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linux/arch/s390/kernel/ptrace.c
Martin Schwidefsky 86f2552bbd [S390] add breaking event address for user space 
Copy the last breaking event address from the lowcore to a new
field in the thread_struct on each system entry. Add a new
ptrace request PTRACE_GET_LAST_BREAK and a new utrace regset
REGSET_LAST_BREAK to query the last breaking event.

This is useful for debugging wild branches in user space code.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-05-17 10:00:15 +02:00

1120 lines
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/*
* arch/s390/kernel/ptrace.c
*
* S390 version
* Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
* Martin Schwidefsky (schwidefsky@de.ibm.com)
*
* Based on 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@cs.nmt.edu)
*
*
* 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/audit.h>
#include <linux/signal.h>
#include <linux/elf.h>
#include <linux/regset.h>
#include <linux/tracehook.h>
#include <linux/seccomp.h>
#include <trace/syscall.h>
#include <asm/compat.h>
#include <asm/segment.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
#include "entry.h"
#ifdef CONFIG_COMPAT
#include "compat_ptrace.h"
#endif
#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>
enum s390_regset {
REGSET_GENERAL,
REGSET_FP,
REGSET_LAST_BREAK,
REGSET_GENERAL_EXTENDED,
};
static void
FixPerRegisters(struct task_struct *task)
{
struct pt_regs *regs;
per_struct *per_info;
per_cr_words cr_words;
regs = task_pt_regs(task);
per_info = (per_struct *) &task->thread.per_info;
per_info->control_regs.bits.em_instruction_fetch =
per_info->single_step | per_info->instruction_fetch;
if (per_info->single_step) {
per_info->control_regs.bits.starting_addr = 0;
#ifdef CONFIG_COMPAT
if (is_compat_task())
per_info->control_regs.bits.ending_addr = 0x7fffffffUL;
else
#endif
per_info->control_regs.bits.ending_addr = PSW_ADDR_INSN;
} else {
per_info->control_regs.bits.starting_addr =
per_info->starting_addr;
per_info->control_regs.bits.ending_addr =
per_info->ending_addr;
}
/*
* if any of the control reg tracing bits are on
* we switch on per in the psw
*/
if (per_info->control_regs.words.cr[0] & PER_EM_MASK)
regs->psw.mask |= PSW_MASK_PER;
else
regs->psw.mask &= ~PSW_MASK_PER;
if (per_info->control_regs.bits.em_storage_alteration)
per_info->control_regs.bits.storage_alt_space_ctl = 1;
else
per_info->control_regs.bits.storage_alt_space_ctl = 0;
if (task == current) {
__ctl_store(cr_words, 9, 11);
if (memcmp(&cr_words, &per_info->control_regs.words,
sizeof(cr_words)) != 0)
__ctl_load(per_info->control_regs.words, 9, 11);
}
}
void user_enable_single_step(struct task_struct *task)
{
task->thread.per_info.single_step = 1;
FixPerRegisters(task);
}
void user_disable_single_step(struct task_struct *task)
{
task->thread.per_info.single_step = 0;
FixPerRegisters(task);
}
/*
* 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);
}
#ifndef CONFIG_64BIT
# define __ADDR_MASK 3
#else
# define __ADDR_MASK 7
#endif
/*
* Read the word at offset addr from the user area of a process. The
* trouble here is that the information is littered over different
* locations. The process registers are found on the kernel stack,
* the floating point stuff and the trace settings are stored in
* the task structure. In addition the different structures in
* struct user contain pad bytes that should be read as zeroes.
* Lovely...
*/
static unsigned long __peek_user(struct task_struct *child, addr_t addr)
{
struct user *dummy = NULL;
addr_t offset, tmp;
if (addr < (addr_t) &dummy->regs.acrs) {
/*
* psw and gprs are stored on the stack
*/
tmp = *(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr);
if (addr == (addr_t) &dummy->regs.psw.mask)
/* Remove per bit from user psw. */
tmp &= ~PSW_MASK_PER;
} else if (addr < (addr_t) &dummy->regs.orig_gpr2) {
/*
* access registers are stored in the thread structure
*/
offset = addr - (addr_t) &dummy->regs.acrs;
#ifdef CONFIG_64BIT
/*
* Very special case: old & broken 64 bit gdb reading
* from acrs[15]. Result is a 64 bit value. Read the
* 32 bit acrs[15] value and shift it by 32. Sick...
*/
if (addr == (addr_t) &dummy->regs.acrs[15])
tmp = ((unsigned long) child->thread.acrs[15]) << 32;
else
#endif
tmp = *(addr_t *)((addr_t) &child->thread.acrs + offset);
} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
/*
* orig_gpr2 is stored on the kernel stack
*/
tmp = (addr_t) task_pt_regs(child)->orig_gpr2;
} else if (addr < (addr_t) &dummy->regs.fp_regs) {
/*
* prevent reads of padding hole between
* orig_gpr2 and fp_regs on s390.
*/
tmp = 0;
} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
/*
* floating point regs. are stored in the thread structure
*/
offset = addr - (addr_t) &dummy->regs.fp_regs;
tmp = *(addr_t *)((addr_t) &child->thread.fp_regs + offset);
if (addr == (addr_t) &dummy->regs.fp_regs.fpc)
tmp &= (unsigned long) FPC_VALID_MASK
<< (BITS_PER_LONG - 32);
} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
/*
* per_info is found in the thread structure
*/
offset = addr - (addr_t) &dummy->regs.per_info;
tmp = *(addr_t *)((addr_t) &child->thread.per_info + offset);
} else
tmp = 0;
return tmp;
}
static int
peek_user(struct task_struct *child, addr_t addr, addr_t data)
{
addr_t tmp, mask;
/*
* Stupid gdb peeks/pokes the access registers in 64 bit with
* an alignment of 4. Programmers from hell...
*/
mask = __ADDR_MASK;
#ifdef CONFIG_64BIT
if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
mask = 3;
#endif
if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
return -EIO;
tmp = __peek_user(child, addr);
return put_user(tmp, (addr_t __user *) data);
}
/*
* Write a word to the user area of a process at location addr. This
* operation does have an additional problem compared to peek_user.
* Stores to the program status word and on the floating point
* control register needs to get checked for validity.
*/
static int __poke_user(struct task_struct *child, addr_t addr, addr_t data)
{
struct user *dummy = NULL;
addr_t offset;
if (addr < (addr_t) &dummy->regs.acrs) {
/*
* psw and gprs are stored on the stack
*/
if (addr == (addr_t) &dummy->regs.psw.mask &&
#ifdef CONFIG_COMPAT
data != PSW_MASK_MERGE(psw_user32_bits, data) &&
#endif
data != PSW_MASK_MERGE(psw_user_bits, data))
/* Invalid psw mask. */
return -EINVAL;
#ifndef CONFIG_64BIT
if (addr == (addr_t) &dummy->regs.psw.addr)
/* I'd like to reject addresses without the
high order bit but older gdb's rely on it */
data |= PSW_ADDR_AMODE;
#endif
*(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;
} else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
/*
* access registers are stored in the thread structure
*/
offset = addr - (addr_t) &dummy->regs.acrs;
#ifdef CONFIG_64BIT
/*
* Very special case: old & broken 64 bit gdb writing
* to acrs[15] with a 64 bit value. Ignore the lower
* half of the value and write the upper 32 bit to
* acrs[15]. Sick...
*/
if (addr == (addr_t) &dummy->regs.acrs[15])
child->thread.acrs[15] = (unsigned int) (data >> 32);
else
#endif
*(addr_t *)((addr_t) &child->thread.acrs + offset) = data;
} else if (addr == (addr_t) &dummy->regs.orig_gpr2) {
/*
* orig_gpr2 is stored on the kernel stack
*/
task_pt_regs(child)->orig_gpr2 = data;
} else if (addr < (addr_t) &dummy->regs.fp_regs) {
/*
* prevent writes of padding hole between
* orig_gpr2 and fp_regs on s390.
*/
return 0;
} else if (addr < (addr_t) (&dummy->regs.fp_regs + 1)) {
/*
* floating point regs. are stored in the thread structure
*/
if (addr == (addr_t) &dummy->regs.fp_regs.fpc &&
(data & ~((unsigned long) FPC_VALID_MASK
<< (BITS_PER_LONG - 32))) != 0)
return -EINVAL;
offset = addr - (addr_t) &dummy->regs.fp_regs;
*(addr_t *)((addr_t) &child->thread.fp_regs + offset) = data;
} else if (addr < (addr_t) (&dummy->regs.per_info + 1)) {
/*
* per_info is found in the thread structure
*/
offset = addr - (addr_t) &dummy->regs.per_info;
*(addr_t *)((addr_t) &child->thread.per_info + offset) = data;
}
FixPerRegisters(child);
return 0;
}
static int
poke_user(struct task_struct *child, addr_t addr, addr_t data)
{
addr_t mask;
/*
* Stupid gdb peeks/pokes the access registers in 64 bit with
* an alignment of 4. Programmers from hell indeed...
*/
mask = __ADDR_MASK;
#ifdef CONFIG_64BIT
if (addr >= (addr_t) &((struct user *) NULL)->regs.acrs &&
addr < (addr_t) &((struct user *) NULL)->regs.orig_gpr2)
mask = 3;
#endif
if ((addr & mask) || addr > sizeof(struct user) - __ADDR_MASK)
return -EIO;
return __poke_user(child, addr, data);
}
long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
ptrace_area parea;
int copied, ret;
switch (request) {
case PTRACE_PEEKUSR:
/* read the word at location addr in the USER area. */
return peek_user(child, addr, data);
case PTRACE_POKEUSR:
/* write the word at location addr in the USER area */
return poke_user(child, addr, data);
case PTRACE_PEEKUSR_AREA:
case PTRACE_POKEUSR_AREA:
if (copy_from_user(&parea, (void __force __user *) addr,
sizeof(parea)))
return -EFAULT;
addr = parea.kernel_addr;
data = parea.process_addr;
copied = 0;
while (copied < parea.len) {
if (request == PTRACE_PEEKUSR_AREA)
ret = peek_user(child, addr, data);
else {
addr_t utmp;
if (get_user(utmp,
(addr_t __force __user *) data))
return -EFAULT;
ret = poke_user(child, addr, utmp);
}
if (ret)
return ret;
addr += sizeof(unsigned long);
data += sizeof(unsigned long);
copied += sizeof(unsigned long);
}
return 0;
case PTRACE_GET_LAST_BREAK:
put_user(task_thread_info(child)->last_break,
(unsigned long __user *) data);
return 0;
default:
/* Removing high order bit from addr (only for 31 bit). */
addr &= PSW_ADDR_INSN;
return ptrace_request(child, request, addr, data);
}
}
#ifdef CONFIG_COMPAT
/*
* Now the fun part starts... a 31 bit program running in the
* 31 bit emulation tracing another program. PTRACE_PEEKTEXT,
* PTRACE_PEEKDATA, PTRACE_POKETEXT and PTRACE_POKEDATA are easy
* to handle, the difference to the 64 bit versions of the requests
* is that the access is done in multiples of 4 byte instead of
* 8 bytes (sizeof(unsigned long) on 31/64 bit).
* The ugly part are PTRACE_PEEKUSR, PTRACE_PEEKUSR_AREA,
* PTRACE_POKEUSR and PTRACE_POKEUSR_AREA. If the traced program
* is a 31 bit program too, the content of struct user can be
* emulated. A 31 bit program peeking into the struct user of
* a 64 bit program is a no-no.
*/
/*
* Same as peek_user but for a 31 bit program.
*/
static u32 __peek_user_compat(struct task_struct *child, addr_t addr)
{
struct user32 *dummy32 = NULL;
per_struct32 *dummy_per32 = NULL;
addr_t offset;
__u32 tmp;
if (addr < (addr_t) &dummy32->regs.acrs) {
/*
* psw and gprs are stored on the stack
*/
if (addr == (addr_t) &dummy32->regs.psw.mask) {
/* Fake a 31 bit psw mask. */
tmp = (__u32)(task_pt_regs(child)->psw.mask >> 32);
tmp = PSW32_MASK_MERGE(psw32_user_bits, tmp);
} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
/* Fake a 31 bit psw address. */
tmp = (__u32) task_pt_regs(child)->psw.addr |
PSW32_ADDR_AMODE31;
} else {
/* gpr 0-15 */
tmp = *(__u32 *)((addr_t) &task_pt_regs(child)->psw +
addr*2 + 4);
}
} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
/*
* access registers are stored in the thread structure
*/
offset = addr - (addr_t) &dummy32->regs.acrs;
tmp = *(__u32*)((addr_t) &child->thread.acrs + offset);
} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
/*
* orig_gpr2 is stored on the kernel stack
*/
tmp = *(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4);
} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
/*
* prevent reads of padding hole between
* orig_gpr2 and fp_regs on s390.
*/
tmp = 0;
} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
/*
* floating point regs. are stored in the thread structure
*/
offset = addr - (addr_t) &dummy32->regs.fp_regs;
tmp = *(__u32 *)((addr_t) &child->thread.fp_regs + offset);
} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
/*
* per_info is found in the thread structure
*/
offset = addr - (addr_t) &dummy32->regs.per_info;
/* This is magic. See per_struct and per_struct32. */
if ((offset >= (addr_t) &dummy_per32->control_regs &&
offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
(offset >= (addr_t) &dummy_per32->starting_addr &&
offset <= (addr_t) &dummy_per32->ending_addr) ||
offset == (addr_t) &dummy_per32->lowcore.words.address)
offset = offset*2 + 4;
else
offset = offset*2;
tmp = *(__u32 *)((addr_t) &child->thread.per_info + offset);
} else
tmp = 0;
return tmp;
}
static int peek_user_compat(struct task_struct *child,
addr_t addr, addr_t data)
{
__u32 tmp;
if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user) - 3)
return -EIO;
tmp = __peek_user_compat(child, addr);
return put_user(tmp, (__u32 __user *) data);
}
/*
* Same as poke_user but for a 31 bit program.
*/
static int __poke_user_compat(struct task_struct *child,
addr_t addr, addr_t data)
{
struct user32 *dummy32 = NULL;
per_struct32 *dummy_per32 = NULL;
__u32 tmp = (__u32) data;
addr_t offset;
if (addr < (addr_t) &dummy32->regs.acrs) {
/*
* psw, gprs, acrs and orig_gpr2 are stored on the stack
*/
if (addr == (addr_t) &dummy32->regs.psw.mask) {
/* Build a 64 bit psw mask from 31 bit mask. */
if (tmp != PSW32_MASK_MERGE(psw32_user_bits, tmp))
/* Invalid psw mask. */
return -EINVAL;
task_pt_regs(child)->psw.mask =
PSW_MASK_MERGE(psw_user32_bits, (__u64) tmp << 32);
} else if (addr == (addr_t) &dummy32->regs.psw.addr) {
/* Build a 64 bit psw address from 31 bit address. */
task_pt_regs(child)->psw.addr =
(__u64) tmp & PSW32_ADDR_INSN;
} else {
/* gpr 0-15 */
*(__u32*)((addr_t) &task_pt_regs(child)->psw
+ addr*2 + 4) = tmp;
}
} else if (addr < (addr_t) (&dummy32->regs.orig_gpr2)) {
/*
* access registers are stored in the thread structure
*/
offset = addr - (addr_t) &dummy32->regs.acrs;
*(__u32*)((addr_t) &child->thread.acrs + offset) = tmp;
} else if (addr == (addr_t) (&dummy32->regs.orig_gpr2)) {
/*
* orig_gpr2 is stored on the kernel stack
*/
*(__u32*)((addr_t) &task_pt_regs(child)->orig_gpr2 + 4) = tmp;
} else if (addr < (addr_t) &dummy32->regs.fp_regs) {
/*
* prevent writess of padding hole between
* orig_gpr2 and fp_regs on s390.
*/
return 0;
} else if (addr < (addr_t) (&dummy32->regs.fp_regs + 1)) {
/*
* floating point regs. are stored in the thread structure
*/
if (addr == (addr_t) &dummy32->regs.fp_regs.fpc &&
(tmp & ~FPC_VALID_MASK) != 0)
/* Invalid floating point control. */
return -EINVAL;
offset = addr - (addr_t) &dummy32->regs.fp_regs;
*(__u32 *)((addr_t) &child->thread.fp_regs + offset) = tmp;
} else if (addr < (addr_t) (&dummy32->regs.per_info + 1)) {
/*
* per_info is found in the thread structure.
*/
offset = addr - (addr_t) &dummy32->regs.per_info;
/*
* This is magic. See per_struct and per_struct32.
* By incident the offsets in per_struct are exactly
* twice the offsets in per_struct32 for all fields.
* The 8 byte fields need special handling though,
* because the second half (bytes 4-7) is needed and
* not the first half.
*/
if ((offset >= (addr_t) &dummy_per32->control_regs &&
offset < (addr_t) (&dummy_per32->control_regs + 1)) ||
(offset >= (addr_t) &dummy_per32->starting_addr &&
offset <= (addr_t) &dummy_per32->ending_addr) ||
offset == (addr_t) &dummy_per32->lowcore.words.address)
offset = offset*2 + 4;
else
offset = offset*2;
*(__u32 *)((addr_t) &child->thread.per_info + offset) = tmp;
}
FixPerRegisters(child);
return 0;
}
static int poke_user_compat(struct task_struct *child,
addr_t addr, addr_t data)
{
if (!is_compat_task() || (addr & 3) || addr > sizeof(struct user32) - 3)
return -EIO;
return __poke_user_compat(child, addr, data);
}
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;
ptrace_area_emu31 parea;
int copied, ret;
switch (request) {
case PTRACE_PEEKUSR:
/* read the word at location addr in the USER area. */
return peek_user_compat(child, addr, data);
case PTRACE_POKEUSR:
/* write the word at location addr in the USER area */
return poke_user_compat(child, addr, data);
case PTRACE_PEEKUSR_AREA:
case PTRACE_POKEUSR_AREA:
if (copy_from_user(&parea, (void __force __user *) addr,
sizeof(parea)))
return -EFAULT;
addr = parea.kernel_addr;
data = parea.process_addr;
copied = 0;
while (copied < parea.len) {
if (request == PTRACE_PEEKUSR_AREA)
ret = peek_user_compat(child, addr, data);
else {
__u32 utmp;
if (get_user(utmp,
(__u32 __force __user *) data))
return -EFAULT;
ret = poke_user_compat(child, addr, utmp);
}
if (ret)
return ret;
addr += sizeof(unsigned int);
data += sizeof(unsigned int);
copied += sizeof(unsigned int);
}
return 0;
case PTRACE_GET_LAST_BREAK:
put_user(task_thread_info(child)->last_break,
(unsigned int __user *) data);
return 0;
}
return compat_ptrace_request(child, request, addr, data);
}
#endif
asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
{
long ret = 0;
/* Do the secure computing check first. */
secure_computing(regs->gprs[2]);
/*
* The sysc_tracesys code in entry.S stored the system
* call number to gprs[2].
*/
if (test_thread_flag(TIF_SYSCALL_TRACE) &&
(tracehook_report_syscall_entry(regs) ||
regs->gprs[2] >= NR_syscalls)) {
/*
* Tracing decided this syscall should not happen or the
* debugger stored an invalid system call number. Skip
* the system call and the system call restart handling.
*/
regs->svcnr = 0;
ret = -1;
}
if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
trace_sys_enter(regs, regs->gprs[2]);
if (unlikely(current->audit_context))
audit_syscall_entry(is_compat_task() ?
AUDIT_ARCH_S390 : AUDIT_ARCH_S390X,
regs->gprs[2], regs->orig_gpr2,
regs->gprs[3], regs->gprs[4],
regs->gprs[5]);
return ret ?: regs->gprs[2];
}
asmlinkage void do_syscall_trace_exit(struct pt_regs *regs)
{
if (unlikely(current->audit_context))
audit_syscall_exit(AUDITSC_RESULT(regs->gprs[2]),
regs->gprs[2]);
if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
trace_sys_exit(regs, regs->gprs[2]);
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, 0);
}
/*
* user_regset definitions.
*/
static int s390_regs_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
if (target == current)
save_access_regs(target->thread.acrs);
if (kbuf) {
unsigned long *k = kbuf;
while (count > 0) {
*k++ = __peek_user(target, pos);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
unsigned long __user *u = ubuf;
while (count > 0) {
if (__put_user(__peek_user(target, pos), u++))
return -EFAULT;
count -= sizeof(*u);
pos += sizeof(*u);
}
}
return 0;
}
static int s390_regs_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
int rc = 0;
if (target == current)
save_access_regs(target->thread.acrs);
if (kbuf) {
const unsigned long *k = kbuf;
while (count > 0 && !rc) {
rc = __poke_user(target, pos, *k++);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
const unsigned long __user *u = ubuf;
while (count > 0 && !rc) {
unsigned long word;
rc = __get_user(word, u++);
if (rc)
break;
rc = __poke_user(target, pos, word);
count -= sizeof(*u);
pos += sizeof(*u);
}
}
if (rc == 0 && target == current)
restore_access_regs(target->thread.acrs);
return rc;
}
static int s390_fpregs_get(struct task_struct *target,
const struct user_regset *regset, unsigned int pos,
unsigned int count, void *kbuf, void __user *ubuf)
{
if (target == current)
save_fp_regs(&target->thread.fp_regs);
return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.fp_regs, 0, -1);
}
static int s390_fpregs_set(struct task_struct *target,
const struct user_regset *regset, unsigned int pos,
unsigned int count, const void *kbuf,
const void __user *ubuf)
{
int rc = 0;
if (target == current)
save_fp_regs(&target->thread.fp_regs);
/* If setting FPC, must validate it first. */
if (count > 0 && pos < offsetof(s390_fp_regs, fprs)) {
u32 fpc[2] = { target->thread.fp_regs.fpc, 0 };
rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fpc,
0, offsetof(s390_fp_regs, fprs));
if (rc)
return rc;
if ((fpc[0] & ~FPC_VALID_MASK) != 0 || fpc[1] != 0)
return -EINVAL;
target->thread.fp_regs.fpc = fpc[0];
}
if (rc == 0 && count > 0)
rc = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
target->thread.fp_regs.fprs,
offsetof(s390_fp_regs, fprs), -1);
if (rc == 0 && target == current)
restore_fp_regs(&target->thread.fp_regs);
return rc;
}
#ifdef CONFIG_64BIT
static int s390_last_break_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
if (count > 0) {
if (kbuf) {
unsigned long *k = kbuf;
*k = task_thread_info(target)->last_break;
} else {
unsigned long __user *u = ubuf;
if (__put_user(task_thread_info(target)->last_break, u))
return -EFAULT;
}
}
return 0;
}
#endif
static const struct user_regset s390_regsets[] = {
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
.n = sizeof(s390_regs) / sizeof(long),
.size = sizeof(long),
.align = sizeof(long),
.get = s390_regs_get,
.set = s390_regs_set,
},
[REGSET_FP] = {
.core_note_type = NT_PRFPREG,
.n = sizeof(s390_fp_regs) / sizeof(long),
.size = sizeof(long),
.align = sizeof(long),
.get = s390_fpregs_get,
.set = s390_fpregs_set,
},
#ifdef CONFIG_64BIT
[REGSET_LAST_BREAK] = {
.core_note_type = NT_S390_LAST_BREAK,
.n = 1,
.size = sizeof(long),
.align = sizeof(long),
.get = s390_last_break_get,
},
#endif
};
static const struct user_regset_view user_s390_view = {
.name = UTS_MACHINE,
.e_machine = EM_S390,
.regsets = s390_regsets,
.n = ARRAY_SIZE(s390_regsets)
};
#ifdef CONFIG_COMPAT
static int s390_compat_regs_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
if (target == current)
save_access_regs(target->thread.acrs);
if (kbuf) {
compat_ulong_t *k = kbuf;
while (count > 0) {
*k++ = __peek_user_compat(target, pos);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
compat_ulong_t __user *u = ubuf;
while (count > 0) {
if (__put_user(__peek_user_compat(target, pos), u++))
return -EFAULT;
count -= sizeof(*u);
pos += sizeof(*u);
}
}
return 0;
}
static int s390_compat_regs_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
int rc = 0;
if (target == current)
save_access_regs(target->thread.acrs);
if (kbuf) {
const compat_ulong_t *k = kbuf;
while (count > 0 && !rc) {
rc = __poke_user_compat(target, pos, *k++);
count -= sizeof(*k);
pos += sizeof(*k);
}
} else {
const compat_ulong_t __user *u = ubuf;
while (count > 0 && !rc) {
compat_ulong_t word;
rc = __get_user(word, u++);
if (rc)
break;
rc = __poke_user_compat(target, pos, word);
count -= sizeof(*u);
pos += sizeof(*u);
}
}
if (rc == 0 && target == current)
restore_access_regs(target->thread.acrs);
return rc;
}
static int s390_compat_regs_high_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
compat_ulong_t *gprs_high;
gprs_high = (compat_ulong_t *)
&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
if (kbuf) {
compat_ulong_t *k = kbuf;
while (count > 0) {
*k++ = *gprs_high;
gprs_high += 2;
count -= sizeof(*k);
}
} else {
compat_ulong_t __user *u = ubuf;
while (count > 0) {
if (__put_user(*gprs_high, u++))
return -EFAULT;
gprs_high += 2;
count -= sizeof(*u);
}
}
return 0;
}
static int s390_compat_regs_high_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
compat_ulong_t *gprs_high;
int rc = 0;
gprs_high = (compat_ulong_t *)
&task_pt_regs(target)->gprs[pos / sizeof(compat_ulong_t)];
if (kbuf) {
const compat_ulong_t *k = kbuf;
while (count > 0) {
*gprs_high = *k++;
*gprs_high += 2;
count -= sizeof(*k);
}
} else {
const compat_ulong_t __user *u = ubuf;
while (count > 0 && !rc) {
unsigned long word;
rc = __get_user(word, u++);
if (rc)
break;
*gprs_high = word;
*gprs_high += 2;
count -= sizeof(*u);
}
}
return rc;
}
static int s390_compat_last_break_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
compat_ulong_t last_break;
if (count > 0) {
last_break = task_thread_info(target)->last_break;
if (kbuf) {
unsigned long *k = kbuf;
*k = last_break;
} else {
unsigned long __user *u = ubuf;
if (__put_user(last_break, u))
return -EFAULT;
}
}
return 0;
}
static const struct user_regset s390_compat_regsets[] = {
[REGSET_GENERAL] = {
.core_note_type = NT_PRSTATUS,
.n = sizeof(s390_compat_regs) / sizeof(compat_long_t),
.size = sizeof(compat_long_t),
.align = sizeof(compat_long_t),
.get = s390_compat_regs_get,
.set = s390_compat_regs_set,
},
[REGSET_FP] = {
.core_note_type = NT_PRFPREG,
.n = sizeof(s390_fp_regs) / sizeof(compat_long_t),
.size = sizeof(compat_long_t),
.align = sizeof(compat_long_t),
.get = s390_fpregs_get,
.set = s390_fpregs_set,
},
[REGSET_LAST_BREAK] = {
.core_note_type = NT_S390_LAST_BREAK,
.n = 1,
.size = sizeof(long),
.align = sizeof(long),
.get = s390_compat_last_break_get,
},
[REGSET_GENERAL_EXTENDED] = {
.core_note_type = NT_S390_HIGH_GPRS,
.n = sizeof(s390_compat_regs_high) / sizeof(compat_long_t),
.size = sizeof(compat_long_t),
.align = sizeof(compat_long_t),
.get = s390_compat_regs_high_get,
.set = s390_compat_regs_high_set,
},
};
static const struct user_regset_view user_s390_compat_view = {
.name = "s390",
.e_machine = EM_S390,
.regsets = s390_compat_regsets,
.n = ARRAY_SIZE(s390_compat_regsets)
};
#endif
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
#ifdef CONFIG_COMPAT
if (test_tsk_thread_flag(task, TIF_31BIT))
return &user_s390_compat_view;
#endif
return &user_s390_view;
}
static const char *gpr_names[NUM_GPRS] = {
"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
};
unsigned long regs_get_register(struct pt_regs *regs, unsigned int offset)
{
if (offset >= NUM_GPRS)
return 0;
return regs->gprs[offset];
}
int regs_query_register_offset(const char *name)
{
unsigned long offset;
if (!name || *name != 'r')
return -EINVAL;
if (strict_strtoul(name + 1, 10, &offset))
return -EINVAL;
if (offset >= NUM_GPRS)
return -EINVAL;
return offset;
}
const char *regs_query_register_name(unsigned int offset)
{
if (offset >= NUM_GPRS)
return NULL;
return gpr_names[offset];
}
static int regs_within_kernel_stack(struct pt_regs *regs, unsigned long addr)
{
unsigned long ksp = kernel_stack_pointer(regs);
return (addr & ~(THREAD_SIZE - 1)) == (ksp & ~(THREAD_SIZE - 1));
}
/**
* regs_get_kernel_stack_nth() - get Nth entry of the stack
* @regs:pt_regs which contains kernel stack pointer.
* @n:stack entry number.
*
* regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
* is specifined by @regs. If the @n th entry is NOT in the kernel stack,
* this returns 0.
*/
unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n)
{
unsigned long addr;
addr = kernel_stack_pointer(regs) + n * sizeof(long);
if (!regs_within_kernel_stack(regs, addr))
return 0;
return *(unsigned long *)addr;
}
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