zap_page_range was originally designed to unmap pages within an address
range that could span multiple vmas. While working on [1], it was
discovered that all callers of zap_page_range pass a range entirely within
a single vma. In addition, the mmu notification call within zap_page
range does not correctly handle ranges that span multiple vmas. When
crossing a vma boundary, a new mmu_notifier_range_init/end call pair with
the new vma should be made.
Instead of fixing zap_page_range, do the following:
- Create a new routine zap_vma_pages() that will remove all pages within
the passed vma. Most users of zap_page_range pass the entire vma and
can use this new routine.
- For callers of zap_page_range not passing the entire vma, instead call
zap_page_range_single().
- Remove zap_page_range.
[1] https://lore.kernel.org/linux-mm/
20221114235507.294320-2-mike.kravetz@oracle.com/
Link: https://lkml.kernel.org/r/20230104002732.232573-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Suggested-by: Peter Xu <peterx@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com> [s390]
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mmap_read_lock(mm);
for_each_vma(vmi, vma) {
- unsigned long size = vma->vm_end - vma->vm_start;
-
if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA64].dm))
- zap_page_range(vma, vma->vm_start, size);
+ zap_vma_pages(vma);
#ifdef CONFIG_COMPAT_VDSO
if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA32].dm))
- zap_page_range(vma, vma->vm_start, size);
+ zap_vma_pages(vma);
#endif
}
mmap_read_lock(mm);
for_each_vma(vmi, vma) {
- unsigned long size = vma->vm_end - vma->vm_start;
-
if (vma_is_special_mapping(vma, &vvar_spec))
- zap_page_range(vma, vma->vm_start, size);
+ zap_vma_pages(vma);
}
mmap_read_unlock(mm);
/*
* When the LPAR lost credits due to core removal or during
* migration, invalidate the existing mapping for the current
- * paste addresses and set windows in-active (zap_page_range in
+ * paste addresses and set windows in-active (zap_vma_pages in
* reconfig_close_windows()).
* New mapping will be done later after migration or new credits
* available. So continue to receive faults if the user space
* is done before the original mmap() and after the ioctl.
*/
if (vma)
- zap_page_range(vma, vma->vm_start,
- vma->vm_end - vma->vm_start);
+ zap_vma_pages(vma);
mmap_write_unlock(task_ref->mm);
mutex_unlock(&task_ref->mmap_mutex);
mmap_read_lock(mm);
for_each_vma(vmi, vma) {
- unsigned long size = vma->vm_end - vma->vm_start;
-
if (vma_is_special_mapping(vma, vdso_info.dm))
- zap_page_range(vma, vma->vm_start, size);
+ zap_vma_pages(vma);
#ifdef CONFIG_COMPAT
if (vma_is_special_mapping(vma, compat_vdso_info.dm))
- zap_page_range(vma, vma->vm_start, size);
+ zap_vma_pages(vma);
#endif
}
mmap_read_lock(mm);
for_each_vma(vmi, vma) {
- unsigned long size = vma->vm_end - vma->vm_start;
-
if (!vma_is_special_mapping(vma, &vvar_mapping))
continue;
- zap_page_range(vma, vma->vm_start, size);
+ zap_vma_pages(vma);
break;
}
mmap_read_unlock(mm);
if (is_vm_hugetlb_page(vma))
continue;
size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
- zap_page_range(vma, vmaddr, size);
+ zap_page_range_single(vma, vmaddr, size, NULL);
}
mmap_read_unlock(gmap->mm);
}
mmap_read_lock(mm);
for_each_vma(vmi, vma) {
- unsigned long size = vma->vm_end - vma->vm_start;
-
if (vma_is_special_mapping(vma, &vvar_mapping))
- zap_page_range(vma, vma->vm_start, size);
+ zap_vma_pages(vma);
}
mmap_read_unlock(mm);
if (vma) {
trace_binder_unmap_user_start(alloc, index);
- zap_page_range(vma, page_addr, PAGE_SIZE);
+ zap_page_range_single(vma, page_addr, PAGE_SIZE, NULL);
trace_binder_unmap_user_end(alloc, index);
}
void zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
unsigned long size);
-void zap_page_range(struct vm_area_struct *vma, unsigned long address,
- unsigned long size);
void zap_page_range_single(struct vm_area_struct *vma, unsigned long address,
unsigned long size, struct zap_details *details);
+static inline void zap_vma_pages(struct vm_area_struct *vma)
+{
+ zap_page_range_single(vma, vma->vm_start,
+ vma->vm_end - vma->vm_start, NULL);
+}
void unmap_vmas(struct mmu_gather *tlb, struct maple_tree *mt,
struct vm_area_struct *start_vma, unsigned long start,
unsigned long end);
mmu_notifier_invalidate_range_end(&range);
}
-/**
- * zap_page_range - remove user pages in a given range
- * @vma: vm_area_struct holding the applicable pages
- * @start: starting address of pages to zap
- * @size: number of bytes to zap
- *
- * Caller must protect the VMA list
- */
-void zap_page_range(struct vm_area_struct *vma, unsigned long start,
- unsigned long size)
-{
- struct maple_tree *mt = &vma->vm_mm->mm_mt;
- unsigned long end = start + size;
- struct mmu_notifier_range range;
- struct mmu_gather tlb;
- MA_STATE(mas, mt, vma->vm_end, vma->vm_end);
-
- lru_add_drain();
- mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm,
- start, start + size);
- tlb_gather_mmu(&tlb, vma->vm_mm);
- update_hiwater_rss(vma->vm_mm);
- mmu_notifier_invalidate_range_start(&range);
- do {
- unmap_single_vma(&tlb, vma, start, range.end, NULL);
- } while ((vma = mas_find(&mas, end - 1)) != NULL);
- mmu_notifier_invalidate_range_end(&range);
- tlb_finish_mmu(&tlb);
-}
-
/**
* zap_page_range_single - remove user pages in a given range
* @vma: vm_area_struct holding the applicable pages
*
* The caller must hold lock_page_memcg(). Most callers have the folio
* locked. A few have the folio blocked from truncation through other
- * means (eg zap_page_range() has it mapped and is holding the page table
+ * means (eg zap_vma_pages() has it mapped and is holding the page table
* lock). This can also be called from mark_buffer_dirty(), which I
* cannot prove is always protected against truncate.
*/
maybe_zap_len = total_bytes_to_map - /* All bytes to map */
*length + /* Mapped or pending */
(pages_remaining * PAGE_SIZE); /* Failed map. */
- zap_page_range(vma, *address, maybe_zap_len);
+ zap_page_range_single(vma, *address, maybe_zap_len, NULL);
err = 0;
}
unsigned long leftover_pages = pages_remaining;
int bytes_mapped;
- /* We called zap_page_range, try to reinsert. */
+ /* We called zap_page_range_single, try to reinsert. */
err = vm_insert_pages(vma, *address,
pending_pages,
&pages_remaining);
total_bytes_to_map = avail_len & ~(PAGE_SIZE - 1);
if (total_bytes_to_map) {
if (!(zc->flags & TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT))
- zap_page_range(vma, address, total_bytes_to_map);
+ zap_page_range_single(vma, address, total_bytes_to_map,
+ NULL);
zc->length = total_bytes_to_map;
zc->recv_skip_hint = 0;
} else {
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