linux/arch/sh/kernel/ptrace_32.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * SuperH process tracing
   4 *
   5 * Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
   6 * Copyright (C) 2002 - 2009  Paul Mundt
   7 *
   8 * Audit support by Yuichi Nakamura <ynakam@hitachisoft.jp>
   9 */
  10#include <linux/kernel.h>
  11#include <linux/sched.h>
  12#include <linux/sched/task_stack.h>
  13#include <linux/mm.h>
  14#include <linux/smp.h>
  15#include <linux/errno.h>
  16#include <linux/ptrace.h>
  17#include <linux/user.h>
  18#include <linux/security.h>
  19#include <linux/signal.h>
  20#include <linux/io.h>
  21#include <linux/audit.h>
  22#include <linux/seccomp.h>
  23#include <linux/elf.h>
  24#include <linux/regset.h>
  25#include <linux/hw_breakpoint.h>
  26#include <linux/uaccess.h>
  27#include <asm/processor.h>
  28#include <asm/mmu_context.h>
  29#include <asm/syscalls.h>
  30#include <asm/fpu.h>
  31
  32#define CREATE_TRACE_POINTS
  33#include <trace/events/syscalls.h>
  34
  35/*
  36 * This routine will get a word off of the process kernel stack.
  37 */
  38static inline int get_stack_long(struct task_struct *task, int offset)
  39{
  40        unsigned char *stack;
  41
  42        stack = (unsigned char *)task_pt_regs(task);
  43        stack += offset;
  44        return (*((int *)stack));
  45}
  46
  47/*
  48 * This routine will put a word on the process kernel stack.
  49 */
  50static inline int put_stack_long(struct task_struct *task, int offset,
  51                                 unsigned long data)
  52{
  53        unsigned char *stack;
  54
  55        stack = (unsigned char *)task_pt_regs(task);
  56        stack += offset;
  57        *(unsigned long *) stack = data;
  58        return 0;
  59}
  60
  61void ptrace_triggered(struct perf_event *bp,
  62                      struct perf_sample_data *data, struct pt_regs *regs)
  63{
  64        struct perf_event_attr attr;
  65
  66        /*
  67         * Disable the breakpoint request here since ptrace has defined a
  68         * one-shot behaviour for breakpoint exceptions.
  69         */
  70        attr = bp->attr;
  71        attr.disabled = true;
  72        modify_user_hw_breakpoint(bp, &attr);
  73}
  74
  75static int set_single_step(struct task_struct *tsk, unsigned long addr)
  76{
  77        struct thread_struct *thread = &tsk->thread;
  78        struct perf_event *bp;
  79        struct perf_event_attr attr;
  80
  81        bp = thread->ptrace_bps[0];
  82        if (!bp) {
  83                ptrace_breakpoint_init(&attr);
  84
  85                attr.bp_addr = addr;
  86                attr.bp_len = HW_BREAKPOINT_LEN_2;
  87                attr.bp_type = HW_BREAKPOINT_R;
  88
  89                bp = register_user_hw_breakpoint(&attr, ptrace_triggered,
  90                                                 NULL, tsk);
  91                if (IS_ERR(bp))
  92                        return PTR_ERR(bp);
  93
  94                thread->ptrace_bps[0] = bp;
  95        } else {
  96                int err;
  97
  98                attr = bp->attr;
  99                attr.bp_addr = addr;
 100                /* reenable breakpoint */
 101                attr.disabled = false;
 102                err = modify_user_hw_breakpoint(bp, &attr);
 103                if (unlikely(err))
 104                        return err;
 105        }
 106
 107        return 0;
 108}
 109
 110void user_enable_single_step(struct task_struct *child)
 111{
 112        unsigned long pc = get_stack_long(child, offsetof(struct pt_regs, pc));
 113
 114        set_tsk_thread_flag(child, TIF_SINGLESTEP);
 115
 116        set_single_step(child, pc);
 117}
 118
 119void user_disable_single_step(struct task_struct *child)
 120{
 121        clear_tsk_thread_flag(child, TIF_SINGLESTEP);
 122}
 123
 124/*
 125 * Called by kernel/ptrace.c when detaching..
 126 *
 127 * Make sure single step bits etc are not set.
 128 */
 129void ptrace_disable(struct task_struct *child)
 130{
 131        user_disable_single_step(child);
 132}
 133
 134static int genregs_get(struct task_struct *target,
 135                       const struct user_regset *regset,
 136                       struct membuf to)
 137{
 138        const struct pt_regs *regs = task_pt_regs(target);
 139
 140        return membuf_write(&to, regs, sizeof(struct pt_regs));
 141}
 142
 143static int genregs_set(struct task_struct *target,
 144                       const struct user_regset *regset,
 145                       unsigned int pos, unsigned int count,
 146                       const void *kbuf, const void __user *ubuf)
 147{
 148        struct pt_regs *regs = task_pt_regs(target);
 149        int ret;
 150
 151        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 152                                 regs->regs,
 153                                 0, 16 * sizeof(unsigned long));
 154        if (!ret && count > 0)
 155                ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 156                                         &regs->pc,
 157                                         offsetof(struct pt_regs, pc),
 158                                         sizeof(struct pt_regs));
 159        if (!ret)
 160                ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 161                                                sizeof(struct pt_regs), -1);
 162
 163        return ret;
 164}
 165
 166#ifdef CONFIG_SH_FPU
 167static int fpregs_get(struct task_struct *target,
 168               const struct user_regset *regset,
 169               struct membuf to)
 170{
 171        int ret;
 172
 173        ret = init_fpu(target);
 174        if (ret)
 175                return ret;
 176
 177        return membuf_write(&to, target->thread.xstate,
 178                            sizeof(struct user_fpu_struct));
 179}
 180
 181static int fpregs_set(struct task_struct *target,
 182                       const struct user_regset *regset,
 183                       unsigned int pos, unsigned int count,
 184                       const void *kbuf, const void __user *ubuf)
 185{
 186        int ret;
 187
 188        ret = init_fpu(target);
 189        if (ret)
 190                return ret;
 191
 192        set_stopped_child_used_math(target);
 193
 194        if ((boot_cpu_data.flags & CPU_HAS_FPU))
 195                return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 196                                          &target->thread.xstate->hardfpu, 0, -1);
 197
 198        return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 199                                  &target->thread.xstate->softfpu, 0, -1);
 200}
 201
 202static int fpregs_active(struct task_struct *target,
 203                         const struct user_regset *regset)
 204{
 205        return tsk_used_math(target) ? regset->n : 0;
 206}
 207#endif
 208
 209#ifdef CONFIG_SH_DSP
 210static int dspregs_get(struct task_struct *target,
 211                       const struct user_regset *regset,
 212                       struct membuf to)
 213{
 214        const struct pt_dspregs *regs =
 215                (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
 216
 217        return membuf_write(&to, regs, sizeof(struct pt_dspregs));
 218}
 219
 220static int dspregs_set(struct task_struct *target,
 221                       const struct user_regset *regset,
 222                       unsigned int pos, unsigned int count,
 223                       const void *kbuf, const void __user *ubuf)
 224{
 225        struct pt_dspregs *regs =
 226                (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
 227        int ret;
 228
 229        ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs,
 230                                 0, sizeof(struct pt_dspregs));
 231        if (!ret)
 232                ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 233                                                sizeof(struct pt_dspregs), -1);
 234
 235        return ret;
 236}
 237
 238static int dspregs_active(struct task_struct *target,
 239                          const struct user_regset *regset)
 240{
 241        struct pt_regs *regs = task_pt_regs(target);
 242
 243        return regs->sr & SR_DSP ? regset->n : 0;
 244}
 245#endif
 246
 247const struct pt_regs_offset regoffset_table[] = {
 248        REGS_OFFSET_NAME(0),
 249        REGS_OFFSET_NAME(1),
 250        REGS_OFFSET_NAME(2),
 251        REGS_OFFSET_NAME(3),
 252        REGS_OFFSET_NAME(4),
 253        REGS_OFFSET_NAME(5),
 254        REGS_OFFSET_NAME(6),
 255        REGS_OFFSET_NAME(7),
 256        REGS_OFFSET_NAME(8),
 257        REGS_OFFSET_NAME(9),
 258        REGS_OFFSET_NAME(10),
 259        REGS_OFFSET_NAME(11),
 260        REGS_OFFSET_NAME(12),
 261        REGS_OFFSET_NAME(13),
 262        REGS_OFFSET_NAME(14),
 263        REGS_OFFSET_NAME(15),
 264        REG_OFFSET_NAME(pc),
 265        REG_OFFSET_NAME(pr),
 266        REG_OFFSET_NAME(sr),
 267        REG_OFFSET_NAME(gbr),
 268        REG_OFFSET_NAME(mach),
 269        REG_OFFSET_NAME(macl),
 270        REG_OFFSET_NAME(tra),
 271        REG_OFFSET_END,
 272};
 273
 274/*
 275 * These are our native regset flavours.
 276 */
 277enum sh_regset {
 278        REGSET_GENERAL,
 279#ifdef CONFIG_SH_FPU
 280        REGSET_FPU,
 281#endif
 282#ifdef CONFIG_SH_DSP
 283        REGSET_DSP,
 284#endif
 285};
 286
 287static const struct user_regset sh_regsets[] = {
 288        /*
 289         * Format is:
 290         *      R0 --> R15
 291         *      PC, PR, SR, GBR, MACH, MACL, TRA
 292         */
 293        [REGSET_GENERAL] = {
 294                .core_note_type = NT_PRSTATUS,
 295                .n              = ELF_NGREG,
 296                .size           = sizeof(long),
 297                .align          = sizeof(long),
 298                .regset_get             = genregs_get,
 299                .set            = genregs_set,
 300        },
 301
 302#ifdef CONFIG_SH_FPU
 303        [REGSET_FPU] = {
 304                .core_note_type = NT_PRFPREG,
 305                .n              = sizeof(struct user_fpu_struct) / sizeof(long),
 306                .size           = sizeof(long),
 307                .align          = sizeof(long),
 308                .regset_get             = fpregs_get,
 309                .set            = fpregs_set,
 310                .active         = fpregs_active,
 311        },
 312#endif
 313
 314#ifdef CONFIG_SH_DSP
 315        [REGSET_DSP] = {
 316                .n              = sizeof(struct pt_dspregs) / sizeof(long),
 317                .size           = sizeof(long),
 318                .align          = sizeof(long),
 319                .regset_get             = dspregs_get,
 320                .set            = dspregs_set,
 321                .active         = dspregs_active,
 322        },
 323#endif
 324};
 325
 326static const struct user_regset_view user_sh_native_view = {
 327        .name           = "sh",
 328        .e_machine      = EM_SH,
 329        .regsets        = sh_regsets,
 330        .n              = ARRAY_SIZE(sh_regsets),
 331};
 332
 333const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 334{
 335        return &user_sh_native_view;
 336}
 337
 338long arch_ptrace(struct task_struct *child, long request,
 339                 unsigned long addr, unsigned long data)
 340{
 341        unsigned long __user *datap = (unsigned long __user *)data;
 342        int ret;
 343
 344        switch (request) {
 345        /* read the word at location addr in the USER area. */
 346        case PTRACE_PEEKUSR: {
 347                unsigned long tmp;
 348
 349                ret = -EIO;
 350                if ((addr & 3) || addr < 0 ||
 351                    addr > sizeof(struct user) - 3)
 352                        break;
 353
 354                if (addr < sizeof(struct pt_regs))
 355                        tmp = get_stack_long(child, addr);
 356                else if (addr >= offsetof(struct user, fpu) &&
 357                         addr < offsetof(struct user, u_fpvalid)) {
 358                        if (!tsk_used_math(child)) {
 359                                if (addr == offsetof(struct user, fpu.fpscr))
 360                                        tmp = FPSCR_INIT;
 361                                else
 362                                        tmp = 0;
 363                        } else {
 364                                unsigned long index;
 365                                ret = init_fpu(child);
 366                                if (ret)
 367                                        break;
 368                                index = addr - offsetof(struct user, fpu);
 369                                tmp = ((unsigned long *)child->thread.xstate)
 370                                        [index >> 2];
 371                        }
 372                } else if (addr == offsetof(struct user, u_fpvalid))
 373                        tmp = !!tsk_used_math(child);
 374                else if (addr == PT_TEXT_ADDR)
 375                        tmp = child->mm->start_code;
 376                else if (addr == PT_DATA_ADDR)
 377                        tmp = child->mm->start_data;
 378                else if (addr == PT_TEXT_END_ADDR)
 379                        tmp = child->mm->end_code;
 380                else if (addr == PT_TEXT_LEN)
 381                        tmp = child->mm->end_code - child->mm->start_code;
 382                else
 383                        tmp = 0;
 384                ret = put_user(tmp, datap);
 385                break;
 386        }
 387
 388        case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 389                ret = -EIO;
 390                if ((addr & 3) || addr < 0 ||
 391                    addr > sizeof(struct user) - 3)
 392                        break;
 393
 394                if (addr < sizeof(struct pt_regs))
 395                        ret = put_stack_long(child, addr, data);
 396                else if (addr >= offsetof(struct user, fpu) &&
 397                         addr < offsetof(struct user, u_fpvalid)) {
 398                        unsigned long index;
 399                        ret = init_fpu(child);
 400                        if (ret)
 401                                break;
 402                        index = addr - offsetof(struct user, fpu);
 403                        set_stopped_child_used_math(child);
 404                        ((unsigned long *)child->thread.xstate)
 405                                [index >> 2] = data;
 406                        ret = 0;
 407                } else if (addr == offsetof(struct user, u_fpvalid)) {
 408                        conditional_stopped_child_used_math(data, child);
 409                        ret = 0;
 410                }
 411                break;
 412
 413        case PTRACE_GETREGS:
 414                return copy_regset_to_user(child, &user_sh_native_view,
 415                                           REGSET_GENERAL,
 416                                           0, sizeof(struct pt_regs),
 417                                           datap);
 418        case PTRACE_SETREGS:
 419                return copy_regset_from_user(child, &user_sh_native_view,
 420                                             REGSET_GENERAL,
 421                                             0, sizeof(struct pt_regs),
 422                                             datap);
 423#ifdef CONFIG_SH_FPU
 424        case PTRACE_GETFPREGS:
 425                return copy_regset_to_user(child, &user_sh_native_view,
 426                                           REGSET_FPU,
 427                                           0, sizeof(struct user_fpu_struct),
 428                                           datap);
 429        case PTRACE_SETFPREGS:
 430                return copy_regset_from_user(child, &user_sh_native_view,
 431                                             REGSET_FPU,
 432                                             0, sizeof(struct user_fpu_struct),
 433                                             datap);
 434#endif
 435#ifdef CONFIG_SH_DSP
 436        case PTRACE_GETDSPREGS:
 437                return copy_regset_to_user(child, &user_sh_native_view,
 438                                           REGSET_DSP,
 439                                           0, sizeof(struct pt_dspregs),
 440                                           datap);
 441        case PTRACE_SETDSPREGS:
 442                return copy_regset_from_user(child, &user_sh_native_view,
 443                                             REGSET_DSP,
 444                                             0, sizeof(struct pt_dspregs),
 445                                             datap);
 446#endif
 447        default:
 448                ret = ptrace_request(child, request, addr, data);
 449                break;
 450        }
 451
 452        return ret;
 453}
 454
 455asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 456{
 457        if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 458            ptrace_report_syscall_entry(regs)) {
 459                regs->regs[0] = -ENOSYS;
 460                return -1;
 461        }
 462
 463        if (secure_computing() == -1)
 464                return -1;
 465
 466        if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 467                trace_sys_enter(regs, regs->regs[0]);
 468
 469        audit_syscall_entry(regs->regs[3], regs->regs[4], regs->regs[5],
 470                            regs->regs[6], regs->regs[7]);
 471
 472        return 0;
 473}
 474
 475asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
 476{
 477        int step;
 478
 479        audit_syscall_exit(regs);
 480
 481        if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 482                trace_sys_exit(regs, regs->regs[0]);
 483
 484        step = test_thread_flag(TIF_SINGLESTEP);
 485        if (step || test_thread_flag(TIF_SYSCALL_TRACE))
 486                ptrace_report_syscall_exit(regs, step);
 487}
 488