Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / arch / arm / kernel / ptrace.c
diff --git a/kernel/arch/arm/kernel/ptrace.c b/kernel/arch/arm/kernel/ptrace.c
new file mode 100644 (file)
index 0000000..ef9119f
--- /dev/null
@@ -0,0 +1,977 @@
+/*
+ *  linux/arch/arm/kernel/ptrace.c
+ *
+ *  By Ross Biro 1/23/92
+ * edited by Linus Torvalds
+ * ARM modifications Copyright (C) 2000 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/sched.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/tracehook.h>
+#include <linux/unistd.h>
+
+#include <asm/pgtable.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 task_struct *tsk, struct pt_regs *regs)
+{
+       siginfo_t info;
+
+       info.si_signo = SIGTRAP;
+       info.si_errno = 0;
+       info.si_code  = TRAP_BRKPT;
+       info.si_addr  = (void __user *)instruction_pointer(regs);
+
+       force_sig_info(SIGTRAP, &info, tsk);
+}
+
+static int break_trap(struct pt_regs *regs, unsigned int instr)
+{
+       ptrace_break(current, 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     = 0xffff,
+       .instr_val      = 0xde01,
+       .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_CRUNCH
+/*
+ * Get the child Crunch state.
+ */
+static int ptrace_getcrunchregs(struct task_struct *tsk, void __user *ufp)
+{
+       struct thread_info *thread = task_thread_info(tsk);
+
+       crunch_task_disable(thread);  /* force it to ram */
+       return copy_to_user(ufp, &thread->crunchstate, CRUNCH_SIZE)
+               ? -EFAULT : 0;
+}
+
+/*
+ * Set the child Crunch state.
+ */
+static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp)
+{
+       struct thread_info *thread = task_thread_info(tsk);
+
+       crunch_task_release(thread);  /* force a reload */
+       return copy_from_user(&thread->crunchstate, ufp, CRUNCH_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;
+       siginfo_t info;
+
+       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);
+
+       info.si_signo   = SIGTRAP;
+       info.si_errno   = (int)num;
+       info.si_code    = TRAP_HWBKPT;
+       info.si_addr    = (void __user *)(bkpt->trigger);
+
+       force_sig_info(SIGTRAP, &info, current);
+}
+
+/*
+ * 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,
+                  unsigned int pos, unsigned int count,
+                  void *kbuf, void __user *ubuf)
+{
+       struct pt_regs *regs = task_pt_regs(target);
+
+       return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                  regs,
+                                  0, sizeof(*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;
+
+       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,
+                  unsigned int pos, unsigned int count,
+                  void *kbuf, void __user *ubuf)
+{
+       return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                  &task_thread_info(target)->fpstate,
+                                  0, 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
+ *
+ * The bounds-checking logic built into user_regset_copyout and friends
+ * means that we can make a simple sequence of calls to map the relevant data
+ * to/from the specified slice of the user regset structure.
+ */
+static int vfp_get(struct task_struct *target,
+                  const struct user_regset *regset,
+                  unsigned int pos, unsigned int count,
+                  void *kbuf, void __user *ubuf)
+{
+       int ret;
+       struct thread_info *thread = task_thread_info(target);
+       struct vfp_hard_struct const *vfp = &thread->vfpstate.hard;
+       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);
+
+       ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                 &vfp->fpregs,
+                                 user_fpregs_offset,
+                                 user_fpregs_offset + sizeof(vfp->fpregs));
+       if (ret)
+               return ret;
+
+       ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
+                                      user_fpregs_offset + sizeof(vfp->fpregs),
+                                      user_fpscr_offset);
+       if (ret)
+               return ret;
+
+       return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
+                                  &vfp->fpscr,
+                                  user_fpscr_offset,
+                                  user_fpscr_offset + sizeof(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;
+
+       vfp_flush_hwstate(thread);
+       thread->vfpstate.hard = new_vfp;
+
+       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),
+               .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),
+               .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),
+               .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)->syscall = data;
+                       ret = 0;
+                       break;
+
+#ifdef CONFIG_CRUNCH
+               case PTRACE_GETCRUNCHREGS:
+                       ret = ptrace_getcrunchregs(child, datap);
+                       break;
+
+               case PTRACE_SETCRUNCHREGS:
+                       ret = ptrace_setcrunchregs(child, datap);
+                       break;
+#endif
+
+#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 tracehook_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)
+               tracehook_report_syscall_exit(regs, 0);
+       else if (tracehook_report_syscall_entry(regs))
+               current_thread_info()->syscall = -1;
+
+       regs->ARM_ip = ip;
+}
+
+asmlinkage int syscall_trace_enter(struct pt_regs *regs, int scno)
+{
+       current_thread_info()->syscall = scno;
+
+       /* Do the secure computing check first; failures should be fast. */
+#ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
+       if (secure_computing() == -1)
+               return -1;
+#else
+       /* XXX: remove this once OABI gets fixed */
+       secure_computing_strict(scno);
+#endif
+
+       if (test_thread_flag(TIF_SYSCALL_TRACE))
+               tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
+
+       scno = current_thread_info()->syscall;
+
+       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))
+               tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
+}