* addis r11, r2, <any> */
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{ insn_d (-1, -1, -1, 0), insn_d (15, 11, 2, 0), 0 },
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/* ld r12, <any>(r11) */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 12, 11, 0, 0), 0 },
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/* addi r11, r11, <any> <optional> */
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{ insn_d (-1, -1, -1, 0), insn_d (14, 11, 11, 0), 1 },
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/* mtctr r12 */
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{ insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
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/* xor r2, r12, r12 <optional> */
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{ -1, 0x7d826278, 1 },
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/* add r11, r11, r2 <optional> */
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{ -1, 0x7d6b1214, 1 },
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/* ld r2, <any>(r11) */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 11, 0, 0), 0 },
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/* ld r11, <any>(r11) <optional> */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 11, 0, 0), 1 },
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/* bctr <optional> */
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{ -1, 0x4e800420, 1 },
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/* cmpldi r2, 0 <optional> */
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{ -1, 0x28220000, 1 },
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{ 0, 0, 0 }
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};
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/* ELFv1 PLT call stub to access PLT entries within +/- 32k of r2.
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A more modern variant of ppc64_standard_linkage3 differing in
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register usage. */
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static struct ppc_insn_pattern ppc64_standard_linkage5[] =
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{
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/* std r2, 40(r1) <optional> */
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{ -1, insn_ds (62, 2, 1, 40, 0), 1 },
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/* ld r12, <any>(r2) */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 12, 2, 0, 0), 0 },
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/* addi r2, r2, <any> <optional> */
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{ insn_d (-1, -1, -1, 0), insn_d (14, 2, 2, 0), 1 },
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/* mtctr r12 */
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{ insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
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/* xor r11, r12, r12 <optional> */
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{ -1, 0x7d8b6278, 1 },
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/* add r2, r2, r11 <optional> */
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{ -1, 0x7c425a14, 1 },
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/* ld r11, <any>(r2) <optional> */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 2, 0, 0), 1 },
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/* ld r2, <any>(r2) */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 2, 0, 0), 0 },
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/* bctr <optional> */
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{ -1, 0x4e800420, 1 },
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/* cmpldi r2, 0 <optional> */
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{ -1, 0x28220000, 1 },
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{ 0, 0, 0 }
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};
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/* ELFv2 PLT call stub to access PLT entries more than +/- 32k from r2. */
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static struct ppc_insn_pattern ppc64_standard_linkage6[] =
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{
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/* std r2, 24(r1) <optional> */
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{ -1, insn_ds (62, 2, 1, 24, 0), 1 },
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/* addis r11, r2, <any> */
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{ insn_d (-1, -1, -1, 0), insn_d (15, 11, 2, 0), 0 },
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/* ld r12, <any>(r11) */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 12, 11, 0, 0), 0 },
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/* mtctr r12 */
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{ insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
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/* bctr */
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{ -1, 0x4e800420, 0 },
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{ 0, 0, 0 }
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};
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/* ELFv2 PLT call stub to access PLT entries within +/- 32k of r2. */
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static struct ppc_insn_pattern ppc64_standard_linkage7[] =
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{
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/* std r2, 24(r1) <optional> */
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{ -1, insn_ds (62, 2, 1, 24, 0), 1 },
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/* ld r12, <any>(r2) */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 12, 2, 0, 0), 0 },
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/* mtctr r12 */
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{ insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
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/* bctr */
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{ -1, 0x4e800420, 0 },
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{ 0, 0, 0 }
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};
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/* ELFv2 PLT call stub to access PLT entries more than +/- 32k from r2,
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supporting fusion. */
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static struct ppc_insn_pattern ppc64_standard_linkage8[] =
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{
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/* std r2, 24(r1) <optional> */
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{ -1, insn_ds (62, 2, 1, 24, 0), 1 },
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/* addis r12, r2, <any> */
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{ insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 },
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/* ld r12, <any>(r12) */
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{ insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 12, 12, 0, 0), 0 },
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/* mtctr r12 */
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{ insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
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/* bctr */
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{ -1, 0x4e800420, 0 },
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{ 0, 0, 0 }
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};
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/* When the dynamic linker is doing lazy symbol resolution, the first
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call to a function in another object will go like this:
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- The user's function calls the linkage function:
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100003d4: 4b ff ff ad bl 10000380 <nnnn.plt_call.printf>
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100003d8: e8 41 00 28 ld r2,40(r1)
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- The linkage function loads the entry point and toc pointer from
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the function descriptor in the PLT, and jumps to it:
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<nnnn.plt_call.printf>:
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10000380: f8 41 00 28 std r2,40(r1)
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10000384: e9 62 80 78 ld r11,-32648(r2)
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10000388: 7d 69 03 a6 mtctr r11
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1000038c: e8 42 80 80 ld r2,-32640(r2)
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10000390: 28 22 00 00 cmpldi r2,0
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10000394: 4c e2 04 20 bnectr+
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10000398: 48 00 03 a0 b 10000738 <printf@plt>
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- But since this is the first time that PLT entry has been used, it
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sends control to its glink entry. That loads the number of the
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PLT entry and jumps to the common glink0 code:
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<printf@plt>:
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10000738: 38 00 00 01 li r0,1
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1000073c: 4b ff ff bc b 100006f8 <__glink_PLTresolve>
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- The common glink0 code then transfers control to the dynamic
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linker's fixup code:
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100006f0: 0000000000010440 .quad plt0 - (. + 16)
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<__glink_PLTresolve>:
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100006f8: 7d 88 02 a6 mflr r12
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100006fc: 42 9f 00 05 bcl 20,4*cr7+so,10000700
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10000700: 7d 68 02 a6 mflr r11
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10000704: e8 4b ff f0 ld r2,-16(r11)
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10000708: 7d 88 03 a6 mtlr r12
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1000070c: 7d 82 5a 14 add r12,r2,r11
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10000710: e9 6c 00 00 ld r11,0(r12)
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10000714: e8 4c 00 08 ld r2,8(r12)
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10000718: 7d 69 03 a6 mtctr r11
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1000071c: e9 6c 00 10 ld r11,16(r12)
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10000720: 4e 80 04 20 bctr
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Eventually, this code will figure out how to skip all of this,
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including the dynamic linker. At the moment, we just get through
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the linkage function. */
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/* If the current thread is about to execute a series of instructions
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at PC matching the ppc64_standard_linkage pattern, and INSN is the result
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from that pattern match, return the code address to which the
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standard linkage function will send them. (This doesn't deal with
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dynamic linker lazy symbol resolution stubs.) */
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static CORE_ADDR
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ppc64_standard_linkage1_target (struct frame_info *frame,
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CORE_ADDR pc, unsigned int *insn)
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{
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struct gdbarch *gdbarch = get_frame_arch (frame);
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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/* The address of the PLT entry this linkage function references. */
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CORE_ADDR plt
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= ((CORE_ADDR) get_frame_register_unsigned (frame,
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tdep->ppc_gp0_regnum + 2)
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+ (ppc_insn_d_field (insn[0]) << 16)
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+ ppc_insn_ds_field (insn[2]));
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return ppc64_plt_entry_point (gdbarch, plt);
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}
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static CORE_ADDR
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ppc64_standard_linkage2_target (struct frame_info *frame,
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CORE_ADDR pc, unsigned int *insn)
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{
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struct gdbarch *gdbarch = get_frame_arch (frame);
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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/* The address of the PLT entry this linkage function references. */
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CORE_ADDR plt
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= ((CORE_ADDR) get_frame_register_unsigned (frame,
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tdep->ppc_gp0_regnum + 2)
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+ (ppc_insn_d_field (insn[1]) << 16)
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+ ppc_insn_ds_field (insn[3]));
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return ppc64_plt_entry_point (gdbarch, plt);
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}
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static CORE_ADDR
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ppc64_standard_linkage3_target (struct frame_info *frame,
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CORE_ADDR pc, unsigned int *insn)
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{
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struct gdbarch *gdbarch = get_frame_arch (frame);
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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/* The address of the PLT entry this linkage function references. */
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CORE_ADDR plt
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= ((CORE_ADDR) get_frame_register_unsigned (frame,
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tdep->ppc_gp0_regnum + 2)
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+ ppc_insn_ds_field (insn[1]));
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return ppc64_plt_entry_point (gdbarch, plt);
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}
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static CORE_ADDR
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ppc64_standard_linkage4_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);
|
|
|
|
CORE_ADDR plt
|
|
= ((CORE_ADDR) get_frame_register_unsigned (frame, tdep->ppc_gp0_regnum + 2)
|
|
+ (ppc_insn_d_field (insn[1]) << 16)
|
|
+ ppc_insn_ds_field (insn[2]));
|
|
|
|
return ppc64_plt_entry_point (gdbarch, plt);
|
|
}
|
|
|
|
|
|
/* Given that we've begun executing a call trampoline at PC, return
|
|
the entry point of the function the trampoline will go to.
|
|
|
|
When the execution direction is EXEC_REVERSE, scan backward to
|
|
check whether we are in the middle of a PLT stub. */
|
|
|
|
static CORE_ADDR
|
|
ppc64_skip_trampoline_code_1 (struct frame_info *frame, CORE_ADDR pc)
|
|
{
|
|
#define MAX(a,b) ((a) > (b) ? (a) : (b))
|
|
unsigned int insns[MAX (MAX (MAX (ARRAY_SIZE (ppc64_standard_linkage1),
|
|
ARRAY_SIZE (ppc64_standard_linkage2)),
|
|
MAX (ARRAY_SIZE (ppc64_standard_linkage3),
|
|
ARRAY_SIZE (ppc64_standard_linkage4))),
|
|
MAX (MAX (ARRAY_SIZE (ppc64_standard_linkage5),
|
|
ARRAY_SIZE (ppc64_standard_linkage6)),
|
|
MAX (ARRAY_SIZE (ppc64_standard_linkage7),
|
|
ARRAY_SIZE (ppc64_standard_linkage8))))
|
|
- 1];
|
|
CORE_ADDR target;
|
|
int scan_limit, i;
|
|
|
|
scan_limit = 1;
|
|
/* When reverse-debugging, scan backward to check whether we are
|
|
in the middle of trampoline code. */
|
|
if (execution_direction == EXEC_REVERSE)
|
|
scan_limit = ARRAY_SIZE (insns) - 1;
|
|
|
|
for (i = 0; i < scan_limit; i++)
|
|
{
|
|
if (i < ARRAY_SIZE (ppc64_standard_linkage8) - 1
|
|
&& ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage8, insns))
|
|
pc = ppc64_standard_linkage4_target (frame, pc, insns);
|
|
else if (i < ARRAY_SIZE (ppc64_standard_linkage7) - 1
|
|
&& ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage7,
|
|
insns))
|
|
pc = ppc64_standard_linkage3_target (frame, pc, insns);
|
|
else if (i < ARRAY_SIZE (ppc64_standard_linkage6) - 1
|
|
&& ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage6,
|
|
insns))
|
|
pc = ppc64_standard_linkage4_target (frame, pc, insns);
|
|
else if (i < ARRAY_SIZE (ppc64_standard_linkage5) - 1
|
|
&& ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage5,
|
|
insns)
|
|
&& (insns[8] != 0 || insns[9] != 0))
|
|
pc = ppc64_standard_linkage3_target (frame, pc, insns);
|
|
else if (i < ARRAY_SIZE (ppc64_standard_linkage4) - 1
|
|
&& ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage4,
|
|
insns)
|
|
&& (insns[9] != 0 || insns[10] != 0))
|
|
pc = ppc64_standard_linkage4_target (frame, pc, insns);
|
|
else if (i < ARRAY_SIZE (ppc64_standard_linkage3) - 1
|
|
&& ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage3,
|
|
insns)
|
|
&& (insns[8] != 0 || insns[9] != 0))
|
|
pc = ppc64_standard_linkage3_target (frame, pc, insns);
|
|
else if (i < ARRAY_SIZE (ppc64_standard_linkage2) - 1
|
|
&& ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage2,
|
|
insns)
|
|
&& (insns[10] != 0 || insns[11] != 0))
|
|
pc = ppc64_standard_linkage2_target (frame, pc, insns);
|
|
else if (i < ARRAY_SIZE (ppc64_standard_linkage1) - 1
|
|
&& ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage1,
|
|
insns))
|
|
pc = ppc64_standard_linkage1_target (frame, pc, insns);
|
|
else
|
|
{
|
|
/* Scan backward one more instructions if doesn't match. */
|
|
pc -= 4;
|
|
continue;
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Wrapper of ppc64_skip_trampoline_code_1 checking also
|
|
ppc_elfv2_skip_entrypoint. */
|
|
|
|
CORE_ADDR
|
|
ppc64_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
|
|
{
|
|
struct gdbarch *gdbarch = get_frame_arch (frame);
|
|
|
|
pc = ppc64_skip_trampoline_code_1 (frame, pc);
|
|
if (pc != 0 && gdbarch_skip_entrypoint_p (gdbarch))
|
|
pc = gdbarch_skip_entrypoint (gdbarch, pc);
|
|
return 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->the_bfd_section->owner,
|
|
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;
|
|
}
|
|
|
|
/* A synthetic 'dot' symbols on ppc64 has the udata.p entry pointing
|
|
back to the original ELF symbol it was derived from. Get the size
|
|
from that symbol. */
|
|
|
|
void
|
|
ppc64_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
|
|
{
|
|
if ((sym->flags & BSF_SYNTHETIC) != 0 && sym->udata.p != NULL)
|
|
{
|
|
elf_symbol_type *elf_sym = (elf_symbol_type *) sym->udata.p;
|
|
SET_MSYMBOL_SIZE (msym, elf_sym->internal_elf_sym.st_size);
|
|
}
|
|
}
|