Commit 49c40fb4 authored Sep 06, 2022 by Matthew Wilcox (Oracle) Committed by Andrew Morton Sep 26, 2022

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.

Link: https://lkml.kernel.org/r/20220906194824.2110408-37-Liam.Howlett@oracle.com


Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Tested-by: Yu Zhao <yuzhao@google.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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

parent a3884621

arch/xtensa/kernel/syscall.c

+12 −6

Original line number	Diff line number	Diff line
		@@ -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