/*
* linux/arch/sh/kernel/ptrace.c
*
* Original x86 implementation:
* By Ross Biro 1/23/92
* edited by Linus Torvalds
*
* SuperH version: Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
* Audit support: Yuichi Nakamura <ynakam@hitachisoft.jp>
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/slab.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/io.h>
#include <linux/audit.h>
#include <linux/seccomp.h>
#include <linux/tracehook.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/mmu_context.h>
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
/*
* This routine will get a word off of the process kernel stack.
*/
static inline int get_stack_long(struct task_struct *task, int offset)
{
unsigned char *stack;
stack = (unsigned char *)task_pt_regs(task);
stack += offset;
return (*((int *)stack));
}
/*
* This routine will put a word on the process kernel stack.
*/
static inline int put_stack_long(struct task_struct *task, int offset,
unsigned long data)
{
unsigned char *stack;
stack = (unsigned char *)task_pt_regs(task);
stack += offset;
*(unsigned long *) stack = data;
return 0;
}
void user_enable_single_step(struct task_struct *child)
{
struct pt_regs *regs = task_pt_regs(child);
long pc;
pc = get_stack_long(child, (long)®s->pc);
/* Next scheduling will set up UBC */
if (child->thread.ubc_pc == 0)
ubc_usercnt += 1;
child->thread.ubc_pc = pc;
set_tsk_thread_flag(child, TIF_SINGLESTEP);
}
void user_disable_single_step(struct task_struct *child)
{
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
/*
* Ensure the UBC is not programmed at the next context switch.
*
* Normally this is not needed but there are sequences such as
* singlestep, signal delivery, and continue that leave the
* ubc_pc non-zero leading to spurious SIGTRAPs.
*/
if (child->thread.ubc_pc != 0) {
ubc_usercnt -= 1;
child->thread.ubc_pc = 0;
}
}
/*
* Called by kernel/ptrace.c when detaching..
*
* Make sure single step bits etc are not set.
*/
void ptrace_disable(struct task_struct *child)
{
user_disable_single_step(child);
}
long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
struct user * dummy = NULL;
int ret;
switch (request) {
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR: {
unsigned long tmp;
ret = -EIO;
if ((addr & 3) || addr < 0 ||
addr > sizeof(struct user) - 3)
break;
if (addr < sizeof(struct pt_regs))
tmp = get_stack_long(child, addr);
else if (addr >= (long) &dummy->fpu &&
addr < (long) &dummy->u_fpvalid) {
if (!tsk_used_math(child)) {
if (addr == (long)&dummy->fpu.fpscr)
tmp = FPSCR_INIT;
else
tmp = 0;
} else
tmp = ((long *)&child->thread.fpu)
[(addr - (long)&dummy->fpu) >> 2];
} else if (addr == (long) &dummy->u_fpvalid)
tmp = !!tsk_used_math(child);
else
tmp = 0;
ret = put_user(tmp, (unsigned long __user *)data);
break;
}
case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
ret = -EIO;
if ((addr & 3) || addr < 0 ||
addr > sizeof(struct user) - 3)
break;
if (addr < sizeof(struct pt_regs))
ret = put_stack_long(child, addr, data);
else if (addr >= (long) &dummy->fpu &&
addr < (long) &dummy->u_fpvalid) {
set_stopped_child_used_math(child);
((long *)&child->thread.fpu)
[(addr - (long)&dummy->fpu) >> 2] = data;
ret = 0;
} else if (addr == (long) &dummy->u_fpvalid) {
conditional_stopped_child_used_math(data, child);
ret = 0;
}
break;
#ifdef CONFIG_SH_DSP
case PTRACE_GETDSPREGS: {
unsigned long dp;
ret = -EIO;
dp = ((unsigned long) child) + THREAD_SIZE -
sizeof(struct pt_dspregs);
if (*((int *) (dp - 4)) == SR_FD) {
copy_to_user((void *)addr, (void *) dp,
sizeof(struct pt_dspregs));
ret = 0;
}
break;
}
case PTRACE_SETDSPREGS: {
unsigned long dp;
ret = -EIO;
dp = ((unsigned long) child) + THREAD_SIZE -
sizeof(struct pt_dspregs);
if (*((int *) (dp - 4)) == SR_FD) {
copy_from_user((void *) dp, (void *)addr,
sizeof(struct pt_dspregs));
ret = 0;
}
break;
}
#endif
#ifdef CONFIG_BINFMT_ELF_FDPIC
case PTRACE_GETFDPIC: {
unsigned long tmp = 0;
switch (addr) {
case PTRACE_GETFDPIC_EXEC:
tmp = child->mm->context.exec_fdpic_loadmap;
break;
case PTRACE_GETFDPIC_INTERP:
tmp = child->mm->context.interp_fdpic_loadmap;
break;
default:
break;
}
ret = 0;
if (put_user(tmp, (unsigned long *) data)) {
ret = -EFAULT;
break;
}
break;
}
#endif
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
static inline int audit_arch(void)
{
int arch = EM_SH;
#ifdef CONFIG_CPU_LITTLE_ENDIAN
arch |= __AUDIT_ARCH_LE;
#endif
return arch;
}
asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
{
long ret = 0;
secure_computing(regs->regs[0]);
if (test_thread_flag(TIF_SYSCALL_TRACE) &&
tracehook_report_syscall_entry(regs))
/*
* Tracing decided this syscall should not happen.
* We'll return a bogus call number to get an ENOSYS
* error, but leave the original number in regs->regs[0].
*/
ret = -1L;
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]);
step = test_thread_flag(TIF_SINGLESTEP);
if (step || test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, step);
}