457 lines
12 KiB
C
457 lines
12 KiB
C
/*
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* linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
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* these modifications are Copyright 2004-2009 Analog Devices Inc.
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*
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* Licensed under the GPL-2
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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/signal.h>
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#include <linux/uaccess.h>
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#include <asm/page.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/asm-offsets.h>
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#include <asm/dma.h>
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#include <asm/fixed_code.h>
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#include <asm/cacheflush.h>
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#include <asm/mem_map.h>
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#define TEXT_OFFSET 0
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/*
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* does not yet catch signals sent when the child dies.
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* in exit.c or in signal.c.
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*/
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/* determines which bits in the SYSCFG reg the user has access to. */
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/* 1 = access 0 = no access */
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#define SYSCFG_MASK 0x0007 /* SYSCFG reg */
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/* sets the trace bits. */
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#define TRACE_BITS 0x0001
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/* Find the stack offset for a register, relative to thread.esp0. */
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#define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
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/*
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* Get the address of the live pt_regs for the specified task.
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* These are saved onto the top kernel stack when the process
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* is not running.
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*
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* Note: if a user thread is execve'd from kernel space, the
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* kernel stack will not be empty on entry to the kernel, so
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* ptracing these tasks will fail.
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*/
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static inline struct pt_regs *get_user_regs(struct task_struct *task)
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{
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return (struct pt_regs *)
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((unsigned long)task_stack_page(task) +
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(THREAD_SIZE - sizeof(struct pt_regs)));
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}
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/*
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* Get all user integer registers.
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*/
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static inline int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
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{
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struct pt_regs regs;
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memcpy(®s, get_user_regs(tsk), sizeof(regs));
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regs.usp = tsk->thread.usp;
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return copy_to_user(uregs, ®s, sizeof(struct pt_regs)) ? -EFAULT : 0;
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}
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/* Mapping from PT_xxx to the stack offset at which the register is
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* saved. Notice that usp has no stack-slot and needs to be treated
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* specially (see get_reg/put_reg below).
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*/
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/*
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* Get contents of register REGNO in task TASK.
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*/
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static inline long get_reg(struct task_struct *task, int regno)
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{
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unsigned char *reg_ptr;
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struct pt_regs *regs =
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(struct pt_regs *)((unsigned long)task_stack_page(task) +
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(THREAD_SIZE - sizeof(struct pt_regs)));
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reg_ptr = (char *)regs;
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switch (regno) {
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case PT_USP:
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return task->thread.usp;
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default:
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if (regno <= 216)
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return *(long *)(reg_ptr + regno);
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}
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/* slight mystery ... never seems to come here but kernel misbehaves without this code! */
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printk(KERN_WARNING "Request to get for unknown register %d\n", regno);
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return 0;
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}
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/*
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* Write contents of register REGNO in task TASK.
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*/
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static inline int
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put_reg(struct task_struct *task, int regno, unsigned long data)
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{
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char *reg_ptr;
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struct pt_regs *regs =
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(struct pt_regs *)((unsigned long)task_stack_page(task) +
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(THREAD_SIZE - sizeof(struct pt_regs)));
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reg_ptr = (char *)regs;
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switch (regno) {
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case PT_PC:
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/*********************************************************************/
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/* At this point the kernel is most likely in exception. */
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/* The RETX register will be used to populate the pc of the process. */
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/*********************************************************************/
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regs->retx = data;
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regs->pc = data;
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break;
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case PT_RETX:
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break; /* regs->retx = data; break; */
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case PT_USP:
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regs->usp = data;
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task->thread.usp = data;
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break;
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default:
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if (regno <= 216)
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*(long *)(reg_ptr + regno) = data;
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}
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return 0;
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}
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/*
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* check that an address falls within the bounds of the target process's memory mappings
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*/
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static inline int is_user_addr_valid(struct task_struct *child,
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unsigned long start, unsigned long len)
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{
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struct vm_area_struct *vma;
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struct sram_list_struct *sraml;
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/* overflow */
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if (start + len < start)
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return -EIO;
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vma = find_vma(child->mm, start);
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if (vma && start >= vma->vm_start && start + len <= vma->vm_end)
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return 0;
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for (sraml = child->mm->context.sram_list; sraml; sraml = sraml->next)
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if (start >= (unsigned long)sraml->addr
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&& start + len < (unsigned long)sraml->addr + sraml->length)
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return 0;
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if (start >= FIXED_CODE_START && start + len < FIXED_CODE_END)
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return 0;
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return -EIO;
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}
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void ptrace_enable(struct task_struct *child)
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{
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unsigned long tmp;
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tmp = get_reg(child, PT_SYSCFG) | (TRACE_BITS);
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put_reg(child, PT_SYSCFG, tmp);
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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 the single step bit is 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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unsigned long tmp;
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/* make sure the single step bit is not set. */
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tmp = get_reg(child, PT_SYSCFG) & ~TRACE_BITS;
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put_reg(child, PT_SYSCFG, tmp);
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}
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long arch_ptrace(struct task_struct *child, long request, long addr, long data)
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{
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int ret;
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unsigned long __user *datap = (unsigned long __user *)data;
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void *paddr = (void *)addr;
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switch (request) {
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/* when I and D space are separate, these will need to be fixed. */
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case PTRACE_PEEKDATA:
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pr_debug("ptrace: PEEKDATA\n");
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/* fall through */
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case PTRACE_PEEKTEXT: /* read word at location addr. */
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{
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unsigned long tmp = 0;
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int copied = 0, to_copy = sizeof(tmp);
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ret = -EIO;
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pr_debug("ptrace: PEEKTEXT at addr 0x%08lx + %i\n", addr, to_copy);
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if (is_user_addr_valid(child, addr, to_copy) < 0)
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break;
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pr_debug("ptrace: user address is valid\n");
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switch (bfin_mem_access_type(addr, to_copy)) {
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case BFIN_MEM_ACCESS_CORE:
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case BFIN_MEM_ACCESS_CORE_ONLY:
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copied = access_process_vm(child, addr, &tmp,
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to_copy, 0);
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if (copied)
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break;
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/* hrm, why didn't that work ... maybe no mapping */
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if (addr >= FIXED_CODE_START &&
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addr + to_copy <= FIXED_CODE_END) {
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copy_from_user_page(0, 0, 0, &tmp, paddr, to_copy);
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copied = to_copy;
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} else if (addr >= BOOT_ROM_START) {
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memcpy(&tmp, paddr, to_copy);
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copied = to_copy;
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}
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break;
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case BFIN_MEM_ACCESS_DMA:
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if (safe_dma_memcpy(&tmp, paddr, to_copy))
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copied = to_copy;
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break;
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case BFIN_MEM_ACCESS_ITEST:
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if (isram_memcpy(&tmp, paddr, to_copy))
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copied = to_copy;
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break;
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default:
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copied = 0;
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break;
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}
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pr_debug("ptrace: copied size %d [0x%08lx]\n", copied, tmp);
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if (copied == to_copy)
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ret = put_user(tmp, datap);
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break;
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}
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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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{
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unsigned long tmp;
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ret = -EIO;
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tmp = 0;
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if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
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printk(KERN_WARNING "ptrace error : PEEKUSR : temporarily returning "
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"0 - %x sizeof(pt_regs) is %lx\n",
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(int)addr, sizeof(struct pt_regs));
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break;
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}
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if (addr == sizeof(struct pt_regs)) {
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/* PT_TEXT_ADDR */
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tmp = child->mm->start_code + TEXT_OFFSET;
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} else if (addr == (sizeof(struct pt_regs) + 4)) {
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/* PT_TEXT_END_ADDR */
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tmp = child->mm->end_code;
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} else if (addr == (sizeof(struct pt_regs) + 8)) {
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/* PT_DATA_ADDR */
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tmp = child->mm->start_data;
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#ifdef CONFIG_BINFMT_ELF_FDPIC
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} else if (addr == (sizeof(struct pt_regs) + 12)) {
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goto case_PTRACE_GETFDPIC_EXEC;
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} else if (addr == (sizeof(struct pt_regs) + 16)) {
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goto case_PTRACE_GETFDPIC_INTERP;
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#endif
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} else {
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tmp = get_reg(child, addr);
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}
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ret = put_user(tmp, datap);
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break;
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}
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#ifdef CONFIG_BINFMT_ELF_FDPIC
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case PTRACE_GETFDPIC: {
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unsigned long tmp = 0;
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switch (addr) {
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case_PTRACE_GETFDPIC_EXEC:
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case PTRACE_GETFDPIC_EXEC:
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tmp = child->mm->context.exec_fdpic_loadmap;
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break;
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case_PTRACE_GETFDPIC_INTERP:
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case PTRACE_GETFDPIC_INTERP:
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tmp = child->mm->context.interp_fdpic_loadmap;
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break;
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default:
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break;
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}
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ret = put_user(tmp, datap);
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break;
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}
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#endif
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/* when I and D space are separate, this will have to be fixed. */
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case PTRACE_POKEDATA:
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pr_debug("ptrace: PTRACE_PEEKDATA\n");
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/* fall through */
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case PTRACE_POKETEXT: /* write the word at location addr. */
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{
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int copied = 0, to_copy = sizeof(data);
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ret = -EIO;
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pr_debug("ptrace: POKETEXT at addr 0x%08lx + %i bytes %lx\n",
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addr, to_copy, data);
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if (is_user_addr_valid(child, addr, to_copy) < 0)
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break;
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pr_debug("ptrace: user address is valid\n");
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switch (bfin_mem_access_type(addr, to_copy)) {
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case BFIN_MEM_ACCESS_CORE:
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case BFIN_MEM_ACCESS_CORE_ONLY:
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copied = access_process_vm(child, addr, &data,
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to_copy, 1);
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if (copied)
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break;
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/* hrm, why didn't that work ... maybe no mapping */
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if (addr >= FIXED_CODE_START &&
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addr + to_copy <= FIXED_CODE_END) {
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copy_to_user_page(0, 0, 0, paddr, &data, to_copy);
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copied = to_copy;
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} else if (addr >= BOOT_ROM_START) {
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memcpy(paddr, &data, to_copy);
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copied = to_copy;
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}
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break;
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case BFIN_MEM_ACCESS_DMA:
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if (safe_dma_memcpy(paddr, &data, to_copy))
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copied = to_copy;
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break;
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case BFIN_MEM_ACCESS_ITEST:
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if (isram_memcpy(paddr, &data, to_copy))
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copied = to_copy;
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break;
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default:
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copied = 0;
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break;
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}
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pr_debug("ptrace: copied size %d\n", copied);
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if (copied == to_copy)
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ret = 0;
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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 > (sizeof(struct pt_regs) + 16))) {
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printk(KERN_WARNING "ptrace error : POKEUSR: temporarily returning 0\n");
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break;
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}
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if (addr >= (sizeof(struct pt_regs))) {
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ret = 0;
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break;
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}
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if (addr == PT_SYSCFG) {
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data &= SYSCFG_MASK;
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data |= get_reg(child, PT_SYSCFG);
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}
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ret = put_reg(child, addr, data);
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break;
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case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
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case PTRACE_CONT: /* restart after signal. */
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pr_debug("ptrace: syscall/cont\n");
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ret = -EIO;
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if (!valid_signal(data))
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break;
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if (request == PTRACE_SYSCALL)
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set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
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else
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clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
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child->exit_code = data;
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ptrace_disable(child);
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pr_debug("ptrace: before wake_up_process\n");
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wake_up_process(child);
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ret = 0;
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break;
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/*
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* make the child exit. Best I can do is send it a sigkill.
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* perhaps it should be put in the status that it wants to
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* exit.
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*/
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case PTRACE_KILL:
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ret = 0;
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if (child->exit_state == EXIT_ZOMBIE) /* already dead */
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break;
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child->exit_code = SIGKILL;
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ptrace_disable(child);
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wake_up_process(child);
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break;
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case PTRACE_SINGLESTEP: /* set the trap flag. */
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pr_debug("ptrace: single step\n");
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ret = -EIO;
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if (!valid_signal(data))
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break;
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clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
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ptrace_enable(child);
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child->exit_code = data;
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wake_up_process(child);
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ret = 0;
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break;
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case PTRACE_GETREGS:
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/* Get all gp regs from the child. */
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ret = ptrace_getregs(child, datap);
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break;
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case PTRACE_SETREGS:
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printk(KERN_WARNING "ptrace: SETREGS: **** NOT IMPLEMENTED ***\n");
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/* Set all gp regs in the child. */
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ret = 0;
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break;
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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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asmlinkage void syscall_trace(void)
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{
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if (!test_thread_flag(TIF_SYSCALL_TRACE))
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return;
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if (!(current->ptrace & PT_PTRACED))
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return;
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/* the 0x80 provides a way for the tracing parent to distinguish
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* between a syscall stop and SIGTRAP delivery
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*/
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ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
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? 0x80 : 0));
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/*
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* this isn't the same as continuing with a signal, but it will do
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* for normal use. strace only continues with a signal if the
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* stopping signal is not SIGTRAP. -brl
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*/
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if (current->exit_code) {
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send_sig(current->exit_code, current, 1);
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current->exit_code = 0;
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}
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}
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