1
linux/arch/powerpc/kernel/ptrace.c
Roland McGrath 44dd3f50d3 [POWERPC] Use user_regset accessors for GPRs
This implements user_regset-style accessors for the powerpc general
registers.  In the future these functions will be the only place that
needs to understand the user_regset layout (core dump format) and how
it maps to the internal representation of user thread state.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-02-07 20:38:57 +11:00

815 lines
20 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/regset.h>
#include <linux/elf.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
static unsigned long get_user_msr(struct task_struct *task)
{
return task->thread.regs->msr | task->thread.fpexc_mode;
}
static int set_user_msr(struct task_struct *task, unsigned long msr)
{
task->thread.regs->msr &= ~MSR_DEBUGCHANGE;
task->thread.regs->msr |= msr & MSR_DEBUGCHANGE;
return 0;
}
/*
* We prevent mucking around with the reserved area of trap
* which are used internally by the kernel.
*/
static int set_user_trap(struct task_struct *task, unsigned long trap)
{
task->thread.regs->trap = trap & 0xfff0;
return 0;
}
/*
* Get contents of register REGNO in task TASK.
*/
unsigned long ptrace_get_reg(struct task_struct *task, int regno)
{
if (task->thread.regs == NULL)
return -EIO;
if (regno == PT_MSR)
return get_user_msr(task);
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_MSR)
return set_user_msr(task, data);
if (regno == PT_TRAP)
return set_user_trap(task, data);
if (regno <= PT_MAX_PUT_REG) {
((unsigned long *)task->thread.regs)[regno] = data;
return 0;
}
return -EIO;
}
static int gpr_get(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
int ret;
if (target->thread.regs == NULL)
return -EIO;
CHECK_FULL_REGS(target->thread.regs);
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
target->thread.regs,
0, offsetof(struct pt_regs, msr));
if (!ret) {
unsigned long msr = get_user_msr(target);
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &msr,
offsetof(struct pt_regs, msr),
offsetof(struct pt_regs, msr) +
sizeof(msr));
}
BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
offsetof(struct pt_regs, msr) + sizeof(long));
if (!ret)
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.regs->orig_gpr3,
offsetof(struct pt_regs, orig_gpr3),
sizeof(struct pt_regs));
if (!ret)
ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
sizeof(struct pt_regs), -1);
return ret;
}
static int gpr_set(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
unsigned long reg;
int ret;
if (target->thread.regs == NULL)
return -EIO;
CHECK_FULL_REGS(target->thread.regs);
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
target->thread.regs,
0, PT_MSR * sizeof(reg));
if (!ret && count > 0) {
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &reg,
PT_MSR * sizeof(reg),
(PT_MSR + 1) * sizeof(reg));
if (!ret)
ret = set_user_msr(target, reg);
}
BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
offsetof(struct pt_regs, msr) + sizeof(long));
if (!ret)
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&target->thread.regs->orig_gpr3,
PT_ORIG_R3 * sizeof(reg),
(PT_MAX_PUT_REG + 1) * sizeof(reg));
if (PT_MAX_PUT_REG + 1 < PT_TRAP && !ret)
ret = user_regset_copyin_ignore(
&pos, &count, &kbuf, &ubuf,
(PT_MAX_PUT_REG + 1) * sizeof(reg),
PT_TRAP * sizeof(reg));
if (!ret && count > 0) {
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &reg,
PT_TRAP * sizeof(reg),
(PT_TRAP + 1) * sizeof(reg));
if (!ret)
ret = set_user_trap(target, reg);
}
if (!ret)
ret = user_regset_copyin_ignore(
&pos, &count, &kbuf, &ubuf,
(PT_TRAP + 1) * sizeof(reg), -1);
return ret;
}
static int fpr_get(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
flush_fp_to_thread(target);
BUILD_BUG_ON(offsetof(struct thread_struct, fpscr) !=
offsetof(struct thread_struct, fpr[32]));
return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.fpr, 0, -1);
}
static int fpr_set(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
flush_fp_to_thread(target);
BUILD_BUG_ON(offsetof(struct thread_struct, fpscr) !=
offsetof(struct thread_struct, fpr[32]));
return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&target->thread.fpr, 0, -1);
}
static int get_fpregs(void __user *data, struct task_struct *task,
int has_fpscr)
{
unsigned int count = has_fpscr ? 33 : 32;
if (!access_ok(VERIFY_WRITE, data, count * sizeof(double)))
return -EFAULT;
return fpr_get(task, NULL, 0, count * sizeof(double), NULL, data);
}
static int set_fpregs(void __user *data, struct task_struct *task,
int has_fpscr)
{
unsigned int count = has_fpscr ? 33 : 32;
if (!access_ok(VERIFY_READ, data, count * sizeof(double)))
return -EFAULT;
return fpr_set(task, NULL, 0, count * sizeof(double), NULL, data);
}
#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.
*/
static int vr_active(struct task_struct *target,
const struct user_regset *regset)
{
flush_altivec_to_thread(target);
return target->thread.used_vr ? regset->n : 0;
}
static int vr_get(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
int ret;
flush_altivec_to_thread(target);
BUILD_BUG_ON(offsetof(struct thread_struct, vscr) !=
offsetof(struct thread_struct, vr[32]));
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.vr, 0,
33 * sizeof(vector128));
if (!ret) {
/*
* Copy out only the low-order word of vrsave.
*/
union {
elf_vrreg_t reg;
u32 word;
} vrsave;
memset(&vrsave, 0, sizeof(vrsave));
vrsave.word = target->thread.vrsave;
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &vrsave,
33 * sizeof(vector128), -1);
}
return ret;
}
static int vr_set(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
int ret;
flush_altivec_to_thread(target);
BUILD_BUG_ON(offsetof(struct thread_struct, vscr) !=
offsetof(struct thread_struct, vr[32]));
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&target->thread.vr, 0, 33 * sizeof(vector128));
if (!ret && count > 0) {
/*
* We use only the first word of vrsave.
*/
union {
elf_vrreg_t reg;
u32 word;
} vrsave;
memset(&vrsave, 0, sizeof(vrsave));
vrsave.word = target->thread.vrsave;
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &vrsave,
33 * sizeof(vector128), -1);
if (!ret)
target->thread.vrsave = vrsave.word;
}
return ret;
}
/*
* Get contents of AltiVec register state in task TASK
*/
static int get_vrregs(unsigned long __user *data, struct task_struct *task)
{
if (!access_ok(VERIFY_WRITE, data,
33 * sizeof(vector128) + sizeof(u32)))
return -EFAULT;
return vr_get(task, NULL, 0, 33 * sizeof(vector128) + sizeof(u32),
NULL, data);
}
/*
* Write contents of AltiVec register state into task TASK.
*/
static int set_vrregs(struct task_struct *task, unsigned long __user *data)
{
if (!access_ok(VERIFY_READ, data, 33 * sizeof(vector128) + sizeof(u32)))
return -EFAULT;
return vr_set(task, NULL, 0, 33 * sizeof(vector128) + sizeof(u32),
NULL, data);
}
#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;
* }
*/
static int evr_active(struct task_struct *target,
const struct user_regset *regset)
{
flush_spe_to_thread(target);
return target->thread.used_spe ? regset->n : 0;
}
static int evr_get(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
int ret;
flush_spe_to_thread(target);
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.evr,
0, sizeof(target->thread.evr));
BUILD_BUG_ON(offsetof(struct thread_struct, acc) + sizeof(u64) !=
offsetof(struct thread_struct, spefscr));
if (!ret)
ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.acc,
sizeof(target->thread.evr), -1);
return ret;
}
static int evr_set(struct task_struct *target, const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
int ret;
flush_spe_to_thread(target);
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&target->thread.evr,
0, sizeof(target->thread.evr));
BUILD_BUG_ON(offsetof(struct thread_struct, acc) + sizeof(u64) !=
offsetof(struct thread_struct, spefscr));
if (!ret)
ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&target->thread.acc,
sizeof(target->thread.evr), -1);
return ret;
}
/*
* Get contents of SPE register state in task TASK.
*/
static int get_evrregs(unsigned long __user *data, struct task_struct *task)
{
if (!access_ok(VERIFY_WRITE, data, 35 * sizeof(u32)))
return -EFAULT;
return evr_get(task, NULL, 0, 35 * sizeof(u32), NULL, data);
}
/*
* Write contents of SPE register state into task TASK.
*/
static int set_evrregs(struct task_struct *task, unsigned long *data)
{
if (!access_ok(VERIFY_READ, data, 35 * sizeof(u32)))
return -EFAULT;
return evr_set(task, NULL, 0, 35 * sizeof(u32), NULL, data);
}
#endif /* CONFIG_SPE */
void user_enable_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);
}
void user_disable_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. */
user_disable_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;
CHECK_FULL_REGS(child->thread.regs);
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;
CHECK_FULL_REGS(child->thread.regs);
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:
ret = generic_ptrace_peekdata(child, addr, 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 = generic_ptrace_pokedata(child, addr, data);
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_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;
#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;
}
CHECK_FULL_REGS(child->thread.regs);
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;
}
CHECK_FULL_REGS(child->thread.regs);
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. */
flush_spe_to_thread(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 */
flush_spe_to_thread(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();
}