|  | /* Common target-dependent code for ppc64 GDB, the GNU debugger. | 
|  |  | 
|  | Copyright (C) 1986-2014 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 "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)                \ | 
|  | ((((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 PLT is the address of a 64-bit PowerPC PLT entry, | 
|  | return the function's entry point.  */ | 
|  |  | 
|  | static CORE_ADDR | 
|  | ppc64_plt_entry_point (struct gdbarch *gdbarch, CORE_ADDR plt) | 
|  | { | 
|  | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | 
|  | /* The first word of the PLT entry is the function entry point.  */ | 
|  | return (CORE_ADDR) read_memory_unsigned_integer (plt, 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 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) */ | 
|  | { -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 */ | 
|  | { -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 struct ppc_insn_pattern ppc64_standard_linkage2[] = | 
|  | { | 
|  | /* std r2, 40(r1) <optional> */ | 
|  | { -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> */ | 
|  | { -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> */ | 
|  | { -1, 0x7d6b5a78, 1 }, | 
|  |  | 
|  | /* add r12, r12, r11 <optional> */ | 
|  | { -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> */ | 
|  | { -1, 0x4e800420, 1 }, | 
|  |  | 
|  | /* cmpldi r2, 0 <optional> */ | 
|  | { -1, 0x28220000, 1 }, | 
|  |  | 
|  | { 0, 0, 0 } | 
|  | }; | 
|  |  | 
|  | /* ELFv1 PLT call stub to access PLT entries within +/- 32k of r2.  */ | 
|  |  | 
|  | static struct ppc_insn_pattern ppc64_standard_linkage3[] = | 
|  | { | 
|  | /* std r2, 40(r1) <optional> */ | 
|  | { -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> */ | 
|  | { -1, 0x7d6b5a78, 1 }, | 
|  |  | 
|  | /* add r2, r2, r11 <optional> */ | 
|  | { -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> */ | 
|  | { -1, 0x4e800420, 1 }, | 
|  |  | 
|  | /* cmpldi r2, 0 <optional> */ | 
|  | { -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 struct ppc_insn_pattern ppc64_standard_linkage4[] = | 
|  | { | 
|  | /* std r2, 40(r1) <optional> */ | 
|  | { -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> */ | 
|  | { -1, 0x7d826278, 1 }, | 
|  |  | 
|  | /* add r11, r11, r2 <optional> */ | 
|  | { -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> */ | 
|  | { -1, 0x4e800420, 1 }, | 
|  |  | 
|  | /* cmpldi r2, 0 <optional> */ | 
|  | { -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 struct ppc_insn_pattern ppc64_standard_linkage5[] = | 
|  | { | 
|  | /* std r2, 40(r1) <optional> */ | 
|  | { -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> */ | 
|  | { -1, 0x7d8b6278, 1 }, | 
|  |  | 
|  | /* add r2, r2, r11 <optional> */ | 
|  | { -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> */ | 
|  | { -1, 0x4e800420, 1 }, | 
|  |  | 
|  | /* cmpldi r2, 0 <optional> */ | 
|  | { -1, 0x28220000, 1 }, | 
|  |  | 
|  | { 0, 0, 0 } | 
|  | }; | 
|  |  | 
|  | /* ELFv2 PLT call stub to access PLT entries more than +/- 32k from r2.  */ | 
|  |  | 
|  | static struct ppc_insn_pattern ppc64_standard_linkage6[] = | 
|  | { | 
|  | /* std r2, 24(r1) <optional> */ | 
|  | { -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 */ | 
|  | { -1, 0x4e800420, 0 }, | 
|  |  | 
|  | { 0, 0, 0 } | 
|  | }; | 
|  |  | 
|  | /* ELFv2 PLT call stub to access PLT entries within +/- 32k of r2.  */ | 
|  |  | 
|  | static struct ppc_insn_pattern ppc64_standard_linkage7[] = | 
|  | { | 
|  | /* std r2, 24(r1) <optional> */ | 
|  | { -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 */ | 
|  | { -1, 0x4e800420, 0 }, | 
|  |  | 
|  | { 0, 0, 0 } | 
|  | }; | 
|  |  | 
|  | /* ELFv2 PLT call stub to access PLT entries more than +/- 32k from r2, | 
|  | supporting fusion.  */ | 
|  |  | 
|  | static struct ppc_insn_pattern ppc64_standard_linkage8[] = | 
|  | { | 
|  | /* std r2, 24(r1) <optional> */ | 
|  | { -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 */ | 
|  | { -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 | 
|  | 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 PLT entry this linkage function references.  */ | 
|  | CORE_ADDR plt | 
|  | = ((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])); | 
|  |  | 
|  | return ppc64_plt_entry_point (gdbarch, plt); | 
|  | } | 
|  |  | 
|  | 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 PLT entry this linkage function references.  */ | 
|  | 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[3])); | 
|  |  | 
|  | return ppc64_plt_entry_point (gdbarch, plt); | 
|  | } | 
|  |  | 
|  | 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 PLT entry this linkage function references.  */ | 
|  | CORE_ADDR plt | 
|  | = ((CORE_ADDR) get_frame_register_unsigned (frame, | 
|  | tdep->ppc_gp0_regnum + 2) | 
|  | + ppc_insn_ds_field (insn[1])); | 
|  |  | 
|  | return ppc64_plt_entry_point (gdbarch, plt); | 
|  | } | 
|  |  | 
|  | static CORE_ADDR | 
|  | 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.  */ | 
|  |  | 
|  | CORE_ADDR | 
|  | ppc64_skip_trampoline_code (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; | 
|  |  | 
|  | if (ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage8, insns)) | 
|  | pc = ppc64_standard_linkage4_target (frame, pc, insns); | 
|  | else if (ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage7, insns)) | 
|  | pc = ppc64_standard_linkage3_target (frame, pc, insns); | 
|  | else if (ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage6, insns)) | 
|  | pc = ppc64_standard_linkage4_target (frame, pc, insns); | 
|  | else if (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 (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 (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 (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 (ppc_insns_match_pattern (frame, pc, ppc64_standard_linkage1, insns)) | 
|  | pc = ppc64_standard_linkage1_target (frame, pc, insns); | 
|  | 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->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); | 
|  | } | 
|  | } |