diff options
| author | Alexander Gordeev <agordeev@linux.ibm.com> | 2023-09-01 08:11:14 +0200 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2023-09-05 20:12:52 +0200 |
| commit | 06fc3b0d2251b550f530a1c42e0f9c5d022476dd (patch) | |
| tree | 2e263b7abd271e0f0f8ad23c426f218c2c36a98a | |
| parent | f59ec04d382d2f2528f439947e215a52703e0094 (diff) | |
| download | xfs-linux-06fc3b0d2251b550f530a1c42e0f9c5d022476dd.tar.gz | |
s390/vmem: do not silently ignore mapping limit
The only interface that allows drivers establishing
liner mappings is vmem_add_mapping(). It does check
a requested range against allowed limits and a call
to modify_pagetable() with an invalid mapping range
is impossible.
Hence, an attempt to map an address range outside of
the identity mapping or vmemmap array could only be
kernel bug.
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| -rw-r--r-- | arch/s390/mm/vmem.c | 18 |
1 files changed, 3 insertions, 15 deletions
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index d734058f28d312..6957d2ed97bf0e 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -290,14 +290,9 @@ out: static void try_free_pmd_table(pud_t *pud, unsigned long start) { - const unsigned long end = start + PUD_SIZE; pmd_t *pmd; int i; - /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */ - if (end > VMALLOC_START) - return; - pmd = pmd_offset(pud, start); for (i = 0; i < PTRS_PER_PMD; i++, pmd++) if (!pmd_none(*pmd)) @@ -362,14 +357,9 @@ out: static void try_free_pud_table(p4d_t *p4d, unsigned long start) { - const unsigned long end = start + P4D_SIZE; pud_t *pud; int i; - /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */ - if (end > VMALLOC_START) - return; - pud = pud_offset(p4d, start); for (i = 0; i < PTRS_PER_PUD; i++, pud++) { if (!pud_none(*pud)) @@ -412,14 +402,9 @@ out: static void try_free_p4d_table(pgd_t *pgd, unsigned long start) { - const unsigned long end = start + PGDIR_SIZE; p4d_t *p4d; int i; - /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */ - if (end > VMALLOC_START) - return; - p4d = p4d_offset(pgd, start); for (i = 0; i < PTRS_PER_P4D; i++, p4d++) { if (!p4d_none(*p4d)) @@ -439,6 +424,9 @@ static int modify_pagetable(unsigned long start, unsigned long end, bool add, if (WARN_ON_ONCE(!PAGE_ALIGNED(start | end))) return -EINVAL; + /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */ + if (WARN_ON_ONCE(end > VMALLOC_START)) + return -EINVAL; for (addr = start; addr < end; addr = next) { next = pgd_addr_end(addr, end); pgd = pgd_offset_k(addr); |