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arch_dump.c (13775B)


      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 }