| /* Common target-dependent code for ppc64 GDB, the GNU debugger. |
| |
| Copyright (C) 1986-2021 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); |
| struct gdbarch_tdep *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); |
| } |
| } |
