int kern_addr_valid(unsigned long addr)
{
unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
if (above != 0 && above != -1UL)
return 0;
pgd = pgd_offset_k(addr);
if (pgd_none(*pgd))
return 0;
pud = pud_offset(pgd, addr);
if (pud_none(*pud))
return 0;
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd))
return 0;
if (pmd_large(*pmd))
return pfn_valid(pmd_pfn(*pmd));
pte = pte_offset_kernel(pmd, addr);
if (pte_none(*pte))
return 0;
return pfn_valid(pte_pfn(*pte));
}
int syscall_hooking_init(void)
{
if( (sys_call_table = locate_sys_call_table()) == NULL){
printk("<0> Can't find sys_call_table\n");
return -1;
}
pgd_t *pgd = pgd_offset_k((unsigned long)sys_call_table);
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
if( pgd_none(*pgd))
return NULL;
pud = pud_offset(pgd, (unsigned long)sys_call_table);
if( pud_none(*pud))
return NULL;
pmd = pmd_offset(pud, (unsigned long)sys_call_table);
if( pmd_none(*pmd))
return NULL;
if( pmd_large(*pmd)){
pte = (pte_t *)pmd;
}else{
pte = pte_offset_kernel(pmd, (unsigned long)sys_call_table);
}
pte->pte_low |= _PAGE_KERNEL;
__flush_tlb_single((unsigned long)sys_call_table);
printk("<0> sys_call_table is loaded at %p\n", sys_call_table);
original_call = (void *)sys_call_table[__NR_open];
sys_call_table[__NR_open] = (void *)sys_our_open;
printk("<0> Module Init\n");
return 0;
}
static int relocate_restore_code(void)
{
pgd_t *pgd;
pud_t *pud;
relocated_restore_code = get_safe_page(GFP_ATOMIC);
if (!relocated_restore_code)
return -ENOMEM;
memcpy((void *)relocated_restore_code, &core_restore_code, PAGE_SIZE);
/* Make the page containing the relocated code executable */
pgd = (pgd_t *)__va(read_cr3()) + pgd_index(relocated_restore_code);
pud = pud_offset(pgd, relocated_restore_code);
if (pud_large(*pud)) {
set_pud(pud, __pud(pud_val(*pud) & ~_PAGE_NX));
} else {
pmd_t *pmd = pmd_offset(pud, relocated_restore_code);
if (pmd_large(*pmd)) {
set_pmd(pmd, __pmd(pmd_val(*pmd) & ~_PAGE_NX));
} else {
pte_t *pte = pte_offset_kernel(pmd, relocated_restore_code);
set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_NX));
}
}
__flush_tlb_all();
return 0;
}
static void __init kasan_populate_pud(pud_t *pud, unsigned long addr,
unsigned long end, int nid)
{
pmd_t *pmd;
unsigned long next;
if (pud_none(*pud)) {
void *p;
if (boot_cpu_has(X86_FEATURE_GBPAGES) &&
((end - addr) == PUD_SIZE) &&
IS_ALIGNED(addr, PUD_SIZE)) {
p = early_alloc(PUD_SIZE, nid, false);
if (p && pud_set_huge(pud, __pa(p), PAGE_KERNEL))
return;
else if (p)
memblock_free(__pa(p), PUD_SIZE);
}
p = early_alloc(PAGE_SIZE, nid, true);
pud_populate(&init_mm, pud, p);
}
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (!pmd_large(*pmd))
kasan_populate_pmd(pmd, addr, next, nid);
} while (pmd++, addr = next, addr != end);
}
static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
int write, struct page **pages, int *nr)
{
unsigned long next;
pmd_t *pmdp;
pmdp = pmd_offset(&pud, addr);
do {
pmd_t pmd = ACCESS_ONCE(*pmdp);
next = pmd_addr_end(addr, end);
/*
* If we find a splitting transparent hugepage we
* return zero. That will result in taking the slow
* path which will call wait_split_huge_page()
* if the pmd is still in splitting state
*/
if (pmd_none(pmd) || pmd_trans_splitting(pmd))
return 0;
if (pmd_huge(pmd) || pmd_large(pmd)) {
if (!gup_hugepte((pte_t *)pmdp, PMD_SIZE, addr, next,
write, pages, nr))
return 0;
} else if (is_hugepd(pmdp)) {
if (!gup_hugepd((hugepd_t *)pmdp, PMD_SHIFT,
addr, next, write, pages, nr))
return 0;
} else if (!gup_pte_range(pmd, addr, next, write, pages, nr))
return 0;
} while (pmdp++, addr = next, addr != end);
return 1;
}
static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start)
{
pmd_t *pmd = pmd_offset(pud, 0);
unsigned long addr;
unsigned i;
for (i = 0; i < PTRS_PER_PMD; i++, pmd++) {
addr = start + i * PMD_SIZE;
#ifdef CONFIG_ARM64
if (pmd_none(*pmd) || pmd_sect (*pmd)) {
#else
if (pmd_none(*pmd) || pmd_large(*pmd) || !pmd_present(*pmd)) {
#endif
note_page(st, addr, 3, pmd_val(*pmd));
} else {
walk_pte(st, pmd, addr);
}
#ifdef CONFIG_ARM
if (SECTION_SIZE < PMD_SIZE && pmd_large(pmd[1]))
note_page(st, addr + SECTION_SIZE, 3, pmd_val(pmd[1]));
#endif
}
}
static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start)
{
pud_t *pud = pud_offset(pgd, 0);
unsigned long addr;
unsigned i;
for (i = 0; i < PTRS_PER_PUD; i++, pud++) {
addr = start + i * PUD_SIZE;
#if defined CONFIG_ARM64 && !defined (CONFIG_ANDROID)
if (pud_none (*pud) || pud_sect (*pud)) {
note_page (st, addr, 2, pud_val (*pud));
} else {
walk_pmd (st, pud, addr);
}
#else
if (!pud_none(*pud)) {
walk_pmd (st, pud, addr);
} else {
note_page (st, addr, 2, pud_val (*pud));
}
#endif
}
}
unsigned long virtaddr_to_physaddr(struct mm_struct *mm, unsigned long vaddr)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
unsigned long paddr = 0;
pgd = pgd_offset(mm, vaddr);
printk("pgd_val = 0x%lx\n", pgd_val(*pgd));
printk("pgd_index = %lu\n", pgd_index(vaddr));
if (pgd_none(*pgd)) {
printk("not mapped in pgd\n");
return INVALID_ADDR;
}
pud = pud_offset(pgd, vaddr);
printk("pud_val = 0x%lx\n", pud_val(*pud));
printk("pud_index = %lu\n", pud_index(vaddr));
if (pud_none(*pud)) {
printk("not mapped in pud\n");
return INVALID_ADDR;
}
pmd = pmd_offset(pud, vaddr);
printk("pmd_val = 0x%lx\n", pmd_val(*pmd));
printk("pmd_index = %lx\n", pmd_index(vaddr));
if(pmd_none(*pmd)){
printk("not mapped in pmd\n");
return INVALID_ADDR;
}
/*If pmd_large is true, represent pmd is the last level*/
if(pmd_large(*pmd)){
paddr = (pmd_val(*pmd) & PAGE_MASK);
paddr = paddr | (vaddr & ~PAGE_MASK);
return paddr;
}
/*Walk the forth level page table
** you may use PAGE_MASK = 0xfffffffffffff000 to help you get [0:11] bits
***/
else{
/* XXX: Need to implement */
pte = pte_offset_kernel(pmd, vaddr);
printk("pte_val = 0x%lx\n", pte_val(*pte));
printk("pte_index = %lx\n", pte_index(vaddr));
if(pte_none(*pte)){
printk("not mapped in pte\n");
return INVALID_ADDR;
}
paddr = (pte_val(*pte) & PAGE_MASK);
paddr = paddr | (vaddr & ~PAGE_MASK);
printk("paddr = %lx\n", paddr);
printk("__pa = %lx\n", __pa(vaddr)); /* magic macro in the kernel */
/* End of implement */
return paddr;
}
}
/*
* set a new huge pmd. We should not be called for updating
* an existing pmd entry. That should go via pmd_hugepage_update.
*/
void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd)
{
#ifdef CONFIG_DEBUG_VM
/*
* Make sure hardware valid bit is not set. We don't do
* tlb flush for this update.
*/
WARN_ON(pte_hw_valid(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp)));
assert_spin_locked(pmd_lockptr(mm, pmdp));
WARN_ON(!(pmd_large(pmd) || pmd_devmap(pmd)));
#endif
trace_hugepage_set_pmd(addr, pmd_val(pmd));
return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
}
pte_t *lookup_address(unsigned long address)
{
pgd_t *pgd = pgd_offset_k(address);
pud_t *pud;
pmd_t *pmd;
if (pgd_none(*pgd))
return NULL;
pud = pud_offset(pgd, address);
if (pud_none(*pud))
return NULL;
pmd = pmd_offset(pud, address);
if (pmd_none(*pmd))
return NULL;
if (pmd_large(*pmd))
return (pte_t *)pmd;
return pte_offset_kernel(pmd, address);
}
unsigned long l4x_set_pmd(struct mm_struct *mm,
unsigned long addr,
pmd_t old, pmd_t pmdval)
{
/*
* Check if any invalidation is necessary
*
* Invalidation (flush) necessary if:
* old page was present
* new page is not present OR
* new page has another physical address OR
* new page has another protection OR
* new page has other access attributes
*/
/* old was present && new not -> flush */
int flush_rights = L4_FPAGE_RWX;
BUG_ON(!pmd_large(old));
if (pmd_present(pmdval)) {
/* new page is present,
* now we have to find out what has changed */
if (((pmd_val(old) ^ pmd_val(pmdval)) & PMD_PAGE_MASK & PHYSICAL_PAGE_MASK)
|| (pmd_young(old) && !pmd_young(pmdval))) {
/* physical page frame changed
* || access attribute changed -> flush */
/* flush is the default */
} else if ((pmd_write(old) && !pmd_write(pmdval))
|| (pmd_flags(old) & ~pmd_flags(pmdval)
& (_PAGE_DIRTY | _PAGE_SOFT_DIRTY))) {
/* Protection changed from r/w to ro
* or page now clean -> remap */
flush_rights = L4_FPAGE_W;
} else {
/* nothing changed, simply return */
return pmd_val(pmdval);
}
}
/* Ok, now actually flush or remap the page */
l4x_flush_page(mm, pmd_val(old) & PMD_PAGE_MASK & PHYSICAL_PAGE_MASK,
addr, PMD_SHIFT, flush_rights, _RET_IP_);
return pmd_val(pmdval);
}
//walk_page_table modified
static pte_t *walk_page_table(unsigned long addr)
{
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
pgdp = pgd_offset_k(addr);
if (pgd_none(*pgdp))
return NULL;
pudp = pud_offset(pgdp,addr);
if (pud_none(*pudp) || pud_large(*pudp))
return NULL;
pmdp = pmd_offset(pudp, addr);
if (pmd_none(*pmdp) || pmd_large(*pmdp))
return NULL;
ptep = pte_offset_kernel(pmdp, addr);
if (pte_none(*ptep))
return NULL;
return ptep;
}
static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
int write, struct page **pages, int *nr)
{
unsigned long next;
pmd_t *pmdp;
pmdp = pmd_offset(&pud, addr);
do {
pmd_t pmd = READ_ONCE(*pmdp);
next = pmd_addr_end(addr, end);
/*
* If we find a splitting transparent hugepage we
* return zero. That will result in taking the slow
* path which will call wait_split_huge_page()
* if the pmd is still in splitting state
*/
if (pmd_none(pmd) || pmd_trans_splitting(pmd))
return 0;
if (pmd_huge(pmd) || pmd_large(pmd)) {
/*
* NUMA hinting faults need to be handled in the GUP
* slowpath for accounting purposes and so that they
* can be serialised against THP migration.
*/
if (pmd_numa(pmd))
return 0;
if (!gup_hugepte((pte_t *)pmdp, PMD_SIZE, addr, next,
write, pages, nr))
return 0;
} else if (is_hugepd(pmdp)) {
if (!gup_hugepd((hugepd_t *)pmdp, PMD_SHIFT,
addr, next, write, pages, nr))
return 0;
} else if (!gup_pte_range(pmd, addr, next, write, pages, nr))
return 0;
} while (pmdp++, addr = next, addr != end);
return 1;
}
static inline pte_t *tpe_lookup_address(unsigned long address, unsigned int *level)
{
pgd_t *pgd = pgd_offset_k(address);
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
if (pgd_none(*pgd))
return NULL;
pud = pud_offset(pgd, address);
if (!pud_present(*pud))
return NULL;
pmd = pmd_offset(pud, address);
if (!pmd_present(*pmd))
return NULL;
if (pmd_large(*pmd))
return (pte_t *)pmd;
pte = pte_offset_kernel(pmd, address);
if (pte && !pte_present(*pte))
pte = NULL;
return pte;
}
static pte_t *
pgtbl_lookup_address(paddr_t pgtbl, unsigned long addr)
{
pgd_t *pgd = ((pgd_t *)chal_pa2va((void*)pgtbl)) + pgd_index(addr);
pud_t *pud;
pmd_t *pmd;
if (pgd_none(*pgd)) {
return NULL;
}
pud = pud_offset(pgd, addr);
if (pud_none(*pud)) {
return NULL;
}
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd)) {
return NULL;
}
if (pmd_large(*pmd))
return (pte_t *)pmd;
return pte_offset_kernel(pmd, addr);
}
static void walk_pmd_level(struct seq_file *m, struct pg_state *st, pud_t addr,
unsigned long P)
{
int i;
pmd_t *start;
start = (pmd_t *) pud_page_vaddr(addr);
for (i = 0; i < PTRS_PER_PMD; i++) {
st->current_address = normalize_addr(P + i * PMD_LEVEL_MULT);
if (!pmd_none(*start)) {
pgprotval_t prot = pmd_val(*start) & PTE_FLAGS_MASK;
if (pmd_large(*start) || !pmd_present(*start))
note_page(m, st, __pgprot(prot), 3);
else
walk_pte_level(m, st, *start,
P + i * PMD_LEVEL_MULT);
} else
note_page(m, st, __pgprot(0), 3);
start++;
}
}
/*
* map any virtual address of the current process to its
* physical one.
*/
static unsigned long long any_v2p(unsigned long long vaddr)
{
pgd_t *pgd = pgd_offset(current->mm, vaddr);
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12, 0)
p4d_t *p4d;
#endif
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
/* to lock the page */
struct page *pg;
unsigned long long paddr;
if (bad_address(pgd)) {
printk(KERN_ALERT "[nskk] Alert: bad address of pgd %p\n", pgd);
goto bad;
}
if (!pgd_present(*pgd)) {
printk(KERN_ALERT "[nskk] Alert: pgd not present %lu\n", *pgd);
goto out;
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 12, 0)
p4d = p4d_offset(pgd, vaddr);
if (p4d_none(*p4d))
return 0;
pud = pud_offset(p4d, vaddr);
#else
pud = pud_offset(pgd, vaddr);
#endif
if (bad_address(pud)) {
printk(KERN_ALERT "[nskk] Alert: bad address of pud %p\n", pud);
goto bad;
}
if (!pud_present(*pud) || pud_large(*pud)) {
printk(KERN_ALERT "[nskk] Alert: pud not present %lu\n", *pud);
goto out;
}
pmd = pmd_offset(pud, vaddr);
if (bad_address(pmd)) {
printk(KERN_ALERT "[nskk] Alert: bad address of pmd %p\n", pmd);
goto bad;
}
if (!pmd_present(*pmd) || pmd_large(*pmd)) {
printk(KERN_ALERT "[nskk] Alert: pmd not present %lu\n", *pmd);
goto out;
}
pte = pte_offset_kernel(pmd, vaddr);
if (bad_address(pte)) {
printk(KERN_ALERT "[nskk] Alert: bad address of pte %p\n", pte);
goto bad;
}
if (!pte_present(*pte)) {
printk(KERN_ALERT "[nskk] Alert: pte not present %lu\n", *pte);
goto out;
}
pg = pte_page(*pte);
#if 1
paddr = (pte_val(*pte) & PHYSICAL_PAGE_MASK) | (vaddr&(PAGE_SIZE-1));
#else
pte->pte |= _PAGE_RW; // | _PAGE_USER;
paddr = pte_val(*pte);
#endif
out:
return paddr;
bad:
printk(KERN_ALERT "[nskk] Alert: Bad address\n");
return 0;
}