target-arm/arch_dump.c

   1 /* Support for writing ELF notes for ARM architectures
   2  *
   3  * Copyright (C) 2015 Red Hat Inc.
   4  *
   5  * Author: Andrew Jones <drjones@redhat.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "cpu.h"
  22 #include "elf.h"
  23 #include "sysemu/dump.h"
  24
  25 /* struct user_pt_regs from arch/arm64/include/uapi/asm/ptrace.h */
  26 struct aarch64_user_regs {
  27     uint64_t regs[31];
  28     uint64_t sp;
  29     uint64_t pc;
  30     uint64_t pstate;
  31 } QEMU_PACKED;
  32
  33 QEMU_BUILD_BUG_ON(sizeof(struct aarch64_user_regs) != 272);
  34
  35 /* struct elf_prstatus from include/uapi/linux/elfcore.h */
  36 struct aarch64_elf_prstatus {
  37     char pad1[32]; /* 32 == offsetof(struct elf_prstatus, pr_pid) */
  38     uint32_t pr_pid;
  39     char pad2[76]; /* 76 == offsetof(struct elf_prstatus, pr_reg) -
  40                             offsetof(struct elf_prstatus, pr_ppid) */
  41     struct aarch64_user_regs pr_reg;
  42     uint32_t pr_fpvalid;
  43     char pad3[4];
  44 } QEMU_PACKED;
  45
  46 QEMU_BUILD_BUG_ON(sizeof(struct aarch64_elf_prstatus) != 392);
  47
  48 /* struct user_fpsimd_state from arch/arm64/include/uapi/asm/ptrace.h
  49  *
  50  * While the vregs member of user_fpsimd_state is of type __uint128_t,
  51  * QEMU uses an array of uint64_t, where the high half of the 128-bit
  52  * value is always in the 2n+1'th index. Thus we also break the 128-
  53  * bit values into two halves in this reproduction of user_fpsimd_state.
  54  */
  55 struct aarch64_user_vfp_state {
  56     uint64_t vregs[64];
  57     uint32_t fpsr;
  58     uint32_t fpcr;
  59     char pad[8];
  60 } QEMU_PACKED;
  61
  62 QEMU_BUILD_BUG_ON(sizeof(struct aarch64_user_vfp_state) != 528);
  63
  64 struct aarch64_note {
  65     Elf64_Nhdr hdr;
  66     char name[8]; /* align_up(sizeof("CORE"), 4) */
  67     union {
  68         struct aarch64_elf_prstatus prstatus;
  69         struct aarch64_user_vfp_state vfp;
  70     };
  71 } QEMU_PACKED;
  72
  73 #define AARCH64_NOTE_HEADER_SIZE offsetof(struct aarch64_note, prstatus)
  74 #define AARCH64_PRSTATUS_NOTE_SIZE \
  75             (AARCH64_NOTE_HEADER_SIZE + sizeof(struct aarch64_elf_prstatus))
  76 #define AARCH64_PRFPREG_NOTE_SIZE \
  77             (AARCH64_NOTE_HEADER_SIZE + sizeof(struct aarch64_user_vfp_state))
  78
  79 static void aarch64_note_init(struct aarch64_note *note, DumpState *s,
  80                               const char *name, Elf64_Word namesz,
  81                               Elf64_Word type, Elf64_Word descsz)
  82 {
  83     memset(note, 0, sizeof(*note));
  84
  85     note->hdr.n_namesz = cpu_to_dump32(s, namesz);
  86     note->hdr.n_descsz = cpu_to_dump32(s, descsz);
  87     note->hdr.n_type = cpu_to_dump32(s, type);
  88
  89     memcpy(note->name, name, namesz);
  90 }
  91
  92 static int aarch64_write_elf64_prfpreg(WriteCoreDumpFunction f,
  93                                        CPUARMState *env, int cpuid,
  94                                        DumpState *s)
  95 {
  96     struct aarch64_note note;
  97     int ret, i;
  98
  99     aarch64_note_init(&note, s, "CORE", 5, NT_PRFPREG, sizeof(note.vfp));
 100
 101     for (i = 0; i < 64; ++i) {
 102         note.vfp.vregs[i] = cpu_to_dump64(s, float64_val(env->vfp.regs[i]));
 103     }
 104
 105     if (s->dump_info.d_endian == ELFDATA2MSB) {
 106         /* For AArch64 we must always swap the vfp.regs's 2n and 2n+1
 107          * entries when generating BE notes, because even big endian
 108          * hosts use 2n+1 for the high half.
 109          */
 110         for (i = 0; i < 32; ++i) {
 111             uint64_t tmp = note.vfp.vregs[2*i];
 112             note.vfp.vregs[2*i] = note.vfp.vregs[2*i+1];
 113             note.vfp.vregs[2*i+1] = tmp;
 114         }
 115     }
 116
 117     note.vfp.fpsr = cpu_to_dump32(s, vfp_get_fpsr(env));
 118     note.vfp.fpcr = cpu_to_dump32(s, vfp_get_fpcr(env));
 119
 120     ret = f(&note, AARCH64_PRFPREG_NOTE_SIZE, s);
 121     if (ret < 0) {
 122         return -1;
 123     }
 124
 125     return 0;
 126 }
 127
 128 int arm_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
 129                              int cpuid, void *opaque)
 130 {
 131     struct aarch64_note note;
 132     CPUARMState *env = &ARM_CPU(cs)->env;
 133     DumpState *s = opaque;
 134     uint64_t pstate, sp;
 135     int ret, i;
 136
 137     aarch64_note_init(&note, s, "CORE", 5, NT_PRSTATUS, sizeof(note.prstatus));
 138
 139     note.prstatus.pr_pid = cpu_to_dump32(s, cpuid);
 140     note.prstatus.pr_fpvalid = cpu_to_dump32(s, 1);
 141
 142     if (!is_a64(env)) {
 143         aarch64_sync_32_to_64(env);
 144         pstate = cpsr_read(env);
 145         sp = 0;
 146     } else {
 147         pstate = pstate_read(env);
 148         sp = env->xregs[31];
 149     }
 150
 151     for (i = 0; i < 31; ++i) {
 152         note.prstatus.pr_reg.regs[i] = cpu_to_dump64(s, env->xregs[i]);
 153     }
 154     note.prstatus.pr_reg.sp = cpu_to_dump64(s, sp);
 155     note.prstatus.pr_reg.pc = cpu_to_dump64(s, env->pc);
 156     note.prstatus.pr_reg.pstate = cpu_to_dump64(s, pstate);
 157
 158     ret = f(&note, AARCH64_PRSTATUS_NOTE_SIZE, s);
 159     if (ret < 0) {
 160         return -1;
 161     }
 162
 163     return aarch64_write_elf64_prfpreg(f, env, cpuid, s);
 164 }
 165
 166 /* struct pt_regs from arch/arm/include/asm/ptrace.h */
 167 struct arm_user_regs {
 168     uint32_t regs[17];
 169     char pad[4];
 170 } QEMU_PACKED;
 171
 172 QEMU_BUILD_BUG_ON(sizeof(struct arm_user_regs) != 72);
 173
 174 /* struct elf_prstatus from include/uapi/linux/elfcore.h */
 175 struct arm_elf_prstatus {
 176     char pad1[24]; /* 24 == offsetof(struct elf_prstatus, pr_pid) */
 177     uint32_t pr_pid;
 178     char pad2[44]; /* 44 == offsetof(struct elf_prstatus, pr_reg) -
 179                             offsetof(struct elf_prstatus, pr_ppid) */
 180     struct arm_user_regs pr_reg;
 181     uint32_t pr_fpvalid;
 182 } QEMU_PACKED arm_elf_prstatus;
 183
 184 QEMU_BUILD_BUG_ON(sizeof(struct arm_elf_prstatus) != 148);
 185
 186 /* struct user_vfp from arch/arm/include/asm/user.h */
 187 struct arm_user_vfp_state {
 188     uint64_t vregs[32];
 189     uint32_t fpscr;
 190 } QEMU_PACKED;
 191
 192 QEMU_BUILD_BUG_ON(sizeof(struct arm_user_vfp_state) != 260);
 193
 194 struct arm_note {
 195     Elf32_Nhdr hdr;
 196     char name[8]; /* align_up(sizeof("LINUX"), 4) */
 197     union {
 198         struct arm_elf_prstatus prstatus;
 199         struct arm_user_vfp_state vfp;
 200     };
 201 } QEMU_PACKED;
 202
 203 #define ARM_NOTE_HEADER_SIZE offsetof(struct arm_note, prstatus)
 204 #define ARM_PRSTATUS_NOTE_SIZE \
 205             (ARM_NOTE_HEADER_SIZE + sizeof(struct arm_elf_prstatus))
 206 #define ARM_VFP_NOTE_SIZE \
 207             (ARM_NOTE_HEADER_SIZE + sizeof(struct arm_user_vfp_state))
 208
 209 static void arm_note_init(struct arm_note *note, DumpState *s,
 210                           const char *name, Elf32_Word namesz,
 211                           Elf32_Word type, Elf32_Word descsz)
 212 {
 213     memset(note, 0, sizeof(*note));
 214
 215     note->hdr.n_namesz = cpu_to_dump32(s, namesz);
 216     note->hdr.n_descsz = cpu_to_dump32(s, descsz);
 217     note->hdr.n_type = cpu_to_dump32(s, type);
 218
 219     memcpy(note->name, name, namesz);
 220 }
 221
 222 static int arm_write_elf32_vfp(WriteCoreDumpFunction f, CPUARMState *env,
 223                                int cpuid, DumpState *s)
 224 {
 225     struct arm_note note;
 226     int ret, i;
 227
 228     arm_note_init(&note, s, "LINUX", 6, NT_ARM_VFP, sizeof(note.vfp));
 229
 230     for (i = 0; i < 32; ++i) {
 231         note.vfp.vregs[i] = cpu_to_dump64(s, float64_val(env->vfp.regs[i]));
 232     }
 233
 234     note.vfp.fpscr = cpu_to_dump32(s, vfp_get_fpscr(env));
 235
 236     ret = f(&note, ARM_VFP_NOTE_SIZE, s);
 237     if (ret < 0) {
 238         return -1;
 239     }
 240
 241     return 0;
 242 }
 243
 244 int arm_cpu_write_elf32_note(WriteCoreDumpFunction f, CPUState *cs,
 245                              int cpuid, void *opaque)
 246 {
 247     struct arm_note note;
 248     CPUARMState *env = &ARM_CPU(cs)->env;
 249     DumpState *s = opaque;
 250     int ret, i, fpvalid = !!arm_feature(env, ARM_FEATURE_VFP);
 251
 252     arm_note_init(&note, s, "CORE", 5, NT_PRSTATUS, sizeof(note.prstatus));
 253
 254     note.prstatus.pr_pid = cpu_to_dump32(s, cpuid);
 255     note.prstatus.pr_fpvalid = cpu_to_dump32(s, fpvalid);
 256
 257     for (i = 0; i < 16; ++i) {
 258         note.prstatus.pr_reg.regs[i] = cpu_to_dump32(s, env->regs[i]);
 259     }
 260     note.prstatus.pr_reg.regs[16] = cpu_to_dump32(s, cpsr_read(env));
 261
 262     ret = f(&note, ARM_PRSTATUS_NOTE_SIZE, s);
 263     if (ret < 0) {
 264         return -1;
 265     } else if (fpvalid) {
 266         return arm_write_elf32_vfp(f, env, cpuid, s);
 267     }
 268
 269     return 0;
 270 }
 271
 272 int cpu_get_dump_info(ArchDumpInfo *info,
 273                       const GuestPhysBlockList *guest_phys_blocks)
 274 {
 275     ARMCPU *cpu = ARM_CPU(first_cpu);
 276     CPUARMState *env = &cpu->env;
 277     GuestPhysBlock *block;
 278     hwaddr lowest_addr = ULLONG_MAX;
 279
 280     /* Take a best guess at the phys_base. If we get it wrong then crash
 281      * will need '--machdep phys_offset=<phys-offset>' added to its command
 282      * line, which isn't any worse than assuming we can use zero, but being
 283      * wrong. This is the same algorithm the crash utility uses when
 284      * attempting to guess as it loads non-dumpfile formatted files.
 285      */
 286     QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
 287         if (block->target_start < lowest_addr) {
 288             lowest_addr = block->target_start;
 289         }
 290     }
 291
 292     if (arm_feature(env, ARM_FEATURE_AARCH64)) {
 293         info->d_machine = EM_AARCH64;
 294         info->d_class = ELFCLASS64;
 295         info->page_size = (1 << 16); /* aarch64 max pagesize */
 296         if (lowest_addr != ULLONG_MAX) {
 297             info->phys_base = lowest_addr;
 298         }
 299     } else {
 300         info->d_machine = EM_ARM;
 301         info->d_class = ELFCLASS32;
 302         info->page_size = (1 << 12);
 303         if (lowest_addr < UINT_MAX) {
 304             info->phys_base = lowest_addr;
 305         }
 306     }
 307
 308     /* We assume the relevant endianness is that of EL1; this is right
 309      * for kernels, but might give the wrong answer if you're trying to
 310      * dump a hypervisor that happens to be running an opposite-endian
 311      * kernel.
 312      */
 313     info->d_endian = (env->cp15.sctlr_el[1] & SCTLR_EE) != 0
 314                      ? ELFDATA2MSB : ELFDATA2LSB;
 315
 316     return 0;
 317 }
 318
 319 ssize_t cpu_get_note_size(int class, int machine, int nr_cpus)
 320 {
 321     ARMCPU *cpu = ARM_CPU(first_cpu);
 322     CPUARMState *env = &cpu->env;
 323     size_t note_size;
 324
 325     if (class == ELFCLASS64) {
 326         note_size = AARCH64_PRSTATUS_NOTE_SIZE;
 327         note_size += AARCH64_PRFPREG_NOTE_SIZE;
 328     } else {
 329         note_size = ARM_PRSTATUS_NOTE_SIZE;
 330         if (arm_feature(env, ARM_FEATURE_VFP)) {
 331             note_size += ARM_VFP_NOTE_SIZE;
 332         }
 333     }
 334
 335     return note_size * nr_cpus;
 336 }