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 // SPDX-License-Identifier: GPL-2.0-only
 /*
  *  linux/arch/arm/kernel/ptrace.c
  *
  *  By Ross Biro 1/23/92
  * edited by Linus Torvalds
  * ARM modifications Copyright (C) 2000 Russell King
  */
 #include <linux/kernel.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/task_stack.h>
 #include <linux/mm.h>
 #include <linux/elf.h>
 #include <linux/smp.h>
 #include <linux/ptrace.h>
 #include <linux/user.h>
 #include <linux/security.h>
 #include <linux/init.h>
 #include <linux/signal.h>
 #include <linux/uaccess.h>
 #include <linux/perf_event.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/regset.h>
 #include <linux/audit.h>
 #include <linux/unistd.h>
 
 #include <asm/syscall.h>
 #include <asm/traps.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/syscalls.h>
 
 #define REG_PC  15
 #define REG_PSR 16
 /*
  * does not yet catch signals sent when the child dies.
  * in exit.c or in signal.c.
  */
 
 #if 0
 /*
  * Breakpoint SWI instruction: SWI &9F0001
  */
 #define BREAKINST_ARM   0xef9f0001
 #define BREAKINST_THUMB 0xdf00      /* fill this in later */
 #else
 /*
  * New breakpoints - use an undefined instruction.  The ARM architecture
  * reference manual guarantees that the following instruction space
  * will produce an undefined instruction exception on all CPUs:
  *
  *  ARM:   xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx
  *  Thumb: 1101 1110 xxxx xxxx
  */
 #define BREAKINST_ARM   0xe7f001f0
 #define BREAKINST_THUMB 0xde01
 #endif
 
 struct pt_regs_offset {
     const char *name;
     int offset;
 };
 
 #define REG_OFFSET_NAME(r) \
     {.name = #r, .offset = offsetof(struct pt_regs, ARM_##r)}
 #define REG_OFFSET_END {.name = NULL, .offset = 0}
 
 static const struct pt_regs_offset regoffset_table[] = {
     REG_OFFSET_NAME(r0),
     REG_OFFSET_NAME(r1),
     REG_OFFSET_NAME(r2),
     REG_OFFSET_NAME(r3),
     REG_OFFSET_NAME(r4),
     REG_OFFSET_NAME(r5),
     REG_OFFSET_NAME(r6),
     REG_OFFSET_NAME(r7),
     REG_OFFSET_NAME(r8),
     REG_OFFSET_NAME(r9),
     REG_OFFSET_NAME(r10),
     REG_OFFSET_NAME(fp),
     REG_OFFSET_NAME(ip),
     REG_OFFSET_NAME(sp),
     REG_OFFSET_NAME(lr),
     REG_OFFSET_NAME(pc),
     REG_OFFSET_NAME(cpsr),
     REG_OFFSET_NAME(ORIG_r0),
     REG_OFFSET_END,
 };
 
 /**
  * regs_query_register_offset() - query register offset from its name
  * @name:   the name of a register
  *
  * regs_query_register_offset() returns the offset of a register in struct
  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
  */
 int regs_query_register_offset(const char *name)
 {
     const struct pt_regs_offset *roff;
     for (roff = regoffset_table; roff->name != NULL; roff++)
         if (!strcmp(roff->name, name))
             return roff->offset;
     return -EINVAL;
 }
 
 /**
  * regs_query_register_name() - query register name from its offset
  * @offset: the offset of a register in struct pt_regs.
  *
  * regs_query_register_name() returns the name of a register from its
  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
  */
 const char *regs_query_register_name(unsigned int offset)
 {
     const struct pt_regs_offset *roff;
     for (roff = regoffset_table; roff->name != NULL; roff++)
         if (roff->offset == offset)
             return roff->name;
     return NULL;
 }
 
 /**
  * regs_within_kernel_stack() - check the address in the stack
  * @regs:      pt_regs which contains kernel stack pointer.
  * @addr:      address which is checked.
  *
  * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
  * If @addr is within the kernel stack, it returns true. If not, returns false.
  */
 bool regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
 {
     return ((addr & ~(THREAD_SIZE - 1))  ==
         (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
 }
 
 /**
  * regs_get_kernel_stack_nth() - get Nth entry of the stack
  * @regs:   pt_regs which contains kernel stack pointer.
  * @n:      stack entry number.
  *
  * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
  * is specified by @regs. If the @n th entry is NOT in the kernel stack,
  * this returns 0.
  */
 unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
 {
     unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
     addr += n;
     if (regs_within_kernel_stack(regs, (unsigned long)addr))
         return *addr;
     else
         return 0;
 }
 
 /*
  * this routine will get a word off of the processes privileged stack.
  * the offset is how far from the base addr as stored in the THREAD.
  * this routine assumes that all the privileged stacks are in our
  * data space.
  */
 static inline long get_user_reg(struct task_struct *task, int offset)
 {
     return task_pt_regs(task)->uregs[offset];
 }
 
 /*
  * this routine will put a word on the processes privileged stack.
  * the offset is how far from the base addr as stored in the THREAD.
  * this routine assumes that all the privileged stacks are in our
  * data space.
  */
 static inline int
 put_user_reg(struct task_struct *task, int offset, long data)
 {
     struct pt_regs newregs, *regs = task_pt_regs(task);
     int ret = -EINVAL;
 
     newregs = *regs;
     newregs.uregs[offset] = data;
 
     if (valid_user_regs(&newregs)) {
         regs->uregs[offset] = data;
         ret = 0;
     }
 
     return ret;
 }
 
 /*
  * Called by kernel/ptrace.c when detaching..
  */
 void ptrace_disable(struct task_struct *child)
 {
     /* Nothing to do. */
 }
 
 /*
  * Handle hitting a breakpoint.
  */
 void ptrace_break(struct pt_regs *regs)
 {
     force_sig_fault(SIGTRAP, TRAP_BRKPT,
             (void __user *)instruction_pointer(regs));
 }
 
 static int break_trap(struct pt_regs *regs, unsigned int instr)
 {
     ptrace_break(regs);
     return 0;
 }
 
 static struct undef_hook arm_break_hook = {
     .instr_mask = 0x0fffffff,
     .instr_val  = 0x07f001f0,
     .cpsr_mask  = PSR_T_BIT,
     .cpsr_val   = 0,
     .fn     = break_trap,
 };
 
 static struct undef_hook thumb_break_hook = {
     .instr_mask = 0xffffffff,
     .instr_val  = 0x0000de01,
     .cpsr_mask  = PSR_T_BIT,
     .cpsr_val   = PSR_T_BIT,
     .fn     = break_trap,
 };
 
 static struct undef_hook thumb2_break_hook = {
     .instr_mask = 0xffffffff,
     .instr_val  = 0xf7f0a000,
     .cpsr_mask  = PSR_T_BIT,
     .cpsr_val   = PSR_T_BIT,
     .fn     = break_trap,
 };
 
 static int __init ptrace_break_init(void)
 {
     register_undef_hook(&arm_break_hook);
     register_undef_hook(&thumb_break_hook);
     register_undef_hook(&thumb2_break_hook);
     return 0;
 }
 
 core_initcall(ptrace_break_init);
 
 /*
  * Read the word at offset "off" into the "struct user".  We
  * actually access the pt_regs stored on the kernel stack.
  */
 static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
                 unsigned long __user *ret)
 {
     unsigned long tmp;
 
     if (off & 3)
         return -EIO;
 
     tmp = 0;
     if (off == PT_TEXT_ADDR)
         tmp = tsk->mm->start_code;
     else if (off == PT_DATA_ADDR)
         tmp = tsk->mm->start_data;
     else if (off == PT_TEXT_END_ADDR)
         tmp = tsk->mm->end_code;
     else if (off < sizeof(struct pt_regs))
         tmp = get_user_reg(tsk, off >> 2);
     else if (off >= sizeof(struct user))
         return -EIO;
 
     return put_user(tmp, ret);
 }
 
 /*
  * Write the word at offset "off" into "struct user".  We
  * actually access the pt_regs stored on the kernel stack.
  */
 static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
                  unsigned long val)
 {
     if (off & 3 || off >= sizeof(struct user))
         return -EIO;
 
     if (off >= sizeof(struct pt_regs))
         return 0;
 
     return put_user_reg(tsk, off >> 2, val);
 }
 
 #ifdef CONFIG_IWMMXT
 
 /*
  * Get the child iWMMXt state.
  */
 static int ptrace_getwmmxregs(struct task_struct *tsk, void __user *ufp)
 {
     struct thread_info *thread = task_thread_info(tsk);
 
     if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
         return -ENODATA;
     iwmmxt_task_disable(thread);  /* force it to ram */
     return copy_to_user(ufp, &thread->fpstate.iwmmxt, IWMMXT_SIZE)
         ? -EFAULT : 0;
 }
 
 /*
  * Set the child iWMMXt state.
  */
 static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp)
 {
     struct thread_info *thread = task_thread_info(tsk);
 
     if (!test_ti_thread_flag(thread, TIF_USING_IWMMXT))
         return -EACCES;
     iwmmxt_task_release(thread);  /* force a reload */
     return copy_from_user(&thread->fpstate.iwmmxt, ufp, IWMMXT_SIZE)
         ? -EFAULT : 0;
 }
 
 #endif
 
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 /*
  * Convert a virtual register number into an index for a thread_info
  * breakpoint array. Breakpoints are identified using positive numbers
  * whilst watchpoints are negative. The registers are laid out as pairs
  * of (address, control), each pair mapping to a unique hw_breakpoint struct.
  * Register 0 is reserved for describing resource information.
  */
 static int ptrace_hbp_num_to_idx(long num)
 {
     if (num < 0)
         num = (ARM_MAX_BRP << 1) - num;
     return (num - 1) >> 1;
 }
 
 /*
  * Returns the virtual register number for the address of the
  * breakpoint at index idx.
  */
 static long ptrace_hbp_idx_to_num(int idx)
 {
     long mid = ARM_MAX_BRP << 1;
     long num = (idx << 1) + 1;
     return num > mid ? mid - num : num;
 }
 
 /*
  * Handle hitting a HW-breakpoint.
  */
 static void ptrace_hbptriggered(struct perf_event *bp,
                      struct perf_sample_data *data,
                      struct pt_regs *regs)
 {
     struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
     long num;
     int i;
 
     for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i)
         if (current->thread.debug.hbp[i] == bp)
             break;
 
     num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i);
 
     force_sig_ptrace_errno_trap((int)num, (void __user *)(bkpt->trigger));
 }
 
 /*
  * Set ptrace breakpoint pointers to zero for this task.
  * This is required in order to prevent child processes from unregistering
  * breakpoints held by their parent.
  */
 void clear_ptrace_hw_breakpoint(struct task_struct *tsk)
 {
     memset(tsk->thread.debug.hbp, 0, sizeof(tsk->thread.debug.hbp));
 }
 
 /*
  * Unregister breakpoints from this task and reset the pointers in
  * the thread_struct.
  */
 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
 {
     int i;
     struct thread_struct *t = &tsk->thread;
 
     for (i = 0; i < ARM_MAX_HBP_SLOTS; i++) {
         if (t->debug.hbp[i]) {
             unregister_hw_breakpoint(t->debug.hbp[i]);
             t->debug.hbp[i] = NULL;
         }
     }
 }
 
 static u32 ptrace_get_hbp_resource_info(void)
 {
     u8 num_brps, num_wrps, debug_arch, wp_len;
     u32 reg = 0;
 
     num_brps    = hw_breakpoint_slots(TYPE_INST);
     num_wrps    = hw_breakpoint_slots(TYPE_DATA);
     debug_arch  = arch_get_debug_arch();
     wp_len      = arch_get_max_wp_len();
 
     reg     |= debug_arch;
     reg     <<= 8;
     reg     |= wp_len;
     reg     <<= 8;
     reg     |= num_wrps;
     reg     <<= 8;
     reg     |= num_brps;
 
     return reg;
 }
 
 static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
 {
     struct perf_event_attr attr;
 
     ptrace_breakpoint_init(&attr);
 
     /* Initialise fields to sane defaults. */
     attr.bp_addr    = 0;
     attr.bp_len = HW_BREAKPOINT_LEN_4;
     attr.bp_type    = type;
     attr.disabled   = 1;
 
     return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL,
                        tsk);
 }
 
 static int ptrace_gethbpregs(struct task_struct *tsk, long num,
                  unsigned long  __user *data)
 {
     u32 reg;
     int idx, ret = 0;
     struct perf_event *bp;
     struct arch_hw_breakpoint_ctrl arch_ctrl;
 
     if (num == 0) {
         reg = ptrace_get_hbp_resource_info();
     } else {
         idx = ptrace_hbp_num_to_idx(num);
         if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
             ret = -EINVAL;
             goto out;
         }
 
         bp = tsk->thread.debug.hbp[idx];
         if (!bp) {
             reg = 0;
             goto put;
         }
 
         arch_ctrl = counter_arch_bp(bp)->ctrl;
 
         /*
          * Fix up the len because we may have adjusted it
          * to compensate for an unaligned address.
          */
         while (!(arch_ctrl.len & 0x1))
             arch_ctrl.len >>= 1;
 
         if (num & 0x1)
             reg = bp->attr.bp_addr;
         else
             reg = encode_ctrl_reg(arch_ctrl);
     }
 
 put:
     if (put_user(reg, data))
         ret = -EFAULT;
 
 out:
     return ret;
 }
 
 static int ptrace_sethbpregs(struct task_struct *tsk, long num,
                  unsigned long __user *data)
 {
     int idx, gen_len, gen_type, implied_type, ret = 0;
     u32 user_val;
     struct perf_event *bp;
     struct arch_hw_breakpoint_ctrl ctrl;
     struct perf_event_attr attr;
 
     if (num == 0)
         goto out;
     else if (num < 0)
         implied_type = HW_BREAKPOINT_RW;
     else
         implied_type = HW_BREAKPOINT_X;
 
     idx = ptrace_hbp_num_to_idx(num);
     if (idx < 0 || idx >= ARM_MAX_HBP_SLOTS) {
         ret = -EINVAL;
         goto out;
     }
 
     if (get_user(user_val, data)) {
         ret = -EFAULT;
         goto out;
     }
 
     bp = tsk->thread.debug.hbp[idx];
     if (!bp) {
         bp = ptrace_hbp_create(tsk, implied_type);
         if (IS_ERR(bp)) {
             ret = PTR_ERR(bp);
             goto out;
         }
         tsk->thread.debug.hbp[idx] = bp;
     }
 
     attr = bp->attr;
 
     if (num & 0x1) {
         /* Address */
         attr.bp_addr    = user_val;
     } else {
         /* Control */
         decode_ctrl_reg(user_val, &ctrl);
         ret = arch_bp_generic_fields(ctrl, &gen_len, &gen_type);
         if (ret)
             goto out;
 
         if ((gen_type & implied_type) != gen_type) {
             ret = -EINVAL;
             goto out;
         }
 
         attr.bp_len = gen_len;
         attr.bp_type    = gen_type;
         attr.disabled   = !ctrl.enabled;
     }
 
     ret = modify_user_hw_breakpoint(bp, &attr);
 out:
     return ret;
 }
 #endif
 
 /* regset get/set implementations */
 
 static int gpr_get(struct task_struct *target,
            const struct user_regset *regset,
            struct membuf to)
 {
     return membuf_write(&to, task_pt_regs(target), sizeof(struct pt_regs));
 }
 
 static int gpr_set(struct task_struct *target,
            const struct user_regset *regset,
            unsigned int pos, unsigned int count,
            const void *kbuf, const void __user *ubuf)
 {
     int ret;
     struct pt_regs newregs = *task_pt_regs(target);
 
     ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                  &newregs,
                  0, sizeof(newregs));
     if (ret)
         return ret;
 
     if (!valid_user_regs(&newregs))
         return -EINVAL;
 
     *task_pt_regs(target) = newregs;
     return 0;
 }
 
 static int fpa_get(struct task_struct *target,
            const struct user_regset *regset,
            struct membuf to)
 {
     return membuf_write(&to, &task_thread_info(target)->fpstate,
                  sizeof(struct user_fp));
 }
 
 static int fpa_set(struct task_struct *target,
            const struct user_regset *regset,
            unsigned int pos, unsigned int count,
            const void *kbuf, const void __user *ubuf)
 {
     struct thread_info *thread = task_thread_info(target);
 
     thread->used_cp[1] = thread->used_cp[2] = 1;
 
     return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
         &thread->fpstate,
         0, sizeof(struct user_fp));
 }
 
 #ifdef CONFIG_VFP
 /*
  * VFP register get/set implementations.
  *
  * With respect to the kernel, struct user_fp is divided into three chunks:
  * 16 or 32 real VFP registers (d0-d15 or d0-31)
  *  These are transferred to/from the real registers in the task's
  *  vfp_hard_struct.  The number of registers depends on the kernel
  *  configuration.
  *
  * 16 or 0 fake VFP registers (d16-d31 or empty)
  *  i.e., the user_vfp structure has space for 32 registers even if
  *  the kernel doesn't have them all.
  *
  *  vfp_get() reads this chunk as zero where applicable
  *  vfp_set() ignores this chunk
  *
  * 1 word for the FPSCR
  */
 static int vfp_get(struct task_struct *target,
            const struct user_regset *regset,
            struct membuf to)
 {
     struct thread_info *thread = task_thread_info(target);
     struct vfp_hard_struct const *vfp = &thread->vfpstate.hard;
     const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
 
     vfp_sync_hwstate(thread);
 
     membuf_write(&to, vfp->fpregs, sizeof(vfp->fpregs));
     membuf_zero(&to, user_fpscr_offset - sizeof(vfp->fpregs));
     return membuf_store(&to, vfp->fpscr);
 }
 
 /*
  * For vfp_set() a read-modify-write is done on the VFP registers,
  * in order to avoid writing back a half-modified set of registers on
  * failure.
  */
 static int vfp_set(struct task_struct *target,
               const struct user_regset *regset,
               unsigned int pos, unsigned int count,
               const void *kbuf, const void __user *ubuf)
 {
     int ret;
     struct thread_info *thread = task_thread_info(target);
     struct vfp_hard_struct new_vfp;
     const size_t user_fpregs_offset = offsetof(struct user_vfp, fpregs);
     const size_t user_fpscr_offset = offsetof(struct user_vfp, fpscr);
 
     vfp_sync_hwstate(thread);
     new_vfp = thread->vfpstate.hard;
 
     ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                   &new_vfp.fpregs,
                   user_fpregs_offset,
                   user_fpregs_offset + sizeof(new_vfp.fpregs));
     if (ret)
         return ret;
 
     ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
                 user_fpregs_offset + sizeof(new_vfp.fpregs),
                 user_fpscr_offset);
     if (ret)
         return ret;
 
     ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
                  &new_vfp.fpscr,
                  user_fpscr_offset,
                  user_fpscr_offset + sizeof(new_vfp.fpscr));
     if (ret)
         return ret;
 
     thread->vfpstate.hard = new_vfp;
     vfp_flush_hwstate(thread);
 
     return 0;
 }
 #endif /* CONFIG_VFP */
 
 enum arm_regset {
     REGSET_GPR,
     REGSET_FPR,
 #ifdef CONFIG_VFP
     REGSET_VFP,
 #endif
 };
 
 static const struct user_regset arm_regsets[] = {
     [REGSET_GPR] = {
         .core_note_type = NT_PRSTATUS,
         .n = ELF_NGREG,
         .size = sizeof(u32),
         .align = sizeof(u32),
         .regset_get = gpr_get,
         .set = gpr_set
     },
     [REGSET_FPR] = {
         /*
          * For the FPA regs in fpstate, the real fields are a mixture
          * of sizes, so pretend that the registers are word-sized:
          */
         .core_note_type = NT_PRFPREG,
         .n = sizeof(struct user_fp) / sizeof(u32),
         .size = sizeof(u32),
         .align = sizeof(u32),
         .regset_get = fpa_get,
         .set = fpa_set
     },
 #ifdef CONFIG_VFP
     [REGSET_VFP] = {
         /*
          * Pretend that the VFP regs are word-sized, since the FPSCR is
          * a single word dangling at the end of struct user_vfp:
          */
         .core_note_type = NT_ARM_VFP,
         .n = ARM_VFPREGS_SIZE / sizeof(u32),
         .size = sizeof(u32),
         .align = sizeof(u32),
         .regset_get = vfp_get,
         .set = vfp_set
     },
 #endif /* CONFIG_VFP */
 };
 
 static const struct user_regset_view user_arm_view = {
     .name = "arm", .e_machine = ELF_ARCH, .ei_osabi = ELF_OSABI,
     .regsets = arm_regsets, .n = ARRAY_SIZE(arm_regsets)
 };
 
 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 {
     return &user_arm_view;
 }
 
 long arch_ptrace(struct task_struct *child, long request,
          unsigned long addr, unsigned long data)
 {
     int ret;
     unsigned long __user *datap = (unsigned long __user *) data;
 
     switch (request) {
         case PTRACE_PEEKUSR:
             ret = ptrace_read_user(child, addr, datap);
             break;
 
         case PTRACE_POKEUSR:
             ret = ptrace_write_user(child, addr, data);
             break;
 
         case PTRACE_GETREGS:
             ret = copy_regset_to_user(child,
                           &user_arm_view, REGSET_GPR,
                           0, sizeof(struct pt_regs),
                           datap);
             break;
 
         case PTRACE_SETREGS:
             ret = copy_regset_from_user(child,
                             &user_arm_view, REGSET_GPR,
                             0, sizeof(struct pt_regs),
                             datap);
             break;
 
         case PTRACE_GETFPREGS:
             ret = copy_regset_to_user(child,
                           &user_arm_view, REGSET_FPR,
                           0, sizeof(union fp_state),
                           datap);
             break;
 
         case PTRACE_SETFPREGS:
             ret = copy_regset_from_user(child,
                             &user_arm_view, REGSET_FPR,
                             0, sizeof(union fp_state),
                             datap);
             break;
 
 #ifdef CONFIG_IWMMXT
         case PTRACE_GETWMMXREGS:
             ret = ptrace_getwmmxregs(child, datap);
             break;
 
         case PTRACE_SETWMMXREGS:
             ret = ptrace_setwmmxregs(child, datap);
             break;
 #endif
 
         case PTRACE_GET_THREAD_AREA:
             ret = put_user(task_thread_info(child)->tp_value[0],
                        datap);
             break;
 
         case PTRACE_SET_SYSCALL:
             task_thread_info(child)->abi_syscall = data &
                             __NR_SYSCALL_MASK;
             ret = 0;
             break;
 
 #ifdef CONFIG_VFP
         case PTRACE_GETVFPREGS:
             ret = copy_regset_to_user(child,
                           &user_arm_view, REGSET_VFP,
                           0, ARM_VFPREGS_SIZE,
                           datap);
             break;
 
         case PTRACE_SETVFPREGS:
             ret = copy_regset_from_user(child,
                             &user_arm_view, REGSET_VFP,
                             0, ARM_VFPREGS_SIZE,
                             datap);
             break;
 #endif
 
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
         case PTRACE_GETHBPREGS:
             ret = ptrace_gethbpregs(child, addr,
                         (unsigned long __user *)data);
             break;
         case PTRACE_SETHBPREGS:
             ret = ptrace_sethbpregs(child, addr,
                         (unsigned long __user *)data);
             break;
 #endif
 
         default:
             ret = ptrace_request(child, request, addr, data);
             break;
     }
 
     return ret;
 }
 
 enum ptrace_syscall_dir {
     PTRACE_SYSCALL_ENTER = 0,
     PTRACE_SYSCALL_EXIT,
 };
 
 static void report_syscall(struct pt_regs *regs, enum ptrace_syscall_dir dir)
 {
     unsigned long ip;
 
     /*
      * IP is used to denote syscall entry/exit:
      * IP = 0 -> entry, =1 -> exit
      */
     ip = regs->ARM_ip;
     regs->ARM_ip = dir;
 
     if (dir == PTRACE_SYSCALL_EXIT)
         ptrace_report_syscall_exit(regs, 0);
     else if (ptrace_report_syscall_entry(regs))
         current_thread_info()->abi_syscall = -1;
 
     regs->ARM_ip = ip;
 }
 
 asmlinkage int syscall_trace_enter(struct pt_regs *regs)
 {
     int scno;
 
     if (test_thread_flag(TIF_SYSCALL_TRACE))
         report_syscall(regs, PTRACE_SYSCALL_ENTER);
 
     /* Do seccomp after ptrace; syscall may have changed. */
 #ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
     if (secure_computing() == -1)
         return -1;
 #else
     /* XXX: remove this once OABI gets fixed */
     secure_computing_strict(syscall_get_nr(current, regs));
 #endif
 
     /* Tracer or seccomp may have changed syscall. */
     scno = syscall_get_nr(current, regs);
 
     if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
         trace_sys_enter(regs, scno);
 
     audit_syscall_entry(scno, regs->ARM_r0, regs->ARM_r1, regs->ARM_r2,
                 regs->ARM_r3);
 
     return scno;
 }
 
 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 {
     /*
      * Audit the syscall before anything else, as a debugger may
      * come in and change the current registers.
      */
     audit_syscall_exit(regs);
 
     /*
      * Note that we haven't updated the ->syscall field for the
      * current thread. This isn't a problem because it will have
      * been set on syscall entry and there hasn't been an opportunity
      * for a PTRACE_SET_SYSCALL since then.
      */
     if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
         trace_sys_exit(regs, regs_return_value(regs));
 
     if (test_thread_flag(TIF_SYSCALL_TRACE))
         report_syscall(regs, PTRACE_SYSCALL_EXIT);
 }

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