Atmosphere/exosphere/userpage.c
2018-02-20 13:51:17 -08:00

62 lines
2.1 KiB
C

#include <stdint.h>
#include "utils.h"
#include "userpage.h"
uint64_t g_secure_page_user_address = NULL;
/* Create a user page reference for the desired address. */
/* Returns 1 on success, 0 on failure. */
int upage_init(upage_ref_t *upage, void *user_address) {
upage->user_page = get_page_for_address(user_address);
upage->secure_page = 0ULL;
if (g_secure_page_user_address != NULL) {
/* Different physical address indicate SPL was rebooted, or another process got access to svcCallSecureMonitor. Panic. */
if (g_secure_page_user_address != upage->user_page) {
panic();
}
upage->secure_page = SECURE_USER_PAGE_ADDR;
} else {
/* Weakly validate SPL's physically random address is in DRAM. */
if (upage->user_page >> 31) {
g_secure_page_user_address = upage->user_page;
/* TODO: Map this page into the MMU and invalidate the TLB. */
upage->secure_page = SECURE_USER_PAGE_ADDR;
}
}
return upage->secure_page != 0ULL;
}
int user_copy_to_secure(upage_ref_t *upage, void *secure_dst, void *user_src, size_t size) {
/* Fail if the page doesn't match. */
if (get_page_for_address(user_src) != upage->user_page) {
return 0;
}
/* Fail if we go past the page boundary. */
if (size != 0 && get_page_for_address(user_src + size - 1) != upage->user_page) {
return 0;
}
void *secure_src = (void *)(upage->secure_page + ((uint64_t)user_src - upage->user_page));
memcpy(secure_dst, secure_src, size);
return 1;
}
int secure_copy_to_user(upage_ref_t *upage, void *user_dst, void *secure_src, size_t size) {
/* Fail if the page doesn't match. */
if (get_page_for_address(user_dst) != upage->user_page) {
return 0;
}
/* Fail if we go past the page boundary. */
if (size != 0 && get_page_for_address(user_dst + size - 1) != upage->user_page) {
return 0;
}
void *secure_dst = (void *)(upage->secure_page + ((uint64_t)user_dst - upage->user_page));
memcpy(secure_dst, secure_src, size);
return 1;
}