linux/arch/mips/kernel/ptrace.c
Atsushi Nemoto 62b14c24b1 [MIPS] Store sign-extend register values for PTRACE_GETREGS
A comment on ptrace_getregs() states "Registers are sign extended to
fill the available space." but it is not true.  Fix code to match the
comment.  Also fix casts on each caller to get rid of some warnings.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2007-10-29 19:35:36 +00:00

503 lines
11 KiB
C

/*
* 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) 1992 Ross Biro
* Copyright (C) Linus Torvalds
* Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
* Copyright (C) 1996 David S. Miller
* Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
* Copyright (C) 1999 MIPS Technologies, Inc.
* Copyright (C) 2000 Ulf Carlsson
*
* At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
* binaries.
*/
#include <linux/compiler.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/user.h>
#include <linux/security.h>
#include <linux/audit.h>
#include <linux/seccomp.h>
#include <asm/byteorder.h>
#include <asm/cpu.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/bootinfo.h>
#include <asm/reg.h>
/*
* 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.. */
}
/*
* Read a general register set. We always use the 64-bit format, even
* for 32-bit kernels and for 32-bit processes on a 64-bit kernel.
* Registers are sign extended to fill the available space.
*/
int ptrace_getregs(struct task_struct *child, __s64 __user *data)
{
struct pt_regs *regs;
int i;
if (!access_ok(VERIFY_WRITE, data, 38 * 8))
return -EIO;
regs = task_pt_regs(child);
for (i = 0; i < 32; i++)
__put_user((long)regs->regs[i], data + i);
__put_user((long)regs->lo, data + EF_LO - EF_R0);
__put_user((long)regs->hi, data + EF_HI - EF_R0);
__put_user((long)regs->cp0_epc, data + EF_CP0_EPC - EF_R0);
__put_user((long)regs->cp0_badvaddr, data + EF_CP0_BADVADDR - EF_R0);
__put_user((long)regs->cp0_status, data + EF_CP0_STATUS - EF_R0);
__put_user((long)regs->cp0_cause, data + EF_CP0_CAUSE - EF_R0);
return 0;
}
/*
* Write a general register set. As for PTRACE_GETREGS, we always use
* the 64-bit format. On a 32-bit kernel only the lower order half
* (according to endianness) will be used.
*/
int ptrace_setregs(struct task_struct *child, __s64 __user *data)
{
struct pt_regs *regs;
int i;
if (!access_ok(VERIFY_READ, data, 38 * 8))
return -EIO;
regs = task_pt_regs(child);
for (i = 0; i < 32; i++)
__get_user(regs->regs[i], data + i);
__get_user(regs->lo, data + EF_LO - EF_R0);
__get_user(regs->hi, data + EF_HI - EF_R0);
__get_user(regs->cp0_epc, data + EF_CP0_EPC - EF_R0);
/* badvaddr, status, and cause may not be written. */
return 0;
}
int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
{
int i;
unsigned int tmp;
if (!access_ok(VERIFY_WRITE, data, 33 * 8))
return -EIO;
if (tsk_used_math(child)) {
fpureg_t *fregs = get_fpu_regs(child);
for (i = 0; i < 32; i++)
__put_user(fregs[i], i + (__u64 __user *) data);
} else {
for (i = 0; i < 32; i++)
__put_user((__u64) -1, i + (__u64 __user *) data);
}
__put_user(child->thread.fpu.fcr31, data + 64);
preempt_disable();
if (cpu_has_fpu) {
unsigned int flags;
if (cpu_has_mipsmt) {
unsigned int vpflags = dvpe();
flags = read_c0_status();
__enable_fpu();
__asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
write_c0_status(flags);
evpe(vpflags);
} else {
flags = read_c0_status();
__enable_fpu();
__asm__ __volatile__("cfc1\t%0,$0" : "=r" (tmp));
write_c0_status(flags);
}
} else {
tmp = 0;
}
preempt_enable();
__put_user(tmp, data + 65);
return 0;
}
int ptrace_setfpregs(struct task_struct *child, __u32 __user *data)
{
fpureg_t *fregs;
int i;
if (!access_ok(VERIFY_READ, data, 33 * 8))
return -EIO;
fregs = get_fpu_regs(child);
for (i = 0; i < 32; i++)
__get_user(fregs[i], i + (__u64 __user *) data);
__get_user(child->thread.fpu.fcr31, data + 64);
/* FIR may not be written. */
return 0;
}
long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
int ret;
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: {
struct pt_regs *regs;
unsigned long tmp = 0;
regs = task_pt_regs(child);
ret = 0; /* Default return value. */
switch (addr) {
case 0 ... 31:
tmp = regs->regs[addr];
break;
case FPR_BASE ... FPR_BASE + 31:
if (tsk_used_math(child)) {
fpureg_t *fregs = get_fpu_regs(child);
#ifdef CONFIG_32BIT
/*
* The odd registers are actually the high
* order bits of the values stored in the even
* registers - unless we're using r2k_switch.S.
*/
if (addr & 1)
tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
else
tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
#endif
#ifdef CONFIG_64BIT
tmp = fregs[addr - FPR_BASE];
#endif
} else {
tmp = -1; /* FP not yet used */
}
break;
case PC:
tmp = regs->cp0_epc;
break;
case CAUSE:
tmp = regs->cp0_cause;
break;
case BADVADDR:
tmp = regs->cp0_badvaddr;
break;
case MMHI:
tmp = regs->hi;
break;
case MMLO:
tmp = regs->lo;
break;
#ifdef CONFIG_CPU_HAS_SMARTMIPS
case ACX:
tmp = regs->acx;
break;
#endif
case FPC_CSR:
tmp = child->thread.fpu.fcr31;
break;
case FPC_EIR: { /* implementation / version register */
unsigned int flags;
#ifdef CONFIG_MIPS_MT_SMTC
unsigned int irqflags;
unsigned int mtflags;
#endif /* CONFIG_MIPS_MT_SMTC */
preempt_disable();
if (!cpu_has_fpu) {
preempt_enable();
break;
}
#ifdef CONFIG_MIPS_MT_SMTC
/* Read-modify-write of Status must be atomic */
local_irq_save(irqflags);
mtflags = dmt();
#endif /* CONFIG_MIPS_MT_SMTC */
if (cpu_has_mipsmt) {
unsigned int vpflags = dvpe();
flags = read_c0_status();
__enable_fpu();
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
evpe(vpflags);
} else {
flags = read_c0_status();
__enable_fpu();
__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
write_c0_status(flags);
}
#ifdef CONFIG_MIPS_MT_SMTC
emt(mtflags);
local_irq_restore(irqflags);
#endif /* CONFIG_MIPS_MT_SMTC */
preempt_enable();
break;
}
case DSP_BASE ... DSP_BASE + 5: {
dspreg_t *dregs;
if (!cpu_has_dsp) {
tmp = 0;
ret = -EIO;
goto out;
}
dregs = __get_dsp_regs(child);
tmp = (unsigned long) (dregs[addr - DSP_BASE]);
break;
}
case DSP_CONTROL:
if (!cpu_has_dsp) {
tmp = 0;
ret = -EIO;
goto out;
}
tmp = child->thread.dsp.dspcontrol;
break;
default:
tmp = 0;
ret = -EIO;
goto out;
}
ret = put_user(tmp, (unsigned long __user *) data);
break;
}
/* when 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;
case PTRACE_POKEUSR: {
struct pt_regs *regs;
ret = 0;
regs = task_pt_regs(child);
switch (addr) {
case 0 ... 31:
regs->regs[addr] = data;
break;
case FPR_BASE ... FPR_BASE + 31: {
fpureg_t *fregs = get_fpu_regs(child);
if (!tsk_used_math(child)) {
/* FP not yet used */
memset(&child->thread.fpu, ~0,
sizeof(child->thread.fpu));
child->thread.fpu.fcr31 = 0;
}
#ifdef CONFIG_32BIT
/*
* The odd registers are actually the high order bits
* of the values stored in the even registers - unless
* we're using r2k_switch.S.
*/
if (addr & 1) {
fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
} else {
fregs[addr - FPR_BASE] &= ~0xffffffffLL;
fregs[addr - FPR_BASE] |= data;
}
#endif
#ifdef CONFIG_64BIT
fregs[addr - FPR_BASE] = data;
#endif
break;
}
case PC:
regs->cp0_epc = data;
break;
case MMHI:
regs->hi = data;
break;
case MMLO:
regs->lo = data;
break;
#ifdef CONFIG_CPU_HAS_SMARTMIPS
case ACX:
regs->acx = data;
break;
#endif
case FPC_CSR:
child->thread.fpu.fcr31 = data;
break;
case DSP_BASE ... DSP_BASE + 5: {
dspreg_t *dregs;
if (!cpu_has_dsp) {
ret = -EIO;
break;
}
dregs = __get_dsp_regs(child);
dregs[addr - DSP_BASE] = data;
break;
}
case DSP_CONTROL:
if (!cpu_has_dsp) {
ret = -EIO;
break;
}
child->thread.dsp.dspcontrol = data;
break;
default:
/* The rest are not allowed. */
ret = -EIO;
break;
}
break;
}
case PTRACE_GETREGS:
ret = ptrace_getregs(child, (__s64 __user *) data);
break;
case PTRACE_SETREGS:
ret = ptrace_setregs(child, (__s64 __user *) data);
break;
case PTRACE_GETFPREGS:
ret = ptrace_getfpregs(child, (__u32 __user *) data);
break;
case PTRACE_SETFPREGS:
ret = ptrace_setfpregs(child, (__u32 __user *) data);
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;
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;
wake_up_process(child);
break;
case PTRACE_GET_THREAD_AREA:
ret = put_user(task_thread_info(child)->tp_value,
(unsigned long __user *) data);
break;
default:
ret = ptrace_request(child, request, addr, data);
break;
}
out:
return ret;
}
static inline int audit_arch(void)
{
int arch = EM_MIPS;
#ifdef CONFIG_64BIT
arch |= __AUDIT_ARCH_64BIT;
#endif
#if defined(__LITTLE_ENDIAN)
arch |= __AUDIT_ARCH_LE;
#endif
return arch;
}
/*
* Notification of system call entry/exit
* - triggered by current->work.syscall_trace
*/
asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
{
/* do the secure computing check first */
if (!entryexit)
secure_computing(regs->regs[0]);
if (unlikely(current->audit_context) && entryexit)
audit_syscall_exit(AUDITSC_RESULT(regs->regs[2]),
regs->regs[2]);
if (!(current->ptrace & PT_PTRACED))
goto out;
if (!test_thread_flag(TIF_SYSCALL_TRACE))
goto out;
/* 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;
}
out:
if (unlikely(current->audit_context) && !entryexit)
audit_syscall_entry(audit_arch(), regs->regs[0],
regs->regs[4], regs->regs[5],
regs->regs[6], regs->regs[7]);
}