aboutsummaryrefslogtreecommitdiff
path: root/target-arm/arch_dump.c
blob: 1a9861f69b964eee3fc85a9e35b0c6a56e080af1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
/* Support for writing ELF notes for ARM architectures
 *
 * Copyright (C) 2015 Red Hat Inc.
 *
 * Author: Andrew Jones <drjones@redhat.com>
 *
 * 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 2 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 <http://www.gnu.org/licenses/>.
 */

#include "qemu/osdep.h"
#include "cpu.h"
#include "elf.h"
#include "sysemu/dump.h"

/* struct user_pt_regs from arch/arm64/include/uapi/asm/ptrace.h */
struct aarch64_user_regs {
    uint64_t regs[31];
    uint64_t sp;
    uint64_t pc;
    uint64_t pstate;
} QEMU_PACKED;

QEMU_BUILD_BUG_ON(sizeof(struct aarch64_user_regs) != 272);

/* struct elf_prstatus from include/uapi/linux/elfcore.h */
struct aarch64_elf_prstatus {
    char pad1[32]; /* 32 == offsetof(struct elf_prstatus, pr_pid) */
    uint32_t pr_pid;
    char pad2[76]; /* 76 == offsetof(struct elf_prstatus, pr_reg) -
                            offsetof(struct elf_prstatus, pr_ppid) */
    struct aarch64_user_regs pr_reg;
    uint32_t pr_fpvalid;
    char pad3[4];
} QEMU_PACKED;

QEMU_BUILD_BUG_ON(sizeof(struct aarch64_elf_prstatus) != 392);

/* struct user_fpsimd_state from arch/arm64/include/uapi/asm/ptrace.h
 *
 * While the vregs member of user_fpsimd_state is of type __uint128_t,
 * QEMU uses an array of uint64_t, where the high half of the 128-bit
 * value is always in the 2n+1'th index. Thus we also break the 128-
 * bit values into two halves in this reproduction of user_fpsimd_state.
 */
struct aarch64_user_vfp_state {
    uint64_t vregs[64];
    uint32_t fpsr;
    uint32_t fpcr;
    char pad[8];
} QEMU_PACKED;

QEMU_BUILD_BUG_ON(sizeof(struct aarch64_user_vfp_state) != 528);

struct aarch64_note {
    Elf64_Nhdr hdr;
    char name[8]; /* align_up(sizeof("CORE"), 4) */
    union {
        struct aarch64_elf_prstatus prstatus;
        struct aarch64_user_vfp_state vfp;
    };
} QEMU_PACKED;

#define AARCH64_NOTE_HEADER_SIZE offsetof(struct aarch64_note, prstatus)
#define AARCH64_PRSTATUS_NOTE_SIZE \
            (AARCH64_NOTE_HEADER_SIZE + sizeof(struct aarch64_elf_prstatus))
#define AARCH64_PRFPREG_NOTE_SIZE \
            (AARCH64_NOTE_HEADER_SIZE + sizeof(struct aarch64_user_vfp_state))

static void aarch64_note_init(struct aarch64_note *note, DumpState *s,
                              const char *name, Elf64_Word namesz,
                              Elf64_Word type, Elf64_Word descsz)
{
    memset(note, 0, sizeof(*note));

    note->hdr.n_namesz = cpu_to_dump32(s, namesz);
    note->hdr.n_descsz = cpu_to_dump32(s, descsz);
    note->hdr.n_type = cpu_to_dump32(s, type);

    memcpy(note->name, name, namesz);
}

static int aarch64_write_elf64_prfpreg(WriteCoreDumpFunction f,
                                       CPUARMState *env, int cpuid,
                                       DumpState *s)
{
    struct aarch64_note note;
    int ret, i;

    aarch64_note_init(&note, s, "CORE", 5, NT_PRFPREG, sizeof(note.vfp));

    for (i = 0; i < 64; ++i) {
        note.vfp.vregs[i] = cpu_to_dump64(s, float64_val(env->vfp.regs[i]));
    }

    if (s->dump_info.d_endian == ELFDATA2MSB) {
        /* For AArch64 we must always swap the vfp.regs's 2n and 2n+1
         * entries when generating BE notes, because even big endian
         * hosts use 2n+1 for the high half.
         */
        for (i = 0; i < 32; ++i) {
            uint64_t tmp = note.vfp.vregs[2*i];
            note.vfp.vregs[2*i] = note.vfp.vregs[2*i+1];
            note.vfp.vregs[2*i+1] = tmp;
        }
    }

    note.vfp.fpsr = cpu_to_dump32(s, vfp_get_fpsr(env));
    note.vfp.fpcr = cpu_to_dump32(s, vfp_get_fpcr(env));

    ret = f(&note, AARCH64_PRFPREG_NOTE_SIZE, s);
    if (ret < 0) {
        return -1;
    }

    return 0;
}

int arm_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
                             int cpuid, void *opaque)
{
    struct aarch64_note note;
    CPUARMState *env = &ARM_CPU(cs)->env;
    DumpState *s = opaque;
    uint64_t pstate, sp;
    int ret, i;

    aarch64_note_init(&note, s, "CORE", 5, NT_PRSTATUS, sizeof(note.prstatus));

    note.prstatus.pr_pid = cpu_to_dump32(s, cpuid);
    note.prstatus.pr_fpvalid = cpu_to_dump32(s, 1);

    if (!is_a64(env)) {
        aarch64_sync_32_to_64(env);
        pstate = cpsr_read(env);
        sp = 0;
    } else {
        pstate = pstate_read(env);
        sp = env->xregs[31];
    }

    for (i = 0; i < 31; ++i) {
        note.prstatus.pr_reg.regs[i] = cpu_to_dump64(s, env->xregs[i]);
    }
    note.prstatus.pr_reg.sp = cpu_to_dump64(s, sp);
    note.prstatus.pr_reg.pc = cpu_to_dump64(s, env->pc);
    note.prstatus.pr_reg.pstate = cpu_to_dump64(s, pstate);

    ret = f(&note, AARCH64_PRSTATUS_NOTE_SIZE, s);
    if (ret < 0) {
        return -1;
    }

    return aarch64_write_elf64_prfpreg(f, env, cpuid, s);
}

/* struct pt_regs from arch/arm/include/asm/ptrace.h */
struct arm_user_regs {
    uint32_t regs[17];
    char pad[4];
} QEMU_PACKED;

QEMU_BUILD_BUG_ON(sizeof(struct arm_user_regs) != 72);

/* struct elf_prstatus from include/uapi/linux/elfcore.h */
struct arm_elf_prstatus {
    char pad1[24]; /* 24 == offsetof(struct elf_prstatus, pr_pid) */
    uint32_t pr_pid;
    char pad2[44]; /* 44 == offsetof(struct elf_prstatus, pr_reg) -
                            offsetof(struct elf_prstatus, pr_ppid) */
    struct arm_user_regs pr_reg;
    uint32_t pr_fpvalid;
} QEMU_PACKED arm_elf_prstatus;

QEMU_BUILD_BUG_ON(sizeof(struct arm_elf_prstatus) != 148);

/* struct user_vfp from arch/arm/include/asm/user.h */
struct arm_user_vfp_state {
    uint64_t vregs[32];
    uint32_t fpscr;
} QEMU_PACKED;

QEMU_BUILD_BUG_ON(sizeof(struct arm_user_vfp_state) != 260);

struct arm_note {
    Elf32_Nhdr hdr;
    char name[8]; /* align_up(sizeof("LINUX"), 4) */
    union {
        struct arm_elf_prstatus prstatus;
        struct arm_user_vfp_state vfp;
    };
} QEMU_PACKED;

#define ARM_NOTE_HEADER_SIZE offsetof(struct arm_note, prstatus)
#define ARM_PRSTATUS_NOTE_SIZE \
            (ARM_NOTE_HEADER_SIZE + sizeof(struct arm_elf_prstatus))
#define ARM_VFP_NOTE_SIZE \
            (ARM_NOTE_HEADER_SIZE + sizeof(struct arm_user_vfp_state))

static void arm_note_init(struct arm_note *note, DumpState *s,
                          const char *name, Elf32_Word namesz,
                          Elf32_Word type, Elf32_Word descsz)
{
    memset(note, 0, sizeof(*note));

    note->hdr.n_namesz = cpu_to_dump32(s, namesz);
    note->hdr.n_descsz = cpu_to_dump32(s, descsz);
    note->hdr.n_type = cpu_to_dump32(s, type);

    memcpy(note->name, name, namesz);
}

static int arm_write_elf32_vfp(WriteCoreDumpFunction f, CPUARMState *env,
                               int cpuid, DumpState *s)
{
    struct arm_note note;
    int ret, i;

    arm_note_init(&note, s, "LINUX", 6, NT_ARM_VFP, sizeof(note.vfp));

    for (i = 0; i < 32; ++i) {
        note.vfp.vregs[i] = cpu_to_dump64(s, float64_val(env->vfp.regs[i]));
    }

    note.vfp.fpscr = cpu_to_dump32(s, vfp_get_fpscr(env));

    ret = f(&note, ARM_VFP_NOTE_SIZE, s);
    if (ret < 0) {
        return -1;
    }

    return 0;
}

int arm_cpu_write_elf32_note(WriteCoreDumpFunction f, CPUState *cs,
                             int cpuid, void *opaque)
{
    struct arm_note note;
    CPUARMState *env = &ARM_CPU(cs)->env;
    DumpState *s = opaque;
    int ret, i, fpvalid = !!arm_feature(env, ARM_FEATURE_VFP);

    arm_note_init(&note, s, "CORE", 5, NT_PRSTATUS, sizeof(note.prstatus));

    note.prstatus.pr_pid = cpu_to_dump32(s, cpuid);
    note.prstatus.pr_fpvalid = cpu_to_dump32(s, fpvalid);

    for (i = 0; i < 16; ++i) {
        note.prstatus.pr_reg.regs[i] = cpu_to_dump32(s, env->regs[i]);
    }
    note.prstatus.pr_reg.regs[16] = cpu_to_dump32(s, cpsr_read(env));

    ret = f(&note, ARM_PRSTATUS_NOTE_SIZE, s);
    if (ret < 0) {
        return -1;
    } else if (fpvalid) {
        return arm_write_elf32_vfp(f, env, cpuid, s);
    }

    return 0;
}

int cpu_get_dump_info(ArchDumpInfo *info,
                      const GuestPhysBlockList *guest_phys_blocks)
{
    ARMCPU *cpu = ARM_CPU(first_cpu);
    CPUARMState *env = &cpu->env;
    GuestPhysBlock *block;
    hwaddr lowest_addr = ULLONG_MAX;

    /* Take a best guess at the phys_base. If we get it wrong then crash
     * will need '--machdep phys_offset=<phys-offset>' added to its command
     * line, which isn't any worse than assuming we can use zero, but being
     * wrong. This is the same algorithm the crash utility uses when
     * attempting to guess as it loads non-dumpfile formatted files.
     */
    QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
        if (block->target_start < lowest_addr) {
            lowest_addr = block->target_start;
        }
    }

    if (arm_feature(env, ARM_FEATURE_AARCH64)) {
        info->d_machine = EM_AARCH64;
        info->d_class = ELFCLASS64;
        info->page_size = (1 << 16); /* aarch64 max pagesize */
        if (lowest_addr != ULLONG_MAX) {
            info->phys_base = lowest_addr;
        }
    } else {
        info->d_machine = EM_ARM;
        info->d_class = ELFCLASS32;
        info->page_size = (1 << 12);
        if (lowest_addr < UINT_MAX) {
            info->phys_base = lowest_addr;
        }
    }

    /* We assume the relevant endianness is that of EL1; this is right
     * for kernels, but might give the wrong answer if you're trying to
     * dump a hypervisor that happens to be running an opposite-endian
     * kernel.
     */
    info->d_endian = (env->cp15.sctlr_el[1] & SCTLR_EE) != 0
                     ? ELFDATA2MSB : ELFDATA2LSB;

    return 0;
}

ssize_t cpu_get_note_size(int class, int machine, int nr_cpus)
{
    ARMCPU *cpu = ARM_CPU(first_cpu);
    CPUARMState *env = &cpu->env;
    size_t note_size;

    if (class == ELFCLASS64) {
        note_size = AARCH64_PRSTATUS_NOTE_SIZE;
        note_size += AARCH64_PRFPREG_NOTE_SIZE;
    } else {
        note_size = ARM_PRSTATUS_NOTE_SIZE;
        if (arm_feature(env, ARM_FEATURE_VFP)) {
            note_size += ARM_VFP_NOTE_SIZE;
        }
    }

    return note_size * nr_cpus;
}