/**
* reparent_to_init() - Reparent the calling kernel thread to the init task.
*
* If a kernel thread is launched as a result of a system call, or if
* it ever exits, it should generally reparent itself to init so that
* it is correctly cleaned up on exit.
*
* The various task state such as scheduling policy and priority may have
* been inherited from a user process, so we reset them to sane values here.
*
* NOTE that reparent_to_init() gives the caller full capabilities.
*/
void reparent_to_init(void)
{
write_lock_irq(&tasklist_lock);
/* Reparent to init */
REMOVE_LINKS(current);
current->p_pptr = child_reaper;
current->p_opptr = child_reaper;
SET_LINKS(current);
/* Set the exit signal to SIGCHLD so we signal init on exit */
current->exit_signal = SIGCHLD;
current->ptrace = 0;
if ((current->policy == SCHED_OTHER) && (task_nice(current) < 0))
set_user_nice(current, 0);
/* cpus_allowed? */
/* rt_priority? */
/* signals? */
current->cap_effective = CAP_INIT_EFF_SET;
current->cap_inheritable = CAP_INIT_INH_SET;
current->cap_permitted = CAP_FULL_SET;
current->keep_capabilities = 0;
memcpy(current->rlim, init_task.rlim, sizeof(*(current->rlim)));
current->user = INIT_USER;
write_unlock_irq(&tasklist_lock);
}
void release(struct task_struct * p)
{
int i;
if (!p)
return;
if (p == current) {
printk("task releasing itself\n");
return;
}
for (i=1 ; i<NR_TASKS ; i++)
if (task[i] == p) {
nr_tasks--;
task[i] = NULL;
REMOVE_LINKS(p);
release_thread(p);
if (STACK_MAGIC != *(unsigned long *)p->kernel_stack_page)
printk(KERN_ALERT "release: %s kernel stack corruption. Aiee\n", p->comm);
free_kernel_stack(p->kernel_stack_page);
current->cmin_flt += p->min_flt + p->cmin_flt;
current->cmaj_flt += p->maj_flt + p->cmaj_flt;
current->cnswap += p->nswap + p->cnswap;
kfree(p);
return;
}
panic("trying to release non-existent task");
}
/*
* ptrace a task: make the debugger its new parent and
* move it to the ptrace list.
*
* Must be called with the tasklist lock write-held.
*/
void __ptrace_link(task_t *child, task_t *new_parent)
{
if (!list_empty(&child->ptrace_list))
BUG();
if (child->parent == new_parent)
return;
list_add(&child->ptrace_list, &child->parent->ptrace_children);
REMOVE_LINKS(child);
child->parent = new_parent;
SET_LINKS(child);
}
/*
* unptrace a task: move it back to its original parent and
* remove it from the ptrace list.
*
* Must be called with the tasklist lock write-held.
*/
void __ptrace_unlink(task_t *child)
{
if (!child->ptrace)
BUG();
child->ptrace = 0;
if (list_empty(&child->ptrace_list))
return;
list_del_init(&child->ptrace_list);
REMOVE_LINKS(child);
child->parent = child->real_parent;
SET_LINKS(child);
}
/*
* unptrace a task: move it back to its original parent and
* remove it from the ptrace list.
*
* Must be called with the tasklist lock write-held.
*/
void __ptrace_unlink(task_t *child)
{
if (!child->ptrace)
BUG();
child->ptrace = 0;
if (!list_empty(&child->ptrace_list)) {
list_del_init(&child->ptrace_list);
REMOVE_LINKS(child);
child->parent = child->real_parent;
SET_LINKS(child);
}
if (child->state == TASK_TRACED)
ptrace_untrace(child);
}
int ptrace_attach(struct task_struct *task)
{
task_lock(task);
if (task->pid <= 1)
goto bad;
if (task == current)
goto bad;
if (!task->mm)
goto bad;
if(((current->uid != task->euid) ||
(current->uid != task->suid) ||
(current->uid != task->uid) ||
(current->gid != task->egid) ||
(current->gid != task->sgid) ||
(!cap_issubset(task->cap_permitted, current->cap_permitted)) ||
(current->gid != task->gid)) && !capable(CAP_SYS_PTRACE))
goto bad;
rmb();
if (!task->mm->dumpable && !capable(CAP_SYS_PTRACE))
goto bad;
/* the same process cannot be attached many times */
if (task->ptrace & PT_PTRACED)
goto bad;
/* Go */
task->ptrace |= PT_PTRACED;
if (capable(CAP_SYS_PTRACE))
task->ptrace |= PT_PTRACE_CAP;
task_unlock(task);
write_lock_irq(&tasklist_lock);
if (task->p_pptr != current) {
REMOVE_LINKS(task);
task->p_pptr = current;
SET_LINKS(task);
}
write_unlock_irq(&tasklist_lock);
send_sig(SIGSTOP, task, 1);
return 0;
bad:
task_unlock(task);
return -EPERM;
}
void release(struct task_struct * p)
{
int i;
if (!p)
return;
if (p == current) {
printk("task releasing itself\n");
return;
}
for (i=1 ; i<NR_TASKS ; i++)
if (task[i] == p) {
task[i] = NULL;
REMOVE_LINKS(p);
free_page(p->kernel_stack_page);
free_page((long) p);
return;
}
panic("trying to release non-existent task");
}
void set_parents(struct task_struct *task,
struct task_struct *real_parent, struct task_struct *parent) {
/*SPEW2("Reparenting %d gets %d and %d as parents.",
task->pid, real_parent->pid, parent->pid);*/
if (task == real_parent || task == parent)
BUG();
list_del_init(&task->ptrace_list); /* always safe... */
task->real_parent = real_parent;
REMOVE_LINKS(task);
task->parent = parent;
SET_LINKS(task);
if (real_parent != parent) {
if (!task->ptrace) /* Sanity check */
printk(KERN_ERR "bproc: different parent but no ptrace! (sps)\n");
list_add(&task->ptrace_list, &real_parent->ptrace_children);
}
}
int ptrace_detach(struct task_struct *child, unsigned int data)
{
if ((unsigned long) data > _NSIG)
return -EIO;
/* Architecture-specific hardware disable .. */
ptrace_disable(child);
/* .. re-parent .. */
child->ptrace = 0;
child->exit_code = data;
write_lock_irq(&tasklist_lock);
REMOVE_LINKS(child);
child->p_pptr = child->p_opptr;
SET_LINKS(child);
write_unlock_irq(&tasklist_lock);
/* .. and wake it up. */
wake_up_process(child);
return 0;
}
void release(struct task_struct * p)
{
if (p != current) {
#ifdef __SMP__
/*
* Wait to make sure the process isn't active on any
* other CPU
*/
for (;;) {
int has_cpu;
spin_lock_irq(&runqueue_lock);
has_cpu = p->has_cpu;
spin_unlock_irq(&runqueue_lock);
if (!has_cpu)
break;
do {
barrier();
} while (p->has_cpu);
}
#endif
free_uid(p);
add_free_taskslot(p->tarray_ptr);
write_lock_irq(&tasklist_lock);
nr_tasks--;
unhash_pid(p);
REMOVE_LINKS(p);
write_unlock_irq(&tasklist_lock);
release_thread(p);
current->cmin_flt += p->min_flt + p->cmin_flt;
current->cmaj_flt += p->maj_flt + p->cmaj_flt;
current->cnswap += p->nswap + p->cnswap;
free_task_struct(p);
} else {
printk("task releasing itself\n");
}
}
int sys_wait4(pid_t pid,unsigned long * stat_addr, int options, struct rusage * ru)
{
int flag;
struct task_struct *p;
unsigned long oldblocked;
if (stat_addr) {
flag = verify_area(VERIFY_WRITE, stat_addr, 4);
if (flag)
return flag;
}
repeat:
current->signal &= ~(1<<(SIGCHLD-1));
flag=0;
for (p = current->p_cptr ; p ; p = p->p_osptr) {
if (pid>0) {
if (p->pid != pid)
continue;
} else if (!pid) {
if (p->pgrp != current->pgrp)
continue;
} else if (pid != -1) {
if (p->pgrp != -pid)
continue;
}
switch (p->state) {
case TASK_STOPPED:
if (!p->exit_code)
continue;
if (!(options & WUNTRACED) && !(p->flags & PF_PTRACED))
continue;
if (stat_addr)
put_fs_long((p->exit_code << 8) | 0x7f,
stat_addr);
p->exit_code = 0;
if (ru != NULL)
getrusage(p, RUSAGE_BOTH, ru);
return p->pid;
case TASK_ZOMBIE:
current->cutime += p->utime + p->cutime;
current->cstime += p->stime + p->cstime;
current->cmin_flt += p->min_flt + p->cmin_flt;
current->cmaj_flt += p->maj_flt + p->cmaj_flt;
if (ru != NULL)
getrusage(p, RUSAGE_BOTH, ru);
flag = p->pid;
if (stat_addr)
put_fs_long(p->exit_code, stat_addr);
if (p->p_opptr != p->p_pptr) {
REMOVE_LINKS(p);
p->p_pptr = p->p_opptr;
SET_LINKS(p);
send_sig(SIGCHLD,p->p_pptr,1);
} else
release(p);
#ifdef DEBUG_PROC_TREE
audit_ptree();
#endif
return flag;
default:
flag=1;
continue;
}
}
if (flag) {
if (options & WNOHANG)
return 0;
current->state=TASK_INTERRUPTIBLE;
oldblocked = current->blocked;
current->blocked &= ~(1<<(SIGCHLD-1));
schedule();
current->blocked = oldblocked;
if (current->signal & ~(current->blocked | (1<<(SIGCHLD-1))))
return -ERESTARTSYS;
else
goto repeat;
}
return -ECHILD;
}
asmlinkage int sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struct rusage * ru)
{
int flag, retval;
struct wait_queue wait = { current, NULL };
struct task_struct *p;
if (options & ~(WNOHANG|WUNTRACED|__WCLONE))
return -EINVAL;
add_wait_queue(¤t->wait_chldexit,&wait);
repeat:
flag = 0;
/* The interruptible state must be set before looking at the
children. This because we want to catch any racy exit from
the children as do_exit() may run under us. The following
read_lock will enforce SMP ordering at the CPU level. */
current->state = TASK_INTERRUPTIBLE;
read_lock(&tasklist_lock);
for (p = current->p_cptr ; p ; p = p->p_osptr) {
if (pid>0) {
if (p->pid != pid)
continue;
} else if (!pid) {
if (p->pgrp != current->pgrp)
continue;
} else if (pid != -1) {
if (p->pgrp != -pid)
continue;
}
/* wait for cloned processes iff the __WCLONE flag is set */
if ((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
continue;
flag = 1;
switch (p->state) {
case TASK_STOPPED:
if (!p->exit_code)
continue;
if (!(options & WUNTRACED) && !(p->flags & PF_PTRACED))
continue;
read_unlock(&tasklist_lock);
current->state = TASK_RUNNING; /* We *must* do this before touching userspace! */
retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
if (!retval && stat_addr)
retval = put_user((p->exit_code << 8) | 0x7f, stat_addr);
if (!retval) {
p->exit_code = 0;
retval = p->pid;
}
goto end_wait4;
case TASK_ZOMBIE:
current->times.tms_cutime += p->times.tms_utime + p->times.tms_cutime;
current->times.tms_cstime += p->times.tms_stime + p->times.tms_cstime;
read_unlock(&tasklist_lock);
current->state = TASK_RUNNING; /* We *must* do this before touching userspace! */
retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
if (!retval && stat_addr)
retval = put_user(p->exit_code, stat_addr);
if (retval)
goto end_wait4;
retval = p->pid;
if (p->p_opptr != p->p_pptr) {
write_lock_irq(&tasklist_lock);
REMOVE_LINKS(p);
p->p_pptr = p->p_opptr;
SET_LINKS(p);
write_unlock_irq(&tasklist_lock);
notify_parent(p, SIGCHLD);
} else
release(p);
#ifdef DEBUG_PROC_TREE
audit_ptree();
#endif
goto end_wait4;
default:
continue;
}
}
read_unlock(&tasklist_lock);
if (flag) {
retval = 0;
if (options & WNOHANG)
goto end_wait4;
retval = -ERESTARTSYS;
if (signal_pending(current))
goto end_wait4;
schedule();
goto repeat;
}
retval = -ECHILD;
end_wait4:
remove_wait_queue(¤t->wait_chldexit,&wait);
current->state = TASK_RUNNING;
return retval;
}
/* 如果成功则返回0 */
asmlinkage int sys_wait4(pid_t pid,unsigned long * stat_addr, int options, struct rusage * ru)
{
int flag, retval;
struct wait_queue wait = { current, NULL };
struct task_struct *p;
if (stat_addr) {
flag = verify_area(VERIFY_WRITE, stat_addr, 4);
if (flag)
return flag;
}
add_wait_queue(¤t->wait_chldexit,&wait);
repeat:
flag=0;
/* p_cptr表示最小的孩子进程，p_opptr表示老的兄弟进程
* 通过该循环可以知道从当前进程的最小进程开始一次向年长的进程开始扫描
*/
for (p = current->p_cptr ; p ; p = p->p_osptr) {
/* 如果pid>0表示等待某个具体的进程，等于0则表示进程组，小于0则表示所有子进程 */
if (pid>0) {
if (p->pid != pid)
continue;
} else if (!pid) {
if (p->pgrp != current->pgrp)
continue;
/* 如果是负数的话，则等待进程组号为-pid的所有子进程*/
} else if (pid != -1) {
if (p->pgrp != -pid)
continue;
}
/* wait for cloned processes iff the __WCLONE flag is set */
if ((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
continue;
flag = 1;
switch (p->state) {
case TASK_STOPPED:
if (!p->exit_code)
continue;
if (!(options & WUNTRACED) && !(p->flags & PF_PTRACED))
continue;
if (stat_addr)
put_fs_long((p->exit_code << 8) | 0x7f,
stat_addr);
p->exit_code = 0;
if (ru != NULL)
getrusage(p, RUSAGE_BOTH, ru);
retval = p->pid;
goto end_wait4;
case TASK_ZOMBIE:
current->cutime += p->utime + p->cutime;
current->cstime += p->stime + p->cstime;
current->cmin_flt += p->min_flt + p->cmin_flt;
current->cmaj_flt += p->maj_flt + p->cmaj_flt;
if (ru != NULL)
getrusage(p, RUSAGE_BOTH, ru);
flag = p->pid;
if (stat_addr)
put_fs_long(p->exit_code, stat_addr);
if (p->p_opptr != p->p_pptr) {
REMOVE_LINKS(p);
p->p_pptr = p->p_opptr;
SET_LINKS(p);
notify_parent(p);
} else
release(p);
#ifdef DEBUG_PROC_TREE
audit_ptree();
#endif
retval = flag;
goto end_wait4;
default:
continue;
}
}
if (flag) {
retval = 0;
/* 如果子进程还在运行，并且选项标记为WNOHANG，
* 则表示不等待，函数直接返回
*/
if (options & WNOHANG)
goto end_wait4;
/* 设置进程为可中断状态，同时调用进程调度函数
*/
current->state=TASK_INTERRUPTIBLE;
schedule();
/* 设置进程收到SIGCHLD信号
*/
current->signal &= ~(1<<(SIGCHLD-1));
retval = -ERESTARTSYS;
/* 如果当前进程的所有信号都被阻塞了，也就是子进程退出时
* 给父进程发送的SIGCHLD信号也被阻塞了，则函数直接返回
*/
if (current->signal & ~current->blocked)
goto end_wait4;
goto repeat;
}
retval = -ECHILD;
end_wait4:
remove_wait_queue(¤t->wait_chldexit,&wait);
return retval;
}
long sys_ptrace(long request, pid_t pid, long addr, long data)
{
struct task_struct *child;
long ret;
lock_kernel();
ret = -EPERM;
if (request == PTRACE_TRACEME) {
/* are we already being traced? */
if (current->ptrace & PT_PTRACED)
goto out;
/* set the ptrace bit in the process flags. */
current->ptrace |= PT_PTRACED;
ret = 0;
goto out;
}
ret = -ESRCH;
read_lock(&tasklist_lock);
child = find_task_by_pid(pid);
if (child)
get_task_struct(child);
read_unlock(&tasklist_lock);
if (!child)
goto out;
ret = -EPERM;
if (pid == 1) /* no messing around with init! */
goto out_tsk;
if (request == PTRACE_ATTACH) {
if (child == current)
goto out_tsk;
if ((!child->dumpable ||
(current->uid != child->euid) ||
(current->uid != child->suid) ||
(current->uid != child->uid) ||
(current->gid != child->egid) ||
(current->gid != child->sgid) ||
(!cap_issubset(child->cap_permitted, current->cap_permitted)) ||
(current->gid != child->gid)) && !capable(CAP_SYS_PTRACE))
goto out_tsk;
/* the same process cannot be attached many times */
if (child->ptrace & PT_PTRACED)
goto out_tsk;
child->ptrace |= PT_PTRACED;
if (child->p_pptr != current) {
unsigned long flags;
write_lock_irqsave(&tasklist_lock, flags);
REMOVE_LINKS(child);
child->p_pptr = current;
SET_LINKS(child);
write_unlock_irqrestore(&tasklist_lock, flags);
}
send_sig(SIGSTOP, child, 1);
ret = 0;
goto out_tsk;
}
ret = -ESRCH;
if (!(child->ptrace & PT_PTRACED))
goto out_tsk;
if (child->state != TASK_STOPPED) {
if (request != PTRACE_KILL)
goto out_tsk;
}
if (child->p_pptr != current)
goto out_tsk;
switch (request) {
case PTRACE_PEEKTEXT: /* read word at location addr. */
case PTRACE_PEEKDATA: {
unsigned long tmp;
int copied;
copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
ret = -EIO;
if (copied != sizeof(tmp))
goto out_tsk;
ret = put_user(tmp,(unsigned long *) data);
goto out_tsk;
}
/* when I and D space are separate, this will have to be fixed. */
case PTRACE_POKETEXT: /* write the word at location addr. */
case PTRACE_POKEDATA:
ret = 0;
if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
goto out_tsk;
ret = -EIO;
goto out_tsk;
/* Read the word at location addr in the USER area. This will need
to change when the kernel no longer saves all regs on a syscall. */
case PTRACE_PEEKUSR: {
unsigned long tmp;
ret = -EIO;
if ((addr & 3) || (unsigned long) addr >= sizeof(struct pt_regs))
goto out_tsk;
tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
ret = put_user(tmp, (unsigned long *) data);
goto out_tsk;
}
/* Write the word at location addr in the USER area. This will need
to change when the kernel no longer saves all regs on a syscall.
FIXME. There is a problem at the moment in that r3-r18 are only
saved if the process is ptraced on syscall entry, and even then
those values are overwritten by actual register values on syscall
exit. */
case PTRACE_POKEUSR:
ret = -EIO;
if ((addr & 3) || (unsigned long) addr >= sizeof(struct pt_regs))
goto out_tsk;
/* XXX This test probably needs adjusting. We probably want to
* allow writes to some bits of PSW, and may want to block writes
* to (some) space registers. Some register values written here
* may be ignored in entry.S:syscall_restore_rfi; e.g. iaoq is
* written with r31/r31+4, and not with the values in pt_regs.
*/
/* Allow writing of gr1-gr31, fr*, sr*, iasq*, iaoq*, sar */
if (addr == PT_PSW || (addr > PT_IAOQ1 && addr != PT_SAR))
goto out_tsk;
*(unsigned long *) ((char *) task_regs(child) + addr) = data;
ret = 0;
goto out_tsk;
case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
case PTRACE_CONT:
ret = -EIO;
if ((unsigned long) data > _NSIG)
goto out_tsk;
child->ptrace &= ~(PT_SINGLESTEP|PT_BLOCKSTEP);
if (request == PTRACE_SYSCALL)
child->ptrace |= PT_TRACESYS;
else
child->ptrace &= ~PT_TRACESYS;
child->exit_code = data;
goto out_wake_notrap;
case PTRACE_KILL:
/*
* 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.
*/
if (child->state == TASK_ZOMBIE) /* already dead */
goto out_tsk;
child->exit_code = SIGKILL;
goto out_wake_notrap;
case PTRACE_SINGLEBLOCK:
ret = -EIO;
if ((unsigned long) data > _NSIG)
goto out_tsk;
child->ptrace &= ~(PT_TRACESYS|PT_SINGLESTEP);
child->ptrace |= PT_BLOCKSTEP;
child->exit_code = data;
/* Enable taken branch trap. */
pa_psw(child)->r = 0;
pa_psw(child)->t = 1;
pa_psw(child)->h = 0;
pa_psw(child)->l = 0;
goto out_wake;
case PTRACE_SINGLESTEP:
ret = -EIO;
if ((unsigned long) data > _NSIG)
goto out_tsk;
child->ptrace &= ~(PT_TRACESYS|PT_BLOCKSTEP);
child->ptrace |= PT_SINGLESTEP;
child->exit_code = data;
if (pa_psw(child)->n) {
struct siginfo si;
/* Nullified, just crank over the queue. */
task_regs(child)->iaoq[0] = task_regs(child)->iaoq[1];
task_regs(child)->iasq[0] = task_regs(child)->iasq[1];
task_regs(child)->iaoq[1] = task_regs(child)->iaoq[0] + 4;
pa_psw(child)->n = 0;
pa_psw(child)->x = 0;
pa_psw(child)->y = 0;
pa_psw(child)->z = 0;
pa_psw(child)->b = 0;
pa_psw(child)->r = 0;
pa_psw(child)->t = 0;
pa_psw(child)->h = 0;
pa_psw(child)->l = 0;
/* Don't wake up the child, but let the
parent know something happened. */
si.si_code = TRAP_TRACE;
si.si_addr = (void *) (task_regs(child)->iaoq[0] & ~3);
si.si_signo = SIGTRAP;
si.si_errno = 0;
force_sig_info(SIGTRAP, &si, child);
//notify_parent(child, SIGCHLD);
//ret = 0;
goto out_wake;
}
/* Enable recovery counter traps. The recovery counter
* itself will be set to zero on a task switch. If the
* task is suspended on a syscall then the syscall return
* path will overwrite the recovery counter with a suitable
* value such that it traps once back in user space. We
* disable interrupts in the childs PSW here also, to avoid
* interrupts while the recovery counter is decrementing.
*/
pa_psw(child)->r = 1;
pa_psw(child)->t = 0;
pa_psw(child)->h = 0;
pa_psw(child)->l = 0;
/* give it a chance to run. */
goto out_wake;
case PTRACE_DETACH:
ret = -EIO;
if ((unsigned long) data > _NSIG)
goto out_tsk;
child->ptrace &= ~(PT_PTRACED|PT_TRACESYS|PT_SINGLESTEP|PT_BLOCKSTEP);
child->exit_code = data;
write_lock_irq(&tasklist_lock);
REMOVE_LINKS(child);
child->p_pptr = child->p_opptr;
SET_LINKS(child);
write_unlock_irq(&tasklist_lock);
goto out_wake_notrap;
default:
ret = -EIO;
goto out_tsk;
}
out_wake_notrap:
/* make sure the trap bits are not set */
pa_psw(child)->r = 0;
pa_psw(child)->t = 0;
pa_psw(child)->h = 0;
pa_psw(child)->l = 0;
out_wake:
wake_up_process(child);
ret = 0;
out_tsk:
free_task_struct(child);
out:
unlock_kernel();
return ret;
}
asmlinkage int sys32_ptrace(long request, long pid, long addr, s32 data)
{
struct task_struct *child;
int ret = -EPERM;
unsigned long flags;
u32 tmp;
int copied;
ptrace_area parea;
lock_kernel();
if (request == PTRACE_TRACEME)
{
/* are we already being traced? */
if (current->ptrace & PT_PTRACED)
goto out;
/* set the ptrace bit in the process flags. */
current->ptrace |= PT_PTRACED;
ret = 0;
goto out;
}
ret = -ESRCH;
read_lock(&tasklist_lock);
child = find_task_by_pid(pid);
read_unlock(&tasklist_lock);
if (!child)
goto out;
ret = -EPERM;
if (pid == 1) /* you may not mess with init */
goto out;
if (request == PTRACE_ATTACH)
{
ret = ptrace_attach(child);
goto out;
}
ret = -ESRCH;
// printk("child=%lX child->flags=%lX",child,child->flags);
/* I added child!=current line so we can get the */
/* ieee_instruction_pointer from the user structure DJB */
if(child!=current)
{
if (!(child->ptrace & PT_PTRACED))
goto out;
if (child->state != TASK_STOPPED)
{
if (request != PTRACE_KILL)
goto out;
}
if (child->p_pptr != current)
goto out;
}
switch (request)
{
/* If I and D space are separate, these will need to be fixed. */
case PTRACE_PEEKTEXT: /* read word at location addr. */
case PTRACE_PEEKDATA:
copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
ret = -EIO;
if (copied != sizeof(tmp))
goto out;
ret = put_user(tmp,(u32 *)(unsigned long)data);
goto out;
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR:
ret=copy_user(child,addr,data,sizeof(u32),1,0);
break;
/* If I and D space are separate, this will have to be fixed. */
case PTRACE_POKETEXT: /* write the word at location addr. */
case PTRACE_POKEDATA:
ret = 0;
if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
goto out;
ret = -EIO;
goto out;
break;
case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
ret=copy_user(child,addr,(addr_t)&data,sizeof(u32),0,1);
break;
case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
case PTRACE_CONT: /* restart after signal. */
ret = -EIO;
if ((unsigned long) data >= _NSIG)
break;
if (request == PTRACE_SYSCALL)
child->ptrace |= PT_TRACESYS;
else
child->ptrace &= ~PT_TRACESYS;
child->exit_code = data;
/* make sure the single step bit is not set. */
clear_single_step(child);
wake_up_process(child);
ret = 0;
break;
/*
* 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:
ret = 0;
if (child->state == TASK_ZOMBIE) /* already dead */
break;
child->exit_code = SIGKILL;
clear_single_step(child);
wake_up_process(child);
/* make sure the single step bit is not set. */
break;
case PTRACE_SINGLESTEP: /* set the trap flag. */
ret = -EIO;
if ((unsigned long) data >= _NSIG)
break;
child->ptrace &= ~PT_TRACESYS;
child->exit_code = data;
set_single_step(child);
/* give it a chance to run. */
wake_up_process(child);
ret = 0;
break;
case PTRACE_DETACH: /* detach a process that was attached. */
ret = -EIO;
if ((unsigned long) data >= _NSIG)
break;
child->ptrace &= ~(PT_PTRACED|PT_TRACESYS);
child->exit_code = data;
write_lock_irqsave(&tasklist_lock, flags);
REMOVE_LINKS(child);
child->p_pptr = child->p_opptr;
SET_LINKS(child);
write_unlock_irqrestore(&tasklist_lock, flags);
/* make sure the single step bit is not set. */
clear_single_step(child);
wake_up_process(child);
ret = 0;
break;
case PTRACE_PEEKUSR_AREA:
case PTRACE_POKEUSR_AREA:
{
ptrace_area_emu31 * parea31 = (void *)addr;
if (!access_ok(VERIFY_READ, parea31, sizeof(*parea31)))
return(-EFAULT);
ret = __get_user(parea.len, &parea31->len);
ret |= __get_user(parea.kernel_addr, &parea31->kernel_addr);
ret |= __get_user(parea.process_addr, &parea31->process_addr);
if(ret==0)
ret=copy_user(child,parea.kernel_addr,parea.process_addr,
parea.len,1,(request==PTRACE_POKEUSR_AREA));
break;
}
default:
ret = -EIO;
break;
}
out:
unlock_kernel();
return ret;
}
asmlinkage long sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struct rusage * ru)
{
int flag, retval;
DECLARE_WAITQUEUE(wait, current);
struct task_struct *tsk;
if (options & ~(WNOHANG|WUNTRACED|__WNOTHREAD|__WCLONE|__WALL))
return -EINVAL;
add_wait_queue(¤t->wait_chldexit,&wait);
repeat:
flag = 0;
current->state = TASK_INTERRUPTIBLE;
read_lock(&tasklist_lock);
tsk = current;
do {
struct task_struct *p;
for (p = tsk->p_cptr ; p ; p = p->p_osptr) {
if (pid>0) {
if (p->pid != pid)
continue;
} else if (!pid) {
if (p->pgrp != current->pgrp)
continue;
} else if (pid != -1) {
if (p->pgrp != -pid)
continue;
}
/* Wait for all children (clone and not) if __WALL is set;
* otherwise, wait for clone children *only* if __WCLONE is
* set; otherwise, wait for non-clone children *only*. (Note:
* A "clone" child here is one that reports to its parent
* using a signal other than SIGCHLD.) */
if (((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
&& !(options & __WALL))
continue;
flag = 1;
switch (p->state) {
case TASK_STOPPED:
if (!p->exit_code)
continue;
if (!(options & WUNTRACED) && !(p->ptrace & PT_PTRACED))
continue;
read_unlock(&tasklist_lock);
retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
if (!retval && stat_addr)
retval = put_user((p->exit_code << 8) | 0x7f, stat_addr);
if (!retval) {
p->exit_code = 0;
retval = p->pid;
}
goto end_wait4;
case TASK_ZOMBIE:
current->times.tms_cutime += p->times.tms_utime + p->times.tms_cutime;
current->times.tms_cstime += p->times.tms_stime + p->times.tms_cstime;
read_unlock(&tasklist_lock);
retval = ru ? getrusage(p, RUSAGE_BOTH, ru) : 0;
if (!retval && stat_addr)
retval = put_user(p->exit_code, stat_addr);
if (retval)
goto end_wait4;
retval = p->pid;
if (p->p_opptr != p->p_pptr) {
write_lock_irq(&tasklist_lock);
REMOVE_LINKS(p);
p->p_pptr = p->p_opptr;
SET_LINKS(p);
do_notify_parent(p, SIGCHLD);
write_unlock_irq(&tasklist_lock);
} else
release_task(p);
goto end_wait4;
default:
continue;
}
}
if (options & __WNOTHREAD)
break;
tsk = next_thread(tsk);
} while (tsk != current);
read_unlock(&tasklist_lock);
if (flag) {
retval = 0;
if (options & WNOHANG)
goto end_wait4;
retval = -ERESTARTSYS;
if (signal_pending(current))
goto end_wait4;
schedule();
goto repeat;
}
retval = -ECHILD;
end_wait4:
current->state = TASK_RUNNING;
remove_wait_queue(¤t->wait_chldexit,&wait);
return retval;
}
asmlinkage int sys_wait4(pid_t pid,unsigned int * stat_addr, int options, struct rusage * ru)
{
int flag, retval;
struct wait_queue wait = { current, NULL };
struct task_struct *p;
if (stat_addr) {
flag = verify_area(VERIFY_WRITE, stat_addr, sizeof(*stat_addr));
if (flag)
return flag;
}
if (ru) {
flag = verify_area(VERIFY_WRITE, ru, sizeof(*ru));
if (flag)
return flag;
}
if (options & ~(WNOHANG|WUNTRACED|__WCLONE))
return -EINVAL;
add_wait_queue(¤t->wait_chldexit,&wait);
repeat:
flag=0;
for (p = current->p_cptr ; p ; p = p->p_osptr) {
if (pid>0) {
if (p->pid != pid)
continue;
} else if (!pid) {
if (p->pgrp != current->pgrp)
continue;
} else if (pid != -1) {
if (p->pgrp != -pid)
continue;
}
/* wait for cloned processes iff the __WCLONE flag is set */
if ((p->exit_signal != SIGCHLD) ^ ((options & __WCLONE) != 0))
continue;
flag = 1;
switch (p->state) {
case TASK_STOPPED:
if (!p->exit_code)
continue;
if (!(options & WUNTRACED) && !(p->flags & PF_PTRACED))
continue;
if (ru != NULL)
getrusage(p, RUSAGE_BOTH, ru);
if (stat_addr)
put_user((p->exit_code << 8) | 0x7f,
stat_addr);
p->exit_code = 0;
retval = p->pid;
goto end_wait4;
case TASK_ZOMBIE:
current->cutime += p->utime + p->cutime;
current->cstime += p->stime + p->cstime;
if (ru != NULL)
getrusage(p, RUSAGE_BOTH, ru);
if (stat_addr)
put_user(p->exit_code, stat_addr);
retval = p->pid;
if (p->p_opptr != p->p_pptr) {
REMOVE_LINKS(p);
p->p_pptr = p->p_opptr;
SET_LINKS(p);
notify_parent(p);
} else
release(p);
#ifdef DEBUG_PROC_TREE
audit_ptree();
#endif
goto end_wait4;
default:
continue;
}
}
if (flag) {
retval = 0;
if (options & WNOHANG)
goto end_wait4;
retval = -ERESTARTSYS;
if (current->signal & ~current->blocked)
goto end_wait4;
current->state=TASK_INTERRUPTIBLE;
schedule();
goto repeat;
}
retval = -ECHILD;
end_wait4:
remove_wait_queue(¤t->wait_chldexit,&wait);
return retval;
}
