// TODO some minor issues
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2001 - 2005 Tensilica Inc.
*
* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
* Chris Zankel <chris@zankel.net>
* Scott Foehner<sfoehner@yahoo.com>,
* Kevin Chea
* Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca>
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/ptrace.h>
#include <asm/elf.h>
#define TEST_KERNEL // verify kernel operations FIXME: remove
/*
* Called by kernel/ptrace.c when detaching..
*
* Make sure single step bits etc are not set.
*/
void ptrace_disable(struct task_struct *child)
{
/* Nothing to do.. */
}
int sys_ptrace(long request, long pid, long addr, long data)
{
struct task_struct *child;
int ret = -EPERM;
lock_kernel();
#if 0
if ((int)request != 1)
printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
(int) request, (int) pid, (unsigned long) addr,
(unsigned long) data);
#endif
if (request == PTRACE_TRACEME) {
/* Are we already being traced? */
if (current->ptrace & PT_PTRACED)
goto out;
if ((ret = security_ptrace(current->parent, current)))
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);
if (child)
get_task_struct(child);
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_tsk;
}
if ((ret = ptrace_check_attach(child, request == PTRACE_KILL)) < 0)
goto out_tsk;
switch (request) {
case PTRACE_PEEKTEXT: /* read word at location addr. */
case PTRACE_PEEKDATA:
{
unsigned long tmp;
int copied;
copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
ret = -EIO;
if (copied != sizeof(tmp))
break;
ret = put_user(tmp,(unsigned long *) data);
goto out;
}
/* Read the word at location addr in the USER area. */
case PTRACE_PEEKUSR:
{
struct pt_regs *regs;
unsigned long tmp;
regs = xtensa_pt_regs(child);
tmp = 0; /* Default return value. */
switch(addr) {
case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
{
int ar = addr - REG_AR_BASE - regs->windowbase * 4;
ar &= (XCHAL_NUM_AREGS - 1);
if (ar < 16 && ar + (regs->wmask >> 4) * 4 >= 0)
tmp = regs->areg[ar];
else
ret = -EIO;
break;
}
case REG_A_BASE ... REG_A_BASE + 15:
tmp = regs->areg[addr - REG_A_BASE];
break;
case REG_PC:
tmp = regs->pc;
break;
case REG_PS:
/* Note: PS.EXCM is not set while user task is running;
* its being set in regs is for exception handling
* convenience. */
tmp = (regs->ps & ~XCHAL_PS_EXCM_MASK);
break;
case REG_WB:
tmp = regs->windowbase;
break;
case REG_WS:
tmp = regs->windowstart;
break;
case REG_LBEG:
tmp = regs->lbeg;
break;
case REG_LEND:
tmp = regs->lend;
break;
case REG_LCOUNT:
tmp = regs->lcount;
break;
case REG_SAR:
tmp = regs->sar;
break;
case REG_DEPC:
tmp = regs->depc;
break;
case REG_EXCCAUSE:
tmp = regs->exccause;
break;
case REG_EXCVADDR:
tmp = regs->excvaddr;
break;
case SYSCALL_NR:
tmp = regs->syscall;
break;
default:
tmp = 0;
ret = -EIO;
goto out;
}
ret = put_user(tmp, (unsigned long *) data);
goto out;
}
case PTRACE_POKETEXT: /* write the word at location addr. */
case PTRACE_POKEDATA:
if (access_process_vm(child, addr, &data, sizeof(data), 1)
== sizeof(data))
break;
ret = -EIO;
goto out;
case PTRACE_POKEUSR:
{
struct pt_regs *regs;
regs = xtensa_pt_regs(child);
switch (addr) {
case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
{
int ar = addr - REG_AR_BASE - regs->windowbase * 4;
if (ar < 16 && ar + (regs->wmask >> 4) * 4 >= 0)
regs->areg[ar & (XCHAL_NUM_AREGS - 1)] = data;
else
ret = -EIO;
break;
}
case REG_A_BASE ... REG_A_BASE + 15:
regs->areg[addr - REG_A_BASE] = data;
break;
case REG_PC:
regs->pc = data;
break;
case SYSCALL_NR:
regs->syscall = data;
break;
#ifdef TEST_KERNEL
case REG_WB:
regs->windowbase = data;
break;
case REG_WS:
regs->windowstart = data;
break;
#endif
default:
/* The rest are not allowed. */
ret = -EIO;
break;
}
break;
}
/* continue and stop at next (return from) syscall */
case PTRACE_SYSCALL:
case PTRACE_CONT: /* restart after signal. */
{
ret = -EIO;
if (!valid_signal(data))
break;
if (request == PTRACE_SYSCALL)
set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
else
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
child->exit_code = data;
/* Make sure the single step bit is not set. */
child->ptrace &= ~PT_SINGLESTEP;
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 == EXIT_ZOMBIE) /* already dead */
break;
child->exit_code = SIGKILL;
child->ptrace &= ~PT_SINGLESTEP;
wake_up_process(child);
break;
case PTRACE_SINGLESTEP:
ret = -EIO;
if (!valid_signal(data))
break;
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
child->ptrace |= PT_SINGLESTEP;
child->exit_code = data;
wake_up_process(child);
ret = 0;
break;
case PTRACE_GETREGS:
{
/* 'data' points to user memory in which to write.
* Mainly due to the non-live register values, we
* reformat the register values into something more
* standard. For convenience, we use the handy
* elf_gregset_t format. */
xtensa_gregset_t format;
struct pt_regs *regs = xtensa_pt_regs(child);
do_copy_regs (&format, regs, child);
/* Now, copy to user space nice and easy... */
ret = 0;
if (copy_to_user((void *)data, &format, sizeof(elf_gregset_t)))
ret = -EFAULT;
break;
}
case PTRACE_SETREGS:
{
/* 'data' points to user memory that contains the new
* values in the elf_gregset_t format. */
xtensa_gregset_t format;
struct pt_regs *regs = xtensa_pt_regs(child);
if (copy_from_user(&format,(void *)data,sizeof(elf_gregset_t))){
ret = -EFAULT;
break;
}
/* FIXME: Perhaps we want some sanity checks on
* these user-space values? See ARM version. Are
* debuggers a security concern? */
do_restore_regs (&format, regs, child);
ret = 0;
break;
}
case PTRACE_GETFPREGS:
{
/* 'data' points to user memory in which to write.
* For convenience, we use the handy
* elf_fpregset_t format. */
elf_fpregset_t fpregs;
struct pt_regs *regs = xtensa_pt_regs(child);
do_save_fpregs (&fpregs, regs, child);
/* Now, copy to user space nice and easy... */
ret = 0;
if (copy_to_user((void *)data, &fpregs, sizeof(elf_fpregset_t)))
ret = -EFAULT;
break;
}
case PTRACE_SETFPREGS:
{
/* 'data' points to user memory that contains the new
* values in the elf_fpregset_t format.
*/
elf_fpregset_t fpregs;
struct pt_regs *regs = xtensa_pt_regs(child);
ret = 0;
if (copy_from_user(&fpregs, (void *)data, sizeof(elf_fpregset_t))) {
ret = -EFAULT;
break;
}
if (do_restore_fpregs (&fpregs, regs, child))
ret = -EIO;
break;
}
case PTRACE_GETFPREGSIZE:
/* 'data' points to 'unsigned long' set to the size
* of elf_fpregset_t
*/
ret = put_user(sizeof(elf_fpregset_t), (unsigned long *) data);
break;
case PTRACE_DETACH: /* detach a process that was attached. */
ret = ptrace_detach(child, data);
break;
default:
ret = ptrace_request(child, request, addr, data);
goto out;
}
out_tsk:
put_task_struct(child);
out:
unlock_kernel();
return ret;
}
void do_syscall_trace(void)
{
if (!test_thread_flag(TIF_SYSCALL_TRACE))
return;
if (!(current->ptrace & PT_PTRACED))
return;
/*
* The 0x80 provides a way for the tracing parent to distinguish
* between a syscall stop and SIGTRAP delivery
*/
ptrace_notify(SIGTRAP|((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
/*
* 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;
}
}
