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![David Engraf](/assets/img/avatar_default.png)
Since commit 34d0b5af50
it is no longer
possible to debug an application using singlestep. The old commit
converted singlestep handling via ptrace to hw_breakpoints. The
hw_breakpoint is disabled when an event is triggered and not re-enabled
again. This patch re-enables the existing hw_breakpoint before the
existing breakpoint is reused.
Signed-off-by: David Engraf <david.engraf@sysgo.com>
Cc: stable@kernel.org
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
538 lines
13 KiB
C
538 lines
13 KiB
C
/*
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* SuperH process tracing
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*
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* Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
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* Copyright (C) 2002 - 2009 Paul Mundt
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*
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* Audit support by Yuichi Nakamura <ynakam@hitachisoft.jp>
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/errno.h>
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#include <linux/ptrace.h>
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#include <linux/user.h>
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#include <linux/security.h>
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#include <linux/signal.h>
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#include <linux/io.h>
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#include <linux/audit.h>
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#include <linux/seccomp.h>
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#include <linux/tracehook.h>
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#include <linux/elf.h>
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#include <linux/regset.h>
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#include <linux/hw_breakpoint.h>
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#include <asm/uaccess.h>
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#include <asm/pgtable.h>
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#include <asm/system.h>
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#include <asm/processor.h>
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#include <asm/mmu_context.h>
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#include <asm/syscalls.h>
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#include <asm/fpu.h>
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#define CREATE_TRACE_POINTS
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#include <trace/events/syscalls.h>
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/*
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* This routine will get a word off of the process kernel stack.
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*/
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static inline int get_stack_long(struct task_struct *task, int offset)
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{
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unsigned char *stack;
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stack = (unsigned char *)task_pt_regs(task);
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stack += offset;
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return (*((int *)stack));
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}
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/*
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* This routine will put a word on the process kernel stack.
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*/
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static inline int put_stack_long(struct task_struct *task, int offset,
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unsigned long data)
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{
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unsigned char *stack;
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stack = (unsigned char *)task_pt_regs(task);
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stack += offset;
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*(unsigned long *) stack = data;
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return 0;
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}
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void ptrace_triggered(struct perf_event *bp, int nmi,
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struct perf_sample_data *data, struct pt_regs *regs)
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{
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struct perf_event_attr attr;
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/*
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* Disable the breakpoint request here since ptrace has defined a
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* one-shot behaviour for breakpoint exceptions.
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*/
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attr = bp->attr;
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attr.disabled = true;
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modify_user_hw_breakpoint(bp, &attr);
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}
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static int set_single_step(struct task_struct *tsk, unsigned long addr)
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{
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struct thread_struct *thread = &tsk->thread;
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struct perf_event *bp;
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struct perf_event_attr attr;
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bp = thread->ptrace_bps[0];
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if (!bp) {
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ptrace_breakpoint_init(&attr);
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attr.bp_addr = addr;
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attr.bp_len = HW_BREAKPOINT_LEN_2;
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attr.bp_type = HW_BREAKPOINT_R;
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bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk);
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if (IS_ERR(bp))
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return PTR_ERR(bp);
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thread->ptrace_bps[0] = bp;
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} else {
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int err;
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attr = bp->attr;
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attr.bp_addr = addr;
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/* reenable breakpoint */
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attr.disabled = false;
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err = modify_user_hw_breakpoint(bp, &attr);
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if (unlikely(err))
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return err;
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}
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return 0;
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}
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void user_enable_single_step(struct task_struct *child)
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{
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unsigned long pc = get_stack_long(child, offsetof(struct pt_regs, pc));
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set_tsk_thread_flag(child, TIF_SINGLESTEP);
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set_single_step(child, pc);
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}
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void user_disable_single_step(struct task_struct *child)
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{
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clear_tsk_thread_flag(child, TIF_SINGLESTEP);
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}
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/*
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* Called by kernel/ptrace.c when detaching..
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*
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* Make sure single step bits etc are not set.
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*/
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void ptrace_disable(struct task_struct *child)
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{
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user_disable_single_step(child);
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}
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static int genregs_get(struct task_struct *target,
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const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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void *kbuf, void __user *ubuf)
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{
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const struct pt_regs *regs = task_pt_regs(target);
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int ret;
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ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
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regs->regs,
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0, 16 * sizeof(unsigned long));
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if (!ret)
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/* PC, PR, SR, GBR, MACH, MACL, TRA */
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ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
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®s->pc,
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offsetof(struct pt_regs, pc),
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sizeof(struct pt_regs));
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if (!ret)
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ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
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sizeof(struct pt_regs), -1);
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return ret;
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}
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static int genregs_set(struct task_struct *target,
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const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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const void *kbuf, const void __user *ubuf)
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{
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struct pt_regs *regs = task_pt_regs(target);
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int ret;
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ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
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regs->regs,
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0, 16 * sizeof(unsigned long));
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if (!ret && count > 0)
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ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
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®s->pc,
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offsetof(struct pt_regs, pc),
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sizeof(struct pt_regs));
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if (!ret)
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ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
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sizeof(struct pt_regs), -1);
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return ret;
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}
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#ifdef CONFIG_SH_FPU
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int fpregs_get(struct task_struct *target,
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const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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void *kbuf, void __user *ubuf)
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{
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int ret;
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ret = init_fpu(target);
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if (ret)
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return ret;
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if ((boot_cpu_data.flags & CPU_HAS_FPU))
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return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
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&target->thread.xstate->hardfpu, 0, -1);
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return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
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&target->thread.xstate->softfpu, 0, -1);
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}
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static int fpregs_set(struct task_struct *target,
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const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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const void *kbuf, const void __user *ubuf)
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{
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int ret;
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ret = init_fpu(target);
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if (ret)
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return ret;
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set_stopped_child_used_math(target);
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if ((boot_cpu_data.flags & CPU_HAS_FPU))
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return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
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&target->thread.xstate->hardfpu, 0, -1);
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return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
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&target->thread.xstate->softfpu, 0, -1);
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}
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static int fpregs_active(struct task_struct *target,
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const struct user_regset *regset)
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{
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return tsk_used_math(target) ? regset->n : 0;
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}
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#endif
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#ifdef CONFIG_SH_DSP
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static int dspregs_get(struct task_struct *target,
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const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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void *kbuf, void __user *ubuf)
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{
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const struct pt_dspregs *regs =
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(struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
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int ret;
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ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs,
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0, sizeof(struct pt_dspregs));
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if (!ret)
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ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
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sizeof(struct pt_dspregs), -1);
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return ret;
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}
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static int dspregs_set(struct task_struct *target,
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const struct user_regset *regset,
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unsigned int pos, unsigned int count,
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const void *kbuf, const void __user *ubuf)
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{
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struct pt_dspregs *regs =
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(struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
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int ret;
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ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs,
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0, sizeof(struct pt_dspregs));
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if (!ret)
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ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
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sizeof(struct pt_dspregs), -1);
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return ret;
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}
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static int dspregs_active(struct task_struct *target,
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const struct user_regset *regset)
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{
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struct pt_regs *regs = task_pt_regs(target);
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return regs->sr & SR_DSP ? regset->n : 0;
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}
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#endif
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const struct pt_regs_offset regoffset_table[] = {
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REGS_OFFSET_NAME(0),
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REGS_OFFSET_NAME(1),
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REGS_OFFSET_NAME(2),
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REGS_OFFSET_NAME(3),
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REGS_OFFSET_NAME(4),
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REGS_OFFSET_NAME(5),
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REGS_OFFSET_NAME(6),
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REGS_OFFSET_NAME(7),
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REGS_OFFSET_NAME(8),
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REGS_OFFSET_NAME(9),
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REGS_OFFSET_NAME(10),
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REGS_OFFSET_NAME(11),
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REGS_OFFSET_NAME(12),
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REGS_OFFSET_NAME(13),
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REGS_OFFSET_NAME(14),
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REGS_OFFSET_NAME(15),
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REG_OFFSET_NAME(pc),
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REG_OFFSET_NAME(pr),
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REG_OFFSET_NAME(sr),
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REG_OFFSET_NAME(gbr),
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REG_OFFSET_NAME(mach),
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REG_OFFSET_NAME(macl),
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REG_OFFSET_NAME(tra),
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REG_OFFSET_END,
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};
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/*
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* These are our native regset flavours.
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*/
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enum sh_regset {
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REGSET_GENERAL,
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#ifdef CONFIG_SH_FPU
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REGSET_FPU,
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#endif
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#ifdef CONFIG_SH_DSP
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REGSET_DSP,
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#endif
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};
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static const struct user_regset sh_regsets[] = {
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/*
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* Format is:
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* R0 --> R15
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* PC, PR, SR, GBR, MACH, MACL, TRA
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*/
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[REGSET_GENERAL] = {
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.core_note_type = NT_PRSTATUS,
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.n = ELF_NGREG,
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.size = sizeof(long),
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.align = sizeof(long),
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.get = genregs_get,
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.set = genregs_set,
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},
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#ifdef CONFIG_SH_FPU
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[REGSET_FPU] = {
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.core_note_type = NT_PRFPREG,
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.n = sizeof(struct user_fpu_struct) / sizeof(long),
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.size = sizeof(long),
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.align = sizeof(long),
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.get = fpregs_get,
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.set = fpregs_set,
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.active = fpregs_active,
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},
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#endif
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#ifdef CONFIG_SH_DSP
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[REGSET_DSP] = {
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.n = sizeof(struct pt_dspregs) / sizeof(long),
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.size = sizeof(long),
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.align = sizeof(long),
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.get = dspregs_get,
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.set = dspregs_set,
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.active = dspregs_active,
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},
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#endif
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};
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static const struct user_regset_view user_sh_native_view = {
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.name = "sh",
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.e_machine = EM_SH,
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.regsets = sh_regsets,
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.n = ARRAY_SIZE(sh_regsets),
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};
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const struct user_regset_view *task_user_regset_view(struct task_struct *task)
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{
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return &user_sh_native_view;
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}
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long arch_ptrace(struct task_struct *child, long request,
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unsigned long addr, unsigned long data)
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{
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unsigned long __user *datap = (unsigned long __user *)data;
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int ret;
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switch (request) {
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/* read the word at location addr in the USER area. */
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case PTRACE_PEEKUSR: {
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unsigned long tmp;
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ret = -EIO;
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if ((addr & 3) || addr < 0 ||
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addr > sizeof(struct user) - 3)
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break;
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if (addr < sizeof(struct pt_regs))
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tmp = get_stack_long(child, addr);
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else if (addr >= offsetof(struct user, fpu) &&
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addr < offsetof(struct user, u_fpvalid)) {
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if (!tsk_used_math(child)) {
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if (addr == offsetof(struct user, fpu.fpscr))
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tmp = FPSCR_INIT;
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else
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tmp = 0;
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} else {
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unsigned long index;
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ret = init_fpu(child);
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if (ret)
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break;
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index = addr - offsetof(struct user, fpu);
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tmp = ((unsigned long *)child->thread.xstate)
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[index >> 2];
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}
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} else if (addr == offsetof(struct user, u_fpvalid))
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tmp = !!tsk_used_math(child);
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else if (addr == PT_TEXT_ADDR)
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tmp = child->mm->start_code;
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else if (addr == PT_DATA_ADDR)
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tmp = child->mm->start_data;
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else if (addr == PT_TEXT_END_ADDR)
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tmp = child->mm->end_code;
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else if (addr == PT_TEXT_LEN)
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tmp = child->mm->end_code - child->mm->start_code;
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else
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tmp = 0;
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ret = put_user(tmp, datap);
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break;
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}
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case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
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ret = -EIO;
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if ((addr & 3) || addr < 0 ||
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addr > sizeof(struct user) - 3)
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break;
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if (addr < sizeof(struct pt_regs))
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ret = put_stack_long(child, addr, data);
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else if (addr >= offsetof(struct user, fpu) &&
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addr < offsetof(struct user, u_fpvalid)) {
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unsigned long index;
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ret = init_fpu(child);
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if (ret)
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break;
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index = addr - offsetof(struct user, fpu);
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set_stopped_child_used_math(child);
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((unsigned long *)child->thread.xstate)
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[index >> 2] = data;
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ret = 0;
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} else if (addr == offsetof(struct user, u_fpvalid)) {
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conditional_stopped_child_used_math(data, child);
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ret = 0;
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}
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break;
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case PTRACE_GETREGS:
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return copy_regset_to_user(child, &user_sh_native_view,
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REGSET_GENERAL,
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0, sizeof(struct pt_regs),
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datap);
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case PTRACE_SETREGS:
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return copy_regset_from_user(child, &user_sh_native_view,
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REGSET_GENERAL,
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0, sizeof(struct pt_regs),
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datap);
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#ifdef CONFIG_SH_FPU
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case PTRACE_GETFPREGS:
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return copy_regset_to_user(child, &user_sh_native_view,
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REGSET_FPU,
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0, sizeof(struct user_fpu_struct),
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datap);
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case PTRACE_SETFPREGS:
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return copy_regset_from_user(child, &user_sh_native_view,
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REGSET_FPU,
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0, sizeof(struct user_fpu_struct),
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datap);
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#endif
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#ifdef CONFIG_SH_DSP
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case PTRACE_GETDSPREGS:
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return copy_regset_to_user(child, &user_sh_native_view,
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REGSET_DSP,
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0, sizeof(struct pt_dspregs),
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datap);
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case PTRACE_SETDSPREGS:
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return copy_regset_from_user(child, &user_sh_native_view,
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REGSET_DSP,
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0, sizeof(struct pt_dspregs),
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datap);
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#endif
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default:
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ret = ptrace_request(child, request, addr, data);
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break;
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}
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return ret;
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}
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static inline int audit_arch(void)
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{
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int arch = EM_SH;
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#ifdef CONFIG_CPU_LITTLE_ENDIAN
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arch |= __AUDIT_ARCH_LE;
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#endif
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return arch;
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}
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asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
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{
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long ret = 0;
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secure_computing(regs->regs[0]);
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if (test_thread_flag(TIF_SYSCALL_TRACE) &&
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tracehook_report_syscall_entry(regs))
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/*
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* Tracing decided this syscall should not happen.
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* We'll return a bogus call number to get an ENOSYS
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* error, but leave the original number in regs->regs[0].
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*/
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ret = -1L;
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if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
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trace_sys_enter(regs, regs->regs[0]);
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|
|
|
if (unlikely(current->audit_context))
|
|
audit_syscall_entry(audit_arch(), regs->regs[3],
|
|
regs->regs[4], regs->regs[5],
|
|
regs->regs[6], regs->regs[7]);
|
|
|
|
return ret ?: regs->regs[0];
|
|
}
|
|
|
|
asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
|
|
{
|
|
int step;
|
|
|
|
if (unlikely(current->audit_context))
|
|
audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]),
|
|
regs->regs[0]);
|
|
|
|
if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
|
|
trace_sys_exit(regs, regs->regs[0]);
|
|
|
|
step = test_thread_flag(TIF_SINGLESTEP);
|
|
if (step || test_thread_flag(TIF_SYSCALL_TRACE))
|
|
tracehook_report_syscall_exit(regs, step);
|
|
}
|