[PATCH 02/10] mm: introduce vma_merge_struct and abstract merge parameters

Lorenzo Stoakes
2024-08-05T12:14:33Z

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

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
---
mm/mmap.c | 76 ++++++++------
mm/vma.c | 297 ++++++++++++++++++++++++++++++++++++++----------------
mm/vma.h | 92 ++++++++---------
3 files changed, 294 insertions(+), 171 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 4a9c2329b09a..f931000c561f 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1369,9 +1369,16 @@ 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;
VMA_ITERATOR(vmi, mm, addr);
+ struct vma_merge_struct vmg = {
+ .vmi = &vmi,
+ .start = addr,
+ .end = end,
+ .flags = vm_flags,
+ .pgoff = pgoff,
+ .file = file,
+ };

/* Check against address space limit. */
if (!may_expand_vm(mm, vm_flags, len >> PAGE_SHIFT)) {
@@ -1405,8 +1412,8 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
vm_flags |= VM_ACCOUNT;
}

- next = vma_next(&vmi);
- prev = vma_prev(&vmi);
+ next = vmg.next = vma_next(&vmi);
+ prev = vmg.prev = vma_prev(&vmi);
if (vm_flags & VM_SPECIAL) {
if (prev)
vma_iter_next_range(&vmi);
@@ -1416,29 +1423,30 @@ 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;
+ }
+
+ if (vma) {
+ 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;
} else if (prev) {
vma_iter_next_range(&vmi);
}

/* Actually expand, if possible */
if (vma &&
- !vma_expand(&vmi, vma, merge_start, merge_end, vm_pgoff, next)) {
+ !vma_expand(&vmi, vma, merge_start, merge_end, vmg.pgoff, next)) {
khugepaged_enter_vma(vma, vm_flags);
goto expanded;
}
@@ -1790,25 +1798,31 @@ 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;
-
- vma_start_write(vma);
-
- 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);
- khugepaged_enter_vma(vma, flags);
- goto out;
+ if (vma && vma->vm_end == addr && !vma_policy(vma)) {
+ struct vma_merge_struct vmg = {
+ .prev = vma,
+ .flags = flags,
+ .pgoff = addr >> PAGE_SHIFT,
+ };
+
+ if (can_vma_merge_after(&vmg)) {
+ vma_iter_config(vmi, vma->vm_start, addr + len);
+ if (vma_iter_prealloc(vmi, vma))
+ goto unacct_fail;
+
+ vma_start_write(vma);
+
+ 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);
+ khugepaged_enter_vma(vma, flags);
+ goto out;
+ }
}

if (vma)
diff --git a/mm/vma.c b/mm/vma.c
index bf0546fe6eab..20c4ce7712c0 100644
--- a/mm/vma.c
+++ b/mm/vma.c
@@ -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, 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, 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;
@@ -180,7 +175,7 @@ void unmap_region(struct mm_struct *mm, struct ma_state *mas,
* VMA Iterator will point to the end VMA.
*/
static int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
- unsigned long addr, int new_below)
+ unsigned long addr, bool new_below)
{
struct vma_prepare vp;
struct vm_area_struct *new;
@@ -261,13 +256,14 @@ static int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
* Split a vma into two pieces at address 'addr', a new vma is allocated
* either for the first part or the tail.
*/
-static int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
- unsigned long addr, int new_below)
+static int split_vma(struct vma_merge_struct *vmg, bool new_below)
{
- if (vma->vm_mm->map_count >= sysctl_max_map_count)
+ if (vmg->vma->vm_mm->map_count >= sysctl_max_map_count)
return -ENOMEM;

- return __split_vma(vmi, vma, addr, new_below);
+ return __split_vma(vmg->vmi, vmg->vma,
+ new_below ? vmg->start : vmg->end,
+ new_below);
}

/*
@@ -712,7 +708,7 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
if (end < vma->vm_end && mm->map_count >= sysctl_max_map_count)
goto map_count_exceeded;

- error = __split_vma(vmi, vma, start, 1);
+ error = __split_vma(vmi, vma, start, true);
if (error)
goto start_split_failed;
}
@@ -725,7 +721,7 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
do {
/* Does it split the end? */
if (next->vm_end > end) {
- error = __split_vma(vmi, next, end, 0);
+ error = __split_vma(vmi, next, end, false);
if (error)
goto end_split_failed;
}
@@ -934,16 +930,10 @@ 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 = container_of(vmg->vmi->mas.tree, struct mm_struct, mm_mt);
+ 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;
@@ -953,16 +943,18 @@ 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) */
@@ -970,27 +962,26 @@ 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;
}

@@ -1041,7 +1032,7 @@ static struct vm_area_struct
remove = curr;
} else { /* case 5 */
adjust = curr;
- adj_start = (end - curr->vm_start);
+ adj_start = end - curr->vm_start;
}
if (!err)
err = dup_anon_vma(prev, curr, &anon_dup);
@@ -1081,13 +1072,13 @@ 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);
@@ -1099,19 +1090,19 @@ 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);
- khugepaged_enter_vma(res, vm_flags);
+ vma_complete(&vp, vmg->vmi, mm);
+ khugepaged_enter_vma(res, vmg->flags);
return res;

prealloc_fail:
@@ -1119,8 +1110,8 @@ static struct vm_area_struct
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;
}

@@ -1137,38 +1128,141 @@ static struct vm_area_struct
* 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, true);

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, false);

if (err)
return ERR_PTR(err);
}

- return vma;
+ return vmg->vma;
+}
+
+/* Assumes addr >= vma->vm_start. */
+static pgoff_t vma_pgoff_offset(struct vm_area_struct *vma, unsigned long addr)
+{
+ return vma->vm_pgoff + PHYS_PFN(addr - vma->vm_start);
+}
+
+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)
+{
+ struct vma_merge_struct vmg = {
+ .vmi = vmi,
+ .prev = prev,
+ .vma = vma,
+ .start = start,
+ .end = end,
+ .flags = new_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),
+ };
+
+ 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)
+{
+ struct vma_merge_struct vmg = {
+ .vmi = vmi,
+ .prev = prev,
+ .vma = vma,
+ .start = start,
+ .end = end,
+ .flags = new_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 = 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)
+{
+ struct vma_merge_struct vmg = {
+ .vmi = vmi,
+ .prev = prev,
+ .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 = new_pol,
+ .uffd_ctx = vma->vm_userfaultfd_ctx,
+ .anon_name = anon_vma_name(vma),
+ };
+
+ 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)
+{
+ struct vma_merge_struct vmg = {
+ .vmi = vmi,
+ .prev = prev,
+ .vma = vma,
+ .start = start,
+ .end = end,
+ .flags = new_flags,
+ .file = vma->vm_file,
+ .anon_vma = vma->anon_vma,
+ .pgoff = vma_pgoff_offset(vma, start),
+ .policy = vma_policy(vma),
+ .uffd_ctx = new_ctx,
+ .anon_name = anon_vma_name(vma),
+ };
+
+ return vma_modify(&vmg);
}

/*
@@ -1180,8 +1274,22 @@ 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));
+ struct vma_merge_struct vmg = {
+ .vmi = vmi,
+ .prev = prev,
+ .vma = vma,
+ .start = start,
+ .end = end,
+ .flags = vma->vm_flags,
+ .file = vma->vm_file,
+ .anon_vma = vma->anon_vma,
+ .pgoff = pgoff,
+ .policy = vma_policy(vma),
+ .uffd_ctx = vma->vm_userfaultfd_ctx,
+ .anon_name = anon_vma_name(vma),
+ };
+
+ return vma_merge(&vmg);
}

/*
@@ -1193,11 +1301,22 @@ struct vm_area_struct *vma_merge_extend(struct vma_iterator *vmi,
unsigned long delta)
{
pgoff_t pgoff = vma->vm_pgoff + vma_pages(vma);
+ struct vma_merge_struct vmg = {
+ .vmi = vmi,
+ .prev = vma,
+ .vma = vma,
+ .start = vma->vm_end,
+ .end = vma->vm_end + delta,
+ .flags = vma->vm_flags,
+ .file = vma->vm_file,
+ .pgoff = pgoff,
+ .policy = vma_policy(vma),
+ .uffd_ctx = vma->vm_userfaultfd_ctx,
+ .anon_name = anon_vma_name(vma),
+ };

/* 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)
diff --git a/mm/vma.h b/mm/vma.h
index 6efdf1768a0a..c31684cc1da6 100644
--- a/mm/vma.h
+++ b/mm/vma.h
@@ -26,6 +26,23 @@ struct unlink_vma_file_batch {
struct vm_area_struct *vmas[8];
};

+/* Represents a VMA merge operation. */
+struct vma_merge_struct {
+ struct vma_iterator *vmi;
+ 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;
+ pgoff_t pgoff;
+ struct file *file;
+ struct anon_vma *anon_vma;
+ struct mempolicy *policy;
+ struct vm_userfaultfd_ctx uffd_ctx;
+ struct anon_vma_name *anon_name;
+};
+
#ifdef CONFIG_DEBUG_VM_MAPLE_TREE
void validate_mm(struct mm_struct *mm);
#else
@@ -72,80 +89,53 @@ void unmap_region(struct mm_struct *mm, struct ma_state *mas,
struct vm_area_struct *next, unsigned long start,
unsigned long end, unsigned long tree_end, bool mm_wr_locked);

-/* 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);
-
-/* 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 following VMA vmg->next?
+ *
+ * Required by mmap_region().
+ */
+bool can_vma_merge_before(struct vma_merge_struct *vmg);
+
+/*
+ * 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,
--
2.45.2