xref: /openbmc/qemu/target/riscv/arch_dump.c (revision 93d7620c)
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, DumpState *s)
68 {
69     struct riscv64_note note;
70     RISCVCPU *cpu = RISCV_CPU(cs);
71     CPURISCVState *env = &cpu->env;
72     int ret, i = 0;
73     const char name[] = "CORE";
74 
75     riscv64_note_init(&note, s, name, sizeof(name),
76                       NT_PRSTATUS, sizeof(note.prstatus));
77 
78     note.prstatus.pr_pid = cpu_to_dump32(s, cpuid);
79 
80     note.prstatus.pr_reg.pc = cpu_to_dump64(s, env->pc);
81 
82     for (i = 0; i < 31; i++) {
83         note.prstatus.pr_reg.regs[i] = cpu_to_dump64(s, env->gpr[i + 1]);
84     }
85 
86     ret = f(&note, RISCV64_PRSTATUS_NOTE_SIZE, s);
87     if (ret < 0) {
88         return -1;
89     }
90 
91     return ret;
92 }
93 
94 struct riscv32_user_regs {
95     uint32_t pc;
96     uint32_t regs[31];
97 } QEMU_PACKED;
98 
99 QEMU_BUILD_BUG_ON(sizeof(struct riscv32_user_regs) != 128);
100 
101 struct riscv32_elf_prstatus {
102     char pad1[24]; /* 24 == offsetof(struct elf_prstatus, pr_pid) */
103     uint32_t pr_pid;
104     char pad2[44]; /* 44 == offsetof(struct elf_prstatus, pr_reg) -
105                             offsetof(struct elf_prstatus, pr_ppid) */
106     struct riscv32_user_regs pr_reg;
107     char pad3[4];
108 } QEMU_PACKED;
109 
110 QEMU_BUILD_BUG_ON(sizeof(struct riscv32_elf_prstatus) != 204);
111 
112 struct riscv32_note {
113     Elf32_Nhdr hdr;
114     char name[8]; /* align_up(sizeof("CORE"), 4) */
115     struct riscv32_elf_prstatus prstatus;
116 } QEMU_PACKED;
117 
118 #define RISCV32_NOTE_HEADER_SIZE offsetof(struct riscv32_note, prstatus)
119 #define RISCV32_PRSTATUS_NOTE_SIZE \
120             (RISCV32_NOTE_HEADER_SIZE + sizeof(struct riscv32_elf_prstatus))
121 
122 static void riscv32_note_init(struct riscv32_note *note, DumpState *s,
123                               const char *name, Elf32_Word namesz,
124                               Elf32_Word type, Elf32_Word descsz)
125 {
126     memset(note, 0, sizeof(*note));
127 
128     note->hdr.n_namesz = cpu_to_dump32(s, namesz);
129     note->hdr.n_descsz = cpu_to_dump32(s, descsz);
130     note->hdr.n_type = cpu_to_dump32(s, type);
131 
132     memcpy(note->name, name, namesz);
133 }
134 
135 int riscv_cpu_write_elf32_note(WriteCoreDumpFunction f, CPUState *cs,
136                                int cpuid, DumpState *s)
137 {
138     struct riscv32_note note;
139     RISCVCPU *cpu = RISCV_CPU(cs);
140     CPURISCVState *env = &cpu->env;
141     int ret, i;
142     const char name[] = "CORE";
143 
144     riscv32_note_init(&note, s, name, sizeof(name),
145                       NT_PRSTATUS, sizeof(note.prstatus));
146 
147     note.prstatus.pr_pid = cpu_to_dump32(s, cpuid);
148 
149     note.prstatus.pr_reg.pc = cpu_to_dump32(s, env->pc);
150 
151     for (i = 0; i < 31; i++) {
152         note.prstatus.pr_reg.regs[i] = cpu_to_dump32(s, env->gpr[i + 1]);
153     }
154 
155     ret = f(&note, RISCV32_PRSTATUS_NOTE_SIZE, s);
156     if (ret < 0) {
157         return -1;
158     }
159 
160     return ret;
161 }
162 
163 int cpu_get_dump_info(ArchDumpInfo *info,
164                       const GuestPhysBlockList *guest_phys_blocks)
165 {
166     RISCVCPU *cpu;
167     CPURISCVState *env;
168 
169     if (first_cpu == NULL) {
170         return -1;
171     }
172     cpu = RISCV_CPU(first_cpu);
173     env = &cpu->env;
174 
175     info->d_machine = EM_RISCV;
176 
177 #if defined(TARGET_RISCV64)
178     info->d_class = ELFCLASS64;
179 #else
180     info->d_class = ELFCLASS32;
181 #endif
182 
183     info->d_endian = (env->mstatus & MSTATUS_UBE) != 0
184                      ? ELFDATA2MSB : ELFDATA2LSB;
185 
186     return 0;
187 }
188 
189 ssize_t cpu_get_note_size(int class, int machine, int nr_cpus)
190 {
191     size_t note_size;
192 
193     if (class == ELFCLASS64) {
194         note_size = RISCV64_PRSTATUS_NOTE_SIZE;
195     } else {
196         note_size = RISCV32_PRSTATUS_NOTE_SIZE;
197     }
198 
199     return note_size * nr_cpus;
200 }
201