+ xtensa-remove-vma-linked-list-walks.patch added to mm-unstable branch

+ xtensa-remove-vma-linked-list-walks.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: xtensa: remove vma linked list walks
has been added to the -mm mm-unstable branch.  Its filename is
     xtensa-remove-vma-linked-list-walks.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/xtensa-remove-vma-linked-list-walks.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: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: xtensa: remove vma linked list walks
Date: Mon, 22 Aug 2022 15:06:19 +0000

Use the VMA iterator instead.  Since VMA can no longer be NULL in the
loop, then deal with out-of-memory outside the loop.  This means a
slightly longer run time in the failure case (-ENOMEM) - it will run to
the end of the VMAs before erroring instead of in the middle of the loop.

Link: https://lkml.kernel.org/r/20220822150128.1562046-37-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/xtensa/kernel/syscall.c |   18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

--- a/arch/xtensa/kernel/syscall.c~xtensa-remove-vma-linked-list-walks
+++ a/arch/xtensa/kernel/syscall.c
@@ -58,6 +58,7 @@ unsigned long arch_get_unmapped_area(str
 		unsigned long len, unsigned long pgoff, unsigned long flags)
 {
 	struct vm_area_struct *vmm;
+	struct vma_iterator vmi;
 
 	if (flags & MAP_FIXED) {
 		/* We do not accept a shared mapping if it would violate
@@ -79,15 +80,20 @@ unsigned long arch_get_unmapped_area(str
 	else
 		addr = PAGE_ALIGN(addr);
 
-	for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
-		/* At this point:  (!vmm || addr < vmm->vm_end). */
-		if (TASK_SIZE - len < addr)
-			return -ENOMEM;
-		if (!vmm || addr + len <= vm_start_gap(vmm))
-			return addr;
+	vma_iter_init(&vmi, current->mm, addr);
+	for_each_vma(vmi, vmm) {
+		/* At this point:  (addr < vmm->vm_end). */
+		if (addr + len <= vm_start_gap(vmm))
+			break;
+
 		addr = vmm->vm_end;
 		if (flags & MAP_SHARED)
 			addr = COLOUR_ALIGN(addr, pgoff);
 	}
+
+	if (TASK_SIZE - len < addr)
+		return -ENOMEM;
+
+	return addr;
 }
 #endif
_

Patches currently in -mm which might be from willy@infradead.org are

support-highmem-pages-in-vmap_pages_range_noflush.patch
mm-add-vma-iterator.patch
mmap-use-the-vma-iterator-in-count_vma_pages_range.patch
proc-remove-vma-rbtree-use-from-nommu.patch
arm64-remove-mmap-linked-list-from-vdso.patch
parisc-remove-mmap-linked-list-from-cache-handling.patch
powerpc-remove-mmap-linked-list-walks.patch
s390-remove-vma-linked-list-walks.patch
x86-remove-vma-linked-list-walks.patch
xtensa-remove-vma-linked-list-walks.patch
cxl-remove-vma-linked-list-walk.patch
optee-remove-vma-linked-list-walk.patch
um-remove-vma-linked-list-walk.patch
coredump-remove-vma-linked-list-walk.patch
exec-use-vma-iterator-instead-of-linked-list.patch
fs-proc-task_mmu-stop-using-linked-list-and-highest_vm_end.patch
acct-use-vma-iterator-instead-of-linked-list.patch
perf-use-vma-iterator.patch
sched-use-maple-tree-iterator-to-walk-vmas.patch
fork-use-vma-iterator.patch
mm-khugepaged-stop-using-vma-linked-list.patch
mm-ksm-use-vma-iterators-instead-of-vma-linked-list.patch
mm-mlock-use-vma-iterator-and-maple-state-instead-of-vma-linked-list.patch
mm-pagewalk-use-vma_find-instead-of-vma-linked-list.patch
i915-use-the-vma-iterator.patch
nommu-remove-uses-of-vma-linked-list.patch