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- /* Common target-dependent code for ppc64 GDB, the GNU debugger.
- Copyright (C) 1986-2022 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 <http://www.gnu.org/licenses/>. */
- #include "defs.h"
- #include "frame.h"
- #include "gdbcore.h"
- #include "infrun.h"
- #include "ppc-tdep.h"
- #include "ppc64-tdep.h"
- #include "elf-bfd.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) \
- ((((unsigned (opcd)) & 0x3f) << 26) \
- | (((unsigned (rts)) & 0x1f) << 21) \
- | (((unsigned (ra)) & 0x1f) << 16) \
- | ((unsigned (d)) & 0xffff))
- #define insn_ds(opcd, rts, ra, d, xo) \
- ((((unsigned (opcd)) & 0x3f) << 26) \
- | (((unsigned (rts)) & 0x1f) << 21) \
- | (((unsigned (ra)) & 0x1f) << 16) \
- | ((unsigned (d)) & 0xfffc) \
- | ((unsigned (xo)) & 0x3))
- #define insn_xfx(opcd, rts, spr, xo) \
- ((((unsigned (opcd)) & 0x3f) << 26) \
- | (((unsigned (rts)) & 0x1f) << 21) \
- | (((unsigned (spr)) & 0x1f) << 16) \
- | (((unsigned (spr)) & 0x3e0) << 6) \
- | (((unsigned (xo)) & 0x3ff) << 1))
- #define prefix(a, b, R, do) \
- (((0x1) << 26) \
- | (((unsigned (a)) & 0x3) << 24) \
- | (((unsigned (b)) & 0x1) << 23) \
- | (((unsigned (R)) & 0x1) << 20) \
- | ((unsigned (do)) & 0x3ffff))
- #define insn_md(opcd, ra, rs, sh, me, rc) \
- ((((unsigned (opcd)) & 0x3f) << 26) \
- | (((unsigned (rs)) & 0x1f) << 21) \
- | (((unsigned (ra)) & 0x1f) << 16) \
- | (((unsigned (sh)) & 0x3e) << 11) \
- | (((unsigned (me)) & 0x3f) << 25) \
- | (((unsigned (sh)) & 0x1) << 1) \
- | ((unsigned (rc)) & 0x1))
- #define insn_x(opcd, rt, ra, rb, opc2) \
- ((((unsigned (opcd)) & 0x3f) << 26) \
- | (((unsigned (rt)) & 0x1f) << 21) \
- | (((unsigned (ra)) & 0x1f) << 16) \
- | (((unsigned (rb)) & 0x3e) << 11) \
- | (((unsigned (opc2)) & 0x3FF) << 1))
- #define insn_xo(opcd, rt, ra, rb, oe, rc, opc2) \
- ((((unsigned (opcd)) & 0x3f) << 26) \
- | (((unsigned (rt)) & 0x1f) << 21) \
- | (((unsigned (ra)) & 0x1f) << 16) \
- | (((unsigned (rb)) & 0x3e) << 11) \
- | (((unsigned (oe)) & 0x1) << 10) \
- | (((unsigned (opc2)) & 0x1FF) << 1) \
- | (((unsigned (rc)))))
- /* PLT_OFF is the TOC-relative offset of a 64-bit PowerPC PLT entry.
- Return the function's entry point. */
- static CORE_ADDR
- ppc64_plt_entry_point (struct frame_info *frame, CORE_ADDR plt_off)
- {
- struct gdbarch *gdbarch = get_frame_arch (frame);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- ppc_gdbarch_tdep *tdep = (ppc_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- CORE_ADDR tocp;
- if (execution_direction == EXEC_REVERSE)
- {
- /* If executing in reverse, r2 will have been stored to the stack. */
- CORE_ADDR sp = get_frame_register_unsigned (frame,
- tdep->ppc_gp0_regnum + 1);
- unsigned int sp_off = tdep->elf_abi == POWERPC_ELF_V1 ? 40 : 24;
- tocp = read_memory_unsigned_integer (sp + sp_off, 8, byte_order);
- }
- else
- tocp = get_frame_register_unsigned (frame, tdep->ppc_gp0_regnum + 2);
- /* The first word of the PLT entry is the function entry point. */
- return read_memory_unsigned_integer (tocp + plt_off, 8, byte_order);
- }
- static CORE_ADDR
- ppc64_plt_pcrel_entry_point (struct frame_info *frame, CORE_ADDR plt_off,
- CORE_ADDR pc)
- {
- struct gdbarch *gdbarch = get_frame_arch (frame);
- enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
- /* Execution direction doesn't matter, entry is pc + plt_off either way.
- The first word of the PLT entry is the function entry point. */
- return read_memory_unsigned_integer (pc + plt_off, 8, byte_order);
- }
- /* Patterns for the standard linkage functions. These are built by
- build_plt_stub in bfd/elf64-ppc.c. */
- /* Old ELFv1 PLT call stub. */
- static const struct ppc_insn_pattern ppc64_standard_linkage1[] =
- {
- /* addis r12, r2, <any> */
- { insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 },
- /* std r2, 40(r1) */
- { (unsigned) -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, 12, 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, 12, 1), 1 },
- /* mtctr r11 */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 11, 9, 467), 0 },
- /* ld r11, <any>(r12) <optional> */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 1 },
- /* bctr */
- { (unsigned) -1, 0x4e800420, 0 },
- { 0, 0, 0 }
- };
- /* ELFv1 PLT call stub to access PLT entries more than +/- 32k from r2.
- Also supports older stub with different placement of std 2,40(1),
- a stub that omits the std 2,40(1), and both versions of power7
- thread safety read barriers. Note that there are actually two more
- instructions following "cmpldi r2, 0", "bnectr+" and "b <glink_i>",
- but there isn't any need to match them. */
- static const struct ppc_insn_pattern ppc64_standard_linkage2[] =
- {
- /* std r2, 40(r1) <optional> */
- { (unsigned) -1, insn_ds (62, 2, 1, 40, 0), 1 },
- /* addis r12, r2, <any> */
- { insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 },
- /* std r2, 40(r1) <optional> */
- { (unsigned) -1, insn_ds (62, 2, 1, 40, 0), 1 },
- /* ld r11, <any>(r12) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 0 },
- /* addi r12, r12, <any> <optional> */
- { 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 },
- /* xor r11, r11, r11 <optional> */
- { (unsigned) -1, 0x7d6b5a78, 1 },
- /* add r12, r12, r11 <optional> */
- { (unsigned) -1, 0x7d8c5a14, 1 },
- /* ld r2, <any>(r12) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 12, 0, 0), 0 },
- /* ld r11, <any>(r12) <optional> */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 12, 0, 0), 1 },
- /* bctr <optional> */
- { (unsigned) -1, 0x4e800420, 1 },
- /* cmpldi r2, 0 <optional> */
- { (unsigned) -1, 0x28220000, 1 },
- { 0, 0, 0 }
- };
- /* ELFv1 PLT call stub to access PLT entries within +/- 32k of r2. */
- static const struct ppc_insn_pattern ppc64_standard_linkage3[] =
- {
- /* std r2, 40(r1) <optional> */
- { (unsigned) -1, insn_ds (62, 2, 1, 40, 0), 1 },
- /* ld r11, <any>(r2) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 2, 0, 0), 0 },
- /* addi r2, r2, <any> <optional> */
- { 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 },
- /* xor r11, r11, r11 <optional> */
- { (unsigned) -1, 0x7d6b5a78, 1 },
- /* add r2, r2, r11 <optional> */
- { (unsigned) -1, 0x7c425a14, 1 },
- /* ld r11, <any>(r2) <optional> */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 2, 0, 0), 1 },
- /* ld r2, <any>(r2) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 2, 0, 0), 0 },
- /* bctr <optional> */
- { (unsigned) -1, 0x4e800420, 1 },
- /* cmpldi r2, 0 <optional> */
- { (unsigned) -1, 0x28220000, 1 },
- { 0, 0, 0 }
- };
- /* ELFv1 PLT call stub to access PLT entries more than +/- 32k from r2.
- A more modern variant of ppc64_standard_linkage2 differing in
- register usage. */
- static const struct ppc_insn_pattern ppc64_standard_linkage4[] =
- {
- /* std r2, 40(r1) <optional> */
- { (unsigned) -1, insn_ds (62, 2, 1, 40, 0), 1 },
- /* addis r11, r2, <any> */
- { insn_d (-1, -1, -1, 0), insn_d (15, 11, 2, 0), 0 },
- /* ld r12, <any>(r11) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 12, 11, 0, 0), 0 },
- /* addi r11, r11, <any> <optional> */
- { insn_d (-1, -1, -1, 0), insn_d (14, 11, 11, 0), 1 },
- /* mtctr r12 */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
- /* xor r2, r12, r12 <optional> */
- { (unsigned) -1, 0x7d826278, 1 },
- /* add r11, r11, r2 <optional> */
- { (unsigned) -1, 0x7d6b1214, 1 },
- /* ld r2, <any>(r11) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 11, 0, 0), 0 },
- /* ld r11, <any>(r11) <optional> */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 11, 0, 0), 1 },
- /* bctr <optional> */
- { (unsigned) -1, 0x4e800420, 1 },
- /* cmpldi r2, 0 <optional> */
- { (unsigned) -1, 0x28220000, 1 },
- { 0, 0, 0 }
- };
- /* ELFv1 PLT call stub to access PLT entries within +/- 32k of r2.
- A more modern variant of ppc64_standard_linkage3 differing in
- register usage. */
- static const struct ppc_insn_pattern ppc64_standard_linkage5[] =
- {
- /* std r2, 40(r1) <optional> */
- { (unsigned) -1, insn_ds (62, 2, 1, 40, 0), 1 },
- /* ld r12, <any>(r2) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 12, 2, 0, 0), 0 },
- /* addi r2, r2, <any> <optional> */
- { insn_d (-1, -1, -1, 0), insn_d (14, 2, 2, 0), 1 },
- /* mtctr r12 */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
- /* xor r11, r12, r12 <optional> */
- { (unsigned) -1, 0x7d8b6278, 1 },
- /* add r2, r2, r11 <optional> */
- { (unsigned) -1, 0x7c425a14, 1 },
- /* ld r11, <any>(r2) <optional> */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 11, 2, 0, 0), 1 },
- /* ld r2, <any>(r2) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 2, 2, 0, 0), 0 },
- /* bctr <optional> */
- { (unsigned) -1, 0x4e800420, 1 },
- /* cmpldi r2, 0 <optional> */
- { (unsigned) -1, 0x28220000, 1 },
- { 0, 0, 0 }
- };
- /* ELFv2 PLT call stub to access PLT entries more than +/- 32k from r2. */
- static const struct ppc_insn_pattern ppc64_standard_linkage6[] =
- {
- /* std r2, 24(r1) <optional> */
- { (unsigned) -1, insn_ds (62, 2, 1, 24, 0), 1 },
- /* addis r11, r2, <any> */
- { insn_d (-1, -1, -1, 0), insn_d (15, 11, 2, 0), 0 },
- /* ld r12, <any>(r11) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 12, 11, 0, 0), 0 },
- /* mtctr r12 */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
- /* bctr */
- { (unsigned) -1, 0x4e800420, 0 },
- { 0, 0, 0 }
- };
- /* ELFv2 PLT call stub to access PLT entries within +/- 32k of r2. */
- static const struct ppc_insn_pattern ppc64_standard_linkage7[] =
- {
- /* std r2, 24(r1) <optional> */
- { (unsigned) -1, insn_ds (62, 2, 1, 24, 0), 1 },
- /* ld r12, <any>(r2) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 12, 2, 0, 0), 0 },
- /* mtctr r12 */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
- /* bctr */
- { (unsigned) -1, 0x4e800420, 0 },
- { 0, 0, 0 }
- };
- /* ELFv2 PLT call stub to access PLT entries more than +/- 32k from r2,
- supporting fusion. */
- static const struct ppc_insn_pattern ppc64_standard_linkage8[] =
- {
- /* std r2, 24(r1) <optional> */
- { (unsigned) -1, insn_ds (62, 2, 1, 24, 0), 1 },
- /* addis r12, r2, <any> */
- { insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 },
- /* ld r12, <any>(r12) */
- { insn_ds (-1, -1, -1, 0, -1), insn_ds (58, 12, 12, 0, 0), 0 },
- /* mtctr r12 */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
- /* bctr */
- { (unsigned) -1, 0x4e800420, 0 },
- { 0, 0, 0 }
- };
- /* Power 10 ELFv2 PLT call stubs */
- static const struct ppc_insn_pattern ppc64_standard_linkage9[] =
- {
- /* std %r2,0+40(%r1) <optional> */
- { insn_ds (-1, -1, -1, 0, 1), insn_ds (62, 2, 1, 40, 0), 1 },
- /* pld r12, <any> */
- { prefix (-1, -1, 1, 0), prefix (0, 0, 1, 0), 0 },
- { insn_d (-1, -1, -1, 0), insn_d (57, 12, 0, 0), 0 },
- /* mtctr r12 */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
- /* bctr */
- { (unsigned) -1, 0x4e800420, 0 },
- { 0, 0, 0 }
- };
- static const struct ppc_insn_pattern ppc64_standard_linkage10[] =
- {
- /* std %r2,0+40(%r1) <optional> */
- { insn_ds (-1, -1, -1, 0, 1), insn_ds (62, 2, 1, 40, 0), 1 },
- /* paddi r12,<any> */
- { prefix (-1, -1, 1, 0), prefix (2, 0, 1, 0), 0 },
- { insn_d (-1, -1, -1, 0), insn_d (14, 12, 0, 0), 0 },
- /* mtctr r12 <optional> */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
- /* bctr */
- { (unsigned) -1, 0x4e800420, 0 },
- { 0, 0, 0 }
- };
- static const struct ppc_insn_pattern ppc64_standard_linkage11[] =
- {
- /* std %r2,0+40(%r1) <optional> */
- { insn_ds (-1, -1, -1, 0, 1), insn_ds (62, 2, 1, 40, 0), 1 },
- /* li %r11,0 <optional> */
- { insn_d (-1, -1, -1, 0), insn_d (14, 11, 0, 0), 1 },
- /* sldi %r11,%r11,34 <eq to rldicr rx,ry,n, 63-n> <optional> */
- { insn_md (-1, -1, -1, 0, 0, 1), insn_md (30, 11, 11, 34, 63-34, 0), 1 },
- /* paddi r12, <any> */
- { prefix (-1, -1, 1, 0), prefix (2, 0, 1, 0), 0 },
- { insn_d (-1, -1, -1, 0), insn_d (14, 12, 0, 0), 0 },
- /* ldx %r12,%r11,%r12 <optional> */
- { (unsigned) -1, insn_x (31, 12, 11, 12, 21), 1 },
- /* add %r12,%r11,%r12 <optional> */
- { (unsigned) -1, insn_xo (31, 12, 11, 12, 0, 0, 40), 1 },
- /* mtctr r12 */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
- /* bctr */ // 13, 14, 15, 16
- { (unsigned) -1, 0x4e800420, 0 },
- { 0, 0, 0 }
- };
- static const struct ppc_insn_pattern ppc64_standard_linkage12[] =
- {
- /* std %r2,0+40(%r1) <optional> */
- { insn_ds (-1, -1, -1, 0, 1), insn_ds (62, 2, 1, 40, 0), 1 },
- /* lis %r11,xxx@ha <equivalent addis rx, 0, val> */
- /* addis r12, r2, <any> */
- { insn_d (-1, -1, -1, 0), insn_d (15, 12, 2, 0), 0 },
- /* ori %r11,%r11,xxx@l */
- { insn_d (-1, -1, -1, 0), insn_d (24, 11, 11, 0), 0 },
- /* sldi %r11,%r11,34 <optional> */
- { (unsigned) -1, insn_md (30, 11, 11, 34, 63-34, 0), 1 },
- /*paddi r12,<any> */
- { prefix (-1, -1, 1, 0), prefix (2, 0, 1, 0), 0 },
- { insn_d (-1, -1, -1, 0), insn_d (14, 12, 0, 0), 0 },
- /* sldi %r11,%r11,34 <optional> */
- { (unsigned) -1, insn_md (30, 11, 11, 34, 63-34, 0), 1 },
- /* ldx %r12,%r11,%r12 <optional> */
- { (unsigned) -1, insn_x (31, 12, 11, 12, 21), 1 },
- /* add %r12,%r11,%r12 <optional> */
- { (unsigned) -1, insn_xo (31, 12, 11, 12, 0, 0, 40), 1 },
- /* mtctr r12 */
- { insn_xfx (-1, -1, -1, -1), insn_xfx (31, 12, 9, 467), 0 },
- /* bctr */ // 17, 18, 19, 20
- { (unsigned) -1, 0x4e800420, 0 },
- { 0, 0, 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:
- 100003d4: 4b ff ff ad bl 10000380 <nnnn.plt_call.printf>
- 100003d8: e8 41 00 28 ld r2,40(r1)
- - The linkage function loads the entry point and toc pointer from
- the function descriptor in the PLT, and jumps to it:
- <nnnn.plt_call.printf>:
- 10000380: f8 41 00 28 std r2,40(r1)
- 10000384: e9 62 80 78 ld r11,-32648(r2)
- 10000388: 7d 69 03 a6 mtctr r11
- 1000038c: e8 42 80 80 ld r2,-32640(r2)
- 10000390: 28 22 00 00 cmpldi r2,0
- 10000394: 4c e2 04 20 bnectr+
- 10000398: 48 00 03 a0 b 10000738 <printf@plt>
- - 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:
- <printf@plt>:
- 10000738: 38 00 00 01 li r0,1
- 1000073c: 4b ff ff bc b 100006f8 <__glink_PLTresolve>
- - The common glink0 code then transfers control to the dynamic
- linker's fixup code:
- 100006f0: 0000000000010440 .quad plt0 - (. + 16)
- <__glink_PLTresolve>:
- 100006f8: 7d 88 02 a6 mflr r12
- 100006fc: 42 9f 00 05 bcl 20,4*cr7+so,10000700
- 10000700: 7d 68 02 a6 mflr r11
- 10000704: e8 4b ff f0 ld r2,-16(r11)
- 10000708: 7d 88 03 a6 mtlr r12
- 1000070c: 7d 82 5a 14 add r12,r2,r11
- 10000710: e9 6c 00 00 ld r11,0(r12)
- 10000714: e8 4c 00 08 ld r2,8(r12)
- 10000718: 7d 69 03 a6 mtctr r11
- 1000071c: e9 6c 00 10 ld r11,16(r12)
- 10000720: 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
- 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, unsigned int *insn)
- {
- CORE_ADDR plt_off = ((ppc_insn_d_field (insn[0]) << 16)
- + ppc_insn_ds_field (insn[2]));
- return ppc64_plt_entry_point (frame, plt_off);
- }
- static CORE_ADDR
- ppc64_standard_linkage2_target (struct frame_info *frame, unsigned int *insn)
- {
- CORE_ADDR plt_off = ((ppc_insn_d_field (insn[1]) << 16)
- + ppc_insn_ds_field (insn[3]));
- return ppc64_plt_entry_point (frame, plt_off);
- }
- static CORE_ADDR
- ppc64_standard_linkage3_target (struct frame_info *frame, unsigned int *insn)
- {
- CORE_ADDR plt_off = ppc_insn_ds_field (insn[1]);
- return ppc64_plt_entry_point (frame, plt_off);
- }
- static CORE_ADDR
- ppc64_standard_linkage4_target (struct frame_info *frame, unsigned int *insn)
- {
- CORE_ADDR plt_off = ((ppc_insn_d_field (insn[1]) << 16)
- + ppc_insn_ds_field (insn[2]));
- return ppc64_plt_entry_point (frame, plt_off);
- }
- static CORE_ADDR
- ppc64_pcrel_linkage1_target (struct frame_info *frame, unsigned int *insn,
- CORE_ADDR pc)
- {
- /* insn[0] is for the std instruction. */
- CORE_ADDR plt_off = ppc_insn_prefix_dform (insn[1], insn[2]);
- return ppc64_plt_pcrel_entry_point (frame, plt_off, pc);
- }
- static CORE_ADDR
- ppc64_pcrel_linkage2_target (struct frame_info *frame, unsigned int *insn,
- CORE_ADDR pc)
- {
- CORE_ADDR plt_off;
- /* insn[0] is for the std instruction.
- insn[1] is for the li r11 instruction */
- plt_off = ppc_insn_prefix_dform (insn[2], insn[3]);
- return ppc64_plt_pcrel_entry_point (frame, plt_off, pc);
- }
- /* 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 (MAX (ARRAY_SIZE (ppc64_standard_linkage5),
- ARRAY_SIZE (ppc64_standard_linkage6)),
- MAX (ARRAY_SIZE (ppc64_standard_linkage7),
- ARRAY_SIZE (ppc64_standard_linkage8))),
- MAX (MAX (ARRAY_SIZE (ppc64_standard_linkage9),
- ARRAY_SIZE (ppc64_standard_linkage10)),
- MAX (ARRAY_SIZE (ppc64_standard_linkage11),
- ARRAY_SIZE (ppc64_standard_linkage12)))))
- - 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_linkage12) - 1
- && ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage12, insns))
- pc = ppc64_pcrel_linkage1_target (frame, insns, pc);
- else if (i < ARRAY_SIZE (ppc64_standard_linkage11) - 1
- && ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage11, insns))
- pc = ppc64_pcrel_linkage2_target (frame, insns, pc);
- else if (i < ARRAY_SIZE (ppc64_standard_linkage10) - 1
- && ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage10, insns))
- pc = ppc64_pcrel_linkage1_target (frame, insns, pc);
- else if (i < ARRAY_SIZE (ppc64_standard_linkage9) - 1
- && ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage9, insns))
- pc = ppc64_pcrel_linkage1_target (frame, insns, pc);
- else if (i < ARRAY_SIZE (ppc64_standard_linkage8) - 1
- && ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage8, insns))
- pc = ppc64_standard_linkage4_target (frame, 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, 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, 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, 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, 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, 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, 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, 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);
- const 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->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);
- }
- }
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