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mm/vma: expand mmap_region() munmap call

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Open code the do_vmi_align_munmap() call so that it can be broken up later
in the series.

This requires exposing a few more vma operations.

Link: https://lkml.kernel.org/r/20240830040101.822209-10-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Liam R. Howlett
2024-08-30 00:00:49 -04:00
committed by Andrew Morton
parent c7c0c3c30f
commit 9014b230d8
3 changed files with 57 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files
mm/mmap.c
+22 -4
View File
@@ -1366,6 +1366,9 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
struct vm_area_struct *next, *prev, *merge;
pgoff_t pglen = len >> PAGE_SHIFT;
unsigned long charged = 0;
struct vma_munmap_struct vms;
struct ma_state mas_detach;
struct maple_tree mt_detach;
unsigned long end = addr + len;
unsigned long merge_start = addr, merge_end = end;
bool writable_file_mapping = false;
@@ -1391,11 +1394,28 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
/* Find the first overlapping VMA */
vma = vma_find(&vmi, end);
if (vma) {
/* Unmap any existing mapping in the area */
error = do_vmi_align_munmap(&vmi, vma, mm, addr, end, uf, false);
mt_init_flags(&mt_detach, vmi.mas.tree->ma_flags & MT_FLAGS_LOCK_MASK);
mt_on_stack(mt_detach);
mas_init(&mas_detach, &mt_detach, /* addr = */ 0);
init_vma_munmap(&vms, &vmi, vma, addr, end, uf, /* unlock = */ false);
/* Prepare to unmap any existing mapping in the area */
error = vms_gather_munmap_vmas(&vms, &mas_detach);
if (error)
return error;
/* Remove any existing mappings from the vma tree */
if (vma_iter_clear_gfp(&vmi, addr, end, GFP_KERNEL))
return -ENOMEM;
/* Unmap any existing mapping in the area */
vms_complete_munmap_vmas(&vms, &mas_detach);
next = vms.next;
prev = vms.prev;
vma_prev(&vmi);
vma = NULL;
} else {
next = vma_next(&vmi);
prev = vma_prev(&vmi);
}
/*
@@ -1408,8 +1428,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
vm_flags |= VM_ACCOUNT;
}
next = vma_next(&vmi);
prev = vma_prev(&vmi);
if (vm_flags & VM_SPECIAL) {
if (prev)
vma_iter_next_range(&vmi);
mm/vma.c
+2 -29
View File
@@ -80,33 +80,6 @@ static void init_multi_vma_prep(struct vma_prepare *vp,
}
/*
* init_vma_munmap() - Initializer wrapper for vma_munmap_struct
* @vms: The vma munmap struct
* @vmi: The vma iterator
* @vma: The first vm_area_struct to munmap
* @start: The aligned start address to munmap
* @end: The aligned end address to munmap
* @uf: The userfaultfd list_head
* @unlock: Unlock after the operation. Only unlocked on success
*/
static inline void init_vma_munmap(struct vma_munmap_struct *vms,
struct vma_iterator *vmi, struct vm_area_struct *vma,
unsigned long start, unsigned long end, struct list_head *uf,
bool unlock)
{
vms->vmi = vmi;
vms->vma = vma;
vms->mm = vma->vm_mm;
vms->start = start;
vms->end = end;
vms->unlock = unlock;
vms->uf = uf;
vms->vma_count = 0;
vms->nr_pages = vms->locked_vm = vms->nr_accounted = 0;
vms->exec_vm = vms->stack_vm = vms->data_vm = 0;
}
/*
* Return true if we can merge this (vm_flags,anon_vma,file,vm_pgoff)
* in front of (at a lower virtual address and file offset than) the vma.
@@ -698,7 +671,7 @@ static inline void abort_munmap_vmas(struct ma_state *mas_detach)
* used for the munmap() and may downgrade the lock - if requested. Everything
* needed to be done once the vma maple tree is updated.
*/
static void vms_complete_munmap_vmas(struct vma_munmap_struct *vms,
void vms_complete_munmap_vmas(struct vma_munmap_struct *vms,
struct ma_state *mas_detach)
{
struct vm_area_struct *vma;
@@ -752,7 +725,7 @@ static void vms_complete_munmap_vmas(struct vma_munmap_struct *vms,
*
* Return: 0 on success, -EPERM on mseal vmas, -ENOMEM otherwise
*/
static int vms_gather_munmap_vmas(struct vma_munmap_struct *vms,
int vms_gather_munmap_vmas(struct vma_munmap_struct *vms,
struct ma_state *mas_detach)
{
struct vm_area_struct *next = NULL;
mm/vma.h
+33
View File
@@ -78,6 +78,39 @@ int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma,
int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma,
unsigned long start, unsigned long end, pgoff_t pgoff);
/*
* init_vma_munmap() - Initializer wrapper for vma_munmap_struct
* @vms: The vma munmap struct
* @vmi: The vma iterator
* @vma: The first vm_area_struct to munmap
* @start: The aligned start address to munmap
* @end: The aligned end address to munmap
* @uf: The userfaultfd list_head
* @unlock: Unlock after the operation. Only unlocked on success
*/
static inline void init_vma_munmap(struct vma_munmap_struct *vms,
struct vma_iterator *vmi, struct vm_area_struct *vma,
unsigned long start, unsigned long end, struct list_head *uf,
bool unlock)
{
vms->vmi = vmi;
vms->vma = vma;
vms->mm = vma->vm_mm;
vms->start = start;
vms->end = end;
vms->unlock = unlock;
vms->uf = uf;
vms->vma_count = 0;
vms->nr_pages = vms->locked_vm = vms->nr_accounted = 0;
vms->exec_vm = vms->stack_vm = vms->data_vm = 0;
}
int vms_gather_munmap_vmas(struct vma_munmap_struct *vms,
struct ma_state *mas_detach);
void vms_complete_munmap_vmas(struct vma_munmap_struct *vms,
struct ma_state *mas_detach);
int
do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
struct mm_struct *mm, unsigned long start,