From: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Thu, 14 Apr 2022 06:07:18 +0000 (-0700)
Subject: xtensa: remove vma linked list walks
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=fcc0814d5f38f7a32aecdd3ef5b0106205f17b33;p=users%2Fjedix%2Flinux-maple.git

xtensa: remove vma linked list walks

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.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/arch/xtensa/kernel/syscall.c b/arch/xtensa/kernel/syscall.c
index 201356faa7e6..b3c2450d6f23 100644
--- a/arch/xtensa/kernel/syscall.c
+++ b/arch/xtensa/kernel/syscall.c
@@ -58,6 +58,7 @@ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
 		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(struct file *filp, unsigned long addr,
 	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