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-rw-r--r--fs/userfaultfd.c70
-rw-r--r--include/linux/mm.h60
-rw-r--r--mm/madvise.c26
-rw-r--r--mm/mempolicy.c26
-rw-r--r--mm/mlock.c25
-rw-r--r--mm/mmap.c48
-rw-r--r--mm/mprotect.c29
7 files changed, 141 insertions, 143 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index a7c6ef764e63..ac616cfbacf5 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -927,20 +927,15 @@ static int userfaultfd_release(struct inode *inode, struct file *file)
continue;
}
new_flags = vma->vm_flags & ~__VM_UFFD_FLAGS;
- prev = vma_merge(&vmi, mm, prev, vma->vm_start, vma->vm_end,
- new_flags, vma->anon_vma,
- vma->vm_file, vma->vm_pgoff,
- vma_policy(vma),
- NULL_VM_UFFD_CTX, anon_vma_name(vma));
- if (prev) {
- vma = prev;
- } else {
- prev = vma;
- }
+ vma = vma_modify_flags_uffd(&vmi, prev, vma, vma->vm_start,
+ vma->vm_end, new_flags,
+ NULL_VM_UFFD_CTX);
vma_start_write(vma);
userfaultfd_set_vm_flags(vma, new_flags);
vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
+
+ prev = vma;
}
mmap_write_unlock(mm);
mmput(mm);
@@ -1331,7 +1326,6 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
unsigned long start, end, vma_end;
struct vma_iterator vmi;
bool wp_async = userfaultfd_wp_async_ctx(ctx);
- pgoff_t pgoff;
user_uffdio_register = (struct uffdio_register __user *) arg;
@@ -1484,28 +1478,14 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
vma_end = min(end, vma->vm_end);
new_flags = (vma->vm_flags & ~__VM_UFFD_FLAGS) | vm_flags;
- pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
- prev = vma_merge(&vmi, mm, prev, start, vma_end, new_flags,
- vma->anon_vma, vma->vm_file, pgoff,
- vma_policy(vma),
- ((struct vm_userfaultfd_ctx){ ctx }),
- anon_vma_name(vma));
- if (prev) {
- /* vma_merge() invalidated the mas */
- vma = prev;
- goto next;
- }
- if (vma->vm_start < start) {
- ret = split_vma(&vmi, vma, start, 1);
- if (ret)
- break;
- }
- if (vma->vm_end > end) {
- ret = split_vma(&vmi, vma, end, 0);
- if (ret)
- break;
+ vma = vma_modify_flags_uffd(&vmi, prev, vma, start, vma_end,
+ new_flags,
+ (struct vm_userfaultfd_ctx){ctx});
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
+ break;
}
- next:
+
/*
* In the vma_merge() successful mprotect-like case 8:
* the next vma was merged into the current one and
@@ -1568,7 +1548,6 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
const void __user *buf = (void __user *)arg;
struct vma_iterator vmi;
bool wp_async = userfaultfd_wp_async_ctx(ctx);
- pgoff_t pgoff;
ret = -EFAULT;
if (copy_from_user(&uffdio_unregister, buf, sizeof(uffdio_unregister)))
@@ -1671,26 +1650,13 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
uffd_wp_range(vma, start, vma_end - start, false);
new_flags = vma->vm_flags & ~__VM_UFFD_FLAGS;
- pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
- prev = vma_merge(&vmi, mm, prev, start, vma_end, new_flags,
- vma->anon_vma, vma->vm_file, pgoff,
- vma_policy(vma),
- NULL_VM_UFFD_CTX, anon_vma_name(vma));
- if (prev) {
- vma = prev;
- goto next;
- }
- if (vma->vm_start < start) {
- ret = split_vma(&vmi, vma, start, 1);
- if (ret)
- break;
- }
- if (vma->vm_end > end) {
- ret = split_vma(&vmi, vma, end, 0);
- if (ret)
- break;
+ vma = vma_modify_flags_uffd(&vmi, prev, vma, start, vma_end,
+ new_flags, NULL_VM_UFFD_CTX);
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
+ break;
}
- next:
+
/*
* In the vma_merge() successful mprotect-like case 8:
* the next vma was merged into the current one and
diff --git a/include/linux/mm.h b/include/linux/mm.h
index fa608cba041f..895feb814620 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3251,6 +3251,66 @@ extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
unsigned long addr, unsigned long len, pgoff_t pgoff,
bool *need_rmap_locks);
extern void exit_mmap(struct mm_struct *);
+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);
+
+/* 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));
+}
+
+/* We are about to modify the VMA's flags and/or anon_name. */
+static inline 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);
+}
+
+/* We are about to modify the VMA's memory policy. */
+static inline 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));
+}
+
+/* We are about to modify the VMA's flags and/or uffd context. */
+static inline 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));
+}
static inline int check_data_rlimit(unsigned long rlim,
unsigned long new,
diff --git a/mm/madvise.c b/mm/madvise.c
index 59e8860c86af..a6b48d4796ba 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -141,7 +141,6 @@ static int madvise_update_vma(struct vm_area_struct *vma,
{
struct mm_struct *mm = vma->vm_mm;
int error;
- pgoff_t pgoff;
VMA_ITERATOR(vmi, mm, start);
if (new_flags == vma->vm_flags && anon_vma_name_eq(anon_vma_name(vma), anon_name)) {
@@ -149,30 +148,13 @@ static int madvise_update_vma(struct vm_area_struct *vma,
return 0;
}
- pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
- *prev = vma_merge(&vmi, mm, *prev, start, end, new_flags,
- vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
- vma->vm_userfaultfd_ctx, anon_name);
- if (*prev) {
- vma = *prev;
- goto success;
- }
+ vma = vma_modify_flags_name(&vmi, *prev, vma, start, end, new_flags,
+ anon_name);
+ if (IS_ERR(vma))
+ return PTR_ERR(vma);
*prev = vma;
- if (start != vma->vm_start) {
- error = split_vma(&vmi, vma, start, 1);
- if (error)
- return error;
- }
-
- if (end != vma->vm_end) {
- error = split_vma(&vmi, vma, end, 0);
- if (error)
- return error;
- }
-
-success:
/* vm_flags is protected by the mmap_lock held in write mode. */
vma_start_write(vma);
vm_flags_reset(vma, new_flags);
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 38a47fa33ef4..8bb5b4b4b395 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -811,10 +811,7 @@ static int mbind_range(struct vma_iterator *vmi, struct vm_area_struct *vma,
struct vm_area_struct **prev, unsigned long start,
unsigned long end, struct mempolicy *new_pol)
{
- struct vm_area_struct *merged;
unsigned long vmstart, vmend;
- pgoff_t pgoff;
- int err;
vmend = min(end, vma->vm_end);
if (start > vma->vm_start) {
@@ -829,26 +826,9 @@ static int mbind_range(struct vma_iterator *vmi, struct vm_area_struct *vma,
return 0;
}
- pgoff = vma->vm_pgoff + ((vmstart - vma->vm_start) >> PAGE_SHIFT);
- merged = vma_merge(vmi, vma->vm_mm, *prev, vmstart, vmend, vma->vm_flags,
- vma->anon_vma, vma->vm_file, pgoff, new_pol,
- vma->vm_userfaultfd_ctx, anon_vma_name(vma));
- if (merged) {
- *prev = merged;
- return vma_replace_policy(merged, new_pol);
- }
-
- if (vma->vm_start != vmstart) {
- err = split_vma(vmi, vma, vmstart, 1);
- if (err)
- return err;
- }
-
- if (vma->vm_end != vmend) {
- err = split_vma(vmi, vma, vmend, 0);
- if (err)
- return err;
- }
+ vma = vma_modify_policy(vmi, *prev, vma, vmstart, vmend, new_pol);
+ if (IS_ERR(vma))
+ return PTR_ERR(vma);
*prev = vma;
return vma_replace_policy(vma, new_pol);
diff --git a/mm/mlock.c b/mm/mlock.c
index 42b6865f8f82..aa44456200e3 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -476,7 +476,6 @@ static int mlock_fixup(struct vma_iterator *vmi, struct vm_area_struct *vma,
unsigned long end, vm_flags_t newflags)
{
struct mm_struct *mm = vma->vm_mm;
- pgoff_t pgoff;
int nr_pages;
int ret = 0;
vm_flags_t oldflags = vma->vm_flags;
@@ -487,28 +486,12 @@ static int mlock_fixup(struct vma_iterator *vmi, struct vm_area_struct *vma,
/* don't set VM_LOCKED or VM_LOCKONFAULT and don't count */
goto out;
- pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
- *prev = vma_merge(vmi, mm, *prev, start, end, newflags,
- vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
- vma->vm_userfaultfd_ctx, anon_vma_name(vma));
- if (*prev) {
- vma = *prev;
- goto success;
- }
-
- if (start != vma->vm_start) {
- ret = split_vma(vmi, vma, start, 1);
- if (ret)
- goto out;
- }
-
- if (end != vma->vm_end) {
- ret = split_vma(vmi, vma, end, 0);
- if (ret)
- goto out;
+ vma = vma_modify_flags(vmi, *prev, vma, start, end, newflags);
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
+ goto out;
}
-success:
/*
* Keep track of amount of locked VM.
*/
diff --git a/mm/mmap.c b/mm/mmap.c
index 673429ee8a9e..bca685820763 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2438,6 +2438,54 @@ int split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
}
/*
+ * We are about to modify one or multiple of a VMA's flags, policy, userfaultfd
+ * context and anonymous VMA name within the range [start, end).
+ *
+ * As a result, we might be able to merge the newly modified VMA range with an
+ * adjacent VMA with identical properties.
+ *
+ * If no merge is possible and the range does not span the entirety of the VMA,
+ * we then need to split the VMA to accommodate the change.
+ *
+ * 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)
+{
+ pgoff_t pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
+ struct vm_area_struct *merged;
+
+ merged = vma_merge(vmi, vma->vm_mm, prev, start, end, vm_flags,
+ vma->anon_vma, vma->vm_file, pgoff, policy,
+ uffd_ctx, anon_name);
+ if (merged)
+ return merged;
+
+ if (vma->vm_start < start) {
+ int err = split_vma(vmi, vma, start, 1);
+
+ if (err)
+ return ERR_PTR(err);
+ }
+
+ if (vma->vm_end > end) {
+ int err = split_vma(vmi, vma, end, 0);
+
+ if (err)
+ return ERR_PTR(err);
+ }
+
+ return vma;
+}
+
+/*
* do_vmi_align_munmap() - munmap the aligned region from @start to @end.
* @vmi: The vma iterator
* @vma: The starting vm_area_struct
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 03e2cec3e669..f1dc8f8c84ef 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -581,7 +581,6 @@ mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb,
long nrpages = (end - start) >> PAGE_SHIFT;
unsigned int mm_cp_flags = 0;
unsigned long charged = 0;
- pgoff_t pgoff;
int error;
if (newflags == oldflags) {
@@ -631,34 +630,14 @@ mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb,
newflags &= ~VM_ACCOUNT;
}
- /*
- * First try to merge with previous and/or next vma.
- */
- pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
- *pprev = vma_merge(vmi, mm, *pprev, start, end, newflags,
- vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
- vma->vm_userfaultfd_ctx, anon_vma_name(vma));
- if (*pprev) {
- vma = *pprev;
- VM_WARN_ON((vma->vm_flags ^ newflags) & ~VM_SOFTDIRTY);
- goto success;
+ vma = vma_modify_flags(vmi, *pprev, vma, start, end, newflags);
+ if (IS_ERR(vma)) {
+ error = PTR_ERR(vma);
+ goto fail;
}
*pprev = vma;
- if (start != vma->vm_start) {
- error = split_vma(vmi, vma, start, 1);
- if (error)
- goto fail;
- }
-
- if (end != vma->vm_end) {
- error = split_vma(vmi, vma, end, 0);
- if (error)
- goto fail;
- }
-
-success:
/*
* vm_flags and vm_page_prot are protected by the mmap_lock
* held in write mode.
generated by cgit (git 2.34.1) at 2024-05-21 09:42:35 +0000