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/* ptrace.c: Sparc process tracing support.
*
* Copyright (C) 1996 David S. Miller (davem@caipfs.rutgers.edu)
*
* Based upon code written by Ross Biro, Linus Torvalds, Bob Manson,
* and David Mosberger.
*
* Added Linux support -miguel (weird, eh?, the orignal code was meant
* to emulate SunOS).
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#define MAGIC_CONSTANT 0x80000000
/* Returning from ptrace is a bit tricky because the syscall return
* low level code assumes any value returned which is negative and
* is a valid errno will mean setting the condition codes to indicate
* an error return. This doesn't work, so we have this hook.
*/
static inline void pt_error_return(struct pt_regs *regs, unsigned long error)
{
regs->u_regs[UREG_I0] = error;
regs->psr |= PSR_C;
regs->pc = regs->npc;
regs->npc += 4;
}
static inline void pt_succ_return(struct pt_regs *regs, unsigned long value)
{
regs->u_regs[UREG_I0] = value;
regs->psr &= ~PSR_C;
regs->pc = regs->npc;
regs->npc += 4;
}
static void
pt_succ_return_linux(struct pt_regs *regs, unsigned long value, long *addr)
{
if(put_user(value, addr))
return pt_error_return(regs, EFAULT);
regs->u_regs[UREG_I0] = 0;
regs->psr &= ~PSR_C;
regs->pc = regs->npc;
regs->npc += 4;
}
static void
pt_os_succ_return (struct pt_regs *regs, unsigned long val, long *addr)
{
if (current->personality == PER_SUNOS)
pt_succ_return (regs, val);
else
pt_succ_return_linux (regs, val, addr);
}
/* Fuck me gently with a chainsaw... */
static inline void read_sunos_user(struct pt_regs *regs, unsigned long offset,
struct task_struct *tsk, long *addr)
{
struct pt_regs *cregs = tsk->thread.kregs;
struct thread_struct *t = &tsk->thread;
int v;
if(offset >= 1024)
offset -= 1024; /* whee... */
if(offset & ((sizeof(unsigned long) - 1))) {
pt_error_return(regs, EIO);
return;
}
if(offset >= 16 && offset < 784) {
offset -= 16; offset >>= 2;
pt_os_succ_return(regs, *(((unsigned long *)(&t->reg_window[0]))+offset), addr);
return;
}
if(offset >= 784 && offset < 832) {
offset -= 784; offset >>= 2;
pt_os_succ_return(regs, *(((unsigned long *)(&t->rwbuf_stkptrs[0]))+offset), addr);
return;
}
switch(offset) {
case 0:
v = t->ksp;
break;
case 4:
v = t->kpc;
break;
case 8:
v = t->kpsr;
break;
case 12:
v = t->uwinmask;
break;
case 832:
v = t->w_saved;
break;
case 896:
v = cregs->u_regs[UREG_I0];
break;
case 900:
v = cregs->u_regs[UREG_I1];
break;
case 904:
v = cregs->u_regs[UREG_I2];
break;
case 908:
v = cregs->u_regs[UREG_I3];
break;
case 912:
v = cregs->u_regs[UREG_I4];
break;
case 916:
v = cregs->u_regs[UREG_I5];
break;
case 920:
v = cregs->u_regs[UREG_I6];
break;
case 924:
if(tsk->thread.flags & MAGIC_CONSTANT)
v = cregs->u_regs[UREG_G1];
else
v = 0;
break;
case 940:
v = cregs->u_regs[UREG_I0];
break;
case 944:
v = cregs->u_regs[UREG_I1];
break;
case 948:
/* Isn't binary compatibility _fun_??? */
if(cregs->psr & PSR_C)
v = cregs->u_regs[UREG_I0] << 24;
else
v = 0;
break;
/* Rest of them are completely unsupported. */
default:
printk("%s [%d]: Wants to read user offset %ld\n",
current->comm, current->pid, offset);
pt_error_return(regs, EIO);
return;
}
if (current->personality == PER_SUNOS)
pt_succ_return (regs, v);
else
pt_succ_return_linux (regs, v, addr);
return;
}
static inline void write_sunos_user(struct pt_regs *regs, unsigned long offset,
struct task_struct *tsk)
{
struct pt_regs *cregs = tsk->thread.kregs;
struct thread_struct *t = &tsk->thread;
unsigned long value = regs->u_regs[UREG_I3];
if(offset >= 1024)
offset -= 1024; /* whee... */
if(offset & ((sizeof(unsigned long) - 1)))
goto failure;
if(offset >= 16 && offset < 784) {
offset -= 16; offset >>= 2;
*(((unsigned long *)(&t->reg_window[0]))+offset) = value;
goto success;
}
if(offset >= 784 && offset < 832) {
offset -= 784; offset >>= 2;
*(((unsigned long *)(&t->rwbuf_stkptrs[0]))+offset) = value;
goto success;
}
switch(offset) {
case 896:
cregs->u_regs[UREG_I0] = value;
break;
case 900:
cregs->u_regs[UREG_I1] = value;
break;
case 904:
cregs->u_regs[UREG_I2] = value;
break;
case 908:
cregs->u_regs[UREG_I3] = value;
break;
case 912:
cregs->u_regs[UREG_I4] = value;
break;
case 916:
cregs->u_regs[UREG_I5] = value;
break;
case 920:
cregs->u_regs[UREG_I6] = value;
break;
case 924:
cregs->u_regs[UREG_I7] = value;
break;
case 940:
cregs->u_regs[UREG_I0] = value;
break;
case 944:
cregs->u_regs[UREG_I1] = value;
break;
/* Rest of them are completely unsupported or "no-touch". */
default:
printk("%s [%d]: Wants to write user offset %ld\n",
current->comm, current->pid, offset);
goto failure;
}
success:
pt_succ_return(regs, 0);
return;
failure:
pt_error_return(regs, EIO);
return;
}
/* #define ALLOW_INIT_TRACING */
/* #define DEBUG_PTRACE */
#ifdef DEBUG_PTRACE
char *pt_rq [] = {
"TRACEME",
"PEEKTEXT",
"PEEKDATA",
"PEEKUSR",
"POKETEXT",
"POKEDATA",
"POKEUSR",
"CONT",
"KILL",
"SINGLESTEP",
"SUNATTACH",
"SUNDETACH",
"GETREGS",
"SETREGS",
"GETFPREGS",
"SETFPREGS",
"READDATA",
"WRITEDATA",
"READTEXT",
"WRITETEXT",
"GETFPAREGS",
"SETFPAREGS",
""
};
#endif
/*
* 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 */
}
asmlinkage void do_ptrace(struct pt_regs *regs)
{
unsigned long request = regs->u_regs[UREG_I0];
unsigned long pid = regs->u_regs[UREG_I1];
unsigned long addr = regs->u_regs[UREG_I2];
unsigned long data = regs->u_regs[UREG_I3];
unsigned long addr2 = regs->u_regs[UREG_I4];
struct task_struct *child;
lock_kernel();
#ifdef DEBUG_PTRACE
{
char *s;
if ((request > 0) && (request < 21))
s = pt_rq [request];
else
s = "unknown";
if (request == PTRACE_POKEDATA && data == 0x91d02001){
printk ("do_ptrace: breakpoint pid=%d, addr=%08lx addr2=%08lx\n",
pid, addr, addr2);
} else
printk("do_ptrace: rq=%s(%d) pid=%d addr=%08lx data=%08lx addr2=%08lx\n",
s, (int) request, (int) pid, addr, data, addr2);
}
#endif
if(request == PTRACE_TRACEME) {
/* are we already being traced? */
if (current->ptrace & PT_PTRACED) {
pt_error_return(regs, EPERM);
goto out;
}
/* set the ptrace bit in the process flags. */
current->ptrace |= PT_PTRACED;
pt_succ_return(regs, 0);
goto out;
}
#ifndef ALLOW_INIT_TRACING
if(pid == 1) {
/* Can't dork with init. */
pt_error_return(regs, EPERM);
goto out;
}
#endif
read_lock(&tasklist_lock);
child = find_task_by_pid(pid);
if (child)
get_task_struct(child);
read_unlock(&tasklist_lock);
if (!child) {
pt_error_return(regs, ESRCH);
goto out;
}
if ((current->personality == PER_SUNOS && request == PTRACE_SUNATTACH)
|| (current->personality != PER_SUNOS && request == PTRACE_ATTACH)) {
if (ptrace_attach(child)) {
pt_error_return(regs, EPERM);
goto out_tsk;
}
pt_succ_return(regs, 0);
goto out_tsk;
}
if (!(child->ptrace & PT_PTRACED)) {
pt_error_return(regs, ESRCH);
goto out_tsk;
}
if(child->state != TASK_STOPPED) {
if(request != PTRACE_KILL) {
pt_error_return(regs, ESRCH);
goto out_tsk;
}
}
if(child->p_pptr != current) {
pt_error_return(regs, ESRCH);
goto out_tsk;
}
switch(request) {
case PTRACE_PEEKTEXT: /* read word at location addr. */
case PTRACE_PEEKDATA: {
unsigned long tmp;
if (access_process_vm(child, addr,
&tmp, sizeof(tmp), 0) == sizeof(tmp))
pt_os_succ_return(regs, tmp, (long *)data);
else
pt_error_return(regs, EIO);
goto out_tsk;
}
case PTRACE_PEEKUSR:
read_sunos_user(regs, addr, child, (long *) data);
goto out_tsk;
case PTRACE_POKEUSR:
write_sunos_user(regs, addr, child);
goto out_tsk;
case PTRACE_POKETEXT: /* write the word at location addr. */
case PTRACE_POKEDATA: {
if (access_process_vm(child, addr,
&data, sizeof(data), 1) == sizeof(data))
pt_succ_return(regs, 0);
else
pt_error_return(regs, EIO);
goto out_tsk;
}
case PTRACE_GETREGS: {
struct pt_regs *pregs = (struct pt_regs *) addr;
struct pt_regs *cregs = child->thread.kregs;
int rval;
rval = verify_area(VERIFY_WRITE, pregs, sizeof(struct pt_regs));
if(rval) {
pt_error_return(regs, -rval);
goto out_tsk;
}
__put_user(cregs->psr, (&pregs->psr));
__put_user(cregs->pc, (&pregs->pc));
__put_user(cregs->npc, (&pregs->npc));
__put_user(cregs->y, (&pregs->y));
for(rval = 1; rval < 16; rval++)
__put_user(cregs->u_regs[rval], (&pregs->u_regs[rval - 1]));
pt_succ_return(regs, 0);
#ifdef DEBUG_PTRACE
printk ("PC=%x nPC=%x o7=%x\n", cregs->pc, cregs->npc, cregs->u_regs [15]);
#endif
goto out_tsk;
}
case PTRACE_SETREGS: {
struct pt_regs *pregs = (struct pt_regs *) addr;
struct pt_regs *cregs = child->thread.kregs;
unsigned long psr, pc, npc, y;
int i;
/* Must be careful, tracing process can only set certain
* bits in the psr.
*/
i = verify_area(VERIFY_READ, pregs, sizeof(struct pt_regs));
if(i) {
pt_error_return(regs, -i);
goto out_tsk;
}
__get_user(psr, (&pregs->psr));
__get_user(pc, (&pregs->pc));
__get_user(npc, (&pregs->npc));
__get_user(y, (&pregs->y));
psr &= PSR_ICC;
cregs->psr &= ~PSR_ICC;
cregs->psr |= psr;
if(!((pc | npc) & 3)) {
cregs->pc = pc;
cregs->npc =npc;
}
cregs->y = y;
for(i = 1; i < 16; i++)
__get_user(cregs->u_regs[i], (&pregs->u_regs[i-1]));
pt_succ_return(regs, 0);
goto out_tsk;
}
case PTRACE_GETFPREGS: {
struct fps {
unsigned long regs[32];
unsigned long fsr;
unsigned long flags;
unsigned long extra;
unsigned long fpqd;
struct fq {
unsigned long *insnaddr;
unsigned long insn;
} fpq[16];
} *fps = (struct fps *) addr;
int i;
i = verify_area(VERIFY_WRITE, fps, sizeof(struct fps));
if(i) {
pt_error_return(regs, -i);
goto out_tsk;
}
for(i = 0; i < 32; i++)
__put_user(child->thread.float_regs[i], (&fps->regs[i]));
__put_user(child->thread.fsr, (&fps->fsr));
__put_user(child->thread.fpqdepth, (&fps->fpqd));
__put_user(0, (&fps->flags));
__put_user(0, (&fps->extra));
for(i = 0; i < 16; i++) {
__put_user(child->thread.fpqueue[i].insn_addr,
(&fps->fpq[i].insnaddr));
__put_user(child->thread.fpqueue[i].insn, (&fps->fpq[i].insn));
}
pt_succ_return(regs, 0);
goto out_tsk;
}
case PTRACE_SETFPREGS: {
struct fps {
unsigned long regs[32];
unsigned long fsr;
unsigned long flags;
unsigned long extra;
unsigned long fpqd;
struct fq {
unsigned long *insnaddr;
unsigned long insn;
} fpq[16];
} *fps = (struct fps *) addr;
int i;
i = verify_area(VERIFY_READ, fps, sizeof(struct fps));
if(i) {
pt_error_return(regs, -i);
goto out_tsk;
}
copy_from_user(&child->thread.float_regs[0], &fps->regs[0], (32 * sizeof(unsigned long)));
__get_user(child->thread.fsr, (&fps->fsr));
__get_user(child->thread.fpqdepth, (&fps->fpqd));
for(i = 0; i < 16; i++) {
__get_user(child->thread.fpqueue[i].insn_addr,
(&fps->fpq[i].insnaddr));
__get_user(child->thread.fpqueue[i].insn, (&fps->fpq[i].insn));
}
pt_succ_return(regs, 0);
goto out_tsk;
}
case PTRACE_READTEXT:
case PTRACE_READDATA: {
int res = ptrace_readdata(child, addr, (void *) addr2, data);
if (res == data) {
pt_succ_return(regs, 0);
goto out_tsk;
}
/* Partial read is an IO failure */
if (res >= 0)
res = -EIO;
pt_error_return(regs, -res);
goto out_tsk;
}
case PTRACE_WRITETEXT:
case PTRACE_WRITEDATA: {
int res = ptrace_writedata(child, (void *) addr2, addr, data);
if (res == data) {
pt_succ_return(regs, 0);
goto out_tsk;
}
/* Partial write is an IO failure */
if (res >= 0)
res = -EIO;
pt_error_return(regs, -res);
goto out_tsk;
}
case PTRACE_SYSCALL: /* continue and stop at (return from) syscall */
addr = 1;
case PTRACE_CONT: { /* restart after signal. */
if ((unsigned long) data > _NSIG) {
pt_error_return(regs, EIO);
goto out_tsk;
}
if (addr != 1) {
if (addr & 3) {
pt_error_return(regs, EINVAL);
goto out_tsk;
}
#ifdef DEBUG_PTRACE
printk ("Original: %08lx %08lx\n", child->thread.kregs->pc, child->thread.kregs->npc);
printk ("Continuing with %08lx %08lx\n", addr, addr+4);
#endif
child->thread.kregs->pc = addr;
child->thread.kregs->npc = addr + 4;
}
if (request == PTRACE_SYSCALL)
child->ptrace |= PT_TRACESYS;
else
child->ptrace &= ~PT_TRACESYS;
child->exit_code = data;
#ifdef DEBUG_PTRACE
printk("CONT: %s [%d]: set exit_code = %x %x %x\n", child->comm,
child->pid, child->exit_code,
child->thread.kregs->pc,
child->thread.kregs->npc);
#endif
wake_up_process(child);
pt_succ_return(regs, 0);
goto out_tsk;
}
/*
* 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: {
if (child->state == TASK_ZOMBIE) { /* already dead */
pt_succ_return(regs, 0);
goto out_tsk;
}
wake_up_process(child);
child->exit_code = SIGKILL;
pt_succ_return(regs, 0);
goto out_tsk;
}
case PTRACE_SUNDETACH: { /* detach a process that was attached. */
int err = ptrace_detach(child, data);
if (err) {
pt_error_return(regs, EIO);
goto out_tsk;
}
pt_succ_return(regs, 0);
goto out_tsk;
}
/* PTRACE_DUMPCORE unsupported... */
default:
pt_error_return(regs, EIO);
goto out_tsk;
}
out_tsk:
if (child)
free_task_struct(child);
out:
unlock_kernel();
}
asmlinkage void syscall_trace(void)
{
#ifdef DEBUG_PTRACE
printk("%s [%d]: syscall_trace\n", current->comm, current->pid);
#endif
if ((current->ptrace & (PT_PTRACED|PT_TRACESYS))
!= (PT_PTRACED|PT_TRACESYS))
return;
current->exit_code = SIGTRAP;
current->state = TASK_STOPPED;
current->thread.flags ^= MAGIC_CONSTANT;
notify_parent(current, SIGCHLD);
schedule();
/*
* 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
*/
#ifdef DEBUG_PTRACE
printk("%s [%d]: syscall_trace exit= %x\n", current->comm,
current->pid, current->exit_code);
#endif
if (current->exit_code) {
send_sig (current->exit_code, current, 1);
current->exit_code = 0;
}
}
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