diff options
Diffstat (limited to 'gdb/ppc64-tdep.c')
| -rw-r--r-- | gdb/ppc64-tdep.c | 142 |
1 files changed, 86 insertions, 56 deletions
diff --git a/gdb/ppc64-tdep.c b/gdb/ppc64-tdep.c index f636b4d..8732182 100644 --- a/gdb/ppc64-tdep.c +++ b/gdb/ppc64-tdep.c @@ -59,9 +59,10 @@ ppc64_desc_entry_point (struct gdbarch *gdbarch, CORE_ADDR desc) return (CORE_ADDR) read_memory_unsigned_integer (desc, 8, byte_order); } -/* Pattern for the standard linkage function. These are built by - build_plt_stub in elf64-ppc.c, whose GLINK argument is always - zero. */ +/* Patterns for the standard linkage functions. These are built by + build_plt_stub in bfd/elf64-ppc.c. */ + +/* Old PLT call stub. */ static struct ppc_insn_pattern ppc64_standard_linkage1[] = { @@ -95,15 +96,23 @@ static struct ppc_insn_pattern ppc64_standard_linkage1[] = { 0, 0, 0 } }; -#define PPC64_STANDARD_LINKAGE1_LEN ARRAY_SIZE (ppc64_standard_linkage1) +/* Current 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) */ - { -1, insn_ds (62, 2, 1, 40, 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 }, @@ -114,24 +123,33 @@ static struct ppc_insn_pattern ppc64_standard_linkage2[] = /* 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 */ - { -1, 0x4e800420, 0 }, + /* bctr <optional> */ + { -1, 0x4e800420, 1 }, + + /* cmpldi r2, 0 <optional> */ + { -1, 0x28220000, 1 }, { 0, 0, 0 } }; -#define PPC64_STANDARD_LINKAGE2_LEN ARRAY_SIZE (ppc64_standard_linkage2) +/* Current PLT call stub to access PLT entries within +/- 32k of r2. */ static struct ppc_insn_pattern ppc64_standard_linkage3[] = { - /* std r2, 40(r1) */ - { -1, insn_ds (62, 2, 1, 40, 0), 0 }, + /* 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 }, @@ -142,56 +160,71 @@ static struct ppc_insn_pattern ppc64_standard_linkage3[] = /* 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 */ - { -1, 0x4e800420, 0 }, + /* bctr <optional> */ + { -1, 0x4e800420, 1 }, + + /* cmpldi r2, 0 <optional> */ + { -1, 0x28220000, 1 }, { 0, 0, 0 } }; -#define PPC64_STANDARD_LINKAGE3_LEN ARRAY_SIZE (ppc64_standard_linkage3) - /* When the dynamic linker is doing lazy symbol resolution, the first call to a function in another object will go like this: - The user's function calls the linkage function: - 100007c4: 4b ff fc d5 bl 10000498 - 100007c8: e8 41 00 28 ld r2,40(r1) + 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 other stuff) from - the function descriptor in the PLT, and jumps to it: + - The linkage function loads the entry point and toc pointer from + the function descriptor in the PLT, and jumps to it: - 10000498: 3d 82 00 00 addis r12,r2,0 - 1000049c: f8 41 00 28 std r2,40(r1) - 100004a0: e9 6c 80 98 ld r11,-32616(r12) - 100004a4: e8 4c 80 a0 ld r2,-32608(r12) - 100004a8: 7d 69 03 a6 mtctr r11 - 100004ac: e9 6c 80 a8 ld r11,-32600(r12) - 100004b0: 4e 80 04 20 bctr + <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: + sends control to its glink entry. That loads the number of the + PLT entry and jumps to the common glink0 code: - 10000c98: 38 00 00 00 li r0,0 - 10000c9c: 4b ff ff dc b 10000c78 + <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: - - 10000c78: e8 41 00 28 ld r2,40(r1) - 10000c7c: 3d 82 00 00 addis r12,r2,0 - 10000c80: e9 6c 80 80 ld r11,-32640(r12) - 10000c84: e8 4c 80 88 ld r2,-32632(r12) - 10000c88: 7d 69 03 a6 mtctr r11 - 10000c8c: e9 6c 80 90 ld r11,-32624(r12) - 10000c90: 4e 80 04 20 bctr + 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 @@ -234,8 +267,8 @@ ppc64_standard_linkage2_target (struct frame_info *frame, CORE_ADDR desc = ((CORE_ADDR) get_frame_register_unsigned (frame, tdep->ppc_gp0_regnum + 2) - + (ppc_insn_d_field (insn[0]) << 16) - + ppc_insn_ds_field (insn[2])); + + (ppc_insn_d_field (insn[1]) << 16) + + ppc_insn_ds_field (insn[3])); /* The first word of the descriptor is the entry point. Return that. */ return ppc64_desc_entry_point (gdbarch, desc); @@ -266,23 +299,20 @@ ppc64_standard_linkage3_target (struct frame_info *frame, CORE_ADDR ppc64_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc) { - unsigned int ppc64_standard_linkage1_insn[PPC64_STANDARD_LINKAGE1_LEN]; - unsigned int ppc64_standard_linkage2_insn[PPC64_STANDARD_LINKAGE2_LEN]; - unsigned int ppc64_standard_linkage3_insn[PPC64_STANDARD_LINKAGE3_LEN]; +#define MAX(a,b) ((a) > (b) ? (a) : (b)) + unsigned int insns[MAX (MAX (ARRAY_SIZE (ppc64_standard_linkage1), + ARRAY_SIZE (ppc64_standard_linkage2)), + ARRAY_SIZE (ppc64_standard_linkage3)) - 1]; CORE_ADDR target; - if (ppc_insns_match_pattern (pc, ppc64_standard_linkage1, - ppc64_standard_linkage1_insn)) - pc = ppc64_standard_linkage1_target (frame, pc, - ppc64_standard_linkage1_insn); - else if (ppc_insns_match_pattern (pc, ppc64_standard_linkage2, - ppc64_standard_linkage2_insn)) - pc = ppc64_standard_linkage2_target (frame, pc, - ppc64_standard_linkage2_insn); - else if (ppc_insns_match_pattern (pc, ppc64_standard_linkage3, - ppc64_standard_linkage3_insn)) - pc = ppc64_standard_linkage3_target (frame, pc, - ppc64_standard_linkage3_insn); + 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; |