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s390/kasan: fix large PMD pages address alignment check

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It is currently possible to initialize a large PMD page when
the address is not aligned on page boundary.

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Alexander Gordeev 2021-08-06 12:55:08 +02:00 committed by Heiko Carstens
parent c42257d640
commit ddd63c85ef
1 changed files with 19 additions and 20 deletions
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39
arch/s390/mm/kasan_init.c
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@ -107,6 +107,9 @@ static void __init kasan_early_pgtable_populate(unsigned long address,
sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;
}
/*
* The first 1MB of 1:1 mapping is mapped with 4KB pages
*/
while (address < end) {
pg_dir = pgd_offset_k(address);
if (pgd_none(*pg_dir)) {
@ -157,30 +160,26 @@ static void __init kasan_early_pgtable_populate(unsigned long address,
pm_dir = pmd_offset(pu_dir, address);
if (pmd_none(*pm_dir)) {
if (mode == POPULATE_ZERO_SHADOW &&
IS_ALIGNED(address, PMD_SIZE) &&
if (IS_ALIGNED(address, PMD_SIZE) &&
end - address >= PMD_SIZE) {
pmd_populate(&init_mm, pm_dir,
kasan_early_shadow_pte);
address = (address + PMD_SIZE) & PMD_MASK;
continue;
}
/* the first megabyte of 1:1 is mapped with 4k pages */
if (has_edat && address && end - address >= PMD_SIZE &&
mode != POPULATE_ZERO_SHADOW) {
void *page;
if (mode == POPULATE_ZERO_SHADOW) {
pmd_populate(&init_mm, pm_dir, kasan_early_shadow_pte);
address = (address + PMD_SIZE) & PMD_MASK;
continue;
} else if (has_edat && address) {
void *page;
if (mode == POPULATE_ONE2ONE) {
page = (void *)address;
} else {
page = kasan_early_alloc_segment();
memset(page, 0, _SEGMENT_SIZE);
if (mode == POPULATE_ONE2ONE) {
page = (void *)address;
} else {
page = kasan_early_alloc_segment();
memset(page, 0, _SEGMENT_SIZE);
}
pmd_val(*pm_dir) = __pa(page) | sgt_prot;
address = (address + PMD_SIZE) & PMD_MASK;
continue;
}
pmd_val(*pm_dir) = __pa(page) | sgt_prot;
address = (address + PMD_SIZE) & PMD_MASK;
continue;
}
pt_dir = kasan_early_pte_alloc();
pmd_populate(&init_mm, pm_dir, pt_dir);
} else if (pmd_large(*pm_dir)) {