alistair23-linux/arch/powerpc/kernel/ptrace.c

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/*
* 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@hq.fsmlabs.com)
* and Paul Mackerras (paulus@samba.org).
*
* 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 <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/security.h>
#include <linux/signal.h>
#include <linux/seccomp.h>
#include <linux/audit.h>
#ifdef CONFIG_PPC32
#include <linux/module.h>
#endif
#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#ifdef CONFIG_PPC64
#include "ptrace-ppc64.h"
#else
#include "ptrace-ppc32.h"
#endif
#include "ptrace-common.h"
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
/*
* 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);
}
long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
int ret = -EPERM;
switch (request) {
/* when I and D space are separate, these will need to be fixed. */
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 __user *) data);
break;
}
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR: {
unsigned long index, tmp;
ret = -EIO;
/* convert to index and check */
#ifdef CONFIG_PPC32
index = (unsigned long) addr >> 2;
if ((addr & 3) || (index > PT_FPSCR)
|| (child->thread.regs == NULL))
#else
index = (unsigned long) addr >> 3;
if ((addr & 7) || (index > PT_FPSCR))
#endif
break;
#ifdef CONFIG_PPC32
CHECK_FULL_REGS(child->thread.regs);
#endif
if (index < PT_FPR0) {
tmp = get_reg(child, (int) index);
} else {
flush_fp_to_thread(child);
tmp = ((unsigned long *)child->thread.fpr)[index - PT_FPR0];
}
ret = put_user(tmp,(unsigned long __user *) data);
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, &data, sizeof(data), 1)
== sizeof(data))
break;
ret = -EIO;
break;
/* write the word at location addr in the USER area */
case PTRACE_POKEUSR: {
unsigned long index;
ret = -EIO;
/* convert to index and check */
#ifdef CONFIG_PPC32
index = (unsigned long) addr >> 2;
if ((addr & 3) || (index > PT_FPSCR)
|| (child->thread.regs == NULL))
#else
index = (unsigned long) addr >> 3;
if ((addr & 7) || (index > PT_FPSCR))
#endif
break;
#ifdef CONFIG_PPC32
CHECK_FULL_REGS(child->thread.regs);
#endif
if (index == PT_ORIG_R3)
break;
if (index < PT_FPR0) {
ret = put_reg(child, index, data);
} else {
flush_fp_to_thread(child);
((unsigned long *)child->thread.fpr)[index - PT_FPR0] = data;
ret = 0;
}
break;
}
case PTRACE_SYSCALL: /* continue and stop at next (return from) 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. */
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->exit_state == EXIT_ZOMBIE) /* already dead */
break;
child->exit_code = SIGKILL;
/* make sure the single step bit is not set. */
clear_single_step(child);
wake_up_process(child);
break;
}
case PTRACE_SINGLESTEP: { /* set the trap flag. */
ret = -EIO;
if (!valid_signal(data))
break;
clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
set_single_step(child);
child->exit_code = data;
/* give it a chance to run. */
wake_up_process(child);
ret = 0;
break;
}
#ifdef CONFIG_PPC64
case PTRACE_GET_DEBUGREG: {
ret = -EINVAL;
/* We only support one DABR and no IABRS at the moment */
if (addr > 0)
break;
ret = put_user(child->thread.dabr,
(unsigned long __user *)data);
break;
}
case PTRACE_SET_DEBUGREG:
ret = ptrace_set_debugreg(child, addr, data);
break;
#endif
case PTRACE_DETACH:
ret = ptrace_detach(child, data);
break;
case PPC_PTRACE_GETREGS: { /* Get GPRs 0 - 31. */
int i;
unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
unsigned long __user *tmp = (unsigned long __user *)addr;
for (i = 0; i < 32; i++) {
ret = put_user(*reg, tmp);
if (ret)
break;
reg++;
tmp++;
}
break;
}
case PPC_PTRACE_SETREGS: { /* Set GPRs 0 - 31. */
int i;
unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
unsigned long __user *tmp = (unsigned long __user *)addr;
for (i = 0; i < 32; i++) {
ret = get_user(*reg, tmp);
if (ret)
break;
reg++;
tmp++;
}
break;
}
#ifdef CONFIG_PPC64
case PPC_PTRACE_GETFPREGS: { /* Get FPRs 0 - 31. */
int i;
unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
unsigned long __user *tmp = (unsigned long __user *)addr;
flush_fp_to_thread(child);
for (i = 0; i < 32; i++) {
ret = put_user(*reg, tmp);
if (ret)
break;
reg++;
tmp++;
}
break;
}
case PPC_PTRACE_SETFPREGS: { /* Get FPRs 0 - 31. */
int i;
unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
unsigned long __user *tmp = (unsigned long __user *)addr;
flush_fp_to_thread(child);
for (i = 0; i < 32; i++) {
ret = get_user(*reg, tmp);
if (ret)
break;
reg++;
tmp++;
}
break;
}
#endif /* CONFIG_PPC64 */
#ifdef CONFIG_ALTIVEC
case PTRACE_GETVRREGS:
/* Get the child altivec register state. */
flush_altivec_to_thread(child);
ret = get_vrregs((unsigned long __user *)data, child);
break;
case PTRACE_SETVRREGS:
/* Set the child altivec register state. */
flush_altivec_to_thread(child);
ret = set_vrregs(child, (unsigned long __user *)data);
break;
#endif
#ifdef CONFIG_SPE
case PTRACE_GETEVRREGS:
/* Get the child spe register state. */
if (child->thread.regs->msr & MSR_SPE)
giveup_spe(child);
ret = get_evrregs((unsigned long __user *)data, child);
break;
case PTRACE_SETEVRREGS:
/* Set the child spe register state. */
/* this is to clear the MSR_SPE bit to force a reload
* of register state from memory */
if (child->thread.regs->msr & MSR_SPE)
giveup_spe(child);
ret = set_evrregs(child, (unsigned long __user *)data);
break;
#endif
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
}
static void do_syscall_trace(void)
{
/* 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;
}
}
void do_syscall_trace_enter(struct pt_regs *regs)
{
secure_computing(regs->gpr[0]);
if (test_thread_flag(TIF_SYSCALL_TRACE)
&& (current->ptrace & PT_PTRACED))
do_syscall_trace();
if (unlikely(current->audit_context)) {
#ifdef CONFIG_PPC64
if (!test_thread_flag(TIF_32BIT))
audit_syscall_entry(AUDIT_ARCH_PPC64,
regs->gpr[0],
regs->gpr[3], regs->gpr[4],
regs->gpr[5], regs->gpr[6]);
else
#endif
audit_syscall_entry(AUDIT_ARCH_PPC,
regs->gpr[0],
regs->gpr[3] & 0xffffffff,
regs->gpr[4] & 0xffffffff,
regs->gpr[5] & 0xffffffff,
regs->gpr[6] & 0xffffffff);
}
}
void do_syscall_trace_leave(struct pt_regs *regs)
{
if (unlikely(current->audit_context))
audit_syscall_exit((regs->ccr&0x10000000)?AUDITSC_FAILURE:AUDITSC_SUCCESS,
regs->result);
if ((test_thread_flag(TIF_SYSCALL_TRACE)
powerpc: Fix various syscall/signal/swapcontext bugs A careful reading of the recent changes to the system call entry/exit paths revealed several problems, plus some things that could be simplified and improved: * 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit path, so it was only doing anything with it once it saw some other bit being set. In other words, the noerror behaviour would apply to the next system call where we had to reschedule or deliver a signal, which is not necessarily the current system call. * 32-bit wasn't doing the call to ptrace_notify in the syscall exit path when the _TIF_SINGLESTEP bit was set. * _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and _TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set by system calls. I took it out of _TIF_USER_WORK_MASK. * On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers to be restored (unless perhaps a signal was delivered or the syscall was traced or single-stepped). Thus the non-volatile registers weren't restored on exit from a signal handler. We probably got away with it mostly because signal handlers written in C wouldn't alter the non-volatile registers. * On 32-bit I simplified the code and made it more like 64-bit by making the syscall exit path jump to ret_from_except to handle preemption and signal delivery. * 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was set - but I think because of that 32-bit was actually restoring the non-volatile registers on exit from a signal handler. * I changed the order of enabling interrupts and saving the non-volatile registers before calling do_syscall_trace_leave; now we enable interrupts first. Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-03-07 19:24:22 -07:00
|| test_thread_flag(TIF_SINGLESTEP))
&& (current->ptrace & PT_PTRACED))
do_syscall_trace();
}