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 */
27struct aarch64_user_regs {
28 uint64_t regs[31];
29 uint64_t sp;
30 uint64_t pc;
31 uint64_t pstate;
32} QEMU_PACKED;
33
34QEMU_BUILD_BUG_ON(sizeof(struct aarch64_user_regs) != 272);
35
36/* struct elf_prstatus from include/uapi/linux/elfcore.h */
37struct 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
47QEMU_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 */
56struct 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
63QEMU_BUILD_BUG_ON(sizeof(struct aarch64_user_vfp_state) != 528);
64
65struct aarch64_note {
66 Elf64_Nhdr hdr;
67 char name[8]; /* align_up(sizeof("CORE"), 4) */
68 union {
69 struct aarch64_elf_prstatus prstatus;
70 struct aarch64_user_vfp_state vfp;
71 };
72} QEMU_PACKED;
73
74#define AARCH64_NOTE_HEADER_SIZE offsetof(struct aarch64_note, prstatus)
75#define AARCH64_PRSTATUS_NOTE_SIZE \
76 (AARCH64_NOTE_HEADER_SIZE + sizeof(struct aarch64_elf_prstatus))
77#define AARCH64_PRFPREG_NOTE_SIZE \
78 (AARCH64_NOTE_HEADER_SIZE + sizeof(struct aarch64_user_vfp_state))
79
80static void aarch64_note_init(struct aarch64_note *note, DumpState *s,
81 const char *name, Elf64_Word namesz,
82 Elf64_Word type, Elf64_Word descsz)
83{
84 memset(note, 0, sizeof(*note));
85
86 note->hdr.n_namesz = cpu_to_dump32(s, namesz);
87 note->hdr.n_descsz = cpu_to_dump32(s, descsz);
88 note->hdr.n_type = cpu_to_dump32(s, type);
89
90 memcpy(note->name, name, namesz);
91}
92
93static int aarch64_write_elf64_prfpreg(WriteCoreDumpFunction f,
94 CPUARMState *env, int cpuid,
95 DumpState *s)
96{
97 struct aarch64_note note;
98 int ret, i;
99
100 aarch64_note_init(&note, s, "CORE", 5, NT_PRFPREG, sizeof(note.vfp));
101
102 for (i = 0; i < 32; ++i) {
103 uint64_t *q = aa64_vfp_qreg(env, i);
104 note.vfp.vregs[2*i + 0] = cpu_to_dump64(s, q[0]);
105 note.vfp.vregs[2*i + 1] = cpu_to_dump64(s, q[1]);
106 }
107
108 if (s->dump_info.d_endian == ELFDATA2MSB) {
109 /* For AArch64 we must always swap the vfp.regs's 2n and 2n+1
110 * entries when generating BE notes, because even big endian
111 * hosts use 2n+1 for the high half.
112 */
113 for (i = 0; i < 32; ++i) {
114 uint64_t tmp = note.vfp.vregs[2*i];
115 note.vfp.vregs[2*i] = note.vfp.vregs[2*i+1];
116 note.vfp.vregs[2*i+1] = tmp;
117 }
118 }
119
120 note.vfp.fpsr = cpu_to_dump32(s, vfp_get_fpsr(env));
121 note.vfp.fpcr = cpu_to_dump32(s, vfp_get_fpcr(env));
122
123 ret = f(&note, AARCH64_PRFPREG_NOTE_SIZE, s);
124 if (ret < 0) {
125 return -1;
126 }
127
128 return 0;
129}
130
131int arm_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
132 int cpuid, void *opaque)
133{
134 struct aarch64_note note;
135 CPUARMState *env = &ARM_CPU(cs)->env;
136 DumpState *s = opaque;
137 uint64_t pstate, sp;
138 int ret, i;
139
140 aarch64_note_init(&note, s, "CORE", 5, NT_PRSTATUS, sizeof(note.prstatus));
141
142 note.prstatus.pr_pid = cpu_to_dump32(s, cpuid);
143 note.prstatus.pr_fpvalid = cpu_to_dump32(s, 1);
144
145 if (!is_a64(env)) {
146 aarch64_sync_32_to_64(env);
147 pstate = cpsr_read(env);
148 sp = 0;
149 } else {
150 pstate = pstate_read(env);
151 sp = env->xregs[31];
152 }
153
154 for (i = 0; i < 31; ++i) {
155 note.prstatus.pr_reg.regs[i] = cpu_to_dump64(s, env->xregs[i]);
156 }
157 note.prstatus.pr_reg.sp = cpu_to_dump64(s, sp);
158 note.prstatus.pr_reg.pc = cpu_to_dump64(s, env->pc);
159 note.prstatus.pr_reg.pstate = cpu_to_dump64(s, pstate);
160
161 ret = f(&note, AARCH64_PRSTATUS_NOTE_SIZE, s);
162 if (ret < 0) {
163 return -1;
164 }
165
166 return aarch64_write_elf64_prfpreg(f, env, cpuid, s);
167}
168
169/* struct pt_regs from arch/arm/include/asm/ptrace.h */
170struct arm_user_regs {
171 uint32_t regs[17];
172 char pad[4];
173} QEMU_PACKED;
174
175QEMU_BUILD_BUG_ON(sizeof(struct arm_user_regs) != 72);
176
177/* struct elf_prstatus from include/uapi/linux/elfcore.h */
178struct arm_elf_prstatus {
179 char pad1[24]; /* 24 == offsetof(struct elf_prstatus, pr_pid) */
180 uint32_t pr_pid;
181 char pad2[44]; /* 44 == offsetof(struct elf_prstatus, pr_reg) -
182 offsetof(struct elf_prstatus, pr_ppid) */
183 struct arm_user_regs pr_reg;
184 uint32_t pr_fpvalid;
185} QEMU_PACKED arm_elf_prstatus;
186
187QEMU_BUILD_BUG_ON(sizeof(struct arm_elf_prstatus) != 148);
188
189/* struct user_vfp from arch/arm/include/asm/user.h */
190struct arm_user_vfp_state {
191 uint64_t vregs[32];
192 uint32_t fpscr;
193} QEMU_PACKED;
194
195QEMU_BUILD_BUG_ON(sizeof(struct arm_user_vfp_state) != 260);
196
197struct arm_note {
198 Elf32_Nhdr hdr;
199 char name[8]; /* align_up(sizeof("LINUX"), 4) */
200 union {
201 struct arm_elf_prstatus prstatus;
202 struct arm_user_vfp_state vfp;
203 };
204} QEMU_PACKED;
205
206#define ARM_NOTE_HEADER_SIZE offsetof(struct arm_note, prstatus)
207#define ARM_PRSTATUS_NOTE_SIZE \
208 (ARM_NOTE_HEADER_SIZE + sizeof(struct arm_elf_prstatus))
209#define ARM_VFP_NOTE_SIZE \
210 (ARM_NOTE_HEADER_SIZE + sizeof(struct arm_user_vfp_state))
211
212static void arm_note_init(struct arm_note *note, DumpState *s,
213 const char *name, Elf32_Word namesz,
214 Elf32_Word type, Elf32_Word descsz)
215{
216 memset(note, 0, sizeof(*note));
217
218 note->hdr.n_namesz = cpu_to_dump32(s, namesz);
219 note->hdr.n_descsz = cpu_to_dump32(s, descsz);
220 note->hdr.n_type = cpu_to_dump32(s, type);
221
222 memcpy(note->name, name, namesz);
223}
224
225static int arm_write_elf32_vfp(WriteCoreDumpFunction f, CPUARMState *env,
226 int cpuid, DumpState *s)
227{
228 struct arm_note note;
229 int ret, i;
230
231 arm_note_init(&note, s, "LINUX", 6, NT_ARM_VFP, sizeof(note.vfp));
232
233 for (i = 0; i < 32; ++i) {
234 note.vfp.vregs[i] = cpu_to_dump64(s, *aa32_vfp_dreg(env, i));
235 }
236
237 note.vfp.fpscr = cpu_to_dump32(s, vfp_get_fpscr(env));
238
239 ret = f(&note, ARM_VFP_NOTE_SIZE, s);
240 if (ret < 0) {
241 return -1;
242 }
243
244 return 0;
245}
246
247int arm_cpu_write_elf32_note(WriteCoreDumpFunction f, CPUState *cs,
248 int cpuid, void *opaque)
249{
250 struct arm_note note;
251 CPUARMState *env = &ARM_CPU(cs)->env;
252 DumpState *s = opaque;
253 int ret, i, fpvalid = !!arm_feature(env, ARM_FEATURE_VFP);
254
255 arm_note_init(&note, s, "CORE", 5, NT_PRSTATUS, sizeof(note.prstatus));
256
257 note.prstatus.pr_pid = cpu_to_dump32(s, cpuid);
258 note.prstatus.pr_fpvalid = cpu_to_dump32(s, fpvalid);
259
260 for (i = 0; i < 16; ++i) {
261 note.prstatus.pr_reg.regs[i] = cpu_to_dump32(s, env->regs[i]);
262 }
263 note.prstatus.pr_reg.regs[16] = cpu_to_dump32(s, cpsr_read(env));
264
265 ret = f(&note, ARM_PRSTATUS_NOTE_SIZE, s);
266 if (ret < 0) {
267 return -1;
268 } else if (fpvalid) {
269 return arm_write_elf32_vfp(f, env, cpuid, s);
270 }
271
272 return 0;
273}
274
275int cpu_get_dump_info(ArchDumpInfo *info,
276 const GuestPhysBlockList *guest_phys_blocks)
277{
278 ARMCPU *cpu;
279 CPUARMState *env;
280 GuestPhysBlock *block;
281 hwaddr lowest_addr = ULLONG_MAX;
282
283 if (first_cpu == NULL) {
284 return -1;
285 }
286
287 cpu = ARM_CPU(first_cpu);
288 env = &cpu->env;
289
290 /* Take a best guess at the phys_base. If we get it wrong then crash
291 * will need '--machdep phys_offset=<phys-offset>' added to its command
292 * line, which isn't any worse than assuming we can use zero, but being
293 * wrong. This is the same algorithm the crash utility uses when
294 * attempting to guess as it loads non-dumpfile formatted files.
295 */
296 QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
297 if (block->target_start < lowest_addr) {
298 lowest_addr = block->target_start;
299 }
300 }
301
302 if (arm_feature(env, ARM_FEATURE_AARCH64)) {
303 info->d_machine = EM_AARCH64;
304 info->d_class = ELFCLASS64;
305 info->page_size = (1 << 16); /* aarch64 max pagesize */
306 if (lowest_addr != ULLONG_MAX) {
307 info->phys_base = lowest_addr;
308 }
309 } else {
310 info->d_machine = EM_ARM;
311 info->d_class = ELFCLASS32;
312 info->page_size = (1 << 12);
313 if (lowest_addr < UINT_MAX) {
314 info->phys_base = lowest_addr;
315 }
316 }
317
318 /* We assume the relevant endianness is that of EL1; this is right
319 * for kernels, but might give the wrong answer if you're trying to
320 * dump a hypervisor that happens to be running an opposite-endian
321 * kernel.
322 */
323 info->d_endian = (env->cp15.sctlr_el[1] & SCTLR_EE) != 0
324 ? ELFDATA2MSB : ELFDATA2LSB;
325
326 return 0;
327}
328
329ssize_t cpu_get_note_size(int class, int machine, int nr_cpus)
330{
331 ARMCPU *cpu = ARM_CPU(first_cpu);
332 CPUARMState *env = &cpu->env;
333 size_t note_size;
334
335 if (class == ELFCLASS64) {
336 note_size = AARCH64_PRSTATUS_NOTE_SIZE;
337 note_size += AARCH64_PRFPREG_NOTE_SIZE;
338 } else {
339 note_size = ARM_PRSTATUS_NOTE_SIZE;
340 if (arm_feature(env, ARM_FEATURE_VFP)) {
341 note_size += ARM_VFP_NOTE_SIZE;
342 }
343 }
344
345 return note_size * nr_cpus;
346}
347