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-rw-r--r--mm/shmem.c149
1 files changed, 139 insertions, 10 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 3a7587a0314d..9c6d22ff44e2 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -34,6 +34,8 @@
#include <linux/uio.h>
#include <linux/khugepaged.h>
+#include <asm/tlbflush.h> /* for arch/microblaze update_mmu_cache() */
+
static struct vfsmount *shm_mnt;
#ifdef CONFIG_SHMEM
@@ -70,6 +72,8 @@ static struct vfsmount *shm_mnt;
#include <linux/syscalls.h>
#include <linux/fcntl.h>
#include <uapi/linux/memfd.h>
+#include <linux/userfaultfd_k.h>
+#include <linux/rmap.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
@@ -115,13 +119,14 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
struct shmem_inode_info *info, pgoff_t index);
static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
struct page **pagep, enum sgp_type sgp,
- gfp_t gfp, struct mm_struct *fault_mm, int *fault_type);
+ gfp_t gfp, struct vm_area_struct *vma,
+ struct vm_fault *vmf, int *fault_type);
int shmem_getpage(struct inode *inode, pgoff_t index,
struct page **pagep, enum sgp_type sgp)
{
return shmem_getpage_gfp(inode, index, pagep, sgp,
- mapping_gfp_mask(inode->i_mapping), NULL, NULL);
+ mapping_gfp_mask(inode->i_mapping), NULL, NULL, NULL);
}
static inline struct shmem_sb_info *SHMEM_SB(struct super_block *sb)
@@ -190,6 +195,11 @@ static const struct inode_operations shmem_special_inode_operations;
static const struct vm_operations_struct shmem_vm_ops;
static struct file_system_type shmem_fs_type;
+bool vma_is_shmem(struct vm_area_struct *vma)
+{
+ return vma->vm_ops == &shmem_vm_ops;
+}
+
static LIST_HEAD(shmem_swaplist);
static DEFINE_MUTEX(shmem_swaplist_mutex);
@@ -1570,7 +1580,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
*/
static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
struct page **pagep, enum sgp_type sgp, gfp_t gfp,
- struct mm_struct *fault_mm, int *fault_type)
+ struct vm_area_struct *vma, struct vm_fault *vmf, int *fault_type)
{
struct address_space *mapping = inode->i_mapping;
struct shmem_inode_info *info = SHMEM_I(inode);
@@ -1624,7 +1634,7 @@ repeat:
* bring it back from swap or allocate.
*/
sbinfo = SHMEM_SB(inode->i_sb);
- charge_mm = fault_mm ? : current->mm;
+ charge_mm = vma ? vma->vm_mm : current->mm;
if (swap.val) {
/* Look it up and read it in.. */
@@ -1634,7 +1644,8 @@ repeat:
if (fault_type) {
*fault_type |= VM_FAULT_MAJOR;
count_vm_event(PGMAJFAULT);
- mem_cgroup_count_vm_event(fault_mm, PGMAJFAULT);
+ mem_cgroup_count_vm_event(charge_mm,
+ PGMAJFAULT);
}
/* Here we actually start the io */
page = shmem_swapin(swap, gfp, info, index);
@@ -1703,6 +1714,11 @@ repeat:
swap_free(swap);
} else {
+ if (vma && userfaultfd_missing(vma)) {
+ *fault_type = handle_userfault(vmf, VM_UFFD_MISSING);
+ return 0;
+ }
+
/* shmem_symlink() */
if (mapping->a_ops != &shmem_aops)
goto alloc_nohuge;
@@ -1965,7 +1981,7 @@ static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
sgp = SGP_NOHUGE;
error = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, sgp,
- gfp, vma->vm_mm, &ret);
+ gfp, vma, vmf, &ret);
if (error)
return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS);
return ret;
@@ -2175,10 +2191,123 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
bool shmem_mapping(struct address_space *mapping)
{
- if (!mapping->host)
- return false;
+ return mapping->a_ops == &shmem_aops;
+}
- return mapping->host->i_sb->s_op == &shmem_ops;
+int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm,
+ pmd_t *dst_pmd,
+ struct vm_area_struct *dst_vma,
+ unsigned long dst_addr,
+ unsigned long src_addr,
+ struct page **pagep)
+{
+ struct inode *inode = file_inode(dst_vma->vm_file);
+ struct shmem_inode_info *info = SHMEM_I(inode);
+ struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
+ struct address_space *mapping = inode->i_mapping;
+ gfp_t gfp = mapping_gfp_mask(mapping);
+ pgoff_t pgoff = linear_page_index(dst_vma, dst_addr);
+ struct mem_cgroup *memcg;
+ spinlock_t *ptl;
+ void *page_kaddr;
+ struct page *page;
+ pte_t _dst_pte, *dst_pte;
+ int ret;
+
+ ret = -ENOMEM;
+ if (shmem_acct_block(info->flags, 1))
+ goto out;
+ if (sbinfo->max_blocks) {
+ if (percpu_counter_compare(&sbinfo->used_blocks,
+ sbinfo->max_blocks) >= 0)
+ goto out_unacct_blocks;
+ percpu_counter_inc(&sbinfo->used_blocks);
+ }
+
+ if (!*pagep) {
+ page = shmem_alloc_page(gfp, info, pgoff);
+ if (!page)
+ goto out_dec_used_blocks;
+
+ page_kaddr = kmap_atomic(page);
+ ret = copy_from_user(page_kaddr, (const void __user *)src_addr,
+ PAGE_SIZE);
+ kunmap_atomic(page_kaddr);
+
+ /* fallback to copy_from_user outside mmap_sem */
+ if (unlikely(ret)) {
+ *pagep = page;
+ if (sbinfo->max_blocks)
+ percpu_counter_add(&sbinfo->used_blocks, -1);
+ shmem_unacct_blocks(info->flags, 1);
+ /* don't free the page */
+ return -EFAULT;
+ }
+ } else {
+ page = *pagep;
+ *pagep = NULL;
+ }
+
+ VM_BUG_ON(PageLocked(page) || PageSwapBacked(page));
+ __SetPageLocked(page);
+ __SetPageSwapBacked(page);
+ __SetPageUptodate(page);
+
+ ret = mem_cgroup_try_charge(page, dst_mm, gfp, &memcg, false);
+ if (ret)
+ goto out_release;
+
+ ret = radix_tree_maybe_preload(gfp & GFP_RECLAIM_MASK);
+ if (!ret) {
+ ret = shmem_add_to_page_cache(page, mapping, pgoff, NULL);
+ radix_tree_preload_end();
+ }
+ if (ret)
+ goto out_release_uncharge;
+
+ mem_cgroup_commit_charge(page, memcg, false, false);
+
+ _dst_pte = mk_pte(page, dst_vma->vm_page_prot);
+ if (dst_vma->vm_flags & VM_WRITE)
+ _dst_pte = pte_mkwrite(pte_mkdirty(_dst_pte));
+
+ ret = -EEXIST;
+ dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
+ if (!pte_none(*dst_pte))
+ goto out_release_uncharge_unlock;
+
+ lru_cache_add_anon(page);
+
+ spin_lock(&info->lock);
+ info->alloced++;
+ inode->i_blocks += BLOCKS_PER_PAGE;
+ shmem_recalc_inode(inode);
+ spin_unlock(&info->lock);
+
+ inc_mm_counter(dst_mm, mm_counter_file(page));
+ page_add_file_rmap(page, false);
+ set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
+
+ /* No need to invalidate - it was non-present before */
+ update_mmu_cache(dst_vma, dst_addr, dst_pte);
+ unlock_page(page);
+ pte_unmap_unlock(dst_pte, ptl);
+ ret = 0;
+out:
+ return ret;
+out_release_uncharge_unlock:
+ pte_unmap_unlock(dst_pte, ptl);
+out_release_uncharge:
+ mem_cgroup_cancel_charge(page, memcg, false);
+out_release:
+ unlock_page(page);
+ put_page(page);
+out_dec_used_blocks:
+ if (sbinfo->max_blocks)
+ percpu_counter_add(&sbinfo->used_blocks, -1);
+out_unacct_blocks:
+ shmem_unacct_blocks(info->flags, 1);
+ goto out;
}
#ifdef CONFIG_TMPFS
@@ -4140,7 +4269,7 @@ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
BUG_ON(mapping->a_ops != &shmem_aops);
error = shmem_getpage_gfp(inode, index, &page, SGP_CACHE,
- gfp, NULL, NULL);
+ gfp, NULL, NULL, NULL);
if (error)
page = ERR_PTR(error);
else
generated by cgit v1.2.3 (git 2.25.1) at 2025-02-13 03:24:26 +0000