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/*
* Misc things
* Copyright (c) by Jaroslav Kysela <perex@jcu.cz>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include "driver.h"
#include <asm/pgtable.h>
static unsigned long get_phys_addr(struct task_struct * p, unsigned long ptr)
{
pgd_t *page_dir;
pmd_t *page_middle;
pte_t pte;
if (!p || !p->mm || ptr >= TASK_SIZE)
return 0;
#ifdef LINUX_2_1
if (!p->mm->pgd) {
printk("get_phys_addr: pid %d has NULL pgd!\n", p->pid);
return 0;
}
#endif
page_dir = pgd_offset(p->mm,ptr);
if (pgd_none(*page_dir))
return 0;
if (pgd_bad(*page_dir)) {
printk("bad page directory entry %08lx\n", pgd_val(*page_dir));
pgd_clear(page_dir);
return 0;
}
page_middle = pmd_offset(page_dir,ptr);
if (pmd_none(*page_middle))
return 0;
if (pmd_bad(*page_middle)) {
printk("bad page middle entry %08lx\n", pmd_val(*page_middle));
pmd_clear(page_middle);
return 0;
}
pte = *pte_offset(page_middle,ptr);
if (!pte_present(pte))
return 0;
return pte_page(pte) + (ptr & ~PAGE_MASK);
}
int snd_task_name( struct task_struct *task, char *name, int size )
{
unsigned long addr, start, end;
int c, idx;
start = current -> mm -> arg_start;
end = current -> mm -> arg_end;
while ( start < end ) {
addr = get_phys_addr( current, start );
if ( !addr ) return -EINVAL;
idx = 0;
do {
c = *(char *)addr++; start++;
name[ idx++ ] = c;
if ( !c ) return 0;
if ( idx > size - 1 ) {
name[ idx ] = 0;
return 0;
}
} while ( start < end );
}
return -EINVAL;
}
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