linux/arch/powerpc/kernel/ptrace32.c
Alexey Kardashevskiy ee4a391661 powerpc: fixing ptrace_get_reg to return an error
Currently ptrace_get_reg returns error as a value
what make impossible to tell whether it is a correct value or error code.

The patch adds a parameter which points to the real return data and
returns an error code.

As get_user_msr() never fails and it is used in multiple places so it has not
been changed by this patch.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
2013-04-18 13:03:57 +10:00

321 lines
8.5 KiB
C

/*
* ptrace for 32-bit processes running on a 64-bit kernel.
*
* 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 COPYING 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/user.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/compat.h>
#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/switch_to.h>
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
/* Macros to workout the correct index for the FPR in the thread struct */
#define FPRNUMBER(i) (((i) - PT_FPR0) >> 1)
#define FPRHALF(i) (((i) - PT_FPR0) & 1)
#define FPRINDEX(i) TS_FPRWIDTH * FPRNUMBER(i) * 2 + FPRHALF(i)
#define FPRINDEX_3264(i) (TS_FPRWIDTH * ((i) - PT_FPR0))
long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
compat_ulong_t caddr, compat_ulong_t cdata)
{
unsigned long addr = caddr;
unsigned long data = cdata;
int ret;
switch (request) {
/*
* Read 4 bytes of the other process' storage
* data is a pointer specifying where the user wants the
* 4 bytes copied into
* addr is a pointer in the user's storage that contains an 8 byte
* address in the other process of the 4 bytes that is to be read
* (this is run in a 32-bit process looking at a 64-bit process)
* when I and D space are separate, these will need to be fixed.
*/
case PPC_PTRACE_PEEKTEXT_3264:
case PPC_PTRACE_PEEKDATA_3264: {
u32 tmp;
int copied;
u32 __user * addrOthers;
ret = -EIO;
/* Get the addr in the other process that we want to read */
if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
break;
copied = access_process_vm(child, (u64)addrOthers, &tmp,
sizeof(tmp), 0);
if (copied != sizeof(tmp))
break;
ret = put_user(tmp, (u32 __user *)data);
break;
}
/* Read a register (specified by ADDR) out of the "user area" */
case PTRACE_PEEKUSR: {
int index;
unsigned long tmp;
ret = -EIO;
/* convert to index and check */
index = (unsigned long) addr >> 2;
if ((addr & 3) || (index > PT_FPSCR32))
break;
CHECK_FULL_REGS(child->thread.regs);
if (index < PT_FPR0) {
ret = ptrace_get_reg(child, index, &tmp);
if (ret)
break;
} else {
flush_fp_to_thread(child);
/*
* the user space code considers the floating point
* to be an array of unsigned int (32 bits) - the
* index passed in is based on this assumption.
*/
tmp = ((unsigned int *)child->thread.fpr)
[FPRINDEX(index)];
}
ret = put_user((unsigned int)tmp, (u32 __user *)data);
break;
}
/*
* Read 4 bytes out of the other process' pt_regs area
* data is a pointer specifying where the user wants the
* 4 bytes copied into
* addr is the offset into the other process' pt_regs structure
* that is to be read
* (this is run in a 32-bit process looking at a 64-bit process)
*/
case PPC_PTRACE_PEEKUSR_3264: {
u32 index;
u32 reg32bits;
u64 tmp;
u32 numReg;
u32 part;
ret = -EIO;
/* Determine which register the user wants */
index = (u64)addr >> 2;
numReg = index / 2;
/* Determine which part of the register the user wants */
if (index % 2)
part = 1; /* want the 2nd half of the register (right-most). */
else
part = 0; /* want the 1st half of the register (left-most). */
/* Validate the input - check to see if address is on the wrong boundary
* or beyond the end of the user area
*/
if ((addr & 3) || numReg > PT_FPSCR)
break;
CHECK_FULL_REGS(child->thread.regs);
if (numReg >= PT_FPR0) {
flush_fp_to_thread(child);
/* get 64 bit FPR */
tmp = ((u64 *)child->thread.fpr)
[FPRINDEX_3264(numReg)];
} else { /* register within PT_REGS struct */
unsigned long tmp2;
ret = ptrace_get_reg(child, numReg, &tmp2);
if (ret)
break;
tmp = tmp2;
}
reg32bits = ((u32*)&tmp)[part];
ret = put_user(reg32bits, (u32 __user *)data);
break;
}
/*
* Write 4 bytes into the other process' storage
* data is the 4 bytes that the user wants written
* addr is a pointer in the user's storage that contains an
* 8 byte address in the other process where the 4 bytes
* that is to be written
* (this is run in a 32-bit process looking at a 64-bit process)
* when I and D space are separate, these will need to be fixed.
*/
case PPC_PTRACE_POKETEXT_3264:
case PPC_PTRACE_POKEDATA_3264: {
u32 tmp = data;
u32 __user * addrOthers;
/* Get the addr in the other process that we want to write into */
ret = -EIO;
if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
break;
ret = 0;
if (access_process_vm(child, (u64)addrOthers, &tmp,
sizeof(tmp), 1) == sizeof(tmp))
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 */
index = (unsigned long) addr >> 2;
if ((addr & 3) || (index > PT_FPSCR32))
break;
CHECK_FULL_REGS(child->thread.regs);
if (index < PT_FPR0) {
ret = ptrace_put_reg(child, index, data);
} else {
flush_fp_to_thread(child);
/*
* the user space code considers the floating point
* to be an array of unsigned int (32 bits) - the
* index passed in is based on this assumption.
*/
((unsigned int *)child->thread.fpr)
[FPRINDEX(index)] = data;
ret = 0;
}
break;
}
/*
* Write 4 bytes into the other process' pt_regs area
* data is the 4 bytes that the user wants written
* addr is the offset into the other process' pt_regs structure
* that is to be written into
* (this is run in a 32-bit process looking at a 64-bit process)
*/
case PPC_PTRACE_POKEUSR_3264: {
u32 index;
u32 numReg;
ret = -EIO;
/* Determine which register the user wants */
index = (u64)addr >> 2;
numReg = index / 2;
/*
* Validate the input - check to see if address is on the
* wrong boundary or beyond the end of the user area
*/
if ((addr & 3) || (numReg > PT_FPSCR))
break;
CHECK_FULL_REGS(child->thread.regs);
if (numReg < PT_FPR0) {
unsigned long freg;
ret = ptrace_get_reg(child, numReg, &freg);
if (ret)
break;
if (index % 2)
freg = (freg & ~0xfffffffful) | (data & 0xfffffffful);
else
freg = (freg & 0xfffffffful) | (data << 32);
ret = ptrace_put_reg(child, numReg, freg);
} else {
u64 *tmp;
flush_fp_to_thread(child);
/* get 64 bit FPR ... */
tmp = &(((u64 *)child->thread.fpr)
[FPRINDEX_3264(numReg)]);
/* ... write the 32 bit part we want */
((u32 *)tmp)[index % 2] = data;
ret = 0;
}
break;
}
case PTRACE_GET_DEBUGREG: {
#ifndef CONFIG_PPC_ADV_DEBUG_REGS
unsigned long dabr_fake;
#endif
ret = -EINVAL;
/* We only support one DABR and no IABRS at the moment */
if (addr > 0)
break;
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
ret = put_user(child->thread.dac1, (u32 __user *)data);
#else
dabr_fake = (
(child->thread.hw_brk.address & (~HW_BRK_TYPE_DABR)) |
(child->thread.hw_brk.type & HW_BRK_TYPE_DABR));
ret = put_user(dabr_fake, (u32 __user *)data);
#endif
break;
}
case PTRACE_GETREGS: /* Get all pt_regs from the child. */
return copy_regset_to_user(
child, task_user_regset_view(current), 0,
0, PT_REGS_COUNT * sizeof(compat_long_t),
compat_ptr(data));
case PTRACE_SETREGS: /* Set all gp regs in the child. */
return copy_regset_from_user(
child, task_user_regset_view(current), 0,
0, PT_REGS_COUNT * sizeof(compat_long_t),
compat_ptr(data));
case PTRACE_GETFPREGS:
case PTRACE_SETFPREGS:
case PTRACE_GETVRREGS:
case PTRACE_SETVRREGS:
case PTRACE_GETVSRREGS:
case PTRACE_SETVSRREGS:
case PTRACE_GETREGS64:
case PTRACE_SETREGS64:
case PTRACE_KILL:
case PTRACE_SINGLESTEP:
case PTRACE_DETACH:
case PTRACE_SET_DEBUGREG:
case PTRACE_SYSCALL:
case PTRACE_CONT:
case PPC_PTRACE_GETHWDBGINFO:
case PPC_PTRACE_SETHWDEBUG:
case PPC_PTRACE_DELHWDEBUG:
ret = arch_ptrace(child, request, addr, data);
break;
default:
ret = compat_ptrace_request(child, request, addr, data);
break;
}
return ret;
}