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 "qemu/osdep.h"
  22 #include "cpu.h"
  23 #include "elf.h"
  24 #include "sysemu/dump.h"
  25
  26 /* struct user_pt_regs from arch/arm64/include/uapi/asm/ptrace.h */
  27 struct aarch64_user_regs {
  28     uint64_t regs[31];
  29     uint64_t sp;
  30     uint64_t pc;
  31     uint64_t pstate;
  32 } QEMU_PACKED;
  33
  34 QEMU_BUILD_BUG_ON(sizeof(struct aarch64_user_regs) != 272);
  35
  36 /* struct elf_prstatus from include/uapi/linux/elfcore.h */
  37 struct aarch64_elf_prstatus {
  38     char pad1[32]; /* 32 == offsetof(struct elf_prstatus, pr_pid) */
  39     uint32_t pr_pid;
  40     char pad2[76]; /* 76 == offsetof(struct elf_prstatus, pr_reg) -
  41                             offsetof(struct elf_prstatus, pr_ppid) */
  42     struct aarch64_user_regs pr_reg;
  43     uint32_t pr_fpvalid;
  44     char pad3[4];
  45 } QEMU_PACKED;
  46
  47 QEMU_BUILD_BUG_ON(sizeof(struct aarch64_elf_prstatus) != 392);
  48
  49 /* struct user_fpsimd_state from arch/arm64/include/uapi/asm/ptrace.h
  50  *
  51  * While the vregs member of user_fpsimd_state is of type __uint128_t,
  52  * QEMU uses an array of uint64_t, where the high half of the 128-bit
  53  * value is always in the 2n+1'th index. Thus we also break the 128-
  54  * bit values into two halves in this reproduction of user_fpsimd_state.
  55  */
  56 struct aarch64_user_vfp_state {
  57     uint64_t vregs[64];
  58     uint32_t fpsr;
  59     uint32_t fpcr;
  60     char pad[8];
  61 } QEMU_PACKED;
  62
  63 QEMU_BUILD_BUG_ON(sizeof(struct aarch64_user_vfp_state) != 528);
  64
  65 /* struct user_sve_header from arch/arm64/include/uapi/asm/ptrace.h */
  66 struct aarch64_user_sve_header {
  67     uint32_t size;
  68     uint32_t max_size;
  69     uint16_t vl;
  70     uint16_t max_vl;
  71     uint16_t flags;
  72     uint16_t reserved;
  73 } QEMU_PACKED;
  74
  75 struct aarch64_note {
  76     Elf64_Nhdr hdr;
  77     char name[8]; /* align_up(sizeof("CORE"), 4) */
  78     union {
  79         struct aarch64_elf_prstatus prstatus;
  80         struct aarch64_user_vfp_state vfp;
  81         struct aarch64_user_sve_header sve;
  82     };
  83 } QEMU_PACKED;
  84
  85 #define AARCH64_NOTE_HEADER_SIZE offsetof(struct aarch64_note, prstatus)
  86 #define AARCH64_PRSTATUS_NOTE_SIZE \
  87             (AARCH64_NOTE_HEADER_SIZE + sizeof(struct aarch64_elf_prstatus))
  88 #define AARCH64_PRFPREG_NOTE_SIZE \
  89             (AARCH64_NOTE_HEADER_SIZE + sizeof(struct aarch64_user_vfp_state))
  90 #define AARCH64_SVE_NOTE_SIZE(env) \
  91             (AARCH64_NOTE_HEADER_SIZE + sve_size(env))
  92
  93 static void aarch64_note_init(struct aarch64_note *note, DumpState *s,
  94                               const char *name, Elf64_Word namesz,
  95                               Elf64_Word type, Elf64_Word descsz)
  96 {
  97     memset(note, 0, sizeof(*note));
  98
  99     note->hdr.n_namesz = cpu_to_dump32(s, namesz);
 100     note->hdr.n_descsz = cpu_to_dump32(s, descsz);
 101     note->hdr.n_type = cpu_to_dump32(s, type);
 102
 103     memcpy(note->name, name, namesz);
 104 }
 105
 106 static int aarch64_write_elf64_prfpreg(WriteCoreDumpFunction f,
 107                                        CPUARMState *env, int cpuid,
 108                                        DumpState *s)
 109 {
 110     struct aarch64_note note;
 111     int ret, i;
 112
 113     aarch64_note_init(&note, s, "CORE", 5, NT_PRFPREG, sizeof(note.vfp));
 114
 115     for (i = 0; i < 32; ++i) {
 116         uint64_t *q = aa64_vfp_qreg(env, i);
 117         note.vfp.vregs[2 * i + 0] = cpu_to_dump64(s, q[0]);
 118         note.vfp.vregs[2 * i + 1] = cpu_to_dump64(s, q[1]);
 119     }
 120
 121     if (s->dump_info.d_endian == ELFDATA2MSB) {
 122         /* For AArch64 we must always swap the vfp.regs's 2n and 2n+1
 123          * entries when generating BE notes, because even big endian
 124          * hosts use 2n+1 for the high half.
 125          */
 126         for (i = 0; i < 32; ++i) {
 127             uint64_t tmp = note.vfp.vregs[2*i];
 128             note.vfp.vregs[2 * i] = note.vfp.vregs[2 * i + 1];
 129             note.vfp.vregs[2 * i + 1] = tmp;
 130         }
 131     }
 132
 133     note.vfp.fpsr = cpu_to_dump32(s, vfp_get_fpsr(env));
 134     note.vfp.fpcr = cpu_to_dump32(s, vfp_get_fpcr(env));
 135
 136     ret = f(&note, AARCH64_PRFPREG_NOTE_SIZE, s);
 137     if (ret < 0) {
 138         return -1;
 139     }
 140
 141     return 0;
 142 }
 143
 144 #ifdef TARGET_AARCH64
 145 static off_t sve_zreg_offset(uint32_t vq, int n)
 146 {
 147     off_t off = sizeof(struct aarch64_user_sve_header);
 148     return ROUND_UP(off, 16) + vq * 16 * n;
 149 }
 150
 151 static off_t sve_preg_offset(uint32_t vq, int n)
 152 {
 153     return sve_zreg_offset(vq, 32) + vq * 16 / 8 * n;
 154 }
 155
 156 static off_t sve_fpsr_offset(uint32_t vq)
 157 {
 158     off_t off = sve_preg_offset(vq, 17);
 159     return ROUND_UP(off, 16);
 160 }
 161
 162 static off_t sve_fpcr_offset(uint32_t vq)
 163 {
 164     return sve_fpsr_offset(vq) + sizeof(uint32_t);
 165 }
 166
 167 static uint32_t sve_current_vq(CPUARMState *env)
 168 {
 169     return sve_vqm1_for_el(env, arm_current_el(env)) + 1;
 170 }
 171
 172 static size_t sve_size_vq(uint32_t vq)
 173 {
 174     off_t off = sve_fpcr_offset(vq) + sizeof(uint32_t);
 175     return ROUND_UP(off, 16);
 176 }
 177
 178 static size_t sve_size(CPUARMState *env)
 179 {
 180     return sve_size_vq(sve_current_vq(env));
 181 }
 182
 183 static int aarch64_write_elf64_sve(WriteCoreDumpFunction f,
 184                                    CPUARMState *env, int cpuid,
 185                                    DumpState *s)
 186 {
 187     struct aarch64_note *note;
 188     ARMCPU *cpu = env_archcpu(env);
 189     uint32_t vq = sve_current_vq(env);
 190     uint64_t tmp[ARM_MAX_VQ * 2], *r;
 191     uint32_t fpr;
 192     uint8_t *buf;
 193     int ret, i;
 194
 195     note = g_malloc0(AARCH64_SVE_NOTE_SIZE(env));
 196     buf = (uint8_t *)&note->sve;
 197
 198     aarch64_note_init(note, s, "LINUX", 6, NT_ARM_SVE, sve_size_vq(vq));
 199
 200     note->sve.size = cpu_to_dump32(s, sve_size_vq(vq));
 201     note->sve.max_size = cpu_to_dump32(s, sve_size_vq(cpu->sve_max_vq));
 202     note->sve.vl = cpu_to_dump16(s, vq * 16);
 203     note->sve.max_vl = cpu_to_dump16(s, cpu->sve_max_vq * 16);
 204     note->sve.flags = cpu_to_dump16(s, 1);
 205
 206     for (i = 0; i < 32; ++i) {
 207         r = sve_bswap64(tmp, &env->vfp.zregs[i].d[0], vq * 2);
 208         memcpy(&buf[sve_zreg_offset(vq, i)], r, vq * 16);
 209     }
 210
 211     for (i = 0; i < 17; ++i) {
 212         r = sve_bswap64(tmp, r = &env->vfp.pregs[i].p[0],
 213                         DIV_ROUND_UP(vq * 2, 8));
 214         memcpy(&buf[sve_preg_offset(vq, i)], r, vq * 16 / 8);
 215     }
 216
 217     fpr = cpu_to_dump32(s, vfp_get_fpsr(env));
 218     memcpy(&buf[sve_fpsr_offset(vq)], &fpr, sizeof(uint32_t));
 219
 220     fpr = cpu_to_dump32(s, vfp_get_fpcr(env));
 221     memcpy(&buf[sve_fpcr_offset(vq)], &fpr, sizeof(uint32_t));
 222
 223     ret = f(note, AARCH64_SVE_NOTE_SIZE(env), s);
 224     g_free(note);
 225
 226     if (ret < 0) {
 227         return -1;
 228     }
 229
 230     return 0;
 231 }
 232 #endif
 233
 234 int arm_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
 235                              int cpuid, DumpState *s)
 236 {
 237     struct aarch64_note note;
 238     ARMCPU *cpu = ARM_CPU(cs);
 239     CPUARMState *env = &cpu->env;
 240     uint64_t pstate, sp;
 241     int ret, i;
 242
 243     aarch64_note_init(&note, s, "CORE", 5, NT_PRSTATUS, sizeof(note.prstatus));
 244
 245     note.prstatus.pr_pid = cpu_to_dump32(s, cpuid);
 246     note.prstatus.pr_fpvalid = cpu_to_dump32(s, 1);
 247
 248     if (!is_a64(env)) {
 249         aarch64_sync_32_to_64(env);
 250         pstate = cpsr_read(env);
 251         sp = 0;
 252     } else {
 253         pstate = pstate_read(env);
 254         sp = env->xregs[31];
 255     }
 256
 257     for (i = 0; i < 31; ++i) {
 258         note.prstatus.pr_reg.regs[i] = cpu_to_dump64(s, env->xregs[i]);
 259     }
 260     note.prstatus.pr_reg.sp = cpu_to_dump64(s, sp);
 261     note.prstatus.pr_reg.pc = cpu_to_dump64(s, env->pc);
 262     note.prstatus.pr_reg.pstate = cpu_to_dump64(s, pstate);
 263
 264     ret = f(&note, AARCH64_PRSTATUS_NOTE_SIZE, s);
 265     if (ret < 0) {
 266         return -1;
 267     }
 268
 269     ret = aarch64_write_elf64_prfpreg(f, env, cpuid, s);
 270     if (ret) {
 271         return ret;
 272     }
 273
 274 #ifdef TARGET_AARCH64
 275     if (cpu_isar_feature(aa64_sve, cpu)) {
 276         ret = aarch64_write_elf64_sve(f, env, cpuid, s);
 277     }
 278 #endif
 279
 280     return ret;
 281 }
 282
 283 /* struct pt_regs from arch/arm/include/asm/ptrace.h */
 284 struct arm_user_regs {
 285     uint32_t regs[17];
 286     char pad[4];
 287 } QEMU_PACKED;
 288
 289 QEMU_BUILD_BUG_ON(sizeof(struct arm_user_regs) != 72);
 290
 291 /* struct elf_prstatus from include/uapi/linux/elfcore.h */
 292 struct arm_elf_prstatus {
 293     char pad1[24]; /* 24 == offsetof(struct elf_prstatus, pr_pid) */
 294     uint32_t pr_pid;
 295     char pad2[44]; /* 44 == offsetof(struct elf_prstatus, pr_reg) -
 296                             offsetof(struct elf_prstatus, pr_ppid) */
 297     struct arm_user_regs pr_reg;
 298     uint32_t pr_fpvalid;
 299 } QEMU_PACKED arm_elf_prstatus;
 300
 301 QEMU_BUILD_BUG_ON(sizeof(struct arm_elf_prstatus) != 148);
 302
 303 /* struct user_vfp from arch/arm/include/asm/user.h */
 304 struct arm_user_vfp_state {
 305     uint64_t vregs[32];
 306     uint32_t fpscr;
 307 } QEMU_PACKED;
 308
 309 QEMU_BUILD_BUG_ON(sizeof(struct arm_user_vfp_state) != 260);
 310
 311 struct arm_note {
 312     Elf32_Nhdr hdr;
 313     char name[8]; /* align_up(sizeof("LINUX"), 4) */
 314     union {
 315         struct arm_elf_prstatus prstatus;
 316         struct arm_user_vfp_state vfp;
 317     };
 318 } QEMU_PACKED;
 319
 320 #define ARM_NOTE_HEADER_SIZE offsetof(struct arm_note, prstatus)
 321 #define ARM_PRSTATUS_NOTE_SIZE \
 322             (ARM_NOTE_HEADER_SIZE + sizeof(struct arm_elf_prstatus))
 323 #define ARM_VFP_NOTE_SIZE \
 324             (ARM_NOTE_HEADER_SIZE + sizeof(struct arm_user_vfp_state))
 325
 326 static void arm_note_init(struct arm_note *note, DumpState *s,
 327                           const char *name, Elf32_Word namesz,
 328                           Elf32_Word type, Elf32_Word descsz)
 329 {
 330     memset(note, 0, sizeof(*note));
 331
 332     note->hdr.n_namesz = cpu_to_dump32(s, namesz);
 333     note->hdr.n_descsz = cpu_to_dump32(s, descsz);
 334     note->hdr.n_type = cpu_to_dump32(s, type);
 335
 336     memcpy(note->name, name, namesz);
 337 }
 338
 339 static int arm_write_elf32_vfp(WriteCoreDumpFunction f, CPUARMState *env,
 340                                int cpuid, DumpState *s)
 341 {
 342     struct arm_note note;
 343     int ret, i;
 344
 345     arm_note_init(&note, s, "LINUX", 6, NT_ARM_VFP, sizeof(note.vfp));
 346
 347     for (i = 0; i < 32; ++i) {
 348         note.vfp.vregs[i] = cpu_to_dump64(s, *aa32_vfp_dreg(env, i));
 349     }
 350
 351     note.vfp.fpscr = cpu_to_dump32(s, vfp_get_fpscr(env));
 352
 353     ret = f(&note, ARM_VFP_NOTE_SIZE, s);
 354     if (ret < 0) {
 355         return -1;
 356     }
 357
 358     return 0;
 359 }
 360
 361 int arm_cpu_write_elf32_note(WriteCoreDumpFunction f, CPUState *cs,
 362                              int cpuid, DumpState *s)
 363 {
 364     struct arm_note note;
 365     ARMCPU *cpu = ARM_CPU(cs);
 366     CPUARMState *env = &cpu->env;
 367     int ret, i;
 368     bool fpvalid = cpu_isar_feature(aa32_vfp_simd, cpu);
 369
 370     arm_note_init(&note, s, "CORE", 5, NT_PRSTATUS, sizeof(note.prstatus));
 371
 372     note.prstatus.pr_pid = cpu_to_dump32(s, cpuid);
 373     note.prstatus.pr_fpvalid = cpu_to_dump32(s, fpvalid);
 374
 375     for (i = 0; i < 16; ++i) {
 376         note.prstatus.pr_reg.regs[i] = cpu_to_dump32(s, env->regs[i]);
 377     }
 378     note.prstatus.pr_reg.regs[16] = cpu_to_dump32(s, cpsr_read(env));
 379
 380     ret = f(&note, ARM_PRSTATUS_NOTE_SIZE, s);
 381     if (ret < 0) {
 382         return -1;
 383     } else if (fpvalid) {
 384         return arm_write_elf32_vfp(f, env, cpuid, s);
 385     }
 386
 387     return 0;
 388 }
 389
 390 int cpu_get_dump_info(ArchDumpInfo *info,
 391                       const GuestPhysBlockList *guest_phys_blocks)
 392 {
 393     ARMCPU *cpu;
 394     CPUARMState *env;
 395     GuestPhysBlock *block;
 396     hwaddr lowest_addr = ULLONG_MAX;
 397
 398     if (first_cpu == NULL) {
 399         return -1;
 400     }
 401
 402     cpu = ARM_CPU(first_cpu);
 403     env = &cpu->env;
 404
 405     /* Take a best guess at the phys_base. If we get it wrong then crash
 406      * will need '--machdep phys_offset=<phys-offset>' added to its command
 407      * line, which isn't any worse than assuming we can use zero, but being
 408      * wrong. This is the same algorithm the crash utility uses when
 409      * attempting to guess as it loads non-dumpfile formatted files.
 410      */
 411     QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
 412         if (block->target_start < lowest_addr) {
 413             lowest_addr = block->target_start;
 414         }
 415     }
 416
 417     if (arm_feature(env, ARM_FEATURE_AARCH64)) {
 418         info->d_machine = EM_AARCH64;
 419         info->d_class = ELFCLASS64;
 420         info->page_size = (1 << 16); /* aarch64 max pagesize */
 421         if (lowest_addr != ULLONG_MAX) {
 422             info->phys_base = lowest_addr;
 423         }
 424     } else {
 425         info->d_machine = EM_ARM;
 426         info->d_class = ELFCLASS32;
 427         info->page_size = (1 << 12);
 428         if (lowest_addr < UINT_MAX) {
 429             info->phys_base = lowest_addr;
 430         }
 431     }
 432
 433     /* We assume the relevant endianness is that of EL1; this is right
 434      * for kernels, but might give the wrong answer if you're trying to
 435      * dump a hypervisor that happens to be running an opposite-endian
 436      * kernel.
 437      */
 438     info->d_endian = (env->cp15.sctlr_el[1] & SCTLR_EE) != 0
 439                      ? ELFDATA2MSB : ELFDATA2LSB;
 440
 441     return 0;
 442 }
 443
 444 ssize_t cpu_get_note_size(int class, int machine, int nr_cpus)
 445 {
 446     ARMCPU *cpu = ARM_CPU(first_cpu);
 447     size_t note_size;
 448
 449     if (class == ELFCLASS64) {
 450         note_size = AARCH64_PRSTATUS_NOTE_SIZE;
 451         note_size += AARCH64_PRFPREG_NOTE_SIZE;
 452 #ifdef TARGET_AARCH64
 453         if (cpu_isar_feature(aa64_sve, cpu)) {
 454             note_size += AARCH64_SVE_NOTE_SIZE(&cpu->env);
 455         }
 456 #endif
 457     } else {
 458         note_size = ARM_PRSTATUS_NOTE_SIZE;
 459         if (cpu_isar_feature(aa32_vfp_simd, cpu)) {
 460             note_size += ARM_VFP_NOTE_SIZE;
 461         }
 462     }
 463
 464     return note_size * nr_cpus;
 465 }