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#include <linux/mm.h>
#include <linux/smp_lock.h>
#include <linux/module.h>
static asmlinkage void no_lcall7(int segment, struct pt_regs * regs);
static unsigned long ident_map[32] = {
0, 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 21, 22, 23,
24, 25, 26, 27, 28, 29, 30, 31
};
struct exec_domain default_exec_domain = {
"Linux", /* name */
no_lcall7, /* lcall7 causes a seg fault. */
0, 0xff, /* All personalities. */
ident_map, /* Identity map signals. */
ident_map, /* - both ways. */
NULL, /* No usage counter. */
NULL /* Nothing after this in the list. */
};
static struct exec_domain *exec_domains = &default_exec_domain;
static rwlock_t exec_domains_lock = RW_LOCK_UNLOCKED;
static asmlinkage void no_lcall7(int segment, struct pt_regs * regs)
{
/*
* This may have been a static linked SVr4 binary, so we would have the
* personality set incorrectly. Check to see whether SVr4 is available,
* and use it, otherwise give the user a SEGV.
*/
set_personality(PER_SVR4);
if (current->exec_domain && current->exec_domain->handler
&& current->exec_domain->handler != no_lcall7) {
current->exec_domain->handler(segment, regs);
return;
}
send_sig(SIGSEGV, current, 1);
}
static struct exec_domain *lookup_exec_domain(unsigned long personality)
{
unsigned long pers = personality & PER_MASK;
struct exec_domain *it;
read_lock(&exec_domains_lock);
for (it=exec_domains; it; it=it->next)
if (pers >= it->pers_low && pers <= it->pers_high) {
if (!try_inc_mod_count(it->module))
continue;
read_unlock(&exec_domains_lock);
return it;
}
read_unlock(&exec_domains_lock);
/* Should never get this far. */
printk(KERN_ERR "No execution domain for personality 0x%02lx\n", pers);
return NULL;
}
int register_exec_domain(struct exec_domain *it)
{
struct exec_domain *tmp;
if (!it)
return -EINVAL;
if (it->next)
return -EBUSY;
write_lock(&exec_domains_lock);
for (tmp=exec_domains; tmp; tmp=tmp->next)
if (tmp == it) {
write_unlock(&exec_domains_lock);
return -EBUSY;
}
it->next = exec_domains;
exec_domains = it;
write_unlock(&exec_domains_lock);
return 0;
}
int unregister_exec_domain(struct exec_domain *it)
{
struct exec_domain ** tmp;
tmp = &exec_domains;
write_lock(&exec_domains_lock);
while (*tmp) {
if (it == *tmp) {
*tmp = it->next;
it->next = NULL;
write_unlock(&exec_domains_lock);
return 0;
}
tmp = &(*tmp)->next;
}
write_unlock(&exec_domains_lock);
return -EINVAL;
}
void __set_personality(unsigned long personality)
{
struct exec_domain *it, *prev;
it = lookup_exec_domain(personality);
if (it == current->exec_domain) {
current->personality = personality;
return;
}
if (!it)
return;
if (atomic_read(¤t->fs->count) != 1) {
struct fs_struct *new = copy_fs_struct(current->fs);
struct fs_struct *old;
if (!new) {
put_exec_domain(it);
return;
}
task_lock(current);
old = current->fs;
current->fs = new;
task_unlock(current);
put_fs_struct(old);
}
/*
* At that point we are guaranteed to be the sole owner of
* current->fs.
*/
current->personality = personality;
prev = current->exec_domain;
current->exec_domain = it;
set_fs_altroot();
put_exec_domain(prev);
}
asmlinkage long sys_personality(unsigned long personality)
{
int ret = current->personality;
if (personality != 0xffffffff) {
set_personality(personality);
if (current->personality != personality)
ret = -EINVAL;
}
return ret;
}
int get_exec_domain_list(char * page)
{
int len = 0;
struct exec_domain * e;
read_lock(&exec_domains_lock);
for (e=exec_domains; e && len < PAGE_SIZE - 80; e=e->next)
len += sprintf(page+len, "%d-%d\t%-16s\t[%s]\n",
e->pers_low, e->pers_high, e->name,
e->module ? e->module->name : "kernel");
read_unlock(&exec_domains_lock);
return len;
}
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