/* * Handling of different ABIs (personalities). * * We group personalities into execution domains which have their * own handlers for kernel entry points, signal mapping, etc... * * 2001-05-06	Complete rewrite,  Christoph Hellwig (hch@infradead.org) */ #include <linux/init.h>#include <linux/kernel.h>#include <linux/kmod.h>#include <linux/module.h>#include <linux/personality.h>#include <linux/proc_fs.h>#include <linux/sched.h>#include <linux/seq_file.h>#include <linux/syscalls.h>#include <linux/sysctl.h>#include <linux/types.h>#include <linux/fs_struct.h>  static void default_handler(int, struct pt_regs *); static struct exec_domain *exec_domains = &default_exec_domain;static DEFINE_RWLOCK(exec_domains_lock);  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 = {	.name		= "Linux",		/* name */	.handler	= default_handler,	/* lcall7 causes a seg fault. */	.pers_low	= 0,			/* PER_LINUX personality. */	.pers_high	= 0,			/* PER_LINUX personality. */	.signal_map	= ident_map,		/* Identity map signals. */	.signal_invmap	= ident_map,		/*  - both ways. */};  static voiddefault_handler(int segment, struct pt_regs *regp){	set_personality(0); 	if (current_thread_info()->exec_domain->handler != default_handler)		current_thread_info()->exec_domain->handler(segment, regp);	else		send_sig(SIGSEGV, current, 1);} static struct exec_domain *lookup_exec_domain(unsigned int personality){	unsigned int pers = personality(personality);	struct exec_domain *ep; 	read_lock(&exec_domains_lock);	for (ep = exec_domains; ep; ep = ep->next) {		if (pers >= ep->pers_low && pers <= ep->pers_high)			if (try_module_get(ep->module))				goto out;	} #ifdef CONFIG_MODULES	read_unlock(&exec_domains_lock);	request_module("personality-%d", pers);	read_lock(&exec_domains_lock); 	for (ep = exec_domains; ep; ep = ep->next) {		if (pers >= ep->pers_low && pers <= ep->pers_high)			if (try_module_get(ep->module))				goto out;	}#endif 	ep = &default_exec_domain;out:	read_unlock(&exec_domains_lock);	return ep;} intregister_exec_domain(struct exec_domain *ep){	struct exec_domain	*tmp;	int			err = -EBUSY; 	if (ep == NULL)		return -EINVAL; 	if (ep->next != NULL)		return -EBUSY; 	write_lock(&exec_domains_lock);	for (tmp = exec_domains; tmp; tmp = tmp->next) {		if (tmp == ep)			goto out;	} 	ep->next = exec_domains;	exec_domains = ep;	err = 0; out:	write_unlock(&exec_domains_lock);	return err;}EXPORT_SYMBOL(register_exec_domain); intunregister_exec_domain(struct exec_domain *ep){	struct exec_domain	**epp; 	epp = &exec_domains;	write_lock(&exec_domains_lock);	for (epp = &exec_domains; *epp; epp = &(*epp)->next) {		if (ep == *epp)			goto unregister;	}	write_unlock(&exec_domains_lock);	return -EINVAL; unregister:	*epp = ep->next;	ep->next = NULL;	write_unlock(&exec_domains_lock);	return 0;}EXPORT_SYMBOL(unregister_exec_domain); int __set_personality(unsigned int personality){	struct exec_domain *oep = current_thread_info()->exec_domain; 	current_thread_info()->exec_domain = lookup_exec_domain(personality);	current->personality = personality;	module_put(oep->module); 	return 0;}EXPORT_SYMBOL(__set_personality); #ifdef CONFIG_PROC_FSstatic int execdomains_proc_show(struct seq_file *m, void *v){	struct exec_domain	*ep; 	read_lock(&exec_domains_lock);	for (ep = exec_domains; ep; ep = ep->next)		seq_printf(m, "%d-%d\t%-16s\t[%s]\n",			       ep->pers_low, ep->pers_high, ep->name,			       module_name(ep->module));	read_unlock(&exec_domains_lock);	return 0;} static int execdomains_proc_open(struct inode *inode, struct file *file){	return single_open(file, execdomains_proc_show, NULL);} static const struct file_operations execdomains_proc_fops = {	.open		= execdomains_proc_open,	.read		= seq_read,	.llseek		= seq_lseek,	.release	= single_release,}; static int __init proc_execdomains_init(void){	proc_create("execdomains", 0, NULL, &execdomains_proc_fops);	return 0;}module_init(proc_execdomains_init);#endif SYSCALL_DEFINE1(personality, unsigned int, personality){	unsigned int old = current->personality; 	if (personality != 0xffffffff)		set_personality(personality); 	return old;}