xref: /openbmc/qemu/target/riscv/arch_dump.c (revision f6476697)
1 /* Support for writing ELF notes for RISC-V architectures
2  *
3  * Copyright (C) 2021 Huawei Technologies Co., Ltd
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2 or later, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include "qemu/osdep.h"
19 #include "cpu.h"
20 #include "elf.h"
21 #include "sysemu/dump.h"
22 
23 /* struct user_regs_struct from arch/riscv/include/uapi/asm/ptrace.h */
24 struct riscv64_user_regs {
25     uint64_t pc;
26     uint64_t regs[31];
27 } QEMU_PACKED;
28 
29 QEMU_BUILD_BUG_ON(sizeof(struct riscv64_user_regs) != 256);
30 
31 /* struct elf_prstatus from include/linux/elfcore.h */
32 struct riscv64_elf_prstatus {
33     char pad1[32]; /* 32 == offsetof(struct elf_prstatus, pr_pid) */
34     uint32_t pr_pid;
35     char pad2[76]; /* 76 == offsetof(struct elf_prstatus, pr_reg) -
36                             offsetof(struct elf_prstatus, pr_ppid) */
37     struct riscv64_user_regs pr_reg;
38     char pad3[8];
39 } QEMU_PACKED;
40 
41 QEMU_BUILD_BUG_ON(sizeof(struct riscv64_elf_prstatus) != 376);
42 
43 struct riscv64_note {
44     Elf64_Nhdr hdr;
45     char name[8]; /* align_up(sizeof("CORE"), 4) */
46     struct riscv64_elf_prstatus prstatus;
47 } QEMU_PACKED;
48 
49 #define RISCV64_NOTE_HEADER_SIZE offsetof(struct riscv64_note, prstatus)
50 #define RISCV64_PRSTATUS_NOTE_SIZE \
51             (RISCV64_NOTE_HEADER_SIZE + sizeof(struct riscv64_elf_prstatus))
52 
53 static void riscv64_note_init(struct riscv64_note *note, DumpState *s,
54                               const char *name, Elf64_Word namesz,
55                               Elf64_Word type, Elf64_Word descsz)
56 {
57     memset(note, 0, sizeof(*note));
58 
59     note->hdr.n_namesz = cpu_to_dump32(s, namesz);
60     note->hdr.n_descsz = cpu_to_dump32(s, descsz);
61     note->hdr.n_type = cpu_to_dump32(s, type);
62 
63     memcpy(note->name, name, namesz);
64 }
65 
66 int riscv_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
67                                int cpuid, void *opaque)
68 {
69     struct riscv64_note note;
70     RISCVCPU *cpu = RISCV_CPU(cs);
71     CPURISCVState *env = &cpu->env;
72     DumpState *s = opaque;
73     int ret, i = 0;
74     const char name[] = "CORE";
75 
76     riscv64_note_init(&note, s, name, sizeof(name),
77                       NT_PRSTATUS, sizeof(note.prstatus));
78 
79     note.prstatus.pr_pid = cpu_to_dump32(s, cpuid);
80 
81     note.prstatus.pr_reg.pc = cpu_to_dump64(s, env->pc);
82 
83     for (i = 0; i < 31; i++) {
84         note.prstatus.pr_reg.regs[i] = cpu_to_dump64(s, env->gpr[i + 1]);
85     }
86 
87     ret = f(&note, RISCV64_PRSTATUS_NOTE_SIZE, s);
88     if (ret < 0) {
89         return -1;
90     }
91 
92     return ret;
93 }
94 
95 struct riscv32_user_regs {
96     uint32_t pc;
97     uint32_t regs[31];
98 } QEMU_PACKED;
99 
100 QEMU_BUILD_BUG_ON(sizeof(struct riscv32_user_regs) != 128);
101 
102 struct riscv32_elf_prstatus {
103     char pad1[24]; /* 24 == offsetof(struct elf_prstatus, pr_pid) */
104     uint32_t pr_pid;
105     char pad2[44]; /* 44 == offsetof(struct elf_prstatus, pr_reg) -
106                             offsetof(struct elf_prstatus, pr_ppid) */
107     struct riscv32_user_regs pr_reg;
108     char pad3[4];
109 } QEMU_PACKED;
110 
111 QEMU_BUILD_BUG_ON(sizeof(struct riscv32_elf_prstatus) != 204);
112 
113 struct riscv32_note {
114     Elf32_Nhdr hdr;
115     char name[8]; /* align_up(sizeof("CORE"), 4) */
116     struct riscv32_elf_prstatus prstatus;
117 } QEMU_PACKED;
118 
119 #define RISCV32_NOTE_HEADER_SIZE offsetof(struct riscv32_note, prstatus)
120 #define RISCV32_PRSTATUS_NOTE_SIZE \
121             (RISCV32_NOTE_HEADER_SIZE + sizeof(struct riscv32_elf_prstatus))
122 
123 static void riscv32_note_init(struct riscv32_note *note, DumpState *s,
124                               const char *name, Elf32_Word namesz,
125                               Elf32_Word type, Elf32_Word descsz)
126 {
127     memset(note, 0, sizeof(*note));
128 
129     note->hdr.n_namesz = cpu_to_dump32(s, namesz);
130     note->hdr.n_descsz = cpu_to_dump32(s, descsz);
131     note->hdr.n_type = cpu_to_dump32(s, type);
132 
133     memcpy(note->name, name, namesz);
134 }
135 
136 int riscv_cpu_write_elf32_note(WriteCoreDumpFunction f, CPUState *cs,
137                                int cpuid, void *opaque)
138 {
139     struct riscv32_note note;
140     RISCVCPU *cpu = RISCV_CPU(cs);
141     CPURISCVState *env = &cpu->env;
142     DumpState *s = opaque;
143     int ret, i;
144     const char name[] = "CORE";
145 
146     riscv32_note_init(&note, s, name, sizeof(name),
147                       NT_PRSTATUS, sizeof(note.prstatus));
148 
149     note.prstatus.pr_pid = cpu_to_dump32(s, cpuid);
150 
151     note.prstatus.pr_reg.pc = cpu_to_dump32(s, env->pc);
152 
153     for (i = 0; i < 31; i++) {
154         note.prstatus.pr_reg.regs[i] = cpu_to_dump32(s, env->gpr[i + 1]);
155     }
156 
157     ret = f(&note, RISCV32_PRSTATUS_NOTE_SIZE, s);
158     if (ret < 0) {
159         return -1;
160     }
161 
162     return ret;
163 }
164 
165 int cpu_get_dump_info(ArchDumpInfo *info,
166                       const GuestPhysBlockList *guest_phys_blocks)
167 {
168     RISCVCPU *cpu;
169     CPURISCVState *env;
170 
171     if (first_cpu == NULL) {
172         return -1;
173     }
174     cpu = RISCV_CPU(first_cpu);
175     env = &cpu->env;
176 
177     info->d_machine = EM_RISCV;
178 
179 #if defined(TARGET_RISCV64)
180     info->d_class = ELFCLASS64;
181 #else
182     info->d_class = ELFCLASS32;
183 #endif
184 
185     info->d_endian = (env->mstatus & MSTATUS_UBE) != 0
186                      ? ELFDATA2MSB : ELFDATA2LSB;
187 
188     return 0;
189 }
190 
191 ssize_t cpu_get_note_size(int class, int machine, int nr_cpus)
192 {
193     size_t note_size;
194 
195     if (class == ELFCLASS64) {
196         note_size = RISCV64_PRSTATUS_NOTE_SIZE;
197     } else {
198         note_size = RISCV32_PRSTATUS_NOTE_SIZE;
199     }
200 
201     return note_size * nr_cpus;
202 }
203