Revision 6fc5bae797a6632bbccdd49a1b6a96121368a4b9 authored by David S. Miller on 29 December 2006, 05:00:23 UTC, committed by David S. Miller on 31 December 2006, 22:06:04 UTC
We were not being careful enough. When we trim the physical memory areas, we have to make sure we don't remove the kernel image or initial ramdisk image ranges. Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent bfff6e9
exec_domain.c
/*
* 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/sched.h>
#include <linux/syscalls.h>
#include <linux/sysctl.h>
#include <linux/types.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 u_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 void
default_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(u_long personality)
{
struct exec_domain * ep;
u_long pers = personality(personality);
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_KMOD
read_unlock(&exec_domains_lock);
request_module("personality-%ld", 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);
}
int
register_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);
}
int
unregister_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;
}
int
__set_personality(u_long personality)
{
struct exec_domain *ep, *oep;
ep = lookup_exec_domain(personality);
if (ep == current_thread_info()->exec_domain) {
current->personality = personality;
module_put(ep->module);
return 0;
}
if (atomic_read(¤t->fs->count) != 1) {
struct fs_struct *fsp, *ofsp;
fsp = copy_fs_struct(current->fs);
if (fsp == NULL) {
module_put(ep->module);
return -ENOMEM;
}
task_lock(current);
ofsp = current->fs;
current->fs = fsp;
task_unlock(current);
put_fs_struct(ofsp);
}
/*
* At that point we are guaranteed to be the sole owner of
* current->fs.
*/
current->personality = personality;
oep = current_thread_info()->exec_domain;
current_thread_info()->exec_domain = ep;
set_fs_altroot();
module_put(oep->module);
return 0;
}
int
get_exec_domain_list(char *page)
{
struct exec_domain *ep;
int len = 0;
read_lock(&exec_domains_lock);
for (ep = exec_domains; ep && len < PAGE_SIZE - 80; ep = ep->next)
len += sprintf(page + len, "%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 (len);
}
asmlinkage long
sys_personality(u_long personality)
{
u_long old = current->personality;
if (personality != 0xffffffff) {
set_personality(personality);
if (current->personality != personality)
return -EINVAL;
}
return (long)old;
}
EXPORT_SYMBOL(register_exec_domain);
EXPORT_SYMBOL(unregister_exec_domain);
EXPORT_SYMBOL(__set_personality);
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