/* PPC GNU/Linux native support. Copyright (C) 1988-2018 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 "observable.h" #include "frame.h" #include "inferior.h" #include "gdbthread.h" #include "gdbcore.h" #include "regcache.h" #include "regset.h" #include "target.h" #include "linux-nat.h" #include #include #include #include #include "gdb_wait.h" #include #include #include "nat/gdb_ptrace.h" #include "inf-ptrace.h" /* Prototypes for supply_gregset etc. */ #include "gregset.h" #include "ppc-tdep.h" #include "ppc-linux-tdep.h" /* Required when using the AUXV. */ #include "elf/common.h" #include "auxv.h" #include "arch/ppc-linux-common.h" #include "arch/ppc-linux-tdesc.h" #include "nat/ppc-linux.h" /* Similarly for the hardware watchpoint support. These requests are used when the PowerPC HWDEBUG ptrace interface is not available. */ #ifndef PTRACE_GET_DEBUGREG #define PTRACE_GET_DEBUGREG 25 #endif #ifndef PTRACE_SET_DEBUGREG #define PTRACE_SET_DEBUGREG 26 #endif #ifndef PTRACE_GETSIGINFO #define PTRACE_GETSIGINFO 0x4202 #endif /* These requests are used when the PowerPC HWDEBUG ptrace interface is available. It exposes the debug facilities of PowerPC processors, as well as additional features of BookE processors, such as ranged breakpoints and watchpoints and hardware-accelerated condition evaluation. */ #ifndef PPC_PTRACE_GETHWDBGINFO /* Not having PPC_PTRACE_GETHWDBGINFO defined means that the PowerPC HWDEBUG ptrace interface is not present in ptrace.h, so we'll have to pretty much include it all here so that the code at least compiles on older systems. */ #define PPC_PTRACE_GETHWDBGINFO 0x89 #define PPC_PTRACE_SETHWDEBUG 0x88 #define PPC_PTRACE_DELHWDEBUG 0x87 struct ppc_debug_info { uint32_t version; /* Only version 1 exists to date. */ uint32_t num_instruction_bps; uint32_t num_data_bps; uint32_t num_condition_regs; uint32_t data_bp_alignment; uint32_t sizeof_condition; /* size of the DVC register. */ uint64_t features; }; /* Features will have bits indicating whether there is support for: */ #define PPC_DEBUG_FEATURE_INSN_BP_RANGE 0x1 #define PPC_DEBUG_FEATURE_INSN_BP_MASK 0x2 #define PPC_DEBUG_FEATURE_DATA_BP_RANGE 0x4 #define PPC_DEBUG_FEATURE_DATA_BP_MASK 0x8 struct ppc_hw_breakpoint { uint32_t version; /* currently, version must be 1 */ uint32_t trigger_type; /* only some combinations allowed */ uint32_t addr_mode; /* address match mode */ uint32_t condition_mode; /* break/watchpoint condition flags */ uint64_t addr; /* break/watchpoint address */ uint64_t addr2; /* range end or mask */ uint64_t condition_value; /* contents of the DVC register */ }; /* Trigger type. */ #define PPC_BREAKPOINT_TRIGGER_EXECUTE 0x1 #define PPC_BREAKPOINT_TRIGGER_READ 0x2 #define PPC_BREAKPOINT_TRIGGER_WRITE 0x4 #define PPC_BREAKPOINT_TRIGGER_RW 0x6 /* Address mode. */ #define PPC_BREAKPOINT_MODE_EXACT 0x0 #define PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE 0x1 #define PPC_BREAKPOINT_MODE_RANGE_EXCLUSIVE 0x2 #define PPC_BREAKPOINT_MODE_MASK 0x3 /* Condition mode. */ #define PPC_BREAKPOINT_CONDITION_NONE 0x0 #define PPC_BREAKPOINT_CONDITION_AND 0x1 #define PPC_BREAKPOINT_CONDITION_EXACT 0x1 #define PPC_BREAKPOINT_CONDITION_OR 0x2 #define PPC_BREAKPOINT_CONDITION_AND_OR 0x3 #define PPC_BREAKPOINT_CONDITION_BE_ALL 0x00ff0000 #define PPC_BREAKPOINT_CONDITION_BE_SHIFT 16 #define PPC_BREAKPOINT_CONDITION_BE(n) \ (1<<((n)+PPC_BREAKPOINT_CONDITION_BE_SHIFT)) #endif /* PPC_PTRACE_GETHWDBGINFO */ /* Feature defined on Linux kernel v3.9: DAWR interface, that enables wider watchpoint (up to 512 bytes). */ #ifndef PPC_DEBUG_FEATURE_DATA_BP_DAWR #define PPC_DEBUG_FEATURE_DATA_BP_DAWR 0x10 #endif /* PPC_DEBUG_FEATURE_DATA_BP_DAWR */ /* Similarly for the general-purpose (gp0 -- gp31) and floating-point registers (fp0 -- fp31). */ #ifndef PTRACE_GETREGS #define PTRACE_GETREGS 12 #endif #ifndef PTRACE_SETREGS #define PTRACE_SETREGS 13 #endif #ifndef PTRACE_GETFPREGS #define PTRACE_GETFPREGS 14 #endif #ifndef PTRACE_SETFPREGS #define PTRACE_SETFPREGS 15 #endif /* This oddity is because the Linux kernel defines elf_vrregset_t as an array of 33 16 bytes long elements. I.e. it leaves out vrsave. However the PTRACE_GETVRREGS and PTRACE_SETVRREGS requests return the vrsave as an extra 4 bytes at the end. I opted for creating a flat array of chars, so that it is easier to manipulate for gdb. There are 32 vector registers 16 bytes longs, plus a VSCR register which is only 4 bytes long, but is fetched as a 16 bytes quantity. Up to here we have the elf_vrregset_t structure. Appended to this there is space for the VRSAVE register: 4 bytes. Even though this vrsave register is not included in the regset typedef, it is handled by the ptrace requests. The layout is like this (where x is the actual value of the vscr reg): */ /* *INDENT-OFF* */ /* Big-Endian: |.|.|.|.|.....|.|.|.|.||.|.|.|x||.| <-------> <-------><-------><-> VR0 VR31 VSCR VRSAVE Little-Endian: |.|.|.|.|.....|.|.|.|.||X|.|.|.||.| <-------> <-------><-------><-> VR0 VR31 VSCR VRSAVE */ /* *INDENT-ON* */ typedef char gdb_vrregset_t[PPC_LINUX_SIZEOF_VRREGSET]; /* This is the layout of the POWER7 VSX registers and the way they overlap with the existing FPR and VMX registers. VSR doubleword 0 VSR doubleword 1 ---------------------------------------------------------------- VSR[0] | FPR[0] | | ---------------------------------------------------------------- VSR[1] | FPR[1] | | ---------------------------------------------------------------- | ... | | | ... | | ---------------------------------------------------------------- VSR[30] | FPR[30] | | ---------------------------------------------------------------- VSR[31] | FPR[31] | | ---------------------------------------------------------------- VSR[32] | VR[0] | ---------------------------------------------------------------- VSR[33] | VR[1] | ---------------------------------------------------------------- | ... | | ... | ---------------------------------------------------------------- VSR[62] | VR[30] | ---------------------------------------------------------------- VSR[63] | VR[31] | ---------------------------------------------------------------- VSX has 64 128bit registers. The first 32 registers overlap with the FP registers (doubleword 0) and hence extend them with additional 64 bits (doubleword 1). The other 32 regs overlap with the VMX registers. */ typedef char gdb_vsxregset_t[PPC_LINUX_SIZEOF_VSXREGSET]; /* On PPC processors that support the Signal Processing Extension (SPE) APU, the general-purpose registers are 64 bits long. However, the ordinary Linux kernel PTRACE_PEEKUSER / PTRACE_POKEUSER ptrace calls only access the lower half of each register, to allow them to behave the same way they do on non-SPE systems. There's a separate pair of calls, PTRACE_GETEVRREGS / PTRACE_SETEVRREGS, that read and write the top halves of all the general-purpose registers at once, along with some SPE-specific registers. GDB itself continues to claim the general-purpose registers are 32 bits long. It has unnamed raw registers that hold the upper halves of the gprs, and the full 64-bit SIMD views of the registers, 'ev0' -- 'ev31', are pseudo-registers that splice the top and bottom halves together. This is the structure filled in by PTRACE_GETEVRREGS and written to the inferior's registers by PTRACE_SETEVRREGS. */ struct gdb_evrregset_t { unsigned long evr[32]; unsigned long long acc; unsigned long spefscr; }; /* Non-zero if our kernel may support the PTRACE_GETVSXREGS and PTRACE_SETVSXREGS requests, for reading and writing the VSX POWER7 registers 0 through 31. Zero if we've tried one of them and gotten an error. Note that VSX registers 32 through 63 overlap with VR registers 0 through 31. */ int have_ptrace_getsetvsxregs = 1; /* Non-zero if our kernel may support the PTRACE_GETVRREGS and PTRACE_SETVRREGS requests, for reading and writing the Altivec registers. Zero if we've tried one of them and gotten an error. */ int have_ptrace_getvrregs = 1; /* Non-zero if our kernel may support the PTRACE_GETEVRREGS and PTRACE_SETEVRREGS requests, for reading and writing the SPE registers. Zero if we've tried one of them and gotten an error. */ int have_ptrace_getsetevrregs = 1; /* Non-zero if our kernel may support the PTRACE_GETREGS and PTRACE_SETREGS requests, for reading and writing the general-purpose registers. Zero if we've tried one of them and gotten an error. */ int have_ptrace_getsetregs = 1; /* Non-zero if our kernel may support the PTRACE_GETFPREGS and PTRACE_SETFPREGS requests, for reading and writing the floating-pointers registers. Zero if we've tried one of them and gotten an error. */ int have_ptrace_getsetfpregs = 1; struct ppc_linux_nat_target final : public linux_nat_target { /* Add our register access methods. */ void fetch_registers (struct regcache *, int) override; void store_registers (struct regcache *, int) override; /* Add our breakpoint/watchpoint methods. */ int can_use_hw_breakpoint (enum bptype, int, int) override; int insert_hw_breakpoint (struct gdbarch *, struct bp_target_info *) override; int remove_hw_breakpoint (struct gdbarch *, struct bp_target_info *) override; int region_ok_for_hw_watchpoint (CORE_ADDR, int) override; int insert_watchpoint (CORE_ADDR, int, enum target_hw_bp_type, struct expression *) override; int remove_watchpoint (CORE_ADDR, int, enum target_hw_bp_type, struct expression *) override; int insert_mask_watchpoint (CORE_ADDR, CORE_ADDR, enum target_hw_bp_type) override; int remove_mask_watchpoint (CORE_ADDR, CORE_ADDR, enum target_hw_bp_type) override; bool stopped_by_watchpoint () override; bool stopped_data_address (CORE_ADDR *) override; bool watchpoint_addr_within_range (CORE_ADDR, CORE_ADDR, int) override; bool can_accel_watchpoint_condition (CORE_ADDR, int, int, struct expression *) override; int masked_watch_num_registers (CORE_ADDR, CORE_ADDR) override; int ranged_break_num_registers () override; const struct target_desc *read_description () override; int auxv_parse (gdb_byte **readptr, gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp) override; /* Override linux_nat_target low methods. */ void low_new_thread (struct lwp_info *lp) override; }; static ppc_linux_nat_target the_ppc_linux_nat_target; /* *INDENT-OFF* */ /* registers layout, as presented by the ptrace interface: PT_R0, PT_R1, PT_R2, PT_R3, PT_R4, PT_R5, PT_R6, PT_R7, PT_R8, PT_R9, PT_R10, PT_R11, PT_R12, PT_R13, PT_R14, PT_R15, PT_R16, PT_R17, PT_R18, PT_R19, PT_R20, PT_R21, PT_R22, PT_R23, PT_R24, PT_R25, PT_R26, PT_R27, PT_R28, PT_R29, PT_R30, PT_R31, PT_FPR0, PT_FPR0 + 2, PT_FPR0 + 4, PT_FPR0 + 6, PT_FPR0 + 8, PT_FPR0 + 10, PT_FPR0 + 12, PT_FPR0 + 14, PT_FPR0 + 16, PT_FPR0 + 18, PT_FPR0 + 20, PT_FPR0 + 22, PT_FPR0 + 24, PT_FPR0 + 26, PT_FPR0 + 28, PT_FPR0 + 30, PT_FPR0 + 32, PT_FPR0 + 34, PT_FPR0 + 36, PT_FPR0 + 38, PT_FPR0 + 40, PT_FPR0 + 42, PT_FPR0 + 44, PT_FPR0 + 46, PT_FPR0 + 48, PT_FPR0 + 50, PT_FPR0 + 52, PT_FPR0 + 54, PT_FPR0 + 56, PT_FPR0 + 58, PT_FPR0 + 60, PT_FPR0 + 62, PT_NIP, PT_MSR, PT_CCR, PT_LNK, PT_CTR, PT_XER, PT_MQ */ /* *INDENT_ON * */ static int ppc_register_u_addr (struct gdbarch *gdbarch, int regno) { int u_addr = -1; struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* NOTE: cagney/2003-11-25: This is the word size used by the ptrace interface, and not the wordsize of the program's ABI. */ int wordsize = sizeof (long); /* General purpose registers occupy 1 slot each in the buffer. */ if (regno >= tdep->ppc_gp0_regnum && regno < tdep->ppc_gp0_regnum + ppc_num_gprs) u_addr = ((regno - tdep->ppc_gp0_regnum + PT_R0) * wordsize); /* Floating point regs: eight bytes each in both 32- and 64-bit ptrace interfaces. Thus, two slots each in 32-bit interface, one slot each in 64-bit interface. */ if (tdep->ppc_fp0_regnum >= 0 && regno >= tdep->ppc_fp0_regnum && regno < tdep->ppc_fp0_regnum + ppc_num_fprs) u_addr = (PT_FPR0 * wordsize) + ((regno - tdep->ppc_fp0_regnum) * 8); /* UISA special purpose registers: 1 slot each. */ if (regno == gdbarch_pc_regnum (gdbarch)) u_addr = PT_NIP * wordsize; if (regno == tdep->ppc_lr_regnum) u_addr = PT_LNK * wordsize; if (regno == tdep->ppc_cr_regnum) u_addr = PT_CCR * wordsize; if (regno == tdep->ppc_xer_regnum) u_addr = PT_XER * wordsize; if (regno == tdep->ppc_ctr_regnum) u_addr = PT_CTR * wordsize; #ifdef PT_MQ if (regno == tdep->ppc_mq_regnum) u_addr = PT_MQ * wordsize; #endif if (regno == tdep->ppc_ps_regnum) u_addr = PT_MSR * wordsize; if (regno == PPC_ORIG_R3_REGNUM) u_addr = PT_ORIG_R3 * wordsize; if (regno == PPC_TRAP_REGNUM) u_addr = PT_TRAP * wordsize; if (tdep->ppc_fpscr_regnum >= 0 && regno == tdep->ppc_fpscr_regnum) { /* NOTE: cagney/2005-02-08: On some 64-bit GNU/Linux systems the kernel headers incorrectly contained the 32-bit definition of PT_FPSCR. For the 32-bit definition, floating-point registers occupy two 32-bit "slots", and the FPSCR lives in the second half of such a slot-pair (hence +1). For 64-bit, the FPSCR instead occupies the full 64-bit 2-word-slot and hence no adjustment is necessary. Hack around this. */ if (wordsize == 8 && PT_FPSCR == (48 + 32 + 1)) u_addr = (48 + 32) * wordsize; /* If the FPSCR is 64-bit wide, we need to fetch the whole 64-bit slot and not just its second word. The PT_FPSCR supplied when GDB is compiled as a 32-bit app doesn't reflect this. */ else if (wordsize == 4 && register_size (gdbarch, regno) == 8 && PT_FPSCR == (48 + 2*32 + 1)) u_addr = (48 + 2*32) * wordsize; else u_addr = PT_FPSCR * wordsize; } return u_addr; } /* The Linux kernel ptrace interface for POWER7 VSX registers uses the registers set mechanism, as opposed to the interface for all the other registers, that stores/fetches each register individually. */ static void fetch_vsx_registers (struct regcache *regcache, int tid, int regno) { int ret; gdb_vsxregset_t regs; const struct regset *vsxregset = ppc_linux_vsxregset (); ret = ptrace (PTRACE_GETVSXREGS, tid, 0, ®s); if (ret < 0) { if (errno == EIO) { have_ptrace_getsetvsxregs = 0; return; } perror_with_name (_("Unable to fetch VSX registers")); } vsxregset->supply_regset (vsxregset, regcache, regno, ®s, PPC_LINUX_SIZEOF_VSXREGSET); } /* The Linux kernel ptrace interface for AltiVec registers uses the registers set mechanism, as opposed to the interface for all the other registers, that stores/fetches each register individually. */ static void fetch_altivec_registers (struct regcache *regcache, int tid, int regno) { int ret; gdb_vrregset_t regs; struct gdbarch *gdbarch = regcache->arch (); const struct regset *vrregset = ppc_linux_vrregset (gdbarch); ret = ptrace (PTRACE_GETVRREGS, tid, 0, ®s); if (ret < 0) { if (errno == EIO) { have_ptrace_getvrregs = 0; return; } perror_with_name (_("Unable to fetch AltiVec registers")); } vrregset->supply_regset (vrregset, regcache, regno, ®s, PPC_LINUX_SIZEOF_VRREGSET); } /* Fetch the top 32 bits of TID's general-purpose registers and the SPE-specific registers, and place the results in EVRREGSET. If we don't support PTRACE_GETEVRREGS, then just fill EVRREGSET with zeros. All the logic to deal with whether or not the PTRACE_GETEVRREGS and PTRACE_SETEVRREGS requests are supported is isolated here, and in set_spe_registers. */ static void get_spe_registers (int tid, struct gdb_evrregset_t *evrregset) { if (have_ptrace_getsetevrregs) { if (ptrace (PTRACE_GETEVRREGS, tid, 0, evrregset) >= 0) return; else { /* EIO means that the PTRACE_GETEVRREGS request isn't supported; we just return zeros. */ if (errno == EIO) have_ptrace_getsetevrregs = 0; else /* Anything else needs to be reported. */ perror_with_name (_("Unable to fetch SPE registers")); } } memset (evrregset, 0, sizeof (*evrregset)); } /* Supply values from TID for SPE-specific raw registers: the upper halves of the GPRs, the accumulator, and the spefscr. REGNO must be the number of an upper half register, acc, spefscr, or -1 to supply the values of all registers. */ static void fetch_spe_register (struct regcache *regcache, int tid, int regno) { struct gdbarch *gdbarch = regcache->arch (); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); struct gdb_evrregset_t evrregs; gdb_assert (sizeof (evrregs.evr[0]) == register_size (gdbarch, tdep->ppc_ev0_upper_regnum)); gdb_assert (sizeof (evrregs.acc) == register_size (gdbarch, tdep->ppc_acc_regnum)); gdb_assert (sizeof (evrregs.spefscr) == register_size (gdbarch, tdep->ppc_spefscr_regnum)); get_spe_registers (tid, &evrregs); if (regno == -1) { int i; for (i = 0; i < ppc_num_gprs; i++) regcache_raw_supply (regcache, tdep->ppc_ev0_upper_regnum + i, &evrregs.evr[i]); } else if (tdep->ppc_ev0_upper_regnum <= regno && regno < tdep->ppc_ev0_upper_regnum + ppc_num_gprs) regcache_raw_supply (regcache, regno, &evrregs.evr[regno - tdep->ppc_ev0_upper_regnum]); if (regno == -1 || regno == tdep->ppc_acc_regnum) regcache_raw_supply (regcache, tdep->ppc_acc_regnum, &evrregs.acc); if (regno == -1 || regno == tdep->ppc_spefscr_regnum) regcache_raw_supply (regcache, tdep->ppc_spefscr_regnum, &evrregs.spefscr); } static void fetch_register (struct regcache *regcache, int tid, int regno) { struct gdbarch *gdbarch = regcache->arch (); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* This isn't really an address. But ptrace thinks of it as one. */ CORE_ADDR regaddr = ppc_register_u_addr (gdbarch, regno); int bytes_transferred; unsigned int offset; /* Offset of registers within the u area. */ gdb_byte buf[PPC_MAX_REGISTER_SIZE]; if (altivec_register_p (gdbarch, regno)) { /* If this is the first time through, or if it is not the first time through, and we have comfirmed that there is kernel support for such a ptrace request, then go and fetch the register. */ if (have_ptrace_getvrregs) { fetch_altivec_registers (regcache, tid, regno); return; } /* If we have discovered that there is no ptrace support for AltiVec registers, fall through and return zeroes, because regaddr will be -1 in this case. */ } if (vsx_register_p (gdbarch, regno)) { if (have_ptrace_getsetvsxregs) { fetch_vsx_registers (regcache, tid, regno); return; } } else if (spe_register_p (gdbarch, regno)) { fetch_spe_register (regcache, tid, regno); return; } if (regaddr == -1) { memset (buf, '\0', register_size (gdbarch, regno)); /* Supply zeroes */ regcache_raw_supply (regcache, regno, buf); return; } /* Read the raw register using sizeof(long) sized chunks. On a 32-bit platform, 64-bit floating-point registers will require two transfers. */ for (bytes_transferred = 0; bytes_transferred < register_size (gdbarch, regno); bytes_transferred += sizeof (long)) { long l; errno = 0; l = ptrace (PTRACE_PEEKUSER, tid, (PTRACE_TYPE_ARG3) regaddr, 0); regaddr += sizeof (long); if (errno != 0) { char message[128]; xsnprintf (message, sizeof (message), "reading register %s (#%d)", gdbarch_register_name (gdbarch, regno), regno); perror_with_name (message); } memcpy (&buf[bytes_transferred], &l, sizeof (l)); } /* Now supply the register. Keep in mind that the regcache's idea of the register's size may not be a multiple of sizeof (long). */ if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_LITTLE) { /* Little-endian values are always found at the left end of the bytes transferred. */ regcache_raw_supply (regcache, regno, buf); } else if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG) { /* Big-endian values are found at the right end of the bytes transferred. */ size_t padding = (bytes_transferred - register_size (gdbarch, regno)); regcache_raw_supply (regcache, regno, buf + padding); } else internal_error (__FILE__, __LINE__, _("fetch_register: unexpected byte order: %d"), gdbarch_byte_order (gdbarch)); } /* This function actually issues the request to ptrace, telling it to get all general-purpose registers and put them into the specified regset. If the ptrace request does not exist, this function returns 0 and properly sets the have_ptrace_* flag. If the request fails, this function calls perror_with_name. Otherwise, if the request succeeds, then the regcache gets filled and 1 is returned. */ static int fetch_all_gp_regs (struct regcache *regcache, int tid) { struct gdbarch *gdbarch = regcache->arch (); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); gdb_gregset_t gregset; if (ptrace (PTRACE_GETREGS, tid, 0, (void *) &gregset) < 0) { if (errno == EIO) { have_ptrace_getsetregs = 0; return 0; } perror_with_name (_("Couldn't get general-purpose registers.")); } supply_gregset (regcache, (const gdb_gregset_t *) &gregset); return 1; } /* This is a wrapper for the fetch_all_gp_regs function. It is responsible for verifying if this target has the ptrace request that can be used to fetch all general-purpose registers at one shot. If it doesn't, then we should fetch them using the old-fashioned way, which is to iterate over the registers and request them one by one. */ static void fetch_gp_regs (struct regcache *regcache, int tid) { struct gdbarch *gdbarch = regcache->arch (); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); int i; if (have_ptrace_getsetregs) if (fetch_all_gp_regs (regcache, tid)) return; /* If we've hit this point, it doesn't really matter which architecture we are using. We just need to read the registers in the "old-fashioned way". */ for (i = 0; i < ppc_num_gprs; i++) fetch_register (regcache, tid, tdep->ppc_gp0_regnum + i); } /* This function actually issues the request to ptrace, telling it to get all floating-point registers and put them into the specified regset. If the ptrace request does not exist, this function returns 0 and properly sets the have_ptrace_* flag. If the request fails, this function calls perror_with_name. Otherwise, if the request succeeds, then the regcache gets filled and 1 is returned. */ static int fetch_all_fp_regs (struct regcache *regcache, int tid) { gdb_fpregset_t fpregs; if (ptrace (PTRACE_GETFPREGS, tid, 0, (void *) &fpregs) < 0) { if (errno == EIO) { have_ptrace_getsetfpregs = 0; return 0; } perror_with_name (_("Couldn't get floating-point registers.")); } supply_fpregset (regcache, (const gdb_fpregset_t *) &fpregs); return 1; } /* This is a wrapper for the fetch_all_fp_regs function. It is responsible for verifying if this target has the ptrace request that can be used to fetch all floating-point registers at one shot. If it doesn't, then we should fetch them using the old-fashioned way, which is to iterate over the registers and request them one by one. */ static void fetch_fp_regs (struct regcache *regcache, int tid) { struct gdbarch *gdbarch = regcache->arch (); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); int i; if (have_ptrace_getsetfpregs) if (fetch_all_fp_regs (regcache, tid)) return; /* If we've hit this point, it doesn't really matter which architecture we are using. We just need to read the registers in the "old-fashioned way". */ for (i = 0; i < ppc_num_fprs; i++) fetch_register (regcache, tid, tdep->ppc_fp0_regnum + i); } static void fetch_ppc_registers (struct regcache *regcache, int tid) { int i; struct gdbarch *gdbarch = regcache->arch (); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); fetch_gp_regs (regcache, tid); if (tdep->ppc_fp0_regnum >= 0) fetch_fp_regs (regcache, tid); fetch_register (regcache, tid, gdbarch_pc_regnum (gdbarch)); if (tdep->ppc_ps_regnum != -1) fetch_register (regcache, tid, tdep->ppc_ps_regnum); if (tdep->ppc_cr_regnum != -1) fetch_register (regcache, tid, tdep->ppc_cr_regnum); if (tdep->ppc_lr_regnum != -1) fetch_register (regcache, tid, tdep->ppc_lr_regnum); if (tdep->ppc_ctr_regnum != -1) fetch_register (regcache, tid, tdep->ppc_ctr_regnum); if (tdep->ppc_xer_regnum != -1) fetch_register (regcache, tid, tdep->ppc_xer_regnum); if (tdep->ppc_mq_regnum != -1) fetch_register (regcache, tid, tdep->ppc_mq_regnum); if (ppc_linux_trap_reg_p (gdbarch)) { fetch_register (regcache, tid, PPC_ORIG_R3_REGNUM); fetch_register (regcache, tid, PPC_TRAP_REGNUM); } if (tdep->ppc_fpscr_regnum != -1) fetch_register (regcache, tid, tdep->ppc_fpscr_regnum); if (have_ptrace_getvrregs) if (tdep->ppc_vr0_regnum != -1 && tdep->ppc_vrsave_regnum != -1) fetch_altivec_registers (regcache, tid, -1); if (have_ptrace_getsetvsxregs) if (tdep->ppc_vsr0_upper_regnum != -1) fetch_vsx_registers (regcache, tid, -1); if (tdep->ppc_ev0_upper_regnum >= 0) fetch_spe_register (regcache, tid, -1); } /* Fetch registers from the child process. Fetch all registers if regno == -1, otherwise fetch all general registers or all floating point registers depending upon the value of regno. */ void ppc_linux_nat_target::fetch_registers (struct regcache *regcache, int regno) { pid_t tid = get_ptrace_pid (regcache->ptid ()); if (regno == -1) fetch_ppc_registers (regcache, tid); else fetch_register (regcache, tid, regno); } static void store_vsx_registers (const struct regcache *regcache, int tid, int regno) { int ret; gdb_vsxregset_t regs; const struct regset *vsxregset = ppc_linux_vsxregset (); ret = ptrace (PTRACE_GETVSXREGS, tid, 0, ®s); if (ret < 0) { if (errno == EIO) { have_ptrace_getsetvsxregs = 0; return; } perror_with_name (_("Unable to fetch VSX registers")); } vsxregset->collect_regset (vsxregset, regcache, regno, ®s, PPC_LINUX_SIZEOF_VSXREGSET); ret = ptrace (PTRACE_SETVSXREGS, tid, 0, ®s); if (ret < 0) perror_with_name (_("Unable to store VSX registers")); } static void store_altivec_registers (const struct regcache *regcache, int tid, int regno) { int ret; gdb_vrregset_t regs; struct gdbarch *gdbarch = regcache->arch (); const struct regset *vrregset = ppc_linux_vrregset (gdbarch); ret = ptrace (PTRACE_GETVRREGS, tid, 0, ®s); if (ret < 0) { if (errno == EIO) { have_ptrace_getvrregs = 0; return; } perror_with_name (_("Unable to fetch AltiVec registers")); } vrregset->collect_regset (vrregset, regcache, regno, ®s, PPC_LINUX_SIZEOF_VRREGSET); ret = ptrace (PTRACE_SETVRREGS, tid, 0, ®s); if (ret < 0) perror_with_name (_("Unable to store AltiVec registers")); } /* Assuming TID referrs to an SPE process, set the top halves of TID's general-purpose registers and its SPE-specific registers to the values in EVRREGSET. If we don't support PTRACE_SETEVRREGS, do nothing. All the logic to deal with whether or not the PTRACE_GETEVRREGS and PTRACE_SETEVRREGS requests are supported is isolated here, and in get_spe_registers. */ static void set_spe_registers (int tid, struct gdb_evrregset_t *evrregset) { if (have_ptrace_getsetevrregs) { if (ptrace (PTRACE_SETEVRREGS, tid, 0, evrregset) >= 0) return; else { /* EIO means that the PTRACE_SETEVRREGS request isn't supported; we fail silently, and don't try the call again. */ if (errno == EIO) have_ptrace_getsetevrregs = 0; else /* Anything else needs to be reported. */ perror_with_name (_("Unable to set SPE registers")); } } } /* Write GDB's value for the SPE-specific raw register REGNO to TID. If REGNO is -1, write the values of all the SPE-specific registers. */ static void store_spe_register (const struct regcache *regcache, int tid, int regno) { struct gdbarch *gdbarch = regcache->arch (); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); struct gdb_evrregset_t evrregs; gdb_assert (sizeof (evrregs.evr[0]) == register_size (gdbarch, tdep->ppc_ev0_upper_regnum)); gdb_assert (sizeof (evrregs.acc) == register_size (gdbarch, tdep->ppc_acc_regnum)); gdb_assert (sizeof (evrregs.spefscr) == register_size (gdbarch, tdep->ppc_spefscr_regnum)); if (regno == -1) /* Since we're going to write out every register, the code below should store to every field of evrregs; if that doesn't happen, make it obvious by initializing it with suspicious values. */ memset (&evrregs, 42, sizeof (evrregs)); else /* We can only read and write the entire EVR register set at a time, so to write just a single register, we do a read-modify-write maneuver. */ get_spe_registers (tid, &evrregs); if (regno == -1) { int i; for (i = 0; i < ppc_num_gprs; i++) regcache_raw_collect (regcache, tdep->ppc_ev0_upper_regnum + i, &evrregs.evr[i]); } else if (tdep->ppc_ev0_upper_regnum <= regno && regno < tdep->ppc_ev0_upper_regnum + ppc_num_gprs) regcache_raw_collect (regcache, regno, &evrregs.evr[regno - tdep->ppc_ev0_upper_regnum]); if (regno == -1 || regno == tdep->ppc_acc_regnum) regcache_raw_collect (regcache, tdep->ppc_acc_regnum, &evrregs.acc); if (regno == -1 || regno == tdep->ppc_spefscr_regnum) regcache_raw_collect (regcache, tdep->ppc_spefscr_regnum, &evrregs.spefscr); /* Write back the modified register set. */ set_spe_registers (tid, &evrregs); } static void store_register (const struct regcache *regcache, int tid, int regno) { struct gdbarch *gdbarch = regcache->arch (); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); /* This isn't really an address. But ptrace thinks of it as one. */ CORE_ADDR regaddr = ppc_register_u_addr (gdbarch, regno); int i; size_t bytes_to_transfer; gdb_byte buf[PPC_MAX_REGISTER_SIZE]; if (altivec_register_p (gdbarch, regno)) { store_altivec_registers (regcache, tid, regno); return; } if (vsx_register_p (gdbarch, regno)) { store_vsx_registers (regcache, tid, regno); return; } else if (spe_register_p (gdbarch, regno)) { store_spe_register (regcache, tid, regno); return; } if (regaddr == -1) return; /* First collect the register. Keep in mind that the regcache's idea of the register's size may not be a multiple of sizeof (long). */ memset (buf, 0, sizeof buf); bytes_to_transfer = align_up (register_size (gdbarch, regno), sizeof (long)); if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_LITTLE) { /* Little-endian values always sit at the left end of the buffer. */ regcache_raw_collect (regcache, regno, buf); } else if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG) { /* Big-endian values sit at the right end of the buffer. */ size_t padding = (bytes_to_transfer - register_size (gdbarch, regno)); regcache_raw_collect (regcache, regno, buf + padding); } for (i = 0; i < bytes_to_transfer; i += sizeof (long)) { long l; memcpy (&l, &buf[i], sizeof (l)); errno = 0; ptrace (PTRACE_POKEUSER, tid, (PTRACE_TYPE_ARG3) regaddr, l); regaddr += sizeof (long); if (errno == EIO && (regno == tdep->ppc_fpscr_regnum || regno == PPC_ORIG_R3_REGNUM || regno == PPC_TRAP_REGNUM)) { /* Some older kernel versions don't allow fpscr, orig_r3 or trap to be written. */ continue; } if (errno != 0) { char message[128]; xsnprintf (message, sizeof (message), "writing register %s (#%d)", gdbarch_register_name (gdbarch, regno), regno); perror_with_name (message); } } } /* This function actually issues the request to ptrace, telling it to store all general-purpose registers present in the specified regset. If the ptrace request does not exist, this function returns 0 and properly sets the have_ptrace_* flag. If the request fails, this function calls perror_with_name. Otherwise, if the request succeeds, then the regcache is stored and 1 is returned. */ static int store_all_gp_regs (const struct regcache *regcache, int tid, int regno) { struct gdbarch *gdbarch = regcache->arch (); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); gdb_gregset_t gregset; if (ptrace (PTRACE_GETREGS, tid, 0, (void *) &gregset) < 0) { if (errno == EIO) { have_ptrace_getsetregs = 0; return 0; } perror_with_name (_("Couldn't get general-purpose registers.")); } fill_gregset (regcache, &gregset, regno); if (ptrace (PTRACE_SETREGS, tid, 0, (void *) &gregset) < 0) { if (errno == EIO) { have_ptrace_getsetregs = 0; return 0; } perror_with_name (_("Couldn't set general-purpose registers.")); } return 1; } /* This is a wrapper for the store_all_gp_regs function. It is responsible for verifying if this target has the ptrace request that can be used to store all general-purpose registers at one shot. If it doesn't, then we should store them using the old-fashioned way, which is to iterate over the registers and store them one by one. */ static void store_gp_regs (const struct regcache *regcache, int tid, int regno) { struct gdbarch *gdbarch = regcache->arch (); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); int i; if (have_ptrace_getsetregs) if (store_all_gp_regs (regcache, tid, regno)) return; /* If we hit this point, it doesn't really matter which architecture we are using. We just need to store the registers in the "old-fashioned way". */ for (i = 0; i < ppc_num_gprs; i++) store_register (regcache, tid, tdep->ppc_gp0_regnum + i); } /* This function actually issues the request to ptrace, telling it to store all floating-point registers present in the specified regset. If the ptrace request does not exist, this function returns 0 and properly sets the have_ptrace_* flag. If the request fails, this function calls perror_with_name. Otherwise, if the request succeeds, then the regcache is stored and 1 is returned. */ static int store_all_fp_regs (const struct regcache *regcache, int tid, int regno) { gdb_fpregset_t fpregs; if (ptrace (PTRACE_GETFPREGS, tid, 0, (void *) &fpregs) < 0) { if (errno == EIO) { have_ptrace_getsetfpregs = 0; return 0; } perror_with_name (_("Couldn't get floating-point registers.")); } fill_fpregset (regcache, &fpregs, regno); if (ptrace (PTRACE_SETFPREGS, tid, 0, (void *) &fpregs) < 0) { if (errno == EIO) { have_ptrace_getsetfpregs = 0; return 0; } perror_with_name (_("Couldn't set floating-point registers.")); } return 1; } /* This is a wrapper for the store_all_fp_regs function. It is responsible for verifying if this target has the ptrace request that can be used to store all floating-point registers at one shot. If it doesn't, then we should store them using the old-fashioned way, which is to iterate over the registers and store them one by one. */ static void store_fp_regs (const struct regcache *regcache, int tid, int regno) { struct gdbarch *gdbarch = regcache->arch (); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); int i; if (have_ptrace_getsetfpregs) if (store_all_fp_regs (regcache, tid, regno)) return; /* If we hit this point, it doesn't really matter which architecture we are using. We just need to store the registers in the "old-fashioned way". */ for (i = 0; i < ppc_num_fprs; i++) store_register (regcache, tid, tdep->ppc_fp0_regnum + i); } static void store_ppc_registers (const struct regcache *regcache, int tid) { int i; struct gdbarch *gdbarch = regcache->arch (); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); store_gp_regs (regcache, tid, -1); if (tdep->ppc_fp0_regnum >= 0) store_fp_regs (regcache, tid, -1); store_register (regcache, tid, gdbarch_pc_regnum (gdbarch)); if (tdep->ppc_ps_regnum != -1) store_register (regcache, tid, tdep->ppc_ps_regnum); if (tdep->ppc_cr_regnum != -1) store_register (regcache, tid, tdep->ppc_cr_regnum); if (tdep->ppc_lr_regnum != -1) store_register (regcache, tid, tdep->ppc_lr_regnum); if (tdep->ppc_ctr_regnum != -1) store_register (regcache, tid, tdep->ppc_ctr_regnum); if (tdep->ppc_xer_regnum != -1) store_register (regcache, tid, tdep->ppc_xer_regnum); if (tdep->ppc_mq_regnum != -1) store_register (regcache, tid, tdep->ppc_mq_regnum); if (tdep->ppc_fpscr_regnum != -1) store_register (regcache, tid, tdep->ppc_fpscr_regnum); if (ppc_linux_trap_reg_p (gdbarch)) { store_register (regcache, tid, PPC_ORIG_R3_REGNUM); store_register (regcache, tid, PPC_TRAP_REGNUM); } if (have_ptrace_getvrregs) if (tdep->ppc_vr0_regnum != -1 && tdep->ppc_vrsave_regnum != -1) store_altivec_registers (regcache, tid, -1); if (have_ptrace_getsetvsxregs) if (tdep->ppc_vsr0_upper_regnum != -1) store_vsx_registers (regcache, tid, -1); if (tdep->ppc_ev0_upper_regnum >= 0) store_spe_register (regcache, tid, -1); } /* Fetch the AT_HWCAP entry from the aux vector. */ static CORE_ADDR ppc_linux_get_hwcap (void) { CORE_ADDR field; if (target_auxv_search (target_stack, AT_HWCAP, &field) != 1) return 0; return field; } /* The cached DABR value, to install in new threads. This variable is used when the PowerPC HWDEBUG ptrace interface is not available. */ static long saved_dabr_value; /* Global structure that will store information about the available features provided by the PowerPC HWDEBUG ptrace interface. */ static struct ppc_debug_info hwdebug_info; /* Global variable that holds the maximum number of slots that the kernel will use. This is only used when PowerPC HWDEBUG ptrace interface is available. */ static size_t max_slots_number = 0; struct hw_break_tuple { long slot; struct ppc_hw_breakpoint *hw_break; }; /* This is an internal VEC created to store information about *points inserted for each thread. This is used when PowerPC HWDEBUG ptrace interface is available. */ typedef struct thread_points { /* The TID to which this *point relates. */ int tid; /* Information about the *point, such as its address, type, etc. Each element inside this vector corresponds to a hardware breakpoint or watchpoint in the thread represented by TID. The maximum size of these vector is MAX_SLOTS_NUMBER. If the hw_break element of the tuple is NULL, then the position in the vector is free. */ struct hw_break_tuple *hw_breaks; } *thread_points_p; DEF_VEC_P (thread_points_p); VEC(thread_points_p) *ppc_threads = NULL; /* The version of the PowerPC HWDEBUG kernel interface that we will use, if available. */ #define PPC_DEBUG_CURRENT_VERSION 1 /* Returns non-zero if we support the PowerPC HWDEBUG ptrace interface. */ static int have_ptrace_hwdebug_interface (void) { static int have_ptrace_hwdebug_interface = -1; if (have_ptrace_hwdebug_interface == -1) { int tid; tid = ptid_get_lwp (inferior_ptid); if (tid == 0) tid = ptid_get_pid (inferior_ptid); /* Check for kernel support for PowerPC HWDEBUG ptrace interface. */ if (ptrace (PPC_PTRACE_GETHWDBGINFO, tid, 0, &hwdebug_info) >= 0) { /* Check whether PowerPC HWDEBUG ptrace interface is functional and provides any supported feature. */ if (hwdebug_info.features != 0) { have_ptrace_hwdebug_interface = 1; max_slots_number = hwdebug_info.num_instruction_bps + hwdebug_info.num_data_bps + hwdebug_info.num_condition_regs; return have_ptrace_hwdebug_interface; } } /* Old school interface and no PowerPC HWDEBUG ptrace support. */ have_ptrace_hwdebug_interface = 0; memset (&hwdebug_info, 0, sizeof (struct ppc_debug_info)); } return have_ptrace_hwdebug_interface; } int ppc_linux_nat_target::can_use_hw_breakpoint (enum bptype type, int cnt, int ot) { int total_hw_wp, total_hw_bp; if (have_ptrace_hwdebug_interface ()) { /* When PowerPC HWDEBUG ptrace interface is available, the number of available hardware watchpoints and breakpoints is stored at the hwdebug_info struct. */ total_hw_bp = hwdebug_info.num_instruction_bps; total_hw_wp = hwdebug_info.num_data_bps; } else { /* When we do not have PowerPC HWDEBUG ptrace interface, we should consider having 1 hardware watchpoint and no hardware breakpoints. */ total_hw_bp = 0; total_hw_wp = 1; } if (type == bp_hardware_watchpoint || type == bp_read_watchpoint || type == bp_access_watchpoint || type == bp_watchpoint) { if (cnt + ot > total_hw_wp) return -1; } else if (type == bp_hardware_breakpoint) { if (total_hw_bp == 0) { /* No hardware breakpoint support. */ return 0; } if (cnt > total_hw_bp) return -1; } if (!have_ptrace_hwdebug_interface ()) { int tid; ptid_t ptid = inferior_ptid; /* We need to know whether ptrace supports PTRACE_SET_DEBUGREG and whether the target has DABR. If either answer is no, the ptrace call will return -1. Fail in that case. */ tid = ptid_get_lwp (ptid); if (tid == 0) tid = ptid_get_pid (ptid); if (ptrace (PTRACE_SET_DEBUGREG, tid, 0, 0) == -1) return 0; } return 1; } int ppc_linux_nat_target::region_ok_for_hw_watchpoint (CORE_ADDR addr, int len) { /* Handle sub-8-byte quantities. */ if (len <= 0) return 0; /* The PowerPC HWDEBUG ptrace interface tells if there are alignment restrictions for watchpoints in the processors. In that case, we use that information to determine the hardcoded watchable region for watchpoints. */ if (have_ptrace_hwdebug_interface ()) { int region_size; /* Embedded DAC-based processors, like the PowerPC 440 have ranged watchpoints and can watch any access within an arbitrary memory region. This is useful to watch arrays and structs, for instance. It takes two hardware watchpoints though. */ if (len > 1 && hwdebug_info.features & PPC_DEBUG_FEATURE_DATA_BP_RANGE && ppc_linux_get_hwcap () & PPC_FEATURE_BOOKE) return 2; /* Check if the processor provides DAWR interface. */ if (hwdebug_info.features & PPC_DEBUG_FEATURE_DATA_BP_DAWR) /* DAWR interface allows to watch up to 512 byte wide ranges which can't cross a 512 byte boundary. */ region_size = 512; else region_size = hwdebug_info.data_bp_alignment; /* Server processors provide one hardware watchpoint and addr+len should fall in the watchable region provided by the ptrace interface. */ if (region_size && (addr + len > (addr & ~(region_size - 1)) + region_size)) return 0; } /* addr+len must fall in the 8 byte watchable region for DABR-based processors (i.e., server processors). Without the new PowerPC HWDEBUG ptrace interface, DAC-based processors (i.e., embedded processors) will use addresses aligned to 4-bytes due to the way the read/write flags are passed in the old ptrace interface. */ else if (((ppc_linux_get_hwcap () & PPC_FEATURE_BOOKE) && (addr + len) > (addr & ~3) + 4) || (addr + len) > (addr & ~7) + 8) return 0; return 1; } /* This function compares two ppc_hw_breakpoint structs field-by-field. */ static int hwdebug_point_cmp (struct ppc_hw_breakpoint *a, struct ppc_hw_breakpoint *b) { return (a->trigger_type == b->trigger_type && a->addr_mode == b->addr_mode && a->condition_mode == b->condition_mode && a->addr == b->addr && a->addr2 == b->addr2 && a->condition_value == b->condition_value); } /* This function can be used to retrieve a thread_points by the TID of the related process/thread. If nothing has been found, and ALLOC_NEW is 0, it returns NULL. If ALLOC_NEW is non-zero, a new thread_points for the provided TID will be created and returned. */ static struct thread_points * hwdebug_find_thread_points_by_tid (int tid, int alloc_new) { int i; struct thread_points *t; for (i = 0; VEC_iterate (thread_points_p, ppc_threads, i, t); i++) if (t->tid == tid) return t; t = NULL; /* Do we need to allocate a new point_item if the wanted one does not exist? */ if (alloc_new) { t = XNEW (struct thread_points); t->hw_breaks = XCNEWVEC (struct hw_break_tuple, max_slots_number); t->tid = tid; VEC_safe_push (thread_points_p, ppc_threads, t); } return t; } /* This function is a generic wrapper that is responsible for inserting a *point (i.e., calling `ptrace' in order to issue the request to the kernel) and registering it internally in GDB. */ static void hwdebug_insert_point (struct ppc_hw_breakpoint *b, int tid) { int i; long slot; gdb::unique_xmalloc_ptr p (XDUP (ppc_hw_breakpoint, b)); struct hw_break_tuple *hw_breaks; struct thread_points *t; struct hw_break_tuple *tuple; errno = 0; slot = ptrace (PPC_PTRACE_SETHWDEBUG, tid, 0, p.get ()); if (slot < 0) perror_with_name (_("Unexpected error setting breakpoint or watchpoint")); /* Everything went fine, so we have to register this *point. */ t = hwdebug_find_thread_points_by_tid (tid, 1); gdb_assert (t != NULL); hw_breaks = t->hw_breaks; /* Find a free element in the hw_breaks vector. */ for (i = 0; i < max_slots_number; i++) if (hw_breaks[i].hw_break == NULL) { hw_breaks[i].slot = slot; hw_breaks[i].hw_break = p.release (); break; } gdb_assert (i != max_slots_number); } /* This function is a generic wrapper that is responsible for removing a *point (i.e., calling `ptrace' in order to issue the request to the kernel), and unregistering it internally at GDB. */ static void hwdebug_remove_point (struct ppc_hw_breakpoint *b, int tid) { int i; struct hw_break_tuple *hw_breaks; struct thread_points *t; t = hwdebug_find_thread_points_by_tid (tid, 0); gdb_assert (t != NULL); hw_breaks = t->hw_breaks; for (i = 0; i < max_slots_number; i++) if (hw_breaks[i].hw_break && hwdebug_point_cmp (hw_breaks[i].hw_break, b)) break; gdb_assert (i != max_slots_number); /* We have to ignore ENOENT errors because the kernel implements hardware breakpoints/watchpoints as "one-shot", that is, they are automatically deleted when hit. */ errno = 0; if (ptrace (PPC_PTRACE_DELHWDEBUG, tid, 0, hw_breaks[i].slot) < 0) if (errno != ENOENT) perror_with_name (_("Unexpected error deleting " "breakpoint or watchpoint")); xfree (hw_breaks[i].hw_break); hw_breaks[i].hw_break = NULL; } /* Return the number of registers needed for a ranged breakpoint. */ int ppc_linux_nat_target::ranged_break_num_registers () { return ((have_ptrace_hwdebug_interface () && hwdebug_info.features & PPC_DEBUG_FEATURE_INSN_BP_RANGE)? 2 : -1); } /* Insert the hardware breakpoint described by BP_TGT. Returns 0 for success, 1 if hardware breakpoints are not supported or -1 for failure. */ int ppc_linux_nat_target::insert_hw_breakpoint (struct gdbarch *gdbarch, struct bp_target_info *bp_tgt) { struct lwp_info *lp; struct ppc_hw_breakpoint p; if (!have_ptrace_hwdebug_interface ()) return -1; p.version = PPC_DEBUG_CURRENT_VERSION; p.trigger_type = PPC_BREAKPOINT_TRIGGER_EXECUTE; p.condition_mode = PPC_BREAKPOINT_CONDITION_NONE; p.addr = (uint64_t) (bp_tgt->placed_address = bp_tgt->reqstd_address); p.condition_value = 0; if (bp_tgt->length) { p.addr_mode = PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE; /* The breakpoint will trigger if the address of the instruction is within the defined range, as follows: p.addr <= address < p.addr2. */ p.addr2 = (uint64_t) bp_tgt->placed_address + bp_tgt->length; } else { p.addr_mode = PPC_BREAKPOINT_MODE_EXACT; p.addr2 = 0; } ALL_LWPS (lp) hwdebug_insert_point (&p, ptid_get_lwp (lp->ptid)); return 0; } int ppc_linux_nat_target::remove_hw_breakpoint (struct gdbarch *gdbarch, struct bp_target_info *bp_tgt) { struct lwp_info *lp; struct ppc_hw_breakpoint p; if (!have_ptrace_hwdebug_interface ()) return -1; p.version = PPC_DEBUG_CURRENT_VERSION; p.trigger_type = PPC_BREAKPOINT_TRIGGER_EXECUTE; p.condition_mode = PPC_BREAKPOINT_CONDITION_NONE; p.addr = (uint64_t) bp_tgt->placed_address; p.condition_value = 0; if (bp_tgt->length) { p.addr_mode = PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE; /* The breakpoint will trigger if the address of the instruction is within the defined range, as follows: p.addr <= address < p.addr2. */ p.addr2 = (uint64_t) bp_tgt->placed_address + bp_tgt->length; } else { p.addr_mode = PPC_BREAKPOINT_MODE_EXACT; p.addr2 = 0; } ALL_LWPS (lp) hwdebug_remove_point (&p, ptid_get_lwp (lp->ptid)); return 0; } static int get_trigger_type (enum target_hw_bp_type type) { int t; if (type == hw_read) t = PPC_BREAKPOINT_TRIGGER_READ; else if (type == hw_write) t = PPC_BREAKPOINT_TRIGGER_WRITE; else t = PPC_BREAKPOINT_TRIGGER_READ | PPC_BREAKPOINT_TRIGGER_WRITE; return t; } /* Insert a new masked watchpoint at ADDR using the mask MASK. RW may be hw_read for a read watchpoint, hw_write for a write watchpoint or hw_access for an access watchpoint. Returns 0 on success and throws an error on failure. */ int ppc_linux_nat_target::insert_mask_watchpoint (CORE_ADDR addr, CORE_ADDR mask, target_hw_bp_type rw) { struct lwp_info *lp; struct ppc_hw_breakpoint p; gdb_assert (have_ptrace_hwdebug_interface ()); p.version = PPC_DEBUG_CURRENT_VERSION; p.trigger_type = get_trigger_type (rw); p.addr_mode = PPC_BREAKPOINT_MODE_MASK; p.condition_mode = PPC_BREAKPOINT_CONDITION_NONE; p.addr = addr; p.addr2 = mask; p.condition_value = 0; ALL_LWPS (lp) hwdebug_insert_point (&p, ptid_get_lwp (lp->ptid)); return 0; } /* Remove a masked watchpoint at ADDR with the mask MASK. RW may be hw_read for a read watchpoint, hw_write for a write watchpoint or hw_access for an access watchpoint. Returns 0 on success and throws an error on failure. */ int ppc_linux_nat_target::remove_mask_watchpoint (CORE_ADDR addr, CORE_ADDR mask, target_hw_bp_type rw) { struct lwp_info *lp; struct ppc_hw_breakpoint p; gdb_assert (have_ptrace_hwdebug_interface ()); p.version = PPC_DEBUG_CURRENT_VERSION; p.trigger_type = get_trigger_type (rw); p.addr_mode = PPC_BREAKPOINT_MODE_MASK; p.condition_mode = PPC_BREAKPOINT_CONDITION_NONE; p.addr = addr; p.addr2 = mask; p.condition_value = 0; ALL_LWPS (lp) hwdebug_remove_point (&p, ptid_get_lwp (lp->ptid)); return 0; } /* Check whether we have at least one free DVC register. */ static int can_use_watchpoint_cond_accel (void) { struct thread_points *p; int tid = ptid_get_lwp (inferior_ptid); int cnt = hwdebug_info.num_condition_regs, i; CORE_ADDR tmp_value; if (!have_ptrace_hwdebug_interface () || cnt == 0) return 0; p = hwdebug_find_thread_points_by_tid (tid, 0); if (p) { for (i = 0; i < max_slots_number; i++) if (p->hw_breaks[i].hw_break != NULL && (p->hw_breaks[i].hw_break->condition_mode != PPC_BREAKPOINT_CONDITION_NONE)) cnt--; /* There are no available slots now. */ if (cnt <= 0) return 0; } return 1; } /* Calculate the enable bits and the contents of the Data Value Compare debug register present in BookE processors. ADDR is the address to be watched, LEN is the length of watched data and DATA_VALUE is the value which will trigger the watchpoint. On exit, CONDITION_MODE will hold the enable bits for the DVC, and CONDITION_VALUE will hold the value which should be put in the DVC register. */ static void calculate_dvc (CORE_ADDR addr, int len, CORE_ADDR data_value, uint32_t *condition_mode, uint64_t *condition_value) { int i, num_byte_enable, align_offset, num_bytes_off_dvc, rightmost_enabled_byte; CORE_ADDR addr_end_data, addr_end_dvc; /* The DVC register compares bytes within fixed-length windows which are word-aligned, with length equal to that of the DVC register. We need to calculate where our watch region is relative to that window and enable comparison of the bytes which fall within it. */ align_offset = addr % hwdebug_info.sizeof_condition; addr_end_data = addr + len; addr_end_dvc = (addr - align_offset + hwdebug_info.sizeof_condition); num_bytes_off_dvc = (addr_end_data > addr_end_dvc)? addr_end_data - addr_end_dvc : 0; num_byte_enable = len - num_bytes_off_dvc; /* Here, bytes are numbered from right to left. */ rightmost_enabled_byte = (addr_end_data < addr_end_dvc)? addr_end_dvc - addr_end_data : 0; *condition_mode = PPC_BREAKPOINT_CONDITION_AND; for (i = 0; i < num_byte_enable; i++) *condition_mode |= PPC_BREAKPOINT_CONDITION_BE (i + rightmost_enabled_byte); /* Now we need to match the position within the DVC of the comparison value with where the watch region is relative to the window (i.e., the ALIGN_OFFSET). */ *condition_value = ((uint64_t) data_value >> num_bytes_off_dvc * 8 << rightmost_enabled_byte * 8); } /* Return the number of memory locations that need to be accessed to evaluate the expression which generated the given value chain. Returns -1 if there's any register access involved, or if there are other kinds of values which are not acceptable in a condition expression (e.g., lval_computed or lval_internalvar). */ static int num_memory_accesses (const std::vector &chain) { int found_memory_cnt = 0; /* The idea here is that evaluating an expression generates a series of values, one holding the value of every subexpression. (The expression a*b+c has five subexpressions: a, b, a*b, c, and a*b+c.) GDB's values hold almost enough information to establish the criteria given above --- they identify memory lvalues, register lvalues, computed values, etcetera. So we can evaluate the expression, and then scan the chain of values that leaves behind to determine the memory locations involved in the evaluation of an expression. However, I don't think that the values returned by inferior function calls are special in any way. So this function may not notice that an expression contains an inferior function call. FIXME. */ for (const value_ref_ptr &iter : chain) { struct value *v = iter.get (); /* Constants and values from the history are fine. */ if (VALUE_LVAL (v) == not_lval || deprecated_value_modifiable (v) == 0) continue; else if (VALUE_LVAL (v) == lval_memory) { /* A lazy memory lvalue is one that GDB never needed to fetch; we either just used its address (e.g., `a' in `a.b') or we never needed it at all (e.g., `a' in `a,b'). */ if (!value_lazy (v)) found_memory_cnt++; } /* Other kinds of values are not fine. */ else return -1; } return found_memory_cnt; } /* Verifies whether the expression COND can be implemented using the DVC (Data Value Compare) register in BookE processors. The expression must test the watch value for equality with a constant expression. If the function returns 1, DATA_VALUE will contain the constant against which the watch value should be compared and LEN will contain the size of the constant. */ static int check_condition (CORE_ADDR watch_addr, struct expression *cond, CORE_ADDR *data_value, int *len) { int pc = 1, num_accesses_left, num_accesses_right; struct value *left_val, *right_val; std::vector left_chain, right_chain; if (cond->elts[0].opcode != BINOP_EQUAL) return 0; fetch_subexp_value (cond, &pc, &left_val, NULL, &left_chain, 0); num_accesses_left = num_memory_accesses (left_chain); if (left_val == NULL || num_accesses_left < 0) return 0; fetch_subexp_value (cond, &pc, &right_val, NULL, &right_chain, 0); num_accesses_right = num_memory_accesses (right_chain); if (right_val == NULL || num_accesses_right < 0) return 0; if (num_accesses_left == 1 && num_accesses_right == 0 && VALUE_LVAL (left_val) == lval_memory && value_address (left_val) == watch_addr) { *data_value = value_as_long (right_val); /* DATA_VALUE is the constant in RIGHT_VAL, but actually has the same type as the memory region referenced by LEFT_VAL. */ *len = TYPE_LENGTH (check_typedef (value_type (left_val))); } else if (num_accesses_left == 0 && num_accesses_right == 1 && VALUE_LVAL (right_val) == lval_memory && value_address (right_val) == watch_addr) { *data_value = value_as_long (left_val); /* DATA_VALUE is the constant in LEFT_VAL, but actually has the same type as the memory region referenced by RIGHT_VAL. */ *len = TYPE_LENGTH (check_typedef (value_type (right_val))); } else return 0; return 1; } /* Return non-zero if the target is capable of using hardware to evaluate the condition expression, thus only triggering the watchpoint when it is true. */ bool ppc_linux_nat_target::can_accel_watchpoint_condition (CORE_ADDR addr, int len, int rw, struct expression *cond) { CORE_ADDR data_value; return (have_ptrace_hwdebug_interface () && hwdebug_info.num_condition_regs > 0 && check_condition (addr, cond, &data_value, &len)); } /* Set up P with the parameters necessary to request a watchpoint covering LEN bytes starting at ADDR and if possible with condition expression COND evaluated by hardware. INSERT tells if we are creating a request for inserting or removing the watchpoint. */ static void create_watchpoint_request (struct ppc_hw_breakpoint *p, CORE_ADDR addr, int len, enum target_hw_bp_type type, struct expression *cond, int insert) { if (len == 1 || !(hwdebug_info.features & PPC_DEBUG_FEATURE_DATA_BP_RANGE)) { int use_condition; CORE_ADDR data_value; use_condition = (insert? can_use_watchpoint_cond_accel () : hwdebug_info.num_condition_regs > 0); if (cond && use_condition && check_condition (addr, cond, &data_value, &len)) calculate_dvc (addr, len, data_value, &p->condition_mode, &p->condition_value); else { p->condition_mode = PPC_BREAKPOINT_CONDITION_NONE; p->condition_value = 0; } p->addr_mode = PPC_BREAKPOINT_MODE_EXACT; p->addr2 = 0; } else { p->addr_mode = PPC_BREAKPOINT_MODE_RANGE_INCLUSIVE; p->condition_mode = PPC_BREAKPOINT_CONDITION_NONE; p->condition_value = 0; /* The watchpoint will trigger if the address of the memory access is within the defined range, as follows: p->addr <= address < p->addr2. Note that the above sentence just documents how ptrace interprets its arguments; the watchpoint is set to watch the range defined by the user _inclusively_, as specified by the user interface. */ p->addr2 = (uint64_t) addr + len; } p->version = PPC_DEBUG_CURRENT_VERSION; p->trigger_type = get_trigger_type (type); p->addr = (uint64_t) addr; } int ppc_linux_nat_target::insert_watchpoint (CORE_ADDR addr, int len, enum target_hw_bp_type type, struct expression *cond) { struct lwp_info *lp; int ret = -1; if (have_ptrace_hwdebug_interface ()) { struct ppc_hw_breakpoint p; create_watchpoint_request (&p, addr, len, type, cond, 1); ALL_LWPS (lp) hwdebug_insert_point (&p, ptid_get_lwp (lp->ptid)); ret = 0; } else { long dabr_value; long read_mode, write_mode; if (ppc_linux_get_hwcap () & PPC_FEATURE_BOOKE) { /* PowerPC 440 requires only the read/write flags to be passed to the kernel. */ read_mode = 1; write_mode = 2; } else { /* PowerPC 970 and other DABR-based processors are required to pass the Breakpoint Translation bit together with the flags. */ read_mode = 5; write_mode = 6; } dabr_value = addr & ~(read_mode | write_mode); switch (type) { case hw_read: /* Set read and translate bits. */ dabr_value |= read_mode; break; case hw_write: /* Set write and translate bits. */ dabr_value |= write_mode; break; case hw_access: /* Set read, write and translate bits. */ dabr_value |= read_mode | write_mode; break; } saved_dabr_value = dabr_value; ALL_LWPS (lp) if (ptrace (PTRACE_SET_DEBUGREG, ptid_get_lwp (lp->ptid), 0, saved_dabr_value) < 0) return -1; ret = 0; } return ret; } int ppc_linux_nat_target::remove_watchpoint (CORE_ADDR addr, int len, enum target_hw_bp_type type, struct expression *cond) { struct lwp_info *lp; int ret = -1; if (have_ptrace_hwdebug_interface ()) { struct ppc_hw_breakpoint p; create_watchpoint_request (&p, addr, len, type, cond, 0); ALL_LWPS (lp) hwdebug_remove_point (&p, ptid_get_lwp (lp->ptid)); ret = 0; } else { saved_dabr_value = 0; ALL_LWPS (lp) if (ptrace (PTRACE_SET_DEBUGREG, ptid_get_lwp (lp->ptid), 0, saved_dabr_value) < 0) return -1; ret = 0; } return ret; } void ppc_linux_nat_target::low_new_thread (struct lwp_info *lp) { int tid = ptid_get_lwp (lp->ptid); if (have_ptrace_hwdebug_interface ()) { int i; struct thread_points *p; struct hw_break_tuple *hw_breaks; if (VEC_empty (thread_points_p, ppc_threads)) return; /* Get a list of breakpoints from any thread. */ p = VEC_last (thread_points_p, ppc_threads); hw_breaks = p->hw_breaks; /* Copy that thread's breakpoints and watchpoints to the new thread. */ for (i = 0; i < max_slots_number; i++) if (hw_breaks[i].hw_break) { /* Older kernels did not make new threads inherit their parent thread's debug state, so we always clear the slot and replicate the debug state ourselves, ensuring compatibility with all kernels. */ /* The ppc debug resource accounting is done through "slots". Ask the kernel the deallocate this specific *point's slot. */ ptrace (PPC_PTRACE_DELHWDEBUG, tid, 0, hw_breaks[i].slot); hwdebug_insert_point (hw_breaks[i].hw_break, tid); } } else ptrace (PTRACE_SET_DEBUGREG, tid, 0, saved_dabr_value); } static void ppc_linux_thread_exit (struct thread_info *tp, int silent) { int i; int tid = ptid_get_lwp (tp->ptid); struct hw_break_tuple *hw_breaks; struct thread_points *t = NULL, *p; if (!have_ptrace_hwdebug_interface ()) return; for (i = 0; VEC_iterate (thread_points_p, ppc_threads, i, p); i++) if (p->tid == tid) { t = p; break; } if (t == NULL) return; VEC_unordered_remove (thread_points_p, ppc_threads, i); hw_breaks = t->hw_breaks; for (i = 0; i < max_slots_number; i++) if (hw_breaks[i].hw_break) xfree (hw_breaks[i].hw_break); xfree (t->hw_breaks); xfree (t); } bool ppc_linux_nat_target::stopped_data_address (CORE_ADDR *addr_p) { siginfo_t siginfo; if (!linux_nat_get_siginfo (inferior_ptid, &siginfo)) return false; if (siginfo.si_signo != SIGTRAP || (siginfo.si_code & 0xffff) != 0x0004 /* TRAP_HWBKPT */) return false; if (have_ptrace_hwdebug_interface ()) { int i; struct thread_points *t; struct hw_break_tuple *hw_breaks; /* The index (or slot) of the *point is passed in the si_errno field. */ int slot = siginfo.si_errno; t = hwdebug_find_thread_points_by_tid (ptid_get_lwp (inferior_ptid), 0); /* Find out if this *point is a hardware breakpoint. If so, we should return 0. */ if (t) { hw_breaks = t->hw_breaks; for (i = 0; i < max_slots_number; i++) if (hw_breaks[i].hw_break && hw_breaks[i].slot == slot && hw_breaks[i].hw_break->trigger_type == PPC_BREAKPOINT_TRIGGER_EXECUTE) return false; } } *addr_p = (CORE_ADDR) (uintptr_t) siginfo.si_addr; return true; } bool ppc_linux_nat_target::stopped_by_watchpoint () { CORE_ADDR addr; return stopped_data_address (&addr); } bool ppc_linux_nat_target::watchpoint_addr_within_range (CORE_ADDR addr, CORE_ADDR start, int length) { int mask; if (have_ptrace_hwdebug_interface () && ppc_linux_get_hwcap () & PPC_FEATURE_BOOKE) return start <= addr && start + length >= addr; else if (ppc_linux_get_hwcap () & PPC_FEATURE_BOOKE) mask = 3; else mask = 7; addr &= ~mask; /* Check whether [start, start+length-1] intersects [addr, addr+mask]. */ return start <= addr + mask && start + length - 1 >= addr; } /* Return the number of registers needed for a masked hardware watchpoint. */ int ppc_linux_nat_target::masked_watch_num_registers (CORE_ADDR addr, CORE_ADDR mask) { if (!have_ptrace_hwdebug_interface () || (hwdebug_info.features & PPC_DEBUG_FEATURE_DATA_BP_MASK) == 0) return -1; else if ((mask & 0xC0000000) != 0xC0000000) { warning (_("The given mask covers kernel address space " "and cannot be used.\n")); return -2; } else return 2; } void ppc_linux_nat_target::store_registers (struct regcache *regcache, int regno) { pid_t tid = get_ptrace_pid (regcache->ptid ()); if (regno >= 0) store_register (regcache, tid, regno); else store_ppc_registers (regcache, tid); } /* Functions for transferring registers between a gregset_t or fpregset_t (see sys/ucontext.h) and gdb's regcache. The word size is that used by the ptrace interface, not the current program's ABI. Eg. if a powerpc64-linux gdb is being used to debug a powerpc32-linux app, we read or write 64-bit gregsets. This is to suit the host libthread_db. */ void supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregsetp) { const struct regset *regset = ppc_linux_gregset (sizeof (long)); ppc_supply_gregset (regset, regcache, -1, gregsetp, sizeof (*gregsetp)); } void fill_gregset (const struct regcache *regcache, gdb_gregset_t *gregsetp, int regno) { const struct regset *regset = ppc_linux_gregset (sizeof (long)); if (regno == -1) memset (gregsetp, 0, sizeof (*gregsetp)); ppc_collect_gregset (regset, regcache, regno, gregsetp, sizeof (*gregsetp)); } void supply_fpregset (struct regcache *regcache, const gdb_fpregset_t * fpregsetp) { const struct regset *regset = ppc_linux_fpregset (); ppc_supply_fpregset (regset, regcache, -1, fpregsetp, sizeof (*fpregsetp)); } void fill_fpregset (const struct regcache *regcache, gdb_fpregset_t *fpregsetp, int regno) { const struct regset *regset = ppc_linux_fpregset (); ppc_collect_fpregset (regset, regcache, regno, fpregsetp, sizeof (*fpregsetp)); } int ppc_linux_nat_target::auxv_parse (gdb_byte **readptr, gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp) { int tid = ptid_get_lwp (inferior_ptid); if (tid == 0) tid = ptid_get_pid (inferior_ptid); int sizeof_auxv_field = ppc_linux_target_wordsize (tid); enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); gdb_byte *ptr = *readptr; if (endptr == ptr) return 0; if (endptr - ptr < sizeof_auxv_field * 2) return -1; *typep = extract_unsigned_integer (ptr, sizeof_auxv_field, byte_order); ptr += sizeof_auxv_field; *valp = extract_unsigned_integer (ptr, sizeof_auxv_field, byte_order); ptr += sizeof_auxv_field; *readptr = ptr; return 1; } const struct target_desc * ppc_linux_nat_target::read_description () { int tid = ptid_get_lwp (inferior_ptid); if (tid == 0) tid = ptid_get_pid (inferior_ptid); if (have_ptrace_getsetevrregs) { struct gdb_evrregset_t evrregset; if (ptrace (PTRACE_GETEVRREGS, tid, 0, &evrregset) >= 0) return tdesc_powerpc_e500l; /* EIO means that the PTRACE_GETEVRREGS request isn't supported. Anything else needs to be reported. */ else if (errno != EIO) perror_with_name (_("Unable to fetch SPE registers")); } struct ppc_linux_features features = ppc_linux_no_features; features.wordsize = ppc_linux_target_wordsize (tid); CORE_ADDR hwcap = ppc_linux_get_hwcap (); if (have_ptrace_getsetvsxregs && (hwcap & PPC_FEATURE_HAS_VSX)) { gdb_vsxregset_t vsxregset; if (ptrace (PTRACE_GETVSXREGS, tid, 0, &vsxregset) >= 0) features.vsx = true; /* EIO means that the PTRACE_GETVSXREGS request isn't supported. Anything else needs to be reported. */ else if (errno != EIO) perror_with_name (_("Unable to fetch VSX registers")); } if (have_ptrace_getvrregs && (hwcap & PPC_FEATURE_HAS_ALTIVEC)) { gdb_vrregset_t vrregset; if (ptrace (PTRACE_GETVRREGS, tid, 0, &vrregset) >= 0) features.altivec = true; /* EIO means that the PTRACE_GETVRREGS request isn't supported. Anything else needs to be reported. */ else if (errno != EIO) perror_with_name (_("Unable to fetch AltiVec registers")); } if (hwcap & PPC_FEATURE_CELL) features.cell = true; features.isa205 = ppc_linux_has_isa205 (hwcap); return ppc_linux_match_description (features); } void _initialize_ppc_linux_nat (void) { linux_target = &the_ppc_linux_nat_target; gdb::observers::thread_exit.attach (ppc_linux_thread_exit); /* Register the target. */ add_inf_child_target (linux_target); }