/* 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.
*/
#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 <asm/pgtable.h>
#include <asm/system.h>
/* change a pid into a task struct. */
static inline struct task_struct * get_task(int pid)
{
int i;
for (i = 1; i < NR_TASKS; i++) {
if (task[i] != NULL && (task[i]->pid == pid))
return task[i];
}
return NULL;
}
/*
* This routine gets a long from any process space by following the page
* tables. NOTE! You should check that the long isn't on a page boundary,
* and that it is in the task area before calling this: this routine does
* no checking.
*/
static unsigned long get_long(struct task_struct * tsk,
struct vm_area_struct * vma, unsigned long addr)
{
pgd_t * pgdir;
pmd_t * pgmiddle;
pte_t * pgtable;
unsigned long page, retval;
repeat:
pgdir = pgd_offset(vma->vm_mm, addr);
if (pgd_none(*pgdir)) {
do_no_page(tsk, vma, addr, 0);
goto repeat;
}
if (pgd_bad(*pgdir)) {
printk("ptrace: bad page directory %08lx\n", pgd_val(*pgdir));
pgd_clear(pgdir);
return 0;
}
pgmiddle = pmd_offset(pgdir, addr);
if (pmd_none(*pgmiddle)) {
do_no_page(tsk, vma, addr, 0);
goto repeat;
}
if (pmd_bad(*pgmiddle)) {
printk("ptrace: bad page middle %08lx\n", pmd_val(*pgmiddle));
pmd_clear(pgmiddle);
return 0;
}
pgtable = pte_offset(pgmiddle, addr);
if (!pte_present(*pgtable)) {
do_no_page(tsk, vma, addr, 0);
goto repeat;
}
page = pte_page(*pgtable);
/* this is a hack for non-kernel-mapped video buffers and similar */
if (page >= high_memory)
return 0;
page += addr & ~PAGE_MASK;
retval = *(unsigned long *) page;
flush_page_to_ram(page);
return retval;
}
/*
* This routine puts a long into any process space by following the page
* tables. NOTE! You should check that the long isn't on a page boundary,
* and that it is in the task area before calling this: this routine does
* no checking.
*
* Now keeps R/W state of page so that a text page stays readonly
* even if a debugger scribbles breakpoints into it. -M.U-
*/
static void put_long(struct task_struct * tsk, struct vm_area_struct * vma,
unsigned long addr, unsigned long data)
{
pgd_t *pgdir;
pmd_t *pgmiddle;
pte_t *pgtable;
unsigned long page;
repeat:
pgdir = pgd_offset(vma->vm_mm, addr);
if (!pgd_present(*pgdir)) {
do_no_page(tsk, vma, addr, 1);
goto repeat;
}
if (pgd_bad(*pgdir)) {
printk("ptrace: bad page directory %08lx\n", pgd_val(*pgdir));
pgd_clear(pgdir);
return;
}
pgmiddle = pmd_offset(pgdir, addr);
if (pmd_none(*pgmiddle)) {
do_no_page(tsk, vma, addr, 1);
goto repeat;
}
if (pmd_bad(*pgmiddle)) {
printk("ptrace: bad page middle %08lx\n", pmd_val(*pgmiddle));
pmd_clear(pgmiddle);
return;
}
pgtable = pte_offset(pgmiddle, addr);
if (!pte_present(*pgtable)) {
do_no_page(tsk, vma, addr, 1);
goto repeat;
}
page = pte_page(*pgtable);
if (!pte_write(*pgtable)) {
do_wp_page(tsk, vma, addr, 1);
goto repeat;
}
/* this is a hack for non-kernel-mapped video buffers and similar */
flush_cache_page(vma, page);
if (page < high_memory) {
*(unsigned long *) (page + (addr & ~PAGE_MASK)) = data;
flush_page_to_ram(page);
}
/* we're bypassing pagetables, so we have to set the dirty bit ourselves */
/* this should also re-instate whatever read-only mode there was before */
set_pte(pgtable, pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
flush_tlb_page(vma, page);
}
static struct vm_area_struct * find_extend_vma(struct task_struct * tsk,
unsigned long addr)
{
struct vm_area_struct * vma;
addr &= PAGE_MASK;
vma = find_vma(tsk,addr);
if (!vma)
return NULL;
if (vma->vm_start <= addr)
return vma;
if (!(vma->vm_flags & VM_GROWSDOWN))
return NULL;
if (vma->vm_end - addr > tsk->rlim[RLIMIT_STACK].rlim_cur)
return NULL;
vma->vm_offset -= vma->vm_start - addr;
vma->vm_start = addr;
return vma;
}
/*
* This routine checks the page boundaries, and that the offset is
* within the task area. It then calls get_long() to read a long.
*/
static int read_long(struct task_struct * tsk, unsigned long addr,
unsigned long * result)
{
struct vm_area_struct * vma = find_extend_vma(tsk, addr);
if (!vma)
return -EIO;
*result = get_long(tsk, vma, addr);
return 0;
}
static int read_byte(struct task_struct *tsk, unsigned long addr,
unsigned char *result)
{
struct vm_area_struct *vma = find_extend_vma(tsk, addr&~3);
unsigned long tmp;
if(!vma)
return -EIO;
tmp = get_long(tsk, vma, (addr & ~3));
switch(addr & 3) {
case 0:
*result = (tmp & 0xff000000)>>24;
break;
case 1:
*result = (tmp & 0x00ff0000)>>16;
break;
case 2:
*result = (tmp & 0x0000ff00)>>8;
break;
case 3:
*result = (tmp & 0x000000ff);
break;
}
return 0;
}
/*
* This routine checks the page boundaries, and that the offset is
* within the task area. It then calls put_long() to write a long.
*/
static int write_long(struct task_struct * tsk, unsigned long addr,
unsigned long data)
{
struct vm_area_struct * vma = find_extend_vma(tsk, addr);
if (!vma)
return -EIO;
put_long(tsk, vma, addr, data);
return 0;
}
static int write_byte(struct task_struct * tsk, unsigned long addr,
unsigned char data)
{
struct vm_area_struct * vma = find_extend_vma(tsk, (addr & ~3));
unsigned long tmp;
if (!vma)
return -EIO;
tmp = get_long(tsk, vma, (addr & ~3));
switch(addr & 3) {
case 0:
tmp &= 0x00ffffff;
tmp |= (data << 24);
break;
case 1:
tmp &= 0xff00ffff;
tmp |= ((data << 16) & 0x00ff0000);
break;
case 2:
tmp &= 0xffff00ff;
tmp |= ((data << 8) & 0x0000ff00);
break;
case 3:
tmp &= 0xffffff00;
tmp |= (data & 0x000000ff);
break;
}
put_long(tsk, vma, (addr & ~3), tmp);
return 0;
}
/* 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;
}
/* Fuck me gently with a chainsaw... */
static inline void read_sunos_user(struct pt_regs *regs, unsigned long offset,
struct task_struct *tsk)
{
struct pt_regs *cregs = tsk->tss.kregs;
struct thread_struct *t = &tsk->tss;
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_succ_return(regs, *(((unsigned long *)(&t->reg_window[0]))+offset));
return;
}
if(offset >= 784 && offset < 832) {
offset -= 784; offset >>= 2;
pt_succ_return(regs, *(((unsigned long *)(&t->rwbuf_stkptrs[0]))+offset));
return;
}
switch(offset) {
case 0:
regs->u_regs[UREG_I0] = t->ksp;
break;
case 4:
regs->u_regs[UREG_I0] = t->kpc;
break;
case 8:
regs->u_regs[UREG_I0] = t->kpsr;
break;
case 12:
regs->u_regs[UREG_I0] = t->uwinmask;
break;
case 832:
regs->u_regs[UREG_I0] = t->w_saved;
break;
case 896:
regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I0];
break;
case 900:
regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I1];
break;
case 904:
regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I2];
break;
case 908:
regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I3];
break;
case 912:
regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I4];
break;
case 916:
regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I5];
break;
case 920:
regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I6];
break;
case 924:
if(tsk->tss.flags & 0x80000000)
regs->u_regs[UREG_I0] = cregs->u_regs[UREG_G1];
else
regs->u_regs[UREG_I0] = 0;
break;
case 940:
regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I0];
break;
case 944:
regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I1];
break;
case 948:
/* Isn't binary compatibility _fun_??? */
if(cregs->psr & PSR_C)
regs->u_regs[UREG_I0] = cregs->u_regs[UREG_I0] << 24;
else
regs->u_regs[UREG_I0] = 0;
break;
/* Rest of them are completely unsupported. */
default:
printk("%s [%d]: Wants to read user offset %d\n",
current->comm, current->pid, offset);
pt_error_return(regs, EIO);
return;
}
regs->psr &= ~PSR_C;
regs->pc = regs->npc;
regs->npc += 4;
return;
}
static inline void write_sunos_user(struct pt_regs *regs, unsigned long offset,
struct task_struct *tsk)
{
struct pt_regs *cregs = tsk->tss.kregs;
struct thread_struct *t = &tsk->tss;
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 %d\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 */
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;
#ifdef DEBUG_PTRACE
printk("do_ptrace: rq=%d pid=%d addr=%08lx data=%08lx addr2=%08lx\n",
(int) request, (int) pid, addr, data, addr2);
#endif
if(request == PTRACE_TRACEME) {
/* are we already being traced? */
if (current->flags & PF_PTRACED) {
pt_error_return(regs, EPERM);
return;
}
/* set the ptrace bit in the process flags. */
current->flags |= PF_PTRACED;
pt_succ_return(regs, 0);
return;
}
#ifndef ALLOW_INIT_TRACING
if(pid == 1) {
/* Can't dork with init. */
pt_error_return(regs, EPERM);
return;
}
#endif
if(!(child = get_task(pid))) {
pt_error_return(regs, ESRCH);
return;
}
if(request == PTRACE_SUNATTACH) {
if(child == current) {
/* Try this under SunOS/Solaris, bwa haha
* You'll never be able to kill the process. ;-)
*/
pt_error_return(regs, EPERM);
return;
}
if((!child->dumpable ||
(current->uid != child->euid) ||
(current->uid != child->uid) ||
(current->gid != child->egid) ||
(current->gid != child->gid)) && !suser()) {
pt_error_return(regs, EPERM);
return;
}
/* the same process cannot be attached many times */
if (child->flags & PF_PTRACED) {
pt_error_return(regs, EPERM);
return;
}
child->flags |= PF_PTRACED;
if(child->p_pptr != current) {
REMOVE_LINKS(child);
child->p_pptr = current;
SET_LINKS(child);
}
send_sig(SIGSTOP, child, 1);
pt_succ_return(regs, 0);
return;
}
if(!(child->flags & PF_PTRACED)) {
pt_error_return(regs, ESRCH);
return;
}
if(child->state != TASK_STOPPED) {
if(request != PTRACE_KILL) {
pt_error_return(regs, ESRCH);
return;
}
}
if(child->p_pptr != current) {
pt_error_return(regs, ESRCH);
return;
}
switch(request) {
case PTRACE_PEEKTEXT: /* read word at location addr. */
case PTRACE_PEEKDATA: {
unsigned long tmp;
int res;
/* Non-word alignment _not_ allowed on Sparc. */
if(addr & (sizeof(unsigned long) - 1)) {
pt_error_return(regs, EINVAL);
return;
}
res = read_long(child, addr, &tmp);
if (res < 0) {
pt_error_return(regs, -res);
return;
}
pt_succ_return(regs, tmp);
return;
}
case PTRACE_PEEKUSR:
read_sunos_user(regs, addr, child);
return;
case PTRACE_POKEUSR:
write_sunos_user(regs, addr, child);
return;
case PTRACE_POKETEXT: /* write the word at location addr. */
case PTRACE_POKEDATA: {
struct vm_area_struct *vma;
int res;
/* Non-word alignment _not_ allowed on Sparc. */
if(addr & (sizeof(unsigned long) - 1)) {
pt_error_return(regs, EINVAL);
return;
}
vma = find_extend_vma(child, addr);
if(vma && request == PTRACE_POKEDATA && (vma->vm_flags & VM_EXEC)) {
pt_error_return(regs, EIO);
return;
}
res = write_long(child, addr, data);
if(res < 0)
pt_error_return(regs, -res);
else
pt_succ_return(regs, res);
return;
}
case PTRACE_GETREGS: {
struct pt_regs *pregs = (struct pt_regs *) addr;
struct pt_regs *cregs = child->tss.kregs;
int rval;
rval = verify_area(VERIFY_WRITE, pregs, sizeof(struct pt_regs) - 4);
if(rval) {
pt_error_return(regs, rval);
return;
}
pregs->psr = cregs->psr;
pregs->pc = cregs->pc;
pregs->npc = cregs->npc;
pregs->y = cregs->y;
for(rval = 1; rval < 16; rval++)
pregs->u_regs[rval - 1] = cregs->u_regs[rval];
pt_succ_return(regs, 0);
return;
}
case PTRACE_SETREGS: {
struct pt_regs *pregs = (struct pt_regs *) addr;
struct pt_regs *cregs = child->tss.kregs;
unsigned long psr;
int rval, i;
rval = verify_area(VERIFY_READ, pregs, sizeof(struct pt_regs) - 4);
if(rval) {
pt_error_return(regs, rval);
return;
}
/* Must be careful, tracing process can only set certain
* bits in the psr.
*/
psr = (pregs->psr) & PSR_ICC;
cregs->psr &= ~PSR_ICC;
cregs->psr |= psr;
if(!((pregs->pc | pregs->npc) & 3)) {
cregs->pc = pregs->pc;
cregs->npc = pregs->npc;
}
cregs->y = pregs->y;
for(i = 1; i < 16; i++)
cregs->u_regs[i] = pregs->u_regs[i-1];
pt_succ_return(regs, 0);
return;
}
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 rval, i;
rval = verify_area(VERIFY_WRITE, fps, sizeof(struct fps));
if(rval) { pt_error_return(regs, rval); return; }
for(i = 0; i < 32; i++)
fps->regs[i] = child->tss.float_regs[i];
fps->fsr = child->tss.fsr;
fps->fpqd = child->tss.fpqdepth;
fps->flags = fps->extra = 0;
for(i = 0; i < 16; i++) {
fps->fpq[i].insnaddr = child->tss.fpqueue[i].insn_addr;
fps->fpq[i].insn = child->tss.fpqueue[i].insn;
}
pt_succ_return(regs, 0);
return;
}
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 rval, i;
rval = verify_area(VERIFY_READ, fps, sizeof(struct fps));
if(rval) { pt_error_return(regs, rval); return; }
for(i = 0; i < 32; i++)
child->tss.float_regs[i] = fps->regs[i];
child->tss.fsr = fps->fsr;
child->tss.fpqdepth = fps->fpqd;
for(i = 0; i < 16; i++) {
child->tss.fpqueue[i].insn_addr = fps->fpq[i].insnaddr;
child->tss.fpqueue[i].insn = fps->fpq[i].insn;
}
pt_succ_return(regs, 0);
return;
}
case PTRACE_READTEXT:
case PTRACE_READDATA: {
unsigned char *dest = (unsigned char *) addr2;
unsigned long src = addr;
unsigned char tmp;
int res, len = data;
res = verify_area(VERIFY_WRITE, (void *) dest, len);
if(res) {
pt_error_return(regs, -res);
return;
}
while(len) {
res = read_byte(child, src, &tmp);
if(res < 0) {
pt_error_return(regs, -res);
return;
}
*dest = tmp;
src++; dest++; len--;
}
pt_succ_return(regs, 0);
return;
}
case PTRACE_WRITETEXT:
case PTRACE_WRITEDATA: {
unsigned char *src = (unsigned char *) addr2;
unsigned long dest = addr;
int res, len = data;
res = verify_area(VERIFY_READ, (void *) src, len);
if(res) {
pt_error_return(regs, -res);
return;
}
while(len) {
res = write_byte(child, dest, *src);
if(res < 0) {
pt_error_return(regs, -res);
return;
}
src++; dest++; len--;
}
pt_succ_return(regs, 0);
return;
}
case PTRACE_SYSCALL: /* continue and stop at (return from) syscall */
data = 0;
addr = 1;
case PTRACE_CONT: { /* restart after signal. */
if ((unsigned long) data > NSIG) {
pt_error_return(regs, EIO);
return;
}
if (request == PTRACE_SYSCALL)
child->flags |= PF_TRACESYS;
else
child->flags &= ~PF_TRACESYS;
child->exit_code = data;
if((addr != 1) & !(addr & 3)) {
child->tss.kregs->pc = addr;
child->tss.kregs->npc = addr + 4;
}
wake_up_process(child);
pt_succ_return(regs, 0);
return;
}
/*
* 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);
return;
}
wake_up_process(child);
child->exit_code = SIGKILL;
pt_succ_return(regs, 0);
return;
}
case PTRACE_SUNDETACH: { /* detach a process that was attached. */
if ((unsigned long) data > NSIG) {
pt_error_return(regs, EIO);
return;
}
child->flags &= ~(PF_PTRACED|PF_TRACESYS);
wake_up_process(child);
child->exit_code = data;
REMOVE_LINKS(child);
child->p_pptr = child->p_opptr;
SET_LINKS(child);
pt_succ_return(regs, 0);
return;
}
/* PTRACE_DUMPCORE unsupported... */
default:
pt_error_return(regs, EIO);
return;
}
}
asmlinkage void syscall_trace(void)
{
#ifdef DEBUG_PTRACE
printk("%s [%d]: syscall_trace\n", current->comm, current->pid);
#endif
if ((current->flags & (PF_PTRACED|PF_TRACESYS))
!= (PF_PTRACED|PF_TRACESYS))
return;
current->exit_code = SIGTRAP;
current->state = TASK_STOPPED;
current->tss.flags ^= 0x80000000;
notify_parent(current);
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
*/
if (current->exit_code)
current->signal |= (1 << (current->exit_code - 1));
current->exit_code = 0;
}
