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kernel-ark/arch/sparc/kernel/ptrace.c
David S. Miller fb65b9619b [PATCH] sparc: Fix PTRACE_CONT bogosity 
SunOS aparently had this weird PTRACE_CONT semantic which
we copied.  If the addr argument is something other than
1, it sets the process program counter to whatever that
value is.

This is different from every other Linux architecture, which
don't do anything with the addr and data args.

This difference in particular breaks the Linux native GDB support
for fork and vfork tracing on sparc and sparc64.

There is no interest in running SunOS binaries using this weird
PTRACE_CONT behavior, so just delete it so we behave like other
platforms do.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-17 18:03:11 -07:00

621 lines
14 KiB
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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 <linux/security.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 __user *addr)
{
if (put_user(value, addr)) {
pt_error_return(regs, EFAULT);
return;
}
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 __user *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 __user *addr)
{
struct pt_regs *cregs = tsk->thread.kregs;
struct thread_info *t = tsk->thread_info;
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_info *t = tsk->thread_info;
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 [] = {
/* 0 */ "TRACEME", "PEEKTEXT", "PEEKDATA", "PEEKUSR",
/* 4 */ "POKETEXT", "POKEDATA", "POKEUSR", "CONT",
/* 8 */ "KILL", "SINGLESTEP", "SUNATTACH", "SUNDETACH",
/* 12 */ "GETREGS", "SETREGS", "GETFPREGS", "SETFPREGS",
/* 16 */ "READDATA", "WRITEDATA", "READTEXT", "WRITETEXT",
/* 20 */ "GETFPAREGS", "SETFPAREGS", "unknown", "unknown",
/* 24 */ "SYSCALL", ""
};
#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;
int ret;
lock_kernel();
#ifdef DEBUG_PTRACE
{
char *s;
if ((request >= 0) && (request <= 24))
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) {
int my_ret;
/* are we already being traced? */
if (current->ptrace & PT_PTRACED) {
pt_error_return(regs, EPERM);
goto out;
}
my_ret = security_ptrace(current->parent, current);
if (my_ret) {
pt_error_return(regs, -my_ret);
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;
}
ret = ptrace_check_attach(child, request == PTRACE_KILL);
if (ret < 0) {
pt_error_return(regs, -ret);
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 __user *)data);
else
pt_error_return(regs, EIO);
goto out_tsk;
}
case PTRACE_PEEKUSR:
read_sunos_user(regs, addr, child, (long __user *) 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 __user *pregs = (struct pt_regs __user *) addr;
struct pt_regs *cregs = child->thread.kregs;
int rval;
if (!access_ok(VERIFY_WRITE, pregs, sizeof(struct pt_regs))) {
rval = -EFAULT;
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 __user *pregs = (struct pt_regs __user *) 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.
*/
if (!access_ok(VERIFY_READ, pregs, sizeof(struct pt_regs))) {
pt_error_return(regs, EFAULT);
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];
};
struct fps __user *fps = (struct fps __user *) addr;
int i;
if (!access_ok(VERIFY_WRITE, fps, sizeof(struct fps))) {
i = -EFAULT;
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];
};
struct fps __user *fps = (struct fps __user *) addr;
int i;
if (!access_ok(VERIFY_READ, fps, sizeof(struct fps))) {
i = -EFAULT;
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 __user *) 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 __user *) 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 (data > _NSIG) {
pt_error_return(regs, EIO);
goto out_tsk;
}
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;
#ifdef DEBUG_PTRACE
printk("CONT: %s [%d]: set exit_code = %x %lx %lx\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->exit_state == EXIT_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: {
int err = ptrace_request(child, request, addr, data);
if (err)
pt_error_return(regs, -err);
else
pt_succ_return(regs, 0);
goto out_tsk;
}
}
out_tsk:
if (child)
put_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 (!test_thread_flag(TIF_SYSCALL_TRACE))
return;
if (!(current->ptrace & PT_PTRACED))
return;
current->thread.flags ^= MAGIC_CONSTANT;
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
*/
#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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