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/*
* arch/s390/kernel/ptrace.c
*
* S390 version
* Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
*
* Based on PowerPC version
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Derived from "arch/m68k/kernel/ptrace.c"
* Copyright (C) 1994 by Hamish Macdonald
* Taken from linux/kernel/ptrace.c and modified for M680x0.
* linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
*
* Modified by Cort Dougan (cort@cs.nmt.edu)
*
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file README.legal in the main directory of
* this archive for more details.
*/
#include <stddef.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <asm/segment.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/system.h>
#include <asm/uaccess.h>
void FixPerRegisters(struct task_struct *task)
{
struct pt_regs *regs = __KSTK_PTREGS(task);
per_struct *per_info=
(per_struct *)&task->thread.per_info;
per_info->control_regs.bits.em_instruction_fetch=
per_info->single_step|per_info->instruction_fetch;
if(per_info->single_step)
{
per_info->control_regs.bits.starting_addr=0;
per_info->control_regs.bits.ending_addr=0x7fffffffUL;
}
else
{
per_info->control_regs.bits.starting_addr=
per_info->starting_addr;
per_info->control_regs.bits.ending_addr=
per_info->ending_addr;
}
/* if any of the control reg tracing bits are on
we switch on per in the psw */
if(per_info->control_regs.words.cr[0]&PER_EM_MASK)
regs->psw.mask |=PSW_PER_MASK;
else
regs->psw.mask &= ~PSW_PER_MASK;
if (per_info->control_regs.bits.em_storage_alteration)
{
per_info->control_regs.bits.storage_alt_space_ctl=1;
//((pgd_t *)__pa(task->mm->pgd))->pgd |= USER_STD_MASK;
}
else
{
per_info->control_regs.bits.storage_alt_space_ctl=0;
//((pgd_t *)__pa(task->mm->pgd))->pgd &= ~USER_STD_MASK;
}
}
void set_single_step(struct task_struct *task)
{
per_struct *per_info=
(per_struct *)&task->thread.per_info;
per_info->single_step=1; /* Single step */
FixPerRegisters(task);
}
void clear_single_step(struct task_struct *task)
{
per_struct *per_info=
(per_struct *)&task->thread.per_info;
per_info->single_step=0;
FixPerRegisters(task);
}
int ptrace_usercopy(addr_t realuseraddr,addr_t copyaddr,int len,int tofromuser,int writeuser,u32 mask)
{
u32 tempuser;
int retval=0;
if(writeuser&&realuseraddr==(addr_t)NULL)
return(0);
if(mask!=0xffffffff)
{
tempuser=*((u32 *)realuseraddr);
if(!writeuser)
{
tempuser&=mask;
realuseraddr=(addr_t)&tempuser;
}
}
if(tofromuser)
{
if(writeuser)
{
retval=copy_from_user((void *)realuseraddr,(void *)copyaddr,len);
}
else
{
if(realuseraddr==(addr_t)NULL)
retval=(clear_user((void *)copyaddr,len)==-EFAULT ? -EIO:0);
else
retval=(copy_to_user((void *)copyaddr,(void *)realuseraddr,len)==-EFAULT ? -EIO:0);
}
}
else
{
if(writeuser)
memcpy((void *)realuseraddr,(void *)copyaddr,len);
else
memcpy((void *)copyaddr,(void *)realuseraddr,len);
}
if(mask!=0xffffffff&&writeuser)
(*((u32 *)realuseraddr))=(((*((u32 *)realuseraddr))&mask)|(tempuser&~mask));
return(retval);
}
int copy_user(struct task_struct *task,saddr_t useraddr,addr_t copyaddr,int len,int tofromuser,int writingtouser)
{
int copylen=0,copymax;
addr_t realuseraddr;
saddr_t enduseraddr=useraddr+len;
u32 mask;
if (useraddr < 0 || enduseraddr > sizeof(struct user)||
(useraddr < PT_ENDREGS && (useraddr&3))||
(enduseraddr < PT_ENDREGS && (enduseraddr&3)))
return (-EIO);
while(len>0)
{
mask=0xffffffff;
if(useraddr<PT_FPC)
{
realuseraddr=((addr_t) __KSTK_PTREGS(task)) + useraddr;
if(useraddr<PT_PSWMASK)
{
copymax=PT_PSWMASK;
}
else if(useraddr<(PT_PSWMASK+4))
{
copymax=(PT_PSWMASK+4);
if(writingtouser)
mask=PSW_MASK_DEBUGCHANGE;
}
else if(useraddr<(PT_PSWADDR+4))
{
copymax=PT_PSWADDR+4;
mask=PSW_ADDR_DEBUGCHANGE;
}
else
copymax=PT_FPC;
}
else if(useraddr<(PT_FPR15_LO+4))
{
copymax=(PT_FPR15_LO+4);
realuseraddr=(addr_t)&(((u8 *)&task->thread.fp_regs)[useraddr-PT_FPC]);
}
else if(useraddr<sizeof(struct user_regs_struct))
{
copymax=sizeof(struct user_regs_struct);
realuseraddr=(addr_t)&(((u8 *)&task->thread.per_info)[useraddr-PT_CR_9]);
}
else
{
copymax=sizeof(struct user);
realuseraddr=(addr_t)NULL;
}
copylen=copymax-useraddr;
copylen=(copylen>len ? len:copylen);
if(ptrace_usercopy(realuseraddr,copyaddr,copylen,tofromuser,writingtouser,mask))
return (-EIO);
copyaddr+=copylen;
len-=copylen;
useraddr+=copylen;
}
FixPerRegisters(task);
return(0);
}
/*
* Called by kernel/ptrace.c when detaching..
*
* Make sure single step bits etc are not set.
*/
void ptrace_disable(struct task_struct *child)
{
/* make sure the single step bit is not set. */
clear_single_step(child);
}
asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
{
struct task_struct *child;
int ret = -EPERM;
unsigned long tmp;
int copied;
ptrace_area parea;
lock_kernel();
if (request == PTRACE_TRACEME)
{
/* are we already being traced? */
if (current->ptrace & PT_PTRACED)
goto out;
/* set the ptrace bit in the process flags. */
current->ptrace |= PT_PTRACED;
ret = 0;
goto out;
}
ret = -ESRCH;
read_lock(&tasklist_lock);
child = find_task_by_pid(pid);
read_unlock(&tasklist_lock);
if (!child)
goto out;
ret = -EPERM;
if (pid == 1) /* you may not mess with init */
goto out;
if (request == PTRACE_ATTACH)
{
ret = ptrace_attach(child);
goto out;
}
ret = -ESRCH;
// printk("child=%lX child->flags=%lX",child,child->flags);
/* I added child!=current line so we can get the */
/* ieee_instruction_pointer from the user structure DJB */
if(child!=current)
{
if (!(child->ptrace & PT_PTRACED))
goto out;
if (child->state != TASK_STOPPED)
{
if (request != PTRACE_KILL)
goto out;
}
if (child->p_pptr != current)
goto out;
}
switch (request)
{
/* If I and D space are separate, these will need to be fixed. */
case PTRACE_PEEKTEXT: /* read word at location addr. */
case PTRACE_PEEKDATA:
copied = access_process_vm(child,ADDR_BITS_REMOVE(addr), &tmp, sizeof(tmp), 0);
ret = -EIO;
if (copied != sizeof(tmp))
goto out;
ret = put_user(tmp,(unsigned long *) data);
goto out;
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR:
ret=copy_user(child,addr,data,sizeof(unsigned long),1,0);
break;
/* If I and D space are separate, this will have to be fixed. */
case PTRACE_POKETEXT: /* write the word at location addr. */
case PTRACE_POKEDATA:
ret = 0;
if (access_process_vm(child,ADDR_BITS_REMOVE(addr), &data, sizeof(data), 1) == sizeof(data))
goto out;
ret = -EIO;
goto out;
break;
case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
ret=copy_user(child,addr,(addr_t)&data,sizeof(unsigned long),0,1);
break;
case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
case PTRACE_CONT: /* restart after signal. */
ret = -EIO;
if ((unsigned long) data >= _NSIG)
break;
if (request == PTRACE_SYSCALL)
child->ptrace |= PT_TRACESYS;
else
child->ptrace &= ~PT_TRACESYS;
child->exit_code = data;
/* make sure the single step bit is not set. */
clear_single_step(child);
wake_up_process(child);
ret = 0;
break;
/*
* make the child exit. Best I can do is send it a sigkill.
* perhaps it should be put in the status that it wants to
* exit.
*/
case PTRACE_KILL:
ret = 0;
if (child->state == TASK_ZOMBIE) /* already dead */
break;
child->exit_code = SIGKILL;
clear_single_step(child);
wake_up_process(child);
/* make sure the single step bit is not set. */
break;
case PTRACE_SINGLESTEP: /* set the trap flag. */
ret = -EIO;
if ((unsigned long) data >= _NSIG)
break;
child->ptrace &= ~PT_TRACESYS;
child->exit_code = data;
set_single_step(child);
/* give it a chance to run. */
wake_up_process(child);
ret = 0;
break;
case PTRACE_DETACH: /* detach a process that was attached. */
ret = ptrace_detach(child, data);
break;
case PTRACE_PEEKUSR_AREA:
case PTRACE_POKEUSR_AREA:
if((ret=copy_from_user(&parea,(void *)addr,sizeof(parea)))==0)
ret=copy_user(child,parea.kernel_addr,parea.process_addr,
parea.len,1,(request==PTRACE_POKEUSR_AREA));
break;
default:
ret = -EIO;
break;
}
out:
unlock_kernel();
return ret;
}
asmlinkage void syscall_trace(void)
{
lock_kernel();
if ((current->ptrace & (PT_PTRACED|PT_TRACESYS))
!= (PT_PTRACED|PT_TRACESYS))
goto out;
current->exit_code = SIGTRAP;
set_current_state(TASK_STOPPED);
notify_parent(current, SIGCHLD);
schedule();
/*
* this isn't the same as continuing with a signal, but it will do
* for normal use. strace only continues with a signal if the
* stopping signal is not SIGTRAP. -brl
*/
if (current->exit_code) {
send_sig(current->exit_code, current, 1);
current->exit_code = 0;
}
out:
unlock_kernel();
}
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