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Diffstat (limited to 'mm/fremap.c')
-rw-r--r--mm/fremap.c86
1 files changed, 53 insertions, 33 deletions
diff --git a/mm/fremap.c b/mm/fremap.c
index a0aaf0e5680..72b8fa36143 100644
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -23,28 +23,44 @@
#include "internal.h"
+static int mm_counter(struct page *page)
+{
+ return PageAnon(page) ? MM_ANONPAGES : MM_FILEPAGES;
+}
+
static void zap_pte(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep)
{
pte_t pte = *ptep;
+ struct page *page;
+ swp_entry_t entry;
if (pte_present(pte)) {
- struct page *page;
-
flush_cache_page(vma, addr, pte_pfn(pte));
pte = ptep_clear_flush(vma, addr, ptep);
page = vm_normal_page(vma, addr, pte);
if (page) {
if (pte_dirty(pte))
set_page_dirty(page);
+ update_hiwater_rss(mm);
+ dec_mm_counter(mm, mm_counter(page));
page_remove_rmap(page);
page_cache_release(page);
+ }
+ } else { /* zap_pte() is not called when pte_none() */
+ if (!pte_file(pte)) {
update_hiwater_rss(mm);
- dec_mm_counter(mm, MM_FILEPAGES);
+ entry = pte_to_swp_entry(pte);
+ if (non_swap_entry(entry)) {
+ if (is_migration_entry(entry)) {
+ page = migration_entry_to_page(entry);
+ dec_mm_counter(mm, mm_counter(page));
+ }
+ } else {
+ free_swap_and_cache(entry);
+ dec_mm_counter(mm, MM_SWAPENTS);
+ }
}
- } else {
- if (!pte_file(pte))
- free_swap_and_cache(pte_to_swp_entry(pte));
pte_clear_not_present_full(mm, addr, ptep, 0);
}
}
@@ -57,17 +73,19 @@ static int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long addr, unsigned long pgoff, pgprot_t prot)
{
int err = -ENOMEM;
- pte_t *pte;
+ pte_t *pte, ptfile;
spinlock_t *ptl;
pte = get_locked_pte(mm, addr, &ptl);
if (!pte)
goto out;
+ ptfile = pgoff_to_pte(pgoff);
+
if (!pte_none(*pte))
zap_pte(mm, vma, addr, pte);
- set_pte_at(mm, addr, pte, pgoff_to_pte(pgoff));
+ set_pte_at(mm, addr, pte, pte_file_mksoft_dirty(ptfile));
/*
* We don't need to run update_mmu_cache() here because the "file pte"
* being installed by install_file_pte() is not a real pte - it's a
@@ -129,6 +147,11 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
struct vm_area_struct *vma;
int err = -EINVAL;
int has_write_lock = 0;
+ vm_flags_t vm_flags = 0;
+
+ pr_warn_once("%s (%d) uses deprecated remap_file_pages() syscall. "
+ "See Documentation/vm/remap_file_pages.txt.\n",
+ current->comm, current->pid);
if (prot)
return err;
@@ -160,15 +183,11 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
/*
* Make sure the vma is shared, that it supports prefaulting,
* and that the remapped range is valid and fully within
- * the single existing vma. vm_private_data is used as a
- * swapout cursor in a VM_NONLINEAR vma.
+ * the single existing vma.
*/
if (!vma || !(vma->vm_flags & VM_SHARED))
goto out;
- if (vma->vm_private_data && !(vma->vm_flags & VM_NONLINEAR))
- goto out;
-
if (!vma->vm_ops || !vma->vm_ops->remap_pages)
goto out;
@@ -177,6 +196,13 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
/* Must set VM_NONLINEAR before any pages are populated. */
if (!(vma->vm_flags & VM_NONLINEAR)) {
+ /*
+ * vm_private_data is used as a swapout cursor
+ * in a VM_NONLINEAR vma.
+ */
+ if (vma->vm_private_data)
+ goto out;
+
/* Don't need a nonlinear mapping, exit success */
if (pgoff == linear_page_index(vma, start)) {
err = 0;
@@ -184,6 +210,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
}
if (!has_write_lock) {
+get_write_lock:
up_read(&mm->mmap_sem);
down_write(&mm->mmap_sem);
has_write_lock = 1;
@@ -198,10 +225,10 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
if (mapping_cap_account_dirty(mapping)) {
unsigned long addr;
struct file *file = get_file(vma->vm_file);
+ /* mmap_region may free vma; grab the info now */
+ vm_flags = vma->vm_flags;
- flags &= MAP_NONBLOCK;
- addr = mmap_region(file, start, size,
- flags, vma->vm_flags, pgoff);
+ addr = mmap_region(file, start, size, vm_flags, pgoff);
fput(file);
if (IS_ERR_VALUE(addr)) {
err = addr;
@@ -209,7 +236,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
BUG_ON(addr != start);
err = 0;
}
- goto out;
+ goto out_freed;
}
mutex_lock(&mapping->i_mmap_mutex);
flush_dcache_mmap_lock(mapping);
@@ -224,28 +251,16 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
/*
* drop PG_Mlocked flag for over-mapped range
*/
- vm_flags_t saved_flags = vma->vm_flags;
+ if (!has_write_lock)
+ goto get_write_lock;
+ vm_flags = vma->vm_flags;
munlock_vma_pages_range(vma, start, start + size);
- vma->vm_flags = saved_flags;
+ vma->vm_flags = vm_flags;
}
mmu_notifier_invalidate_range_start(mm, start, start + size);
err = vma->vm_ops->remap_pages(vma, start, size, pgoff);
mmu_notifier_invalidate_range_end(mm, start, start + size);
- if (!err && !(flags & MAP_NONBLOCK)) {
- if (vma->vm_flags & VM_LOCKED) {
- /*
- * might be mapping previously unmapped range of file
- */
- mlock_vma_pages_range(vma, start, start + size);
- } else {
- if (unlikely(has_write_lock)) {
- downgrade_write(&mm->mmap_sem);
- has_write_lock = 0;
- }
- make_pages_present(start, start+size);
- }
- }
/*
* We can't clear VM_NONLINEAR because we'd have to do
@@ -254,10 +269,15 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
*/
out:
+ if (vma)
+ vm_flags = vma->vm_flags;
+out_freed:
if (likely(!has_write_lock))
up_read(&mm->mmap_sem);
else
up_write(&mm->mmap_sem);
+ if (!err && ((vm_flags & VM_LOCKED) || !(flags & MAP_NONBLOCK)))
+ mm_populate(start, size);
return err;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 20:30:55 +0000