The patch titled
Subject: mm: change mprotect_fixup to vma iterator
has been added to the -mm mm-unstable branch. Its filename is
mm-change-mprotect_fixup-to-vma-iterator.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-change-mprotect_fixup-to-vma-iterator.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Subject: mm: change mprotect_fixup to vma iterator
Date: Thu, 5 Jan 2023 19:15:56 +0000
Use the vma iterator so that the iterator can be invalidated or updated
to avoid each caller doing so.
Link: https://lkml.kernel.org/r/20230105191517.3099082-16-Liam.Howlett@xxxxxxxxxx
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/exec.c | 5 +++-
include/linux/mm.h | 6 ++---
mm/mprotect.c | 47 ++++++++++++++++++++-----------------------
3 files changed, 29 insertions(+), 29 deletions(-)
--- a/fs/exec.c~mm-change-mprotect_fixup-to-vma-iterator
+++ a/fs/exec.c
@@ -758,6 +758,7 @@ int setup_arg_pages(struct linux_binprm
unsigned long stack_expand;
unsigned long rlim_stack;
struct mmu_gather tlb;
+ struct vma_iterator vmi;
#ifdef CONFIG_STACK_GROWSUP
/* Limit stack size */
@@ -812,8 +813,10 @@ int setup_arg_pages(struct linux_binprm
vm_flags |= mm->def_flags;
vm_flags |= VM_STACK_INCOMPLETE_SETUP;
+ vma_iter_init(&vmi, mm, vma->vm_start);
+
tlb_gather_mmu(&tlb, mm);
- ret = mprotect_fixup(&tlb, vma, &prev, vma->vm_start, vma->vm_end,
+ ret = mprotect_fixup(&vmi, &tlb, vma, &prev, vma->vm_start, vma->vm_end,
vm_flags);
tlb_finish_mmu(&tlb);
--- a/include/linux/mm.h~mm-change-mprotect_fixup-to-vma-iterator
+++ a/include/linux/mm.h
@@ -2173,9 +2173,9 @@ bool can_change_pte_writable(struct vm_a
extern long change_protection(struct mmu_gather *tlb,
struct vm_area_struct *vma, unsigned long start,
unsigned long end, unsigned long cp_flags);
-extern int mprotect_fixup(struct mmu_gather *tlb, struct vm_area_struct *vma,
- struct vm_area_struct **pprev, unsigned long start,
- unsigned long end, unsigned long newflags);
+extern int mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb,
+ struct vm_area_struct *vma, struct vm_area_struct **pprev,
+ unsigned long start, unsigned long end, unsigned long newflags);
/*
* doesn't attempt to fault and will return short.
--- a/mm/mprotect.c~mm-change-mprotect_fixup-to-vma-iterator
+++ a/mm/mprotect.c
@@ -585,9 +585,9 @@ static const struct mm_walk_ops prot_non
};
int
-mprotect_fixup(struct mmu_gather *tlb, struct vm_area_struct *vma,
- struct vm_area_struct **pprev, unsigned long start,
- unsigned long end, unsigned long newflags)
+mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb,
+ struct vm_area_struct *vma, struct vm_area_struct **pprev,
+ unsigned long start, unsigned long end, unsigned long newflags)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long oldflags = vma->vm_flags;
@@ -642,7 +642,7 @@ mprotect_fixup(struct mmu_gather *tlb, s
* First try to merge with previous and/or next vma.
*/
pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
- *pprev = vma_merge(mm, *pprev, start, end, newflags,
+ *pprev = vmi_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) {
@@ -654,13 +654,13 @@ mprotect_fixup(struct mmu_gather *tlb, s
*pprev = vma;
if (start != vma->vm_start) {
- error = split_vma(mm, vma, start, 1);
+ error = vmi_split_vma(vmi, mm, vma, start, 1);
if (error)
goto fail;
}
if (end != vma->vm_end) {
- error = split_vma(mm, vma, end, 0);
+ error = vmi_split_vma(vmi, mm, vma, end, 0);
if (error)
goto fail;
}
@@ -709,7 +709,7 @@ static int do_mprotect_pkey(unsigned lon
const bool rier = (current->personality & READ_IMPLIES_EXEC) &&
(prot & PROT_READ);
struct mmu_gather tlb;
- MA_STATE(mas, ¤t->mm->mm_mt, 0, 0);
+ struct vma_iterator vmi;
start = untagged_addr(start);
@@ -741,8 +741,8 @@ static int do_mprotect_pkey(unsigned lon
if ((pkey != -1) && !mm_pkey_is_allocated(current->mm, pkey))
goto out;
- mas_set(&mas, start);
- vma = mas_find(&mas, ULONG_MAX);
+ vma_iter_init(&vmi, current->mm, start);
+ vma = vma_find(&vmi, end);
error = -ENOMEM;
if (!vma)
goto out;
@@ -765,18 +765,22 @@ static int do_mprotect_pkey(unsigned lon
}
}
+ prev = vma_prev(&vmi);
if (start > vma->vm_start)
prev = vma;
- else
- prev = mas_prev(&mas, 0);
tlb_gather_mmu(&tlb, current->mm);
- for (nstart = start ; ; ) {
+ nstart = start;
+ tmp = vma->vm_start;
+ for_each_vma_range(vmi, vma, end) {
unsigned long mask_off_old_flags;
unsigned long newflags;
int new_vma_pkey;
- /* Here we know that vma->vm_start <= nstart < vma->vm_end. */
+ if (vma->vm_start != tmp) {
+ error = -ENOMEM;
+ break;
+ }
/* Does the application expect PROT_READ to imply PROT_EXEC */
if (rier && (vma->vm_flags & VM_MAYEXEC))
@@ -819,25 +823,18 @@ static int do_mprotect_pkey(unsigned lon
break;
}
- error = mprotect_fixup(&tlb, vma, &prev, nstart, tmp, newflags);
+ error = mprotect_fixup(&vmi, &tlb, vma, &prev, nstart, tmp, newflags);
if (error)
break;
nstart = tmp;
-
- if (nstart < prev->vm_end)
- nstart = prev->vm_end;
- if (nstart >= end)
- break;
-
- vma = find_vma(current->mm, prev->vm_end);
- if (!vma || vma->vm_start != nstart) {
- error = -ENOMEM;
- break;
- }
prot = reqprot;
}
tlb_finish_mmu(&tlb);
+
+ if (vma_iter_end(&vmi) < end)
+ error = -ENOMEM;
+
out:
mmap_write_unlock(current->mm);
return error;
_
Patches currently in -mm which might be from Liam.Howlett@xxxxxxxxxx are
maple_tree-add-mas_init-function.patch
maple_tree-fix-potential-rcu-issue.patch
maple_tree-reduce-user-error-potential.patch
test_maple_tree-test-modifications-while-iterating.patch
mm-expand-vma-iterator-interface.patch
mm-mmap-convert-brk-to-use-vma-iterator.patch
kernel-fork-convert-forking-to-using-the-vmi-iterator.patch
mmap-convert-vma_link-vma-iterator.patch
mm-mmap-remove-preallocation-from-do_mas_align_munmap.patch
mmap-change-do_mas_munmap-and-do_mas_aligned_munmap-to-use-vma-iterator.patch
mmap-convert-vma_expand-to-use-vma-iterator.patch
mm-add-temporary-vma-iterator-versions-of-vma_merge-split_vma-and-__split_vma.patch
ipc-shm-use-the-vma-iterator-for-munmap-calls.patch
userfaultfd-use-vma-iterator.patch
mm-change-mprotect_fixup-to-vma-iterator.patch
mlock-convert-mlock-to-vma-iterator.patch
coredump-convert-to-vma-iterator.patch
mempolicy-convert-to-vma-iterator.patch
task_mmu-convert-to-vma-iterator.patch
sched-convert-to-vma-iterator.patch
madvise-use-vmi-iterator-for-__split_vma-and-vma_merge.patch
mmap-pass-through-vmi-iterator-to-__split_vma.patch
mmap-use-vmi-version-of-vma_merge.patch
mm-mremap-use-vmi-version-of-vma_merge.patch
mm-switch-vma_merge-split_vma-and-__split_vma-to-vma-iterator.patch
mmap-convert-__vma_adjust-to-use-vma-iterator.patch
mm-pass-through-vma-iterator-to-__vma_adjust.patch
madvise-use-split_vma-instead-of-__split_vma.patch
mm-remove-unnecessary-write-to-vma-iterator-in-__vma_adjust.patch
mm-pass-vma-iterator-through-to-__vma_adjust.patch
mm-add-vma-iterator-to-vma_adjust-arguments.patch
mmap-clean-up-mmap_region-unrolling.patch
mm-change-munmap-splitting-order-and-move_vma.patch
mm-mmap-move-anon_vma-setting-in-__vma_adjust.patch
mm-mmap-refactor-locking-out-of-__vma_adjust.patch
mm-mmap-use-vma_prepare-and-vma_complete-in-vma_expand.patch
mm-mmap-introduce-init_vma_prep-and-init_multi_vma_prep.patch
mm-dont-use-__vma_adjust-in-__split_vma.patch
mm-mmap-dont-use-__vma_adjust-in-shift_arg_pages.patch
mm-mmap-introduce-dup_vma_anon-helper.patch
mm-mmap-convert-do_brk_flags-to-use-vma_prepare-and-vma_complete.patch
mm-mmap-remove-__vma_adjust.patch
vma_merge-set-vma-iterator-to-correct-position.patch
