[PATCH 17/30] mm: prefer vma_[start,end]_pgoff() to vma->vm_pgoff in kernel/
From: Lorenzo Stoakes
Date: Mon Jun 29 2026 - 08:34:05 EST
Be consistent in using vma_start_pgoff() and vma_end_pgoff(), which clearly
indicates which part of the VMA the page offset refers to and aids
greppability.
This is part of a broader series laying the ground to provide a virtual
page offset for MAP_PRIVATE-file backed anon folios.
No functional change intended.
Signed-off-by: Lorenzo Stoakes <ljs@xxxxxxxxxx>
---
kernel/dma/coherent.c | 7 ++++---
kernel/dma/direct.c | 6 ++++--
kernel/dma/mapping.c | 8 +++++---
kernel/dma/ops_helpers.c | 4 ++--
kernel/events/core.c | 20 +++++++++++---------
kernel/events/uprobes.c | 11 +++++++----
kernel/kcov.c | 2 +-
kernel/trace/ring_buffer.c | 3 ++-
8 files changed, 36 insertions(+), 25 deletions(-)
diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c
index bcdc0f76d2e8..2d3195eb7e83 100644
--- a/kernel/dma/coherent.c
+++ b/kernel/dma/coherent.c
@@ -236,14 +236,15 @@ static int __dma_mmap_from_coherent(struct dma_coherent_mem *mem,
{
if (mem && vaddr >= mem->virt_base && vaddr + size <=
(mem->virt_base + ((dma_addr_t)mem->size << PAGE_SHIFT))) {
- unsigned long off = vma->vm_pgoff;
+ const pgoff_t pgoff_start = vma_start_pgoff(vma);
+ const pgoff_t pgoff_end = vma_end_pgoff(vma);
int start = (vaddr - mem->virt_base) >> PAGE_SHIFT;
unsigned long user_count = vma_pages(vma);
int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
*ret = -ENXIO;
- if (off < count && user_count <= count - off) {
- unsigned long pfn = mem->pfn_base + start + off;
+ if (pgoff_start < count && pgoff_end <= count) {
+ unsigned long pfn = mem->pfn_base + start + pgoff_start;
*ret = remap_pfn_range(vma, vma->vm_start, pfn,
user_count << PAGE_SHIFT,
vma->vm_page_prot);
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 4391b797d4db..436310d6e4a2 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -534,6 +534,8 @@ int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma,
unsigned long user_count = vma_pages(vma);
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long pfn = PHYS_PFN(dma_to_phys(dev, dma_addr));
+ const pgoff_t pgoff_start = vma_start_pgoff(vma);
+ const pgoff_t pgoff_end = vma_end_pgoff(vma);
int ret = -ENXIO;
vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs);
@@ -545,9 +547,9 @@ int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma,
if (dma_mmap_from_global_coherent(vma, cpu_addr, size, &ret))
return ret;
- if (vma->vm_pgoff >= count || user_count > count - vma->vm_pgoff)
+ if (pgoff_start >= count || pgoff_end > count)
return -ENXIO;
- return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
+ return remap_pfn_range(vma, vma->vm_start, pfn + pgoff_start,
user_count << PAGE_SHIFT, vma->vm_page_prot);
}
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 4fe04669e5e6..c986639044e9 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -761,12 +761,14 @@ EXPORT_SYMBOL_GPL(dma_free_pages);
int dma_mmap_pages(struct device *dev, struct vm_area_struct *vma,
size_t size, struct page *page)
{
- unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ const pgoff_t pgoff_start = vma_start_pgoff(vma);
+ const pgoff_t pgoff_end = vma_end_pgoff(vma);
+ const unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
- if (vma->vm_pgoff >= count || vma_pages(vma) > count - vma->vm_pgoff)
+ if (pgoff_start >= count || pgoff_end > count)
return -ENXIO;
return remap_pfn_range(vma, vma->vm_start,
- page_to_pfn(page) + vma->vm_pgoff,
+ page_to_pfn(page) + pgoff_start,
vma_pages(vma) << PAGE_SHIFT, vma->vm_page_prot);
}
EXPORT_SYMBOL_GPL(dma_mmap_pages);
diff --git a/kernel/dma/ops_helpers.c b/kernel/dma/ops_helpers.c
index 20caf9cabf69..6b5f9208d31c 100644
--- a/kernel/dma/ops_helpers.c
+++ b/kernel/dma/ops_helpers.c
@@ -39,7 +39,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
#ifdef CONFIG_MMU
unsigned long user_count = vma_pages(vma);
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
- unsigned long off = vma->vm_pgoff;
+ unsigned long off = vma_start_pgoff(vma);
struct page *page = dma_common_vaddr_to_page(cpu_addr);
int ret = -ENXIO;
@@ -52,7 +52,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
return -ENXIO;
return remap_pfn_range(vma, vma->vm_start,
- page_to_pfn(page) + vma->vm_pgoff,
+ page_to_pfn(page) + vma_start_pgoff(vma),
user_count << PAGE_SHIFT, vma->vm_page_prot);
#else
return -ENXIO;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 954c36e28101..d6d2d557ccb8 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -6998,7 +6998,7 @@ static void perf_mmap_open(struct vm_area_struct *vma)
refcount_inc(&event->mmap_count);
refcount_inc(&event->rb->mmap_count);
- if (vma->vm_pgoff)
+ if (vma_start_pgoff(vma))
refcount_inc(&event->rb->aux_mmap_count);
if (mapped)
@@ -7032,7 +7032,7 @@ static void perf_mmap_close(struct vm_area_struct *vma)
* The AUX buffer is strictly a sub-buffer, serialize using aux_mutex
* to avoid complications.
*/
- if (rb_has_aux(rb) && vma->vm_pgoff == rb->aux_pgoff &&
+ if (rb_has_aux(rb) && vma_start_pgoff(vma) == rb->aux_pgoff &&
refcount_dec_and_mutex_lock(&rb->aux_mmap_count, &rb->aux_mutex)) {
/*
* Stop all AUX events that are writing to this buffer,
@@ -7190,7 +7190,8 @@ static int map_range(struct perf_buffer *rb, struct vm_area_struct *vma)
*/
for (pagenum = 0; pagenum < nr_pages; pagenum++) {
unsigned long va = vma->vm_start + PAGE_SIZE * pagenum;
- struct page *page = perf_mmap_to_page(rb, vma->vm_pgoff + pagenum);
+ struct page *page = perf_mmap_to_page(rb,
+ vma_start_pgoff(vma) + pagenum);
if (page == NULL) {
err = -EINVAL;
@@ -7348,6 +7349,7 @@ static int perf_mmap_aux(struct vm_area_struct *vma, struct perf_event *event,
u64 aux_offset, aux_size;
struct perf_buffer *rb;
int ret, rb_flags = 0;
+ const pgoff_t pgoff_start = vma_start_pgoff(vma);
rb = event->rb;
if (!rb)
@@ -7366,11 +7368,11 @@ static int perf_mmap_aux(struct vm_area_struct *vma, struct perf_event *event,
if (aux_offset < perf_data_size(rb) + PAGE_SIZE)
return -EINVAL;
- if (aux_offset != vma->vm_pgoff << PAGE_SHIFT)
+ if (aux_offset != pgoff_start << PAGE_SHIFT)
return -EINVAL;
/* already mapped with a different offset */
- if (rb_has_aux(rb) && rb->aux_pgoff != vma->vm_pgoff)
+ if (rb_has_aux(rb) && rb->aux_pgoff != pgoff_start)
return -EINVAL;
if (aux_size != nr_pages * PAGE_SIZE)
@@ -7400,7 +7402,7 @@ static int perf_mmap_aux(struct vm_area_struct *vma, struct perf_event *event,
if (vma->vm_flags & VM_WRITE)
rb_flags |= RING_BUFFER_WRITABLE;
- ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages,
+ ret = rb_alloc_aux(rb, event, pgoff_start, nr_pages,
event->attr.aux_watermark, rb_flags);
if (ret) {
refcount_dec(&rb->mmap_count);
@@ -7457,7 +7459,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
if (event->state <= PERF_EVENT_STATE_REVOKED)
return -ENODEV;
- if (vma->vm_pgoff == 0)
+ if (!vma_start_pgoff(vma))
ret = perf_mmap_rb(vma, event, nr_pages);
else
ret = perf_mmap_aux(vma, event, nr_pages);
@@ -9884,7 +9886,7 @@ static bool perf_addr_filter_vma_adjust(struct perf_addr_filter *filter,
struct perf_addr_filter_range *fr)
{
unsigned long vma_size = vma->vm_end - vma->vm_start;
- unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
+ unsigned long off = vma_start_pgoff(vma) << PAGE_SHIFT;
struct file *file = vma->vm_file;
if (!perf_addr_filter_match(filter, file, off, vma_size))
@@ -9974,7 +9976,7 @@ void perf_event_mmap(struct vm_area_struct *vma)
/* .tid */
.start = vma->vm_start,
.len = vma->vm_end - vma->vm_start,
- .pgoff = (u64)vma->vm_pgoff << PAGE_SHIFT,
+ .pgoff = (u64)vma_start_pgoff(vma) << PAGE_SHIFT,
},
/* .maj (attr_mmap2 only) */
/* .min (attr_mmap2 only) */
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index f23cebacbc6d..244651380ca1 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -144,12 +144,14 @@ static bool valid_vma(struct vm_area_struct *vma, bool is_register)
static unsigned long offset_to_vaddr(struct vm_area_struct *vma, loff_t offset)
{
- return vma->vm_start + offset - ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
+ return vma->vm_start + offset -
+ ((loff_t)vma_start_pgoff(vma) << PAGE_SHIFT);
}
static loff_t vaddr_to_offset(struct vm_area_struct *vma, unsigned long vaddr)
{
- return ((loff_t)vma->vm_pgoff << PAGE_SHIFT) + (vaddr - vma->vm_start);
+ return ((loff_t)vma_start_pgoff(vma) << PAGE_SHIFT) +
+ (vaddr - vma->vm_start);
}
/**
@@ -1482,7 +1484,7 @@ static int unapply_uprobe(struct uprobe *uprobe, struct mm_struct *mm)
file_inode(vma->vm_file) != uprobe->inode)
continue;
- offset = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
+ offset = (loff_t)vma_start_pgoff(vma) << PAGE_SHIFT;
if (uprobe->offset < offset ||
uprobe->offset >= offset + vma->vm_end - vma->vm_start)
continue;
@@ -2453,7 +2455,8 @@ static struct uprobe *find_active_uprobe_speculative(unsigned long bp_vaddr)
if (!vm_file)
return NULL;
- offset = (loff_t)(vma->vm_pgoff << PAGE_SHIFT) + (bp_vaddr - vma->vm_start);
+ offset = (loff_t)(vma_start_pgoff(vma) << PAGE_SHIFT) +
+ (bp_vaddr - vma->vm_start);
uprobe = find_uprobe_rcu(vm_file->f_inode, offset);
if (!uprobe)
return NULL;
diff --git a/kernel/kcov.c b/kernel/kcov.c
index 1df373fb562b..b19b473c366a 100644
--- a/kernel/kcov.c
+++ b/kernel/kcov.c
@@ -512,7 +512,7 @@ static int kcov_mmap(struct file *filep, struct vm_area_struct *vma)
spin_lock_irqsave(&kcov->lock, flags);
size = kcov->size * sizeof(unsigned long);
- if (kcov->area == NULL || vma->vm_pgoff != 0 ||
+ if (kcov->area == NULL || vma_start_pgoff(vma) ||
vma->vm_end - vma->vm_start != size) {
res = -EINVAL;
goto exit;
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 56a328e94395..dfa493d54ef9 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -7613,7 +7613,8 @@ static int __rb_inc_dec_mapped(struct ring_buffer_per_cpu *cpu_buffer,
static int __rb_map_vma(struct ring_buffer_per_cpu *cpu_buffer,
struct vm_area_struct *vma)
{
- unsigned long nr_subbufs, nr_pages, nr_vma_pages, pgoff = vma->vm_pgoff;
+ unsigned long nr_subbufs, nr_pages, nr_vma_pages;
+ pgoff_t pgoff = vma_start_pgoff(vma);
unsigned int subbuf_pages, subbuf_order;
struct page **pages __free(kfree) = NULL;
int p = 0, s = 0;
--
2.54.0