kernel-ark/arch/powerpc/kernel/ptrace.c
Benjamin Herrenschmidt 6d110da8c3 [POWERPC] powerpc: ptrace can set DABR on both 32 and 64 bits
Allow ptrace to set dabr in the thread structure for both 32 and 64 bits,
though only 64 bits actually uses that field, it's actually defined in both.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14 22:29:57 +10:00

676 lines
16 KiB
C

/*
* 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>
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
/*
* Set of msr bits that gdb can change on behalf of a process.
*/
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
#define MSR_DEBUGCHANGE 0
#else
#define MSR_DEBUGCHANGE (MSR_SE | MSR_BE)
#endif
/*
* Max register writeable via put_reg
*/
#ifdef CONFIG_PPC32
#define PT_MAX_PUT_REG PT_MQ
#else
#define PT_MAX_PUT_REG PT_CCR
#endif
/*
* Get contents of register REGNO in task TASK.
*/
unsigned long ptrace_get_reg(struct task_struct *task, int regno)
{
unsigned long tmp = 0;
if (task->thread.regs == NULL)
return -EIO;
if (regno == PT_MSR) {
tmp = ((unsigned long *)task->thread.regs)[PT_MSR];
return tmp | task->thread.fpexc_mode;
}
if (regno < (sizeof(struct pt_regs) / sizeof(unsigned long)))
return ((unsigned long *)task->thread.regs)[regno];
return -EIO;
}
/*
* Write contents of register REGNO in task TASK.
*/
int ptrace_put_reg(struct task_struct *task, int regno, unsigned long data)
{
if (task->thread.regs == NULL)
return -EIO;
if (regno <= PT_MAX_PUT_REG || regno == PT_TRAP) {
if (regno == PT_MSR)
data = (data & MSR_DEBUGCHANGE)
| (task->thread.regs->msr & ~MSR_DEBUGCHANGE);
/* We prevent mucking around with the reserved area of trap
* which are used internally by the kernel
*/
if (regno == PT_TRAP)
data &= 0xfff0;
((unsigned long *)task->thread.regs)[regno] = data;
return 0;
}
return -EIO;
}
static int get_fpregs(void __user *data, struct task_struct *task,
int has_fpscr)
{
unsigned int count = has_fpscr ? 33 : 32;
if (copy_to_user(data, task->thread.fpr, count * sizeof(double)))
return -EFAULT;
return 0;
}
static int set_fpregs(void __user *data, struct task_struct *task,
int has_fpscr)
{
unsigned int count = has_fpscr ? 33 : 32;
if (copy_from_user(task->thread.fpr, data, count * sizeof(double)))
return -EFAULT;
return 0;
}
#ifdef CONFIG_ALTIVEC
/*
* Get/set all the altivec registers vr0..vr31, vscr, vrsave, in one go.
* The transfer totals 34 quadword. Quadwords 0-31 contain the
* corresponding vector registers. Quadword 32 contains the vscr as the
* last word (offset 12) within that quadword. Quadword 33 contains the
* vrsave as the first word (offset 0) within the quadword.
*
* This definition of the VMX state is compatible with the current PPC32
* ptrace interface. This allows signal handling and ptrace to use the
* same structures. This also simplifies the implementation of a bi-arch
* (combined (32- and 64-bit) gdb.
*/
/*
* Get contents of AltiVec register state in task TASK
*/
static int get_vrregs(unsigned long __user *data, struct task_struct *task)
{
unsigned long regsize;
/* copy AltiVec registers VR[0] .. VR[31] */
regsize = 32 * sizeof(vector128);
if (copy_to_user(data, task->thread.vr, regsize))
return -EFAULT;
data += (regsize / sizeof(unsigned long));
/* copy VSCR */
regsize = 1 * sizeof(vector128);
if (copy_to_user(data, &task->thread.vscr, regsize))
return -EFAULT;
data += (regsize / sizeof(unsigned long));
/* copy VRSAVE */
if (put_user(task->thread.vrsave, (u32 __user *)data))
return -EFAULT;
return 0;
}
/*
* Write contents of AltiVec register state into task TASK.
*/
static int set_vrregs(struct task_struct *task, unsigned long __user *data)
{
unsigned long regsize;
/* copy AltiVec registers VR[0] .. VR[31] */
regsize = 32 * sizeof(vector128);
if (copy_from_user(task->thread.vr, data, regsize))
return -EFAULT;
data += (regsize / sizeof(unsigned long));
/* copy VSCR */
regsize = 1 * sizeof(vector128);
if (copy_from_user(&task->thread.vscr, data, regsize))
return -EFAULT;
data += (regsize / sizeof(unsigned long));
/* copy VRSAVE */
if (get_user(task->thread.vrsave, (u32 __user *)data))
return -EFAULT;
return 0;
}
#endif /* CONFIG_ALTIVEC */
#ifdef CONFIG_SPE
/*
* For get_evrregs/set_evrregs functions 'data' has the following layout:
*
* struct {
* u32 evr[32];
* u64 acc;
* u32 spefscr;
* }
*/
/*
* Get contents of SPE register state in task TASK.
*/
static int get_evrregs(unsigned long *data, struct task_struct *task)
{
int i;
if (!access_ok(VERIFY_WRITE, data, 35 * sizeof(unsigned long)))
return -EFAULT;
/* copy SPEFSCR */
if (__put_user(task->thread.spefscr, &data[34]))
return -EFAULT;
/* copy SPE registers EVR[0] .. EVR[31] */
for (i = 0; i < 32; i++, data++)
if (__put_user(task->thread.evr[i], data))
return -EFAULT;
/* copy ACC */
if (__put_user64(task->thread.acc, (unsigned long long *)data))
return -EFAULT;
return 0;
}
/*
* Write contents of SPE register state into task TASK.
*/
static int set_evrregs(struct task_struct *task, unsigned long *data)
{
int i;
if (!access_ok(VERIFY_READ, data, 35 * sizeof(unsigned long)))
return -EFAULT;
/* copy SPEFSCR */
if (__get_user(task->thread.spefscr, &data[34]))
return -EFAULT;
/* copy SPE registers EVR[0] .. EVR[31] */
for (i = 0; i < 32; i++, data++)
if (__get_user(task->thread.evr[i], data))
return -EFAULT;
/* copy ACC */
if (__get_user64(task->thread.acc, (unsigned long long*)data))
return -EFAULT;
return 0;
}
#endif /* CONFIG_SPE */
static void set_single_step(struct task_struct *task)
{
struct pt_regs *regs = task->thread.regs;
if (regs != NULL) {
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
task->thread.dbcr0 = DBCR0_IDM | DBCR0_IC;
regs->msr |= MSR_DE;
#else
regs->msr |= MSR_SE;
#endif
}
set_tsk_thread_flag(task, TIF_SINGLESTEP);
}
static void clear_single_step(struct task_struct *task)
{
struct pt_regs *regs = task->thread.regs;
if (regs != NULL) {
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
task->thread.dbcr0 = 0;
regs->msr &= ~MSR_DE;
#else
regs->msr &= ~MSR_SE;
#endif
}
clear_tsk_thread_flag(task, TIF_SINGLESTEP);
}
static int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
unsigned long data)
{
/* We only support one DABR and no IABRS at the moment */
if (addr > 0)
return -EINVAL;
/* The bottom 3 bits are flags */
if ((data & ~0x7UL) >= TASK_SIZE)
return -EIO;
/* Ensure translation is on */
if (data && !(data & DABR_TRANSLATION))
return -EIO;
task->thread.dabr = data;
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);
}
/*
* Here are the old "legacy" powerpc specific getregs/setregs ptrace calls,
* we mark them as obsolete now, they will be removed in a future version
*/
static long arch_ptrace_old(struct task_struct *child, long request, long addr,
long data)
{
int ret = -EPERM;
switch(request) {
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;
}
case PPC_PTRACE_GETFPREGS: { /* Get FPRs 0 - 31. */
flush_fp_to_thread(child);
ret = get_fpregs((void __user *)addr, child, 0);
break;
}
case PPC_PTRACE_SETFPREGS: { /* Get FPRs 0 - 31. */
flush_fp_to_thread(child);
ret = set_fpregs((void __user *)addr, child, 0);
break;
}
}
return ret;
}
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;
CHECK_FULL_REGS(child->thread.regs);
if (index < PT_FPR0) {
tmp = ptrace_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;
CHECK_FULL_REGS(child->thread.regs);
if (index < PT_FPR0) {
ret = ptrace_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;
}
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;
case PTRACE_DETACH:
ret = ptrace_detach(child, data);
break;
#ifdef CONFIG_PPC64
case PTRACE_GETREGS64:
#endif
case PTRACE_GETREGS: { /* Get all pt_regs from the child. */
int ui;
if (!access_ok(VERIFY_WRITE, (void __user *)data,
sizeof(struct pt_regs))) {
ret = -EIO;
break;
}
ret = 0;
for (ui = 0; ui < PT_REGS_COUNT; ui ++) {
ret |= __put_user(ptrace_get_reg(child, ui),
(unsigned long __user *) data);
data += sizeof(long);
}
break;
}
#ifdef CONFIG_PPC64
case PTRACE_SETREGS64:
#endif
case PTRACE_SETREGS: { /* Set all gp regs in the child. */
unsigned long tmp;
int ui;
if (!access_ok(VERIFY_READ, (void __user *)data,
sizeof(struct pt_regs))) {
ret = -EIO;
break;
}
ret = 0;
for (ui = 0; ui < PT_REGS_COUNT; ui ++) {
ret = __get_user(tmp, (unsigned long __user *) data);
if (ret)
break;
ptrace_put_reg(child, ui, tmp);
data += sizeof(long);
}
break;
}
case PTRACE_GETFPREGS: { /* Get the child FPU state (FPR0...31 + FPSCR) */
flush_fp_to_thread(child);
ret = get_fpregs((void __user *)data, child, 1);
break;
}
case PTRACE_SETFPREGS: { /* Set the child FPU state (FPR0...31 + FPSCR) */
flush_fp_to_thread(child);
ret = set_fpregs((void __user *)data, child, 1);
break;
}
#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
/* Old reverse args ptrace callss */
case PPC_PTRACE_GETREGS: /* Get GPRs 0 - 31. */
case PPC_PTRACE_SETREGS: /* Set GPRs 0 - 31. */
case PPC_PTRACE_GETFPREGS: /* Get FPRs 0 - 31. */
case PPC_PTRACE_SETFPREGS: /* Get FPRs 0 - 31. */
ret = arch_ptrace_old(child, request, addr, data);
break;
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)
|| test_thread_flag(TIF_SINGLESTEP))
&& (current->ptrace & PT_PTRACED))
do_syscall_trace();
}