Commit b17269a5 authored by Peter Xu's avatar Peter Xu Committed by Andrew Morton
Browse files

mm/access_process_vm: use the new follow_pfnmap API 

Use the new API that can understand huge pfn mappings.

Link: https://lkml.kernel.org/r/20240826204353.2228736-16-peterx@redhat.com


Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent e6bc784c

mm/memory.c

+14 −14
Original line number Diff line number Diff line
@@ -6341,34 +6341,34 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, 
	resource_size_t phys_addr;

	unsigned long prot = 0;

	void __iomem *maddr;

	pte_t *ptep, pte;

	spinlock_t *ptl;

	int offset = offset_in_page(addr);

	int ret = -EINVAL;

	bool writable;

	struct follow_pfnmap_args args = { .vma = vma, .address = addr };



retry:

	if (follow_pte(vma, addr, &ptep, &ptl))

	if (follow_pfnmap_start(&args))

		return -EINVAL;

	pte = ptep_get(ptep);

	pte_unmap_unlock(ptep, ptl);

	prot = pgprot_val(args.pgprot);

	phys_addr = (resource_size_t)args.pfn << PAGE_SHIFT;

	writable = args.writable;

	follow_pfnmap_end(&args);



	prot = pgprot_val(pte_pgprot(pte));

	phys_addr = (resource_size_t)pte_pfn(pte) << PAGE_SHIFT;



	if ((write & FOLL_WRITE) && !pte_write(pte))

	if ((write & FOLL_WRITE) && !writable)

		return -EINVAL;



	maddr = ioremap_prot(phys_addr, PAGE_ALIGN(len + offset), prot);

	if (!maddr)

		return -ENOMEM;



	if (follow_pte(vma, addr, &ptep, &ptl))

	if (follow_pfnmap_start(&args))

		goto out_unmap;



	if (!pte_same(pte, ptep_get(ptep))) {

		pte_unmap_unlock(ptep, ptl);

	if ((prot != pgprot_val(args.pgprot)) ||

	    (phys_addr != (args.pfn << PAGE_SHIFT)) ||

	    (writable != args.writable)) {

		follow_pfnmap_end(&args);

		iounmap(maddr);



		goto retry;

	}
@@ -6377,7 +6377,7 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr, 
	else

		memcpy_fromio(buf, maddr + offset, len);

	ret = len;

	pte_unmap_unlock(ptep, ptl);

	follow_pfnmap_end(&args);

out_unmap:

	iounmap(maddr);