1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright 2010 Tilera Corporation. All Rights Reserved. 4 * Copyright 2015 Regents of the University of California 5 * Copyright 2017 SiFive 6 * 7 * Copied from arch/tile/kernel/ptrace.c 8 */ 9 10 #include <asm/ptrace.h> 11 #include <asm/syscall.h> 12 #include <asm/thread_info.h> 13 #include <asm/switch_to.h> 14 #include <linux/audit.h> 15 #include <linux/compat.h> 16 #include <linux/ptrace.h> 17 #include <linux/elf.h> 18 #include <linux/regset.h> 19 #include <linux/sched.h> 20 #include <linux/sched/task_stack.h> 21 22 enum riscv_regset { 23 REGSET_X, 24 #ifdef CONFIG_FPU 25 REGSET_F, 26 #endif 27 }; 28 29 static int riscv_gpr_get(struct task_struct *target, 30 const struct user_regset *regset, 31 struct membuf to) 32 { 33 return membuf_write(&to, task_pt_regs(target), 34 sizeof(struct user_regs_struct)); 35 } 36 37 static int riscv_gpr_set(struct task_struct *target, 38 const struct user_regset *regset, 39 unsigned int pos, unsigned int count, 40 const void *kbuf, const void __user *ubuf) 41 { 42 struct pt_regs *regs; 43 44 regs = task_pt_regs(target); 45 return user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 0, -1); 46 } 47 48 #ifdef CONFIG_FPU 49 static int riscv_fpr_get(struct task_struct *target, 50 const struct user_regset *regset, 51 struct membuf to) 52 { 53 struct __riscv_d_ext_state *fstate = &target->thread.fstate; 54 55 if (target == current) 56 fstate_save(current, task_pt_regs(current)); 57 58 membuf_write(&to, fstate, offsetof(struct __riscv_d_ext_state, fcsr)); 59 membuf_store(&to, fstate->fcsr); 60 return membuf_zero(&to, 4); // explicitly pad 61 } 62 63 static int riscv_fpr_set(struct task_struct *target, 64 const struct user_regset *regset, 65 unsigned int pos, unsigned int count, 66 const void *kbuf, const void __user *ubuf) 67 { 68 int ret; 69 struct __riscv_d_ext_state *fstate = &target->thread.fstate; 70 71 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, fstate, 0, 72 offsetof(struct __riscv_d_ext_state, fcsr)); 73 if (!ret) { 74 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, fstate, 0, 75 offsetof(struct __riscv_d_ext_state, fcsr) + 76 sizeof(fstate->fcsr)); 77 } 78 79 return ret; 80 } 81 #endif 82 83 static const struct user_regset riscv_user_regset[] = { 84 [REGSET_X] = { 85 .core_note_type = NT_PRSTATUS, 86 .n = ELF_NGREG, 87 .size = sizeof(elf_greg_t), 88 .align = sizeof(elf_greg_t), 89 .regset_get = riscv_gpr_get, 90 .set = riscv_gpr_set, 91 }, 92 #ifdef CONFIG_FPU 93 [REGSET_F] = { 94 .core_note_type = NT_PRFPREG, 95 .n = ELF_NFPREG, 96 .size = sizeof(elf_fpreg_t), 97 .align = sizeof(elf_fpreg_t), 98 .regset_get = riscv_fpr_get, 99 .set = riscv_fpr_set, 100 }, 101 #endif 102 }; 103 104 static const struct user_regset_view riscv_user_native_view = { 105 .name = "riscv", 106 .e_machine = EM_RISCV, 107 .regsets = riscv_user_regset, 108 .n = ARRAY_SIZE(riscv_user_regset), 109 }; 110 111 struct pt_regs_offset { 112 const char *name; 113 int offset; 114 }; 115 116 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)} 117 #define REG_OFFSET_END {.name = NULL, .offset = 0} 118 119 static const struct pt_regs_offset regoffset_table[] = { 120 REG_OFFSET_NAME(epc), 121 REG_OFFSET_NAME(ra), 122 REG_OFFSET_NAME(sp), 123 REG_OFFSET_NAME(gp), 124 REG_OFFSET_NAME(tp), 125 REG_OFFSET_NAME(t0), 126 REG_OFFSET_NAME(t1), 127 REG_OFFSET_NAME(t2), 128 REG_OFFSET_NAME(s0), 129 REG_OFFSET_NAME(s1), 130 REG_OFFSET_NAME(a0), 131 REG_OFFSET_NAME(a1), 132 REG_OFFSET_NAME(a2), 133 REG_OFFSET_NAME(a3), 134 REG_OFFSET_NAME(a4), 135 REG_OFFSET_NAME(a5), 136 REG_OFFSET_NAME(a6), 137 REG_OFFSET_NAME(a7), 138 REG_OFFSET_NAME(s2), 139 REG_OFFSET_NAME(s3), 140 REG_OFFSET_NAME(s4), 141 REG_OFFSET_NAME(s5), 142 REG_OFFSET_NAME(s6), 143 REG_OFFSET_NAME(s7), 144 REG_OFFSET_NAME(s8), 145 REG_OFFSET_NAME(s9), 146 REG_OFFSET_NAME(s10), 147 REG_OFFSET_NAME(s11), 148 REG_OFFSET_NAME(t3), 149 REG_OFFSET_NAME(t4), 150 REG_OFFSET_NAME(t5), 151 REG_OFFSET_NAME(t6), 152 REG_OFFSET_NAME(status), 153 REG_OFFSET_NAME(badaddr), 154 REG_OFFSET_NAME(cause), 155 REG_OFFSET_NAME(orig_a0), 156 REG_OFFSET_END, 157 }; 158 159 /** 160 * regs_query_register_offset() - query register offset from its name 161 * @name: the name of a register 162 * 163 * regs_query_register_offset() returns the offset of a register in struct 164 * pt_regs from its name. If the name is invalid, this returns -EINVAL; 165 */ 166 int regs_query_register_offset(const char *name) 167 { 168 const struct pt_regs_offset *roff; 169 170 for (roff = regoffset_table; roff->name != NULL; roff++) 171 if (!strcmp(roff->name, name)) 172 return roff->offset; 173 return -EINVAL; 174 } 175 176 /** 177 * regs_within_kernel_stack() - check the address in the stack 178 * @regs: pt_regs which contains kernel stack pointer. 179 * @addr: address which is checked. 180 * 181 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 182 * If @addr is within the kernel stack, it returns true. If not, returns false. 183 */ 184 static bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr) 185 { 186 return (addr & ~(THREAD_SIZE - 1)) == 187 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)); 188 } 189 190 /** 191 * regs_get_kernel_stack_nth() - get Nth entry of the stack 192 * @regs: pt_regs which contains kernel stack pointer. 193 * @n: stack entry number. 194 * 195 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 196 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 197 * this returns 0. 198 */ 199 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n) 200 { 201 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 202 203 addr += n; 204 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 205 return *addr; 206 else 207 return 0; 208 } 209 210 void ptrace_disable(struct task_struct *child) 211 { 212 } 213 214 long arch_ptrace(struct task_struct *child, long request, 215 unsigned long addr, unsigned long data) 216 { 217 long ret = -EIO; 218 219 switch (request) { 220 default: 221 ret = ptrace_request(child, request, addr, data); 222 break; 223 } 224 225 return ret; 226 } 227 228 #ifdef CONFIG_COMPAT 229 static int compat_riscv_gpr_get(struct task_struct *target, 230 const struct user_regset *regset, 231 struct membuf to) 232 { 233 struct compat_user_regs_struct cregs; 234 235 regs_to_cregs(&cregs, task_pt_regs(target)); 236 237 return membuf_write(&to, &cregs, 238 sizeof(struct compat_user_regs_struct)); 239 } 240 241 static int compat_riscv_gpr_set(struct task_struct *target, 242 const struct user_regset *regset, 243 unsigned int pos, unsigned int count, 244 const void *kbuf, const void __user *ubuf) 245 { 246 int ret; 247 struct compat_user_regs_struct cregs; 248 249 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &cregs, 0, -1); 250 251 cregs_to_regs(&cregs, task_pt_regs(target)); 252 253 return ret; 254 } 255 256 static const struct user_regset compat_riscv_user_regset[] = { 257 [REGSET_X] = { 258 .core_note_type = NT_PRSTATUS, 259 .n = ELF_NGREG, 260 .size = sizeof(compat_elf_greg_t), 261 .align = sizeof(compat_elf_greg_t), 262 .regset_get = compat_riscv_gpr_get, 263 .set = compat_riscv_gpr_set, 264 }, 265 #ifdef CONFIG_FPU 266 [REGSET_F] = { 267 .core_note_type = NT_PRFPREG, 268 .n = ELF_NFPREG, 269 .size = sizeof(elf_fpreg_t), 270 .align = sizeof(elf_fpreg_t), 271 .regset_get = riscv_fpr_get, 272 .set = riscv_fpr_set, 273 }, 274 #endif 275 }; 276 277 static const struct user_regset_view compat_riscv_user_native_view = { 278 .name = "riscv", 279 .e_machine = EM_RISCV, 280 .regsets = compat_riscv_user_regset, 281 .n = ARRAY_SIZE(compat_riscv_user_regset), 282 }; 283 284 long compat_arch_ptrace(struct task_struct *child, compat_long_t request, 285 compat_ulong_t caddr, compat_ulong_t cdata) 286 { 287 long ret = -EIO; 288 289 switch (request) { 290 default: 291 ret = compat_ptrace_request(child, request, caddr, cdata); 292 break; 293 } 294 295 return ret; 296 } 297 #endif /* CONFIG_COMPAT */ 298 299 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 300 { 301 #ifdef CONFIG_COMPAT 302 if (test_tsk_thread_flag(task, TIF_32BIT)) 303 return &compat_riscv_user_native_view; 304 else 305 #endif 306 return &riscv_user_native_view; 307 } 308