/* Target-dependent code for GDB, the GNU debugger. Copyright (C) 1986-2013 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 . */ #include "defs.h" #include "frame.h" #include "inferior.h" #include "symtab.h" #include "target.h" #include "gdbcore.h" #include "gdbcmd.h" #include "symfile.h" #include "objfiles.h" #include "regcache.h" #include "value.h" #include "osabi.h" #include "regset.h" #include "solib-svr4.h" #include "solib-spu.h" #include "solib.h" #include "solist.h" #include "ppc-tdep.h" #include "ppc64-tdep.h" #include "ppc-linux-tdep.h" #include "glibc-tdep.h" #include "trad-frame.h" #include "frame-unwind.h" #include "tramp-frame.h" #include "observer.h" #include "auxv.h" #include "elf/common.h" #include "exceptions.h" #include "arch-utils.h" #include "spu-tdep.h" #include "xml-syscall.h" #include "linux-tdep.h" #include "stap-probe.h" #include "ax.h" #include "ax-gdb.h" #include "cli/cli-utils.h" #include "parser-defs.h" #include "user-regs.h" #include #include "elf-bfd.h" /* for elfcore_write_* */ #include "features/rs6000/powerpc-32l.c" #include "features/rs6000/powerpc-altivec32l.c" #include "features/rs6000/powerpc-cell32l.c" #include "features/rs6000/powerpc-vsx32l.c" #include "features/rs6000/powerpc-isa205-32l.c" #include "features/rs6000/powerpc-isa205-altivec32l.c" #include "features/rs6000/powerpc-isa205-vsx32l.c" #include "features/rs6000/powerpc-64l.c" #include "features/rs6000/powerpc-altivec64l.c" #include "features/rs6000/powerpc-cell64l.c" #include "features/rs6000/powerpc-vsx64l.c" #include "features/rs6000/powerpc-isa205-64l.c" #include "features/rs6000/powerpc-isa205-altivec64l.c" #include "features/rs6000/powerpc-isa205-vsx64l.c" #include "features/rs6000/powerpc-e500l.c" /* Shared library operations for PowerPC-Linux. */ static struct target_so_ops powerpc_so_ops; /* The syscall's XML filename for PPC and PPC64. */ #define XML_SYSCALL_FILENAME_PPC "syscalls/ppc-linux.xml" #define XML_SYSCALL_FILENAME_PPC64 "syscalls/ppc64-linux.xml" /* ppc_linux_memory_remove_breakpoints attempts to remove a breakpoint in much the same fashion as memory_remove_breakpoint in mem-break.c, but is careful not to write back the previous contents if the code in question has changed in between inserting the breakpoint and removing it. Here is the problem that we're trying to solve... Once upon a time, before introducing this function to remove breakpoints from the inferior, setting a breakpoint on a shared library function prior to running the program would not work properly. In order to understand the problem, it is first necessary to understand a little bit about dynamic linking on this platform. A call to a shared library function is accomplished via a bl (branch-and-link) instruction whose branch target is an entry in the procedure linkage table (PLT). The PLT in the object file is uninitialized. To gdb, prior to running the program, the entries in the PLT are all zeros. Once the program starts running, the shared libraries are loaded and the procedure linkage table is initialized, but the entries in the table are not (necessarily) resolved. Once a function is actually called, the code in the PLT is hit and the function is resolved. In order to better illustrate this, an example is in order; the following example is from the gdb testsuite. We start the program shmain. [kev@arroyo testsuite]$ ../gdb gdb.base/shmain [...] We place two breakpoints, one on shr1 and the other on main. (gdb) b shr1 Breakpoint 1 at 0x100409d4 (gdb) b main Breakpoint 2 at 0x100006a0: file gdb.base/shmain.c, line 44. Examine the instruction (and the immediatly following instruction) upon which the breakpoint was placed. Note that the PLT entry for shr1 contains zeros. (gdb) x/2i 0x100409d4 0x100409d4 : .long 0x0 0x100409d8 : .long 0x0 Now run 'til main. (gdb) r Starting program: gdb.base/shmain Breakpoint 1 at 0xffaf790: file gdb.base/shr1.c, line 19. Breakpoint 2, main () at gdb.base/shmain.c:44 44 g = 1; Examine the PLT again. Note that the loading of the shared library has initialized the PLT to code which loads a constant (which I think is an index into the GOT) into r11 and then branchs a short distance to the code which actually does the resolving. (gdb) x/2i 0x100409d4 0x100409d4 : li r11,4 0x100409d8 : b 0x10040984 (gdb) c Continuing. Breakpoint 1, shr1 (x=1) at gdb.base/shr1.c:19 19 l = 1; Now we've hit the breakpoint at shr1. (The breakpoint was reset from the PLT entry to the actual shr1 function after the shared library was loaded.) Note that the PLT entry has been resolved to contain a branch that takes us directly to shr1. (The real one, not the PLT entry.) (gdb) x/2i 0x100409d4 0x100409d4 : b 0xffaf76c 0x100409d8 : b 0x10040984 The thing to note here is that the PLT entry for shr1 has been changed twice. Now the problem should be obvious. GDB places a breakpoint (a trap instruction) on the zero value of the PLT entry for shr1. Later on, after the shared library had been loaded and the PLT initialized, GDB gets a signal indicating this fact and attempts (as it always does when it stops) to remove all the breakpoints. The breakpoint removal was causing the former contents (a zero word) to be written back to the now initialized PLT entry thus destroying a portion of the initialization that had occurred only a short time ago. When execution continued, the zero word would be executed as an instruction an illegal instruction trap was generated instead. (0 is not a legal instruction.) The fix for this problem was fairly straightforward. The function memory_remove_breakpoint from mem-break.c was copied to this file, modified slightly, and renamed to ppc_linux_memory_remove_breakpoint. In tm-linux.h, MEMORY_REMOVE_BREAKPOINT is defined to call this new function. The differences between ppc_linux_memory_remove_breakpoint () and memory_remove_breakpoint () are minor. All that the former does that the latter does not is check to make sure that the breakpoint location actually contains a breakpoint (trap instruction) prior to attempting to write back the old contents. If it does contain a trap instruction, we allow the old contents to be written back. Otherwise, we silently do nothing. The big question is whether memory_remove_breakpoint () should be changed to have the same functionality. The downside is that more traffic is generated for remote targets since we'll have an extra fetch of a memory word each time a breakpoint is removed. For the time being, we'll leave this self-modifying-code-friendly version in ppc-linux-tdep.c, but it ought to be migrated somewhere else in the event that some other platform has similar needs with regard to removing breakpoints in some potentially self modifying code. */ static int ppc_linux_memory_remove_breakpoint (struct gdbarch *gdbarch, struct bp_target_info *bp_tgt) { CORE_ADDR addr = bp_tgt->placed_address; const unsigned char *bp; int val; int bplen; gdb_byte old_contents[BREAKPOINT_MAX]; struct cleanup *cleanup; /* Determine appropriate breakpoint contents and size for this address. */ bp = gdbarch_breakpoint_from_pc (gdbarch, &addr, &bplen); if (bp == NULL) error (_("Software breakpoints not implemented for this target.")); /* Make sure we see the memory breakpoints. */ cleanup = make_show_memory_breakpoints_cleanup (1); val = target_read_memory (addr, old_contents, bplen); /* If our breakpoint is no longer at the address, this means that the program modified the code on us, so it is wrong to put back the old value. */ if (val == 0 && memcmp (bp, old_contents, bplen) == 0) val = target_write_raw_memory (addr, bp_tgt->shadow_contents, bplen); do_cleanups (cleanup); return val; } /* For historic reasons, PPC 32 GNU/Linux follows PowerOpen rather than the 32 bit SYSV R4 ABI structure return convention - all structures, no matter their size, are put in memory. Vectors, which were added later, do get returned in a register though. */ static enum return_value_convention ppc_linux_return_value (struct gdbarch *gdbarch, struct value *function, struct type *valtype, struct regcache *regcache, gdb_byte *readbuf, const gdb_byte *writebuf) { if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT || TYPE_CODE (valtype) == TYPE_CODE_UNION) && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8) && TYPE_VECTOR (valtype))) return RETURN_VALUE_STRUCT_CONVENTION; else return ppc_sysv_abi_return_value (gdbarch, function, valtype, regcache, readbuf, writebuf); } static struct core_regset_section ppc_linux_vsx_regset_sections[] = { { ".reg", 48 * 4, "general-purpose" }, { ".reg2", 264, "floating-point" }, { ".reg-ppc-vmx", 544, "ppc Altivec" }, { ".reg-ppc-vsx", 256, "POWER7 VSX" }, { NULL, 0} }; static struct core_regset_section ppc_linux_vmx_regset_sections[] = { { ".reg", 48 * 4, "general-purpose" }, { ".reg2", 264, "floating-point" }, { ".reg-ppc-vmx", 544, "ppc Altivec" }, { NULL, 0} }; static struct core_regset_section ppc_linux_fp_regset_sections[] = { { ".reg", 48 * 4, "general-purpose" }, { ".reg2", 264, "floating-point" }, { NULL, 0} }; static struct core_regset_section ppc64_linux_vsx_regset_sections[] = { { ".reg", 48 * 8, "general-purpose" }, { ".reg2", 264, "floating-point" }, { ".reg-ppc-vmx", 544, "ppc Altivec" }, { ".reg-ppc-vsx", 256, "POWER7 VSX" }, { NULL, 0} }; static struct core_regset_section ppc64_linux_vmx_regset_sections[] = { { ".reg", 48 * 8, "general-purpose" }, { ".reg2", 264, "floating-point" }, { ".reg-ppc-vmx", 544, "ppc Altivec" }, { NULL, 0} }; static struct core_regset_section ppc64_linux_fp_regset_sections[] = { { ".reg", 48 * 8, "general-purpose" }, { ".reg2", 264, "floating-point" }, { NULL, 0} }; /* PLT stub in executable. */ static struct ppc_insn_pattern powerpc32_plt_stub[] = { { 0xffff0000, 0x3d600000, 0 }, /* lis r11, xxxx */ { 0xffff0000, 0x816b0000, 0 }, /* lwz r11, xxxx(r11) */ { 0xffffffff, 0x7d6903a6, 0 }, /* mtctr r11 */ { 0xffffffff, 0x4e800420, 0 }, /* bctr */ { 0, 0, 0 } }; /* PLT stub in shared library. */ static struct ppc_insn_pattern powerpc32_plt_stub_so[] = { { 0xffff0000, 0x817e0000, 0 }, /* lwz r11, xxxx(r30) */ { 0xffffffff, 0x7d6903a6, 0 }, /* mtctr r11 */ { 0xffffffff, 0x4e800420, 0 }, /* bctr */ { 0xffffffff, 0x60000000, 0 }, /* nop */ { 0, 0, 0 } }; #define POWERPC32_PLT_STUB_LEN ARRAY_SIZE (powerpc32_plt_stub) /* Check if PC is in PLT stub. For non-secure PLT, stub is in .plt section. For secure PLT, stub is in .text and we need to check instruction patterns. */ static int powerpc_linux_in_dynsym_resolve_code (CORE_ADDR pc) { struct minimal_symbol *sym; /* Check whether PC is in the dynamic linker. This also checks whether it is in the .plt section, used by non-PIC executables. */ if (svr4_in_dynsym_resolve_code (pc)) return 1; /* Check if we are in the resolver. */ sym = lookup_minimal_symbol_by_pc (pc); if (sym != NULL && (strcmp (SYMBOL_LINKAGE_NAME (sym), "__glink") == 0 || strcmp (SYMBOL_LINKAGE_NAME (sym), "__glink_PLTresolve") == 0)) return 1; return 0; } /* Follow PLT stub to actual routine. */ static CORE_ADDR ppc_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc) { int insnbuf[POWERPC32_PLT_STUB_LEN]; struct gdbarch *gdbarch = get_frame_arch (frame); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); CORE_ADDR target = 0; if (ppc_insns_match_pattern (pc, powerpc32_plt_stub, insnbuf)) { /* Insn pattern is lis r11, xxxx lwz r11, xxxx(r11) Branch target is in r11. */ target = (ppc_insn_d_field (insnbuf[0]) << 16) | ppc_insn_d_field (insnbuf[1]); target = read_memory_unsigned_integer (target, 4, byte_order); } if (ppc_insns_match_pattern (pc, powerpc32_plt_stub_so, insnbuf)) { /* Insn pattern is lwz r11, xxxx(r30) Branch target is in r11. */ target = get_frame_register_unsigned (frame, tdep->ppc_gp0_regnum + 30) + ppc_insn_d_field (insnbuf[0]); target = read_memory_unsigned_integer (target, 4, byte_order); } return target; } /* Wrappers to handle Linux-only registers. */ static void ppc_linux_supply_gregset (const struct regset *regset, struct regcache *regcache, int regnum, const void *gregs, size_t len) { const struct ppc_reg_offsets *offsets = regset->descr; ppc_supply_gregset (regset, regcache, regnum, gregs, len); if (ppc_linux_trap_reg_p (get_regcache_arch (regcache))) { /* "orig_r3" is stored 2 slots after "pc". */ if (regnum == -1 || regnum == PPC_ORIG_R3_REGNUM) ppc_supply_reg (regcache, PPC_ORIG_R3_REGNUM, gregs, offsets->pc_offset + 2 * offsets->gpr_size, offsets->gpr_size); /* "trap" is stored 8 slots after "pc". */ if (regnum == -1 || regnum == PPC_TRAP_REGNUM) ppc_supply_reg (regcache, PPC_TRAP_REGNUM, gregs, offsets->pc_offset + 8 * offsets->gpr_size, offsets->gpr_size); } } static void ppc_linux_collect_gregset (const struct regset *regset, const struct regcache *regcache, int regnum, void *gregs, size_t len) { const struct ppc_reg_offsets *offsets = regset->descr; /* Clear areas in the linux gregset not written elsewhere. */ if (regnum == -1) memset (gregs, 0, len); ppc_collect_gregset (regset, regcache, regnum, gregs, len); if (ppc_linux_trap_reg_p (get_regcache_arch (regcache))) { /* "orig_r3" is stored 2 slots after "pc". */ if (regnum == -1 || regnum == PPC_ORIG_R3_REGNUM) ppc_collect_reg (regcache, PPC_ORIG_R3_REGNUM, gregs, offsets->pc_offset + 2 * offsets->gpr_size, offsets->gpr_size); /* "trap" is stored 8 slots after "pc". */ if (regnum == -1 || regnum == PPC_TRAP_REGNUM) ppc_collect_reg (regcache, PPC_TRAP_REGNUM, gregs, offsets->pc_offset + 8 * offsets->gpr_size, offsets->gpr_size); } } /* Regset descriptions. */ static const struct ppc_reg_offsets ppc32_linux_reg_offsets = { /* General-purpose registers. */ /* .r0_offset = */ 0, /* .gpr_size = */ 4, /* .xr_size = */ 4, /* .pc_offset = */ 128, /* .ps_offset = */ 132, /* .cr_offset = */ 152, /* .lr_offset = */ 144, /* .ctr_offset = */ 140, /* .xer_offset = */ 148, /* .mq_offset = */ 156, /* Floating-point registers. */ /* .f0_offset = */ 0, /* .fpscr_offset = */ 256, /* .fpscr_size = */ 8, /* AltiVec registers. */ /* .vr0_offset = */ 0, /* .vscr_offset = */ 512 + 12, /* .vrsave_offset = */ 528 }; static const struct ppc_reg_offsets ppc64_linux_reg_offsets = { /* General-purpose registers. */ /* .r0_offset = */ 0, /* .gpr_size = */ 8, /* .xr_size = */ 8, /* .pc_offset = */ 256, /* .ps_offset = */ 264, /* .cr_offset = */ 304, /* .lr_offset = */ 288, /* .ctr_offset = */ 280, /* .xer_offset = */ 296, /* .mq_offset = */ 312, /* Floating-point registers. */ /* .f0_offset = */ 0, /* .fpscr_offset = */ 256, /* .fpscr_size = */ 8, /* AltiVec registers. */ /* .vr0_offset = */ 0, /* .vscr_offset = */ 512 + 12, /* .vrsave_offset = */ 528 }; static const struct regset ppc32_linux_gregset = { &ppc32_linux_reg_offsets, ppc_linux_supply_gregset, ppc_linux_collect_gregset, NULL }; static const struct regset ppc64_linux_gregset = { &ppc64_linux_reg_offsets, ppc_linux_supply_gregset, ppc_linux_collect_gregset, NULL }; static const struct regset ppc32_linux_fpregset = { &ppc32_linux_reg_offsets, ppc_supply_fpregset, ppc_collect_fpregset, NULL }; static const struct regset ppc32_linux_vrregset = { &ppc32_linux_reg_offsets, ppc_supply_vrregset, ppc_collect_vrregset, NULL }; static const struct regset ppc32_linux_vsxregset = { &ppc32_linux_reg_offsets, ppc_supply_vsxregset, ppc_collect_vsxregset, NULL }; const struct regset * ppc_linux_gregset (int wordsize) { return wordsize == 8 ? &ppc64_linux_gregset : &ppc32_linux_gregset; } const struct regset * ppc_linux_fpregset (void) { return &ppc32_linux_fpregset; } static const struct regset * ppc_linux_regset_from_core_section (struct gdbarch *core_arch, const char *sect_name, size_t sect_size) { struct gdbarch_tdep *tdep = gdbarch_tdep (core_arch); if (strcmp (sect_name, ".reg") == 0) { if (tdep->wordsize == 4) return &ppc32_linux_gregset; else return &ppc64_linux_gregset; } if (strcmp (sect_name, ".reg2") == 0) return &ppc32_linux_fpregset; if (strcmp (sect_name, ".reg-ppc-vmx") == 0) return &ppc32_linux_vrregset; if (strcmp (sect_name, ".reg-ppc-vsx") == 0) return &ppc32_linux_vsxregset; return NULL; } static void ppc_linux_sigtramp_cache (struct frame_info *this_frame, struct trad_frame_cache *this_cache, CORE_ADDR func, LONGEST offset, int bias) { CORE_ADDR base; CORE_ADDR regs; CORE_ADDR gpregs; CORE_ADDR fpregs; int i; struct gdbarch *gdbarch = get_frame_arch (this_frame); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); base = get_frame_register_unsigned (this_frame, gdbarch_sp_regnum (gdbarch)); if (bias > 0 && get_frame_pc (this_frame) != func) /* See below, some signal trampolines increment the stack as their first instruction, need to compensate for that. */ base -= bias; /* Find the address of the register buffer pointer. */ regs = base + offset; /* Use that to find the address of the corresponding register buffers. */ gpregs = read_memory_unsigned_integer (regs, tdep->wordsize, byte_order); fpregs = gpregs + 48 * tdep->wordsize; /* General purpose. */ for (i = 0; i < 32; i++) { int regnum = i + tdep->ppc_gp0_regnum; trad_frame_set_reg_addr (this_cache, regnum, gpregs + i * tdep->wordsize); } trad_frame_set_reg_addr (this_cache, gdbarch_pc_regnum (gdbarch), gpregs + 32 * tdep->wordsize); trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, gpregs + 35 * tdep->wordsize); trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, gpregs + 36 * tdep->wordsize); trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, gpregs + 37 * tdep->wordsize); trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, gpregs + 38 * tdep->wordsize); if (ppc_linux_trap_reg_p (gdbarch)) { trad_frame_set_reg_addr (this_cache, PPC_ORIG_R3_REGNUM, gpregs + 34 * tdep->wordsize); trad_frame_set_reg_addr (this_cache, PPC_TRAP_REGNUM, gpregs + 40 * tdep->wordsize); } if (ppc_floating_point_unit_p (gdbarch)) { /* Floating point registers. */ for (i = 0; i < 32; i++) { int regnum = i + gdbarch_fp0_regnum (gdbarch); trad_frame_set_reg_addr (this_cache, regnum, fpregs + i * tdep->wordsize); } trad_frame_set_reg_addr (this_cache, tdep->ppc_fpscr_regnum, fpregs + 32 * tdep->wordsize); } trad_frame_set_id (this_cache, frame_id_build (base, func)); } static void ppc32_linux_sigaction_cache_init (const struct tramp_frame *self, struct frame_info *this_frame, struct trad_frame_cache *this_cache, CORE_ADDR func) { ppc_linux_sigtramp_cache (this_frame, this_cache, func, 0xd0 /* Offset to ucontext_t. */ + 0x30 /* Offset to .reg. */, 0); } static void ppc64_linux_sigaction_cache_init (const struct tramp_frame *self, struct frame_info *this_frame, struct trad_frame_cache *this_cache, CORE_ADDR func) { ppc_linux_sigtramp_cache (this_frame, this_cache, func, 0x80 /* Offset to ucontext_t. */ + 0xe0 /* Offset to .reg. */, 128); } static void ppc32_linux_sighandler_cache_init (const struct tramp_frame *self, struct frame_info *this_frame, struct trad_frame_cache *this_cache, CORE_ADDR func) { ppc_linux_sigtramp_cache (this_frame, this_cache, func, 0x40 /* Offset to ucontext_t. */ + 0x1c /* Offset to .reg. */, 0); } static void ppc64_linux_sighandler_cache_init (const struct tramp_frame *self, struct frame_info *this_frame, struct trad_frame_cache *this_cache, CORE_ADDR func) { ppc_linux_sigtramp_cache (this_frame, this_cache, func, 0x80 /* Offset to struct sigcontext. */ + 0x38 /* Offset to .reg. */, 128); } static struct tramp_frame ppc32_linux_sigaction_tramp_frame = { SIGTRAMP_FRAME, 4, { { 0x380000ac, -1 }, /* li r0, 172 */ { 0x44000002, -1 }, /* sc */ { TRAMP_SENTINEL_INSN }, }, ppc32_linux_sigaction_cache_init }; static struct tramp_frame ppc64_linux_sigaction_tramp_frame = { SIGTRAMP_FRAME, 4, { { 0x38210080, -1 }, /* addi r1,r1,128 */ { 0x380000ac, -1 }, /* li r0, 172 */ { 0x44000002, -1 }, /* sc */ { TRAMP_SENTINEL_INSN }, }, ppc64_linux_sigaction_cache_init }; static struct tramp_frame ppc32_linux_sighandler_tramp_frame = { SIGTRAMP_FRAME, 4, { { 0x38000077, -1 }, /* li r0,119 */ { 0x44000002, -1 }, /* sc */ { TRAMP_SENTINEL_INSN }, }, ppc32_linux_sighandler_cache_init }; static struct tramp_frame ppc64_linux_sighandler_tramp_frame = { SIGTRAMP_FRAME, 4, { { 0x38210080, -1 }, /* addi r1,r1,128 */ { 0x38000077, -1 }, /* li r0,119 */ { 0x44000002, -1 }, /* sc */ { TRAMP_SENTINEL_INSN }, }, ppc64_linux_sighandler_cache_init }; /* Address to use for displaced stepping. When debugging a stand-alone SPU executable, entry_point_address () will point to an SPU local-store address and is thus not usable as displaced stepping location. We use the auxiliary vector to determine the PowerPC-side entry point address instead. */ static CORE_ADDR ppc_linux_entry_point_addr = 0; static void ppc_linux_inferior_created (struct target_ops *target, int from_tty) { ppc_linux_entry_point_addr = 0; } static CORE_ADDR ppc_linux_displaced_step_location (struct gdbarch *gdbarch) { if (ppc_linux_entry_point_addr == 0) { CORE_ADDR addr; /* Determine entry point from target auxiliary vector. */ if (target_auxv_search (¤t_target, AT_ENTRY, &addr) <= 0) error (_("Cannot find AT_ENTRY auxiliary vector entry.")); /* Make certain that the address points at real code, and not a function descriptor. */ addr = gdbarch_convert_from_func_ptr_addr (gdbarch, addr, ¤t_target); /* Inferior calls also use the entry point as a breakpoint location. We don't want displaced stepping to interfere with those breakpoints, so leave space. */ ppc_linux_entry_point_addr = addr + 2 * PPC_INSN_SIZE; } return ppc_linux_entry_point_addr; } /* Return 1 if PPC_ORIG_R3_REGNUM and PPC_TRAP_REGNUM are usable. */ int ppc_linux_trap_reg_p (struct gdbarch *gdbarch) { /* If we do not have a target description with registers, then the special registers will not be included in the register set. */ if (!tdesc_has_registers (gdbarch_target_desc (gdbarch))) return 0; /* If we do, then it is safe to check the size. */ return register_size (gdbarch, PPC_ORIG_R3_REGNUM) > 0 && register_size (gdbarch, PPC_TRAP_REGNUM) > 0; } /* Return the current system call's number present in the r0 register. When the function fails, it returns -1. */ static LONGEST ppc_linux_get_syscall_number (struct gdbarch *gdbarch, ptid_t ptid) { struct regcache *regcache = get_thread_regcache (ptid); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); struct cleanup *cleanbuf; /* The content of a register */ gdb_byte *buf; /* The result */ LONGEST ret; /* Make sure we're in a 32- or 64-bit machine */ gdb_assert (tdep->wordsize == 4 || tdep->wordsize == 8); buf = (gdb_byte *) xmalloc (tdep->wordsize * sizeof (gdb_byte)); cleanbuf = make_cleanup (xfree, buf); /* Getting the system call number from the register. When dealing with PowerPC architecture, this information is stored at 0th register. */ regcache_cooked_read (regcache, tdep->ppc_gp0_regnum, buf); ret = extract_signed_integer (buf, tdep->wordsize, byte_order); do_cleanups (cleanbuf); return ret; } static void ppc_linux_write_pc (struct regcache *regcache, CORE_ADDR pc) { struct gdbarch *gdbarch = get_regcache_arch (regcache); regcache_cooked_write_unsigned (regcache, gdbarch_pc_regnum (gdbarch), pc); /* Set special TRAP register to -1 to prevent the kernel from messing with the PC we just installed, if we happen to be within an interrupted system call that the kernel wants to restart. Note that after we return from the dummy call, the TRAP and ORIG_R3 registers will be automatically restored, and the kernel continues to restart the system call at this point. */ if (ppc_linux_trap_reg_p (gdbarch)) regcache_cooked_write_unsigned (regcache, PPC_TRAP_REGNUM, -1); } static int ppc_linux_spu_section (bfd *abfd, asection *asect, void *user_data) { return strncmp (bfd_section_name (abfd, asect), "SPU/", 4) == 0; } static const struct target_desc * ppc_linux_core_read_description (struct gdbarch *gdbarch, struct target_ops *target, bfd *abfd) { asection *cell = bfd_sections_find_if (abfd, ppc_linux_spu_section, NULL); asection *altivec = bfd_get_section_by_name (abfd, ".reg-ppc-vmx"); asection *vsx = bfd_get_section_by_name (abfd, ".reg-ppc-vsx"); asection *section = bfd_get_section_by_name (abfd, ".reg"); if (! section) return NULL; switch (bfd_section_size (abfd, section)) { case 48 * 4: if (cell) return tdesc_powerpc_cell32l; else if (vsx) return tdesc_powerpc_vsx32l; else if (altivec) return tdesc_powerpc_altivec32l; else return tdesc_powerpc_32l; case 48 * 8: if (cell) return tdesc_powerpc_cell64l; else if (vsx) return tdesc_powerpc_vsx64l; else if (altivec) return tdesc_powerpc_altivec64l; else return tdesc_powerpc_64l; default: return NULL; } } /* Implementation of `gdbarch_stap_is_single_operand', as defined in gdbarch.h. */ static int ppc_stap_is_single_operand (struct gdbarch *gdbarch, const char *s) { return (*s == 'i' /* Literal number. */ || (isdigit (*s) && s[1] == '(' && isdigit (s[2])) /* Displacement. */ || (*s == '(' && isdigit (s[1])) /* Register indirection. */ || isdigit (*s)); /* Register value. */ } /* Implementation of `gdbarch_stap_parse_special_token', as defined in gdbarch.h. */ static int ppc_stap_parse_special_token (struct gdbarch *gdbarch, struct stap_parse_info *p) { if (isdigit (*p->arg)) { /* This temporary pointer is needed because we have to do a lookahead. We could be dealing with a register displacement, and in such case we would not need to do anything. */ const char *s = p->arg; char *regname; int len; struct stoken str; while (isdigit (*s)) ++s; if (*s == '(') { /* It is a register displacement indeed. Returning 0 means we are deferring the treatment of this case to the generic parser. */ return 0; } len = s - p->arg; regname = alloca (len + 2); regname[0] = 'r'; strncpy (regname + 1, p->arg, len); ++len; regname[len] = '\0'; if (user_reg_map_name_to_regnum (gdbarch, regname, len) == -1) error (_("Invalid register name `%s' on expression `%s'."), regname, p->saved_arg); write_exp_elt_opcode (OP_REGISTER); str.ptr = regname; str.length = len; write_exp_string (str); write_exp_elt_opcode (OP_REGISTER); p->arg = s; } else { /* All the other tokens should be handled correctly by the generic parser. */ return 0; } return 1; } /* Cell/B.E. active SPE context tracking support. */ static struct objfile *spe_context_objfile = NULL; static CORE_ADDR spe_context_lm_addr = 0; static CORE_ADDR spe_context_offset = 0; static ptid_t spe_context_cache_ptid; static CORE_ADDR spe_context_cache_address; /* Hook into inferior_created, solib_loaded, and solib_unloaded observers to track whether we've loaded a version of libspe2 (as static or dynamic library) that provides the __spe_current_active_context variable. */ static void ppc_linux_spe_context_lookup (struct objfile *objfile) { struct minimal_symbol *sym; if (!objfile) { spe_context_objfile = NULL; spe_context_lm_addr = 0; spe_context_offset = 0; spe_context_cache_ptid = minus_one_ptid; spe_context_cache_address = 0; return; } sym = lookup_minimal_symbol ("__spe_current_active_context", NULL, objfile); if (sym) { spe_context_objfile = objfile; spe_context_lm_addr = svr4_fetch_objfile_link_map (objfile); spe_context_offset = SYMBOL_VALUE_ADDRESS (sym); spe_context_cache_ptid = minus_one_ptid; spe_context_cache_address = 0; return; } } static void ppc_linux_spe_context_inferior_created (struct target_ops *t, int from_tty) { struct objfile *objfile; ppc_linux_spe_context_lookup (NULL); ALL_OBJFILES (objfile) ppc_linux_spe_context_lookup (objfile); } static void ppc_linux_spe_context_solib_loaded (struct so_list *so) { if (strstr (so->so_original_name, "/libspe") != NULL) { solib_read_symbols (so, 0); ppc_linux_spe_context_lookup (so->objfile); } } static void ppc_linux_spe_context_solib_unloaded (struct so_list *so) { if (so->objfile == spe_context_objfile) ppc_linux_spe_context_lookup (NULL); } /* Retrieve contents of the N'th element in the current thread's linked SPE context list into ID and NPC. Return the address of said context element, or 0 if not found. */ static CORE_ADDR ppc_linux_spe_context (int wordsize, enum bfd_endian byte_order, int n, int *id, unsigned int *npc) { CORE_ADDR spe_context = 0; gdb_byte buf[16]; int i; /* Quick exit if we have not found __spe_current_active_context. */ if (!spe_context_objfile) return 0; /* Look up cached address of thread-local variable. */ if (!ptid_equal (spe_context_cache_ptid, inferior_ptid)) { struct target_ops *target = ¤t_target; volatile struct gdb_exception ex; while (target && !target->to_get_thread_local_address) target = find_target_beneath (target); if (!target) return 0; TRY_CATCH (ex, RETURN_MASK_ERROR) { /* We do not call target_translate_tls_address here, because svr4_fetch_objfile_link_map may invalidate the frame chain, which must not do while inside a frame sniffer. Instead, we have cached the lm_addr value, and use that to directly call the target's to_get_thread_local_address. */ spe_context_cache_address = target->to_get_thread_local_address (target, inferior_ptid, spe_context_lm_addr, spe_context_offset); spe_context_cache_ptid = inferior_ptid; } if (ex.reason < 0) return 0; } /* Read variable value. */ if (target_read_memory (spe_context_cache_address, buf, wordsize) == 0) spe_context = extract_unsigned_integer (buf, wordsize, byte_order); /* Cyle through to N'th linked list element. */ for (i = 0; i < n && spe_context; i++) if (target_read_memory (spe_context + align_up (12, wordsize), buf, wordsize) == 0) spe_context = extract_unsigned_integer (buf, wordsize, byte_order); else spe_context = 0; /* Read current context. */ if (spe_context && target_read_memory (spe_context, buf, 12) != 0) spe_context = 0; /* Extract data elements. */ if (spe_context) { if (id) *id = extract_signed_integer (buf, 4, byte_order); if (npc) *npc = extract_unsigned_integer (buf + 4, 4, byte_order); } return spe_context; } /* Cell/B.E. cross-architecture unwinder support. */ struct ppu2spu_cache { struct frame_id frame_id; struct regcache *regcache; }; static struct gdbarch * ppu2spu_prev_arch (struct frame_info *this_frame, void **this_cache) { struct ppu2spu_cache *cache = *this_cache; return get_regcache_arch (cache->regcache); } static void ppu2spu_this_id (struct frame_info *this_frame, void **this_cache, struct frame_id *this_id) { struct ppu2spu_cache *cache = *this_cache; *this_id = cache->frame_id; } static struct value * ppu2spu_prev_register (struct frame_info *this_frame, void **this_cache, int regnum) { struct ppu2spu_cache *cache = *this_cache; struct gdbarch *gdbarch = get_regcache_arch (cache->regcache); gdb_byte *buf; buf = alloca (register_size (gdbarch, regnum)); if (regnum < gdbarch_num_regs (gdbarch)) regcache_raw_read (cache->regcache, regnum, buf); else gdbarch_pseudo_register_read (gdbarch, cache->regcache, regnum, buf); return frame_unwind_got_bytes (this_frame, regnum, buf); } struct ppu2spu_data { struct gdbarch *gdbarch; int id; unsigned int npc; gdb_byte gprs[128*16]; }; static int ppu2spu_unwind_register (void *src, int regnum, gdb_byte *buf) { struct ppu2spu_data *data = src; enum bfd_endian byte_order = gdbarch_byte_order (data->gdbarch); if (regnum >= 0 && regnum < SPU_NUM_GPRS) memcpy (buf, data->gprs + 16*regnum, 16); else if (regnum == SPU_ID_REGNUM) store_unsigned_integer (buf, 4, byte_order, data->id); else if (regnum == SPU_PC_REGNUM) store_unsigned_integer (buf, 4, byte_order, data->npc); else return REG_UNAVAILABLE; return REG_VALID; } static int ppu2spu_sniffer (const struct frame_unwind *self, struct frame_info *this_frame, void **this_prologue_cache) { struct gdbarch *gdbarch = get_frame_arch (this_frame); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); struct ppu2spu_data data; struct frame_info *fi; CORE_ADDR base, func, backchain, spe_context; gdb_byte buf[8]; int n = 0; /* Count the number of SPU contexts already in the frame chain. */ for (fi = get_next_frame (this_frame); fi; fi = get_next_frame (fi)) if (get_frame_type (fi) == ARCH_FRAME && gdbarch_bfd_arch_info (get_frame_arch (fi))->arch == bfd_arch_spu) n++; base = get_frame_sp (this_frame); func = get_frame_pc (this_frame); if (target_read_memory (base, buf, tdep->wordsize)) return 0; backchain = extract_unsigned_integer (buf, tdep->wordsize, byte_order); spe_context = ppc_linux_spe_context (tdep->wordsize, byte_order, n, &data.id, &data.npc); if (spe_context && base <= spe_context && spe_context < backchain) { char annex[32]; /* Find gdbarch for SPU. */ struct gdbarch_info info; gdbarch_info_init (&info); info.bfd_arch_info = bfd_lookup_arch (bfd_arch_spu, bfd_mach_spu); info.byte_order = BFD_ENDIAN_BIG; info.osabi = GDB_OSABI_LINUX; info.tdep_info = (void *) &data.id; data.gdbarch = gdbarch_find_by_info (info); if (!data.gdbarch) return 0; xsnprintf (annex, sizeof annex, "%d/regs", data.id); if (target_read (¤t_target, TARGET_OBJECT_SPU, annex, data.gprs, 0, sizeof data.gprs) == sizeof data.gprs) { struct ppu2spu_cache *cache = FRAME_OBSTACK_CALLOC (1, struct ppu2spu_cache); struct address_space *aspace = get_frame_address_space (this_frame); struct regcache *regcache = regcache_xmalloc (data.gdbarch, aspace); struct cleanup *cleanups = make_cleanup_regcache_xfree (regcache); regcache_save (regcache, ppu2spu_unwind_register, &data); discard_cleanups (cleanups); cache->frame_id = frame_id_build (base, func); cache->regcache = regcache; *this_prologue_cache = cache; return 1; } } return 0; } static void ppu2spu_dealloc_cache (struct frame_info *self, void *this_cache) { struct ppu2spu_cache *cache = this_cache; regcache_xfree (cache->regcache); } static const struct frame_unwind ppu2spu_unwind = { ARCH_FRAME, default_frame_unwind_stop_reason, ppu2spu_this_id, ppu2spu_prev_register, NULL, ppu2spu_sniffer, ppu2spu_dealloc_cache, ppu2spu_prev_arch, }; static void ppc_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); struct tdesc_arch_data *tdesc_data = (void *) info.tdep_info; linux_init_abi (info, gdbarch); /* PPC GNU/Linux uses either 64-bit or 128-bit long doubles; where 128-bit, they are IBM long double, not IEEE quad long double as in the System V ABI PowerPC Processor Supplement. We can safely let them default to 128-bit, since the debug info will give the size of type actually used in each case. */ set_gdbarch_long_double_bit (gdbarch, 16 * TARGET_CHAR_BIT); set_gdbarch_long_double_format (gdbarch, floatformats_ibm_long_double); /* Handle inferior calls during interrupted system calls. */ set_gdbarch_write_pc (gdbarch, ppc_linux_write_pc); /* Get the syscall number from the arch's register. */ set_gdbarch_get_syscall_number (gdbarch, ppc_linux_get_syscall_number); /* SystemTap functions. */ set_gdbarch_stap_integer_prefix (gdbarch, "i"); set_gdbarch_stap_register_indirection_prefix (gdbarch, "("); set_gdbarch_stap_register_indirection_suffix (gdbarch, ")"); set_gdbarch_stap_gdb_register_prefix (gdbarch, "r"); set_gdbarch_stap_is_single_operand (gdbarch, ppc_stap_is_single_operand); set_gdbarch_stap_parse_special_token (gdbarch, ppc_stap_parse_special_token); if (tdep->wordsize == 4) { /* Until November 2001, gcc did not comply with the 32 bit SysV R4 ABI requirement that structures less than or equal to 8 bytes should be returned in registers. Instead GCC was using the AIX/PowerOpen ABI - everything returned in memory (well ignoring vectors that is). When this was corrected, it wasn't fixed for GNU/Linux native platform. Use the PowerOpen struct convention. */ set_gdbarch_return_value (gdbarch, ppc_linux_return_value); set_gdbarch_memory_remove_breakpoint (gdbarch, ppc_linux_memory_remove_breakpoint); /* Shared library handling. */ set_gdbarch_skip_trampoline_code (gdbarch, ppc_skip_trampoline_code); set_solib_svr4_fetch_link_map_offsets (gdbarch, svr4_ilp32_fetch_link_map_offsets); /* Setting the correct XML syscall filename. */ set_xml_syscall_file_name (XML_SYSCALL_FILENAME_PPC); /* Trampolines. */ tramp_frame_prepend_unwinder (gdbarch, &ppc32_linux_sigaction_tramp_frame); tramp_frame_prepend_unwinder (gdbarch, &ppc32_linux_sighandler_tramp_frame); /* BFD target for core files. */ if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_LITTLE) set_gdbarch_gcore_bfd_target (gdbarch, "elf32-powerpcle"); else set_gdbarch_gcore_bfd_target (gdbarch, "elf32-powerpc"); /* Supported register sections. */ if (tdesc_find_feature (info.target_desc, "org.gnu.gdb.power.vsx")) set_gdbarch_core_regset_sections (gdbarch, ppc_linux_vsx_regset_sections); else if (tdesc_find_feature (info.target_desc, "org.gnu.gdb.power.altivec")) set_gdbarch_core_regset_sections (gdbarch, ppc_linux_vmx_regset_sections); else set_gdbarch_core_regset_sections (gdbarch, ppc_linux_fp_regset_sections); if (powerpc_so_ops.in_dynsym_resolve_code == NULL) { powerpc_so_ops = svr4_so_ops; /* Override dynamic resolve function. */ powerpc_so_ops.in_dynsym_resolve_code = powerpc_linux_in_dynsym_resolve_code; } set_solib_ops (gdbarch, &powerpc_so_ops); set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver); } if (tdep->wordsize == 8) { /* Handle PPC GNU/Linux 64-bit function pointers (which are really function descriptors). */ set_gdbarch_convert_from_func_ptr_addr (gdbarch, ppc64_convert_from_func_ptr_addr); /* Shared library handling. */ set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code); set_solib_svr4_fetch_link_map_offsets (gdbarch, svr4_lp64_fetch_link_map_offsets); /* Setting the correct XML syscall filename. */ set_xml_syscall_file_name (XML_SYSCALL_FILENAME_PPC64); /* Trampolines. */ tramp_frame_prepend_unwinder (gdbarch, &ppc64_linux_sigaction_tramp_frame); tramp_frame_prepend_unwinder (gdbarch, &ppc64_linux_sighandler_tramp_frame); /* BFD target for core files. */ if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_LITTLE) set_gdbarch_gcore_bfd_target (gdbarch, "elf64-powerpcle"); else set_gdbarch_gcore_bfd_target (gdbarch, "elf64-powerpc"); /* Supported register sections. */ if (tdesc_find_feature (info.target_desc, "org.gnu.gdb.power.vsx")) set_gdbarch_core_regset_sections (gdbarch, ppc64_linux_vsx_regset_sections); else if (tdesc_find_feature (info.target_desc, "org.gnu.gdb.power.altivec")) set_gdbarch_core_regset_sections (gdbarch, ppc64_linux_vmx_regset_sections); else set_gdbarch_core_regset_sections (gdbarch, ppc64_linux_fp_regset_sections); } /* PPC32 uses a different prpsinfo32 compared to most other Linux archs. */ if (tdep->wordsize == 4) set_gdbarch_elfcore_write_linux_prpsinfo (gdbarch, elfcore_write_ppc_linux_prpsinfo32); set_gdbarch_regset_from_core_section (gdbarch, ppc_linux_regset_from_core_section); set_gdbarch_core_read_description (gdbarch, ppc_linux_core_read_description); /* Enable TLS support. */ set_gdbarch_fetch_tls_load_module_address (gdbarch, svr4_fetch_objfile_link_map); if (tdesc_data) { const struct tdesc_feature *feature; /* If we have target-described registers, then we can safely reserve a number for PPC_ORIG_R3_REGNUM and PPC_TRAP_REGNUM (whether they are described or not). */ gdb_assert (gdbarch_num_regs (gdbarch) <= PPC_ORIG_R3_REGNUM); set_gdbarch_num_regs (gdbarch, PPC_TRAP_REGNUM + 1); /* If they are present, then assign them to the reserved number. */ feature = tdesc_find_feature (info.target_desc, "org.gnu.gdb.power.linux"); if (feature != NULL) { tdesc_numbered_register (feature, tdesc_data, PPC_ORIG_R3_REGNUM, "orig_r3"); tdesc_numbered_register (feature, tdesc_data, PPC_TRAP_REGNUM, "trap"); } } /* Enable Cell/B.E. if supported by the target. */ if (tdesc_compatible_p (info.target_desc, bfd_lookup_arch (bfd_arch_spu, bfd_mach_spu))) { /* Cell/B.E. multi-architecture support. */ set_spu_solib_ops (gdbarch); /* Cell/B.E. cross-architecture unwinder support. */ frame_unwind_prepend_unwinder (gdbarch, &ppu2spu_unwind); /* The default displaced_step_at_entry_point doesn't work for SPU stand-alone executables. */ set_gdbarch_displaced_step_location (gdbarch, ppc_linux_displaced_step_location); } set_gdbarch_get_siginfo_type (gdbarch, linux_get_siginfo_type); } /* Provide a prototype to silence -Wmissing-prototypes. */ extern initialize_file_ftype _initialize_ppc_linux_tdep; void _initialize_ppc_linux_tdep (void) { /* Register for all sub-familes of the POWER/PowerPC: 32-bit and 64-bit PowerPC, and the older rs6k. */ gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc, GDB_OSABI_LINUX, ppc_linux_init_abi); gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc64, GDB_OSABI_LINUX, ppc_linux_init_abi); gdbarch_register_osabi (bfd_arch_rs6000, bfd_mach_rs6k, GDB_OSABI_LINUX, ppc_linux_init_abi); /* Attach to inferior_created observer. */ observer_attach_inferior_created (ppc_linux_inferior_created); /* Attach to observers to track __spe_current_active_context. */ observer_attach_inferior_created (ppc_linux_spe_context_inferior_created); observer_attach_solib_loaded (ppc_linux_spe_context_solib_loaded); observer_attach_solib_unloaded (ppc_linux_spe_context_solib_unloaded); /* Initialize the Linux target descriptions. */ initialize_tdesc_powerpc_32l (); initialize_tdesc_powerpc_altivec32l (); initialize_tdesc_powerpc_cell32l (); initialize_tdesc_powerpc_vsx32l (); initialize_tdesc_powerpc_isa205_32l (); initialize_tdesc_powerpc_isa205_altivec32l (); initialize_tdesc_powerpc_isa205_vsx32l (); initialize_tdesc_powerpc_64l (); initialize_tdesc_powerpc_altivec64l (); initialize_tdesc_powerpc_cell64l (); initialize_tdesc_powerpc_vsx64l (); initialize_tdesc_powerpc_isa205_64l (); initialize_tdesc_powerpc_isa205_altivec64l (); initialize_tdesc_powerpc_isa205_vsx64l (); initialize_tdesc_powerpc_e500l (); }