mm: introduce vma_merge_struct and abstract vma_merge(),vma_modify()

Rather than passing around huge numbers of parameters to numerous helper
functions, abstract them into a single struct that we thread through the
operation, the vma_merge_struct ('vmg').

Adjust vma_merge() and vma_modify() to accept this parameter, as well as
predicate functions can_vma_merge_before(), can_vma_merge_after(), and the
vma_modify_...() helper functions.

Also introduce VMG_STATE() and VMG_VMA_STATE() helper macros to allow for
easy vmg declaration.

We additionally remove the requirement that vma_merge() is passed a VMA
object representing the candidate new VMA.  Previously it used this to
obtain the mm_struct, file and anon_vma properties of the proposed range
(a rather confusing state of affairs), which are now provided by the vmg
directly.

We also remove the pgoff calculation previously performed vma_modify(),
and instead calculate this in VMG_VMA_STATE() via the vma_pgoff_offset()
helper.

Link: https://lkml.kernel.org/r/a955aad09d81329f6fbeb636b2dd10cde7b73dab.1725040657.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
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: 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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Lorenzo Stoakes 2024-08-30 19:10:15 +01:00 committed by Andrew Morton
parent 955db39676
commit 2f1c6611b0
4 changed files with 242 additions and 203 deletions

View File

@ -1373,10 +1373,11 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
unsigned long end = addr + len;
unsigned long merge_start = addr, merge_end = end;
bool writable_file_mapping = false;
pgoff_t vm_pgoff;
int error = -ENOMEM;
VMA_ITERATOR(vmi, mm, addr);
VMG_STATE(vmg, mm, &vmi, addr, end, vm_flags, pgoff);
vmg.file = file;
/* Find the first overlapping VMA */
vma = vma_find(&vmi, end);
init_vma_munmap(&vms, &vmi, vma, addr, end, uf, /* unlock = */ false);
@ -1389,12 +1390,12 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
if (error)
goto gather_failed;
next = vms.next;
prev = vms.prev;
next = vmg.next = vms.next;
prev = vmg.prev = vms.prev;
vma = NULL;
} else {
next = vma_next(&vmi);
prev = vma_prev(&vmi);
next = vmg.next = vma_next(&vmi);
prev = vmg.prev = vma_prev(&vmi);
if (prev)
vma_iter_next_range(&vmi);
}
@ -1414,6 +1415,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
vms.nr_accounted = 0;
vm_flags |= VM_ACCOUNT;
vmg.flags = vm_flags;
}
if (vm_flags & VM_SPECIAL)
@ -1422,28 +1424,31 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
/* Attempt to expand an old mapping */
/* Check next */
if (next && next->vm_start == end && !vma_policy(next) &&
can_vma_merge_before(next, vm_flags, NULL, file, pgoff+pglen,
NULL_VM_UFFD_CTX, NULL)) {
can_vma_merge_before(&vmg)) {
merge_end = next->vm_end;
vma = next;
vm_pgoff = next->vm_pgoff - pglen;
vmg.pgoff = next->vm_pgoff - pglen;
/*
* We set this here so if we will merge with the previous VMA in
* the code below, can_vma_merge_after() ensures anon_vma
* compatibility between prev and next.
*/
vmg.anon_vma = vma->anon_vma;
vmg.uffd_ctx = vma->vm_userfaultfd_ctx;
}
/* Check prev */
if (prev && prev->vm_end == addr && !vma_policy(prev) &&
(vma ? can_vma_merge_after(prev, vm_flags, vma->anon_vma, file,
pgoff, vma->vm_userfaultfd_ctx, NULL) :
can_vma_merge_after(prev, vm_flags, NULL, file, pgoff,
NULL_VM_UFFD_CTX, NULL))) {
can_vma_merge_after(&vmg)) {
merge_start = prev->vm_start;
vma = prev;
vm_pgoff = prev->vm_pgoff;
vmg.pgoff = prev->vm_pgoff;
vma_prev(&vmi); /* Equivalent to going to the previous range */
}
if (vma) {
/* Actually expand, if possible */
if (!vma_expand(&vmi, vma, merge_start, merge_end, vm_pgoff, next)) {
if (!vma_expand(&vmi, vma, merge_start, merge_end, vmg.pgoff, next)) {
khugepaged_enter_vma(vma, vm_flags);
goto expanded;
}
@ -1774,26 +1779,29 @@ static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma,
* Expand the existing vma if possible; Note that singular lists do not
* occur after forking, so the expand will only happen on new VMAs.
*/
if (vma && vma->vm_end == addr && !vma_policy(vma) &&
can_vma_merge_after(vma, flags, NULL, NULL,
addr >> PAGE_SHIFT, NULL_VM_UFFD_CTX, NULL)) {
vma_iter_config(vmi, vma->vm_start, addr + len);
if (vma_iter_prealloc(vmi, vma))
goto unacct_fail;
if (vma && vma->vm_end == addr && !vma_policy(vma)) {
VMG_STATE(vmg, mm, vmi, addr, addr + len, flags, PHYS_PFN(addr));
vma_start_write(vma);
vmg.prev = vma;
if (can_vma_merge_after(&vmg)) {
vma_iter_config(vmi, vma->vm_start, addr + len);
if (vma_iter_prealloc(vmi, vma))
goto unacct_fail;
init_vma_prep(&vp, vma);
vma_prepare(&vp);
vma_adjust_trans_huge(vma, vma->vm_start, addr + len, 0);
vma->vm_end = addr + len;
vm_flags_set(vma, VM_SOFTDIRTY);
vma_iter_store(vmi, vma);
vma_start_write(vma);
vma_complete(&vp, vmi, mm);
validate_mm(mm);
khugepaged_enter_vma(vma, flags);
goto out;
init_vma_prep(&vp, vma);
vma_prepare(&vp);
vma_adjust_trans_huge(vma, vma->vm_start, addr + len, 0);
vma->vm_end = addr + len;
vm_flags_set(vma, VM_SOFTDIRTY);
vma_iter_store(vmi, vma);
vma_complete(&vp, vmi, mm);
validate_mm(mm);
khugepaged_enter_vma(vma, flags);
goto out;
}
}
if (vma)

207
mm/vma.c
View File

@ -7,16 +7,18 @@
#include "vma_internal.h"
#include "vma.h"
/*
* If the vma has a ->close operation then the driver probably needs to release
* per-vma resources, so we don't attempt to merge those if the caller indicates
* the current vma may be removed as part of the merge.
*/
static inline bool is_mergeable_vma(struct vm_area_struct *vma,
struct file *file, unsigned long vm_flags,
struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
struct anon_vma_name *anon_name, bool may_remove_vma)
static inline bool is_mergeable_vma(struct vma_merge_struct *vmg, bool merge_next)
{
struct vm_area_struct *vma = merge_next ? vmg->next : vmg->prev;
/*
* If the vma has a ->close operation then the driver probably needs to
* release per-vma resources, so we don't attempt to merge those if the
* caller indicates the current vma may be removed as part of the merge,
* which is the case if we are attempting to merge the next VMA into
* this one.
*/
bool may_remove_vma = merge_next;
/*
* VM_SOFTDIRTY should not prevent from VMA merging, if we
* match the flags but dirty bit -- the caller should mark
@ -25,15 +27,15 @@ static inline bool is_mergeable_vma(struct vm_area_struct *vma,
* the kernel to generate new VMAs when old one could be
* extended instead.
*/
if ((vma->vm_flags ^ vm_flags) & ~VM_SOFTDIRTY)
if ((vma->vm_flags ^ vmg->flags) & ~VM_SOFTDIRTY)
return false;
if (vma->vm_file != file)
if (vma->vm_file != vmg->file)
return false;
if (may_remove_vma && vma->vm_ops && vma->vm_ops->close)
return false;
if (!is_mergeable_vm_userfaultfd_ctx(vma, vm_userfaultfd_ctx))
if (!is_mergeable_vm_userfaultfd_ctx(vma, vmg->uffd_ctx))
return false;
if (!anon_vma_name_eq(anon_vma_name(vma), anon_name))
if (!anon_vma_name_eq(anon_vma_name(vma), vmg->anon_name))
return false;
return true;
}
@ -94,16 +96,16 @@ static void init_multi_vma_prep(struct vma_prepare *vp,
* We assume the vma may be removed as part of the merge.
*/
bool
can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
struct anon_vma *anon_vma, struct file *file,
pgoff_t vm_pgoff, struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
struct anon_vma_name *anon_name)
can_vma_merge_before(struct vma_merge_struct *vmg)
{
if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx, anon_name, true) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
if (vma->vm_pgoff == vm_pgoff)
pgoff_t pglen = PHYS_PFN(vmg->end - vmg->start);
if (is_mergeable_vma(vmg, /* merge_next = */ true) &&
is_mergeable_anon_vma(vmg->anon_vma, vmg->next->anon_vma, vmg->next)) {
if (vmg->next->vm_pgoff == vmg->pgoff + pglen)
return true;
}
return false;
}
@ -116,18 +118,11 @@ can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
*
* We assume that vma is not removed as part of the merge.
*/
bool
can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
struct anon_vma *anon_vma, struct file *file,
pgoff_t vm_pgoff, struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
struct anon_vma_name *anon_name)
bool can_vma_merge_after(struct vma_merge_struct *vmg)
{
if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx, anon_name, false) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
pgoff_t vm_pglen;
vm_pglen = vma_pages(vma);
if (vma->vm_pgoff + vm_pglen == vm_pgoff)
if (is_mergeable_vma(vmg, /* merge_next = */ false) &&
is_mergeable_anon_vma(vmg->anon_vma, vmg->prev->anon_vma, vmg->prev)) {
if (vmg->prev->vm_pgoff + vma_pages(vmg->prev) == vmg->pgoff)
return true;
}
return false;
@ -1017,16 +1012,10 @@ int do_vmi_munmap(struct vma_iterator *vmi, struct mm_struct *mm,
* **** is not represented - it will be merged and the vma containing the
* area is returned, or the function will return NULL
*/
static struct vm_area_struct
*vma_merge(struct vma_iterator *vmi, struct vm_area_struct *prev,
struct vm_area_struct *src, unsigned long addr, unsigned long end,
unsigned long vm_flags, pgoff_t pgoff, struct mempolicy *policy,
struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
struct anon_vma_name *anon_name)
static struct vm_area_struct *vma_merge(struct vma_merge_struct *vmg)
{
struct mm_struct *mm = src->vm_mm;
struct anon_vma *anon_vma = src->anon_vma;
struct file *file = src->vm_file;
struct mm_struct *mm = vmg->mm;
struct vm_area_struct *prev = vmg->prev;
struct vm_area_struct *curr, *next, *res;
struct vm_area_struct *vma, *adjust, *remove, *remove2;
struct vm_area_struct *anon_dup = NULL;
@ -1036,16 +1025,18 @@ static struct vm_area_struct
bool merge_prev = false;
bool merge_next = false;
bool vma_expanded = false;
unsigned long addr = vmg->start;
unsigned long end = vmg->end;
unsigned long vma_start = addr;
unsigned long vma_end = end;
pgoff_t pglen = (end - addr) >> PAGE_SHIFT;
pgoff_t pglen = PHYS_PFN(end - addr);
long adj_start = 0;
/*
* We later require that vma->vm_flags == vm_flags,
* so this tests vma->vm_flags & VM_SPECIAL, too.
*/
if (vm_flags & VM_SPECIAL)
if (vmg->flags & VM_SPECIAL)
return NULL;
/* Does the input range span an existing VMA? (cases 5 - 8) */
@ -1053,27 +1044,26 @@ static struct vm_area_struct
if (!curr || /* cases 1 - 4 */
end == curr->vm_end) /* cases 6 - 8, adjacent VMA */
next = vma_lookup(mm, end);
next = vmg->next = vma_lookup(mm, end);
else
next = NULL; /* case 5 */
next = vmg->next = NULL; /* case 5 */
if (prev) {
vma_start = prev->vm_start;
vma_pgoff = prev->vm_pgoff;
/* Can we merge the predecessor? */
if (addr == prev->vm_end && mpol_equal(vma_policy(prev), policy)
&& can_vma_merge_after(prev, vm_flags, anon_vma, file,
pgoff, vm_userfaultfd_ctx, anon_name)) {
if (addr == prev->vm_end && mpol_equal(vma_policy(prev), vmg->policy)
&& can_vma_merge_after(vmg)) {
merge_prev = true;
vma_prev(vmi);
vma_prev(vmg->vmi);
}
}
/* Can we merge the successor? */
if (next && mpol_equal(policy, vma_policy(next)) &&
can_vma_merge_before(next, vm_flags, anon_vma, file, pgoff+pglen,
vm_userfaultfd_ctx, anon_name)) {
if (next && mpol_equal(vmg->policy, vma_policy(next)) &&
can_vma_merge_before(vmg)) {
merge_next = true;
}
@ -1164,13 +1154,13 @@ static struct vm_area_struct
vma_expanded = true;
if (vma_expanded) {
vma_iter_config(vmi, vma_start, vma_end);
vma_iter_config(vmg->vmi, vma_start, vma_end);
} else {
vma_iter_config(vmi, adjust->vm_start + adj_start,
vma_iter_config(vmg->vmi, adjust->vm_start + adj_start,
adjust->vm_end);
}
if (vma_iter_prealloc(vmi, vma))
if (vma_iter_prealloc(vmg->vmi, vma))
goto prealloc_fail;
init_multi_vma_prep(&vp, vma, adjust, remove, remove2);
@ -1182,20 +1172,20 @@ static struct vm_area_struct
vma_set_range(vma, vma_start, vma_end, vma_pgoff);
if (vma_expanded)
vma_iter_store(vmi, vma);
vma_iter_store(vmg->vmi, vma);
if (adj_start) {
adjust->vm_start += adj_start;
adjust->vm_pgoff += adj_start >> PAGE_SHIFT;
if (adj_start < 0) {
WARN_ON(vma_expanded);
vma_iter_store(vmi, next);
vma_iter_store(vmg->vmi, next);
}
}
vma_complete(&vp, vmi, mm);
vma_complete(&vp, vmg->vmi, mm);
validate_mm(mm);
khugepaged_enter_vma(res, vm_flags);
khugepaged_enter_vma(res, vmg->flags);
return res;
prealloc_fail:
@ -1203,8 +1193,8 @@ prealloc_fail:
unlink_anon_vmas(anon_dup);
anon_vma_fail:
vma_iter_set(vmi, addr);
vma_iter_load(vmi);
vma_iter_set(vmg->vmi, addr);
vma_iter_load(vmg->vmi);
return NULL;
}
@ -1221,32 +1211,27 @@ anon_vma_fail:
* The function returns either the merged VMA, the original VMA if a split was
* required instead, or an error if the split failed.
*/
struct vm_area_struct *vma_modify(struct vma_iterator *vmi,
struct vm_area_struct *prev,
struct vm_area_struct *vma,
unsigned long start, unsigned long end,
unsigned long vm_flags,
struct mempolicy *policy,
struct vm_userfaultfd_ctx uffd_ctx,
struct anon_vma_name *anon_name)
static struct vm_area_struct *vma_modify(struct vma_merge_struct *vmg)
{
pgoff_t pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
struct vm_area_struct *vma = vmg->vma;
struct vm_area_struct *merged;
merged = vma_merge(vmi, prev, vma, start, end, vm_flags,
pgoff, policy, uffd_ctx, anon_name);
/* First, try to merge. */
merged = vma_merge(vmg);
if (merged)
return merged;
if (vma->vm_start < start) {
int err = split_vma(vmi, vma, start, 1);
/* Split any preceding portion of the VMA. */
if (vma->vm_start < vmg->start) {
int err = split_vma(vmg->vmi, vma, vmg->start, 1);
if (err)
return ERR_PTR(err);
}
if (vma->vm_end > end) {
int err = split_vma(vmi, vma, end, 0);
/* Split any trailing portion of the VMA. */
if (vma->vm_end > vmg->end) {
int err = split_vma(vmg->vmi, vma, vmg->end, 0);
if (err)
return ERR_PTR(err);
@ -1255,6 +1240,65 @@ struct vm_area_struct *vma_modify(struct vma_iterator *vmi,
return vma;
}
struct vm_area_struct *vma_modify_flags(
struct vma_iterator *vmi, struct vm_area_struct *prev,
struct vm_area_struct *vma, unsigned long start, unsigned long end,
unsigned long new_flags)
{
VMG_VMA_STATE(vmg, vmi, prev, vma, start, end);
vmg.flags = new_flags;
return vma_modify(&vmg);
}
struct vm_area_struct
*vma_modify_flags_name(struct vma_iterator *vmi,
struct vm_area_struct *prev,
struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
unsigned long new_flags,
struct anon_vma_name *new_name)
{
VMG_VMA_STATE(vmg, vmi, prev, vma, start, end);
vmg.flags = new_flags;
vmg.anon_name = new_name;
return vma_modify(&vmg);
}
struct vm_area_struct
*vma_modify_policy(struct vma_iterator *vmi,
struct vm_area_struct *prev,
struct vm_area_struct *vma,
unsigned long start, unsigned long end,
struct mempolicy *new_pol)
{
VMG_VMA_STATE(vmg, vmi, prev, vma, start, end);
vmg.policy = new_pol;
return vma_modify(&vmg);
}
struct vm_area_struct
*vma_modify_flags_uffd(struct vma_iterator *vmi,
struct vm_area_struct *prev,
struct vm_area_struct *vma,
unsigned long start, unsigned long end,
unsigned long new_flags,
struct vm_userfaultfd_ctx new_ctx)
{
VMG_VMA_STATE(vmg, vmi, prev, vma, start, end);
vmg.flags = new_flags;
vmg.uffd_ctx = new_ctx;
return vma_modify(&vmg);
}
/*
* Attempt to merge a newly mapped VMA with those adjacent to it. The caller
* must ensure that [start, end) does not overlap any existing VMA.
@ -1264,8 +1308,11 @@ struct vm_area_struct
struct vm_area_struct *vma, unsigned long start,
unsigned long end, pgoff_t pgoff)
{
return vma_merge(vmi, prev, vma, start, end, vma->vm_flags, pgoff,
vma_policy(vma), vma->vm_userfaultfd_ctx, anon_vma_name(vma));
VMG_VMA_STATE(vmg, vmi, prev, vma, start, end);
vmg.pgoff = pgoff;
return vma_merge(&vmg);
}
/*
@ -1276,12 +1323,10 @@ struct vm_area_struct *vma_merge_extend(struct vma_iterator *vmi,
struct vm_area_struct *vma,
unsigned long delta)
{
pgoff_t pgoff = vma->vm_pgoff + vma_pages(vma);
VMG_VMA_STATE(vmg, vmi, vma, vma, vma->vm_end, vma->vm_end + delta);
/* vma is specified as prev, so case 1 or 2 will apply. */
return vma_merge(vmi, vma, vma, vma->vm_end, vma->vm_end + delta,
vma->vm_flags, pgoff, vma_policy(vma),
vma->vm_userfaultfd_ctx, anon_vma_name(vma));
return vma_merge(&vmg);
}
void unlink_file_vma_batch_init(struct unlink_vma_file_batch *vb)

125
mm/vma.h
View File

@ -52,6 +52,59 @@ struct vma_munmap_struct {
unsigned long data_vm;
};
/* Represents a VMA merge operation. */
struct vma_merge_struct {
struct mm_struct *mm;
struct vma_iterator *vmi;
pgoff_t pgoff;
struct vm_area_struct *prev;
struct vm_area_struct *next; /* Modified by vma_merge(). */
struct vm_area_struct *vma; /* Either a new VMA or the one being modified. */
unsigned long start;
unsigned long end;
unsigned long flags;
struct file *file;
struct anon_vma *anon_vma;
struct mempolicy *policy;
struct vm_userfaultfd_ctx uffd_ctx;
struct anon_vma_name *anon_name;
};
/* Assumes addr >= vma->vm_start. */
static inline pgoff_t vma_pgoff_offset(struct vm_area_struct *vma,
unsigned long addr)
{
return vma->vm_pgoff + PHYS_PFN(addr - vma->vm_start);
}
#define VMG_STATE(name, mm_, vmi_, start_, end_, flags_, pgoff_) \
struct vma_merge_struct name = { \
.mm = mm_, \
.vmi = vmi_, \
.start = start_, \
.end = end_, \
.flags = flags_, \
.pgoff = pgoff_, \
}
#define VMG_VMA_STATE(name, vmi_, prev_, vma_, start_, end_) \
struct vma_merge_struct name = { \
.mm = vma_->vm_mm, \
.vmi = vmi_, \
.prev = prev_, \
.next = NULL, \
.vma = vma_, \
.start = start_, \
.end = end_, \
.flags = vma_->vm_flags, \
.pgoff = vma_pgoff_offset(vma_, start_), \
.file = vma_->vm_file, \
.anon_vma = vma_->anon_vma, \
.policy = vma_policy(vma_), \
.uffd_ctx = vma_->vm_userfaultfd_ctx, \
.anon_name = anon_vma_name(vma_), \
}
#ifdef CONFIG_DEBUG_VM_MAPLE_TREE
void validate_mm(struct mm_struct *mm);
#else
@ -212,80 +265,52 @@ void remove_vma(struct vm_area_struct *vma, bool unreachable, bool closed);
void unmap_region(struct ma_state *mas, struct vm_area_struct *vma,
struct vm_area_struct *prev, struct vm_area_struct *next);
/* Required by mmap_region(). */
bool
can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
struct anon_vma *anon_vma, struct file *file,
pgoff_t vm_pgoff, struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
struct anon_vma_name *anon_name);
/*
* Can we merge the VMA described by vmg into the following VMA vmg->next?
*
* Required by mmap_region().
*/
bool can_vma_merge_before(struct vma_merge_struct *vmg);
/* Required by mmap_region() and do_brk_flags(). */
bool
can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
struct anon_vma *anon_vma, struct file *file,
pgoff_t vm_pgoff, struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
struct anon_vma_name *anon_name);
struct vm_area_struct *vma_modify(struct vma_iterator *vmi,
struct vm_area_struct *prev,
struct vm_area_struct *vma,
unsigned long start, unsigned long end,
unsigned long vm_flags,
struct mempolicy *policy,
struct vm_userfaultfd_ctx uffd_ctx,
struct anon_vma_name *anon_name);
/*
* Can we merge the VMA described by vmg into the preceding VMA vmg->prev?
*
* Required by mmap_region() and do_brk_flags().
*/
bool can_vma_merge_after(struct vma_merge_struct *vmg);
/* We are about to modify the VMA's flags. */
static inline struct vm_area_struct
*vma_modify_flags(struct vma_iterator *vmi,
struct vm_area_struct *prev,
struct vm_area_struct *vma,
unsigned long start, unsigned long end,
unsigned long new_flags)
{
return vma_modify(vmi, prev, vma, start, end, new_flags,
vma_policy(vma), vma->vm_userfaultfd_ctx,
anon_vma_name(vma));
}
struct vm_area_struct *vma_modify_flags(struct vma_iterator *vmi,
struct vm_area_struct *prev, struct vm_area_struct *vma,
unsigned long start, unsigned long end,
unsigned long new_flags);
/* We are about to modify the VMA's flags and/or anon_name. */
static inline struct vm_area_struct
struct vm_area_struct
*vma_modify_flags_name(struct vma_iterator *vmi,
struct vm_area_struct *prev,
struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
unsigned long new_flags,
struct anon_vma_name *new_name)
{
return vma_modify(vmi, prev, vma, start, end, new_flags,
vma_policy(vma), vma->vm_userfaultfd_ctx, new_name);
}
struct anon_vma_name *new_name);
/* We are about to modify the VMA's memory policy. */
static inline struct vm_area_struct
struct vm_area_struct
*vma_modify_policy(struct vma_iterator *vmi,
struct vm_area_struct *prev,
struct vm_area_struct *vma,
unsigned long start, unsigned long end,
struct mempolicy *new_pol)
{
return vma_modify(vmi, prev, vma, start, end, vma->vm_flags,
new_pol, vma->vm_userfaultfd_ctx, anon_vma_name(vma));
}
struct mempolicy *new_pol);
/* We are about to modify the VMA's flags and/or uffd context. */
static inline struct vm_area_struct
struct vm_area_struct
*vma_modify_flags_uffd(struct vma_iterator *vmi,
struct vm_area_struct *prev,
struct vm_area_struct *vma,
unsigned long start, unsigned long end,
unsigned long new_flags,
struct vm_userfaultfd_ctx new_ctx)
{
return vma_modify(vmi, prev, vma, start, end, new_flags,
vma_policy(vma), new_ctx, anon_vma_name(vma));
}
struct vm_userfaultfd_ctx new_ctx);
struct vm_area_struct
*vma_merge_new_vma(struct vma_iterator *vmi, struct vm_area_struct *prev,

View File

@ -22,26 +22,6 @@ static bool fail_prealloc;
*/
#include "../../../mm/vma.c"
/*
* Temporarily forward-ported from a future in which vmg's are used for merging.
*/
struct vma_merge_struct {
struct mm_struct *mm;
struct vma_iterator *vmi;
pgoff_t pgoff;
struct vm_area_struct *prev;
struct vm_area_struct *next; /* Modified by vma_merge(). */
struct vm_area_struct *vma; /* Either a new VMA or the one being modified. */
unsigned long start;
unsigned long end;
unsigned long flags;
struct file *file;
struct anon_vma *anon_vma;
struct mempolicy *policy;
struct vm_userfaultfd_ctx uffd_ctx;
struct anon_vma_name *anon_name;
};
const struct vm_operations_struct vma_dummy_vm_ops;
static struct anon_vma dummy_anon_vma;
@ -115,14 +95,6 @@ static struct vm_area_struct *alloc_and_link_vma(struct mm_struct *mm,
/* Helper function which provides a wrapper around a merge new VMA operation. */
static struct vm_area_struct *merge_new(struct vma_merge_struct *vmg)
{
/* vma_merge() needs a VMA to determine mm, anon_vma, and file. */
struct vm_area_struct dummy = {
.vm_mm = vmg->mm,
.vm_flags = vmg->flags,
.anon_vma = vmg->anon_vma,
.vm_file = vmg->file,
};
/*
* For convenience, get prev and next VMAs. Which the new VMA operation
* requires.
@ -131,8 +103,7 @@ static struct vm_area_struct *merge_new(struct vma_merge_struct *vmg)
vmg->prev = vma_prev(vmg->vmi);
vma_iter_set(vmg->vmi, vmg->start);
return vma_merge_new_vma(vmg->vmi, vmg->prev, &dummy, vmg->start,
vmg->end, vmg->pgoff);
return vma_merge(vmg);
}
/*
@ -141,17 +112,7 @@ static struct vm_area_struct *merge_new(struct vma_merge_struct *vmg)
*/
static struct vm_area_struct *merge_existing(struct vma_merge_struct *vmg)
{
/* vma_merge() needs a VMA to determine mm, anon_vma, and file. */
struct vm_area_struct dummy = {
.vm_mm = vmg->mm,
.vm_flags = vmg->flags,
.anon_vma = vmg->anon_vma,
.vm_file = vmg->file,
};
return vma_merge(vmg->vmi, vmg->prev, &dummy, vmg->start, vmg->end,
vmg->flags, vmg->pgoff, vmg->policy, vmg->uffd_ctx,
vmg->anon_name);
return vma_merge(vmg);
}
/*