Commit dadbb612 authored by Souptick Joarder's avatar Souptick Joarder Committed by Linus Torvalds
Browse files

mm/gup.c: convert to use get_user_{page|pages}_fast_only() 



API __get_user_pages_fast() renamed to get_user_pages_fast_only() to
align with pin_user_pages_fast_only().

As part of this we will get rid of write parameter.  Instead caller will
pass FOLL_WRITE to get_user_pages_fast_only().  This will not change any
existing functionality of the API.

All the callers are changed to pass FOLL_WRITE.

Also introduce get_user_page_fast_only(), and use it in a few places
that hard-code nr_pages to 1.

Updated the documentation of the API.

Signed-off-by: default avatarSouptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarJohn Hubbard <jhubbard@nvidia.com>
Reviewed-by: Paul Mackerras <paulus@ozlabs.org>		[arch/powerpc/kvm]
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Michal Suchanek <msuchanek@suse.de>
Link: http://lkml.kernel.org/r/1590396812-31277-1-git-send-email-jrdr.linux@gmail.com


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e77132e7

arch/powerpc/kvm/book3s_64_mmu_hv.c

+1 −1
Original line number Diff line number Diff line
@@ -581,7 +581,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, 
	 * We always ask for write permission since the common case

	 * is that the page is writable.

	 */

	if (__get_user_pages_fast(hva, 1, 1, &page) == 1) {

	if (get_user_page_fast_only(hva, FOLL_WRITE, &page)) {

		write_ok = true;

	} else {

		/* Call KVM generic code to do the slow-path check */

arch/powerpc/kvm/book3s_64_mmu_radix.c

+1 −1
Original line number Diff line number Diff line
@@ -795,7 +795,7 @@ int kvmppc_book3s_instantiate_page(struct kvm_vcpu *vcpu, 
	 * is that the page is writable.

	 */

	hva = gfn_to_hva_memslot(memslot, gfn);

	if (!kvm_ro && __get_user_pages_fast(hva, 1, 1, &page) == 1) {

	if (!kvm_ro && get_user_page_fast_only(hva, FOLL_WRITE, &page)) {

		upgrade_write = true;

	} else {

		unsigned long pfn;

arch/powerpc/perf/callchain_64.c

+1 −3
Original line number Diff line number Diff line
@@ -30,11 +30,9 @@ int read_user_stack_slow(void __user *ptr, void *buf, int nb) 
	unsigned long addr = (unsigned long) ptr;

	unsigned long offset;

	struct page *page;

	int nrpages;

	void *kaddr;



	nrpages = __get_user_pages_fast(addr, 1, 1, &page);

	if (nrpages == 1) {

	if (get_user_page_fast_only(addr, FOLL_WRITE, &page)) {

		kaddr = page_address(page);



		/* align address to page boundary */

include/linux/mm.h

+8 −2
Original line number Diff line number Diff line
@@ -1824,10 +1824,16 @@ extern int mprotect_fixup(struct vm_area_struct *vma, 
/*

 * doesn't attempt to fault and will return short.

 */

int __get_user_pages_fast(unsigned long start, int nr_pages, int write,

			  struct page **pages);

int get_user_pages_fast_only(unsigned long start, int nr_pages,

			     unsigned int gup_flags, struct page **pages);

int pin_user_pages_fast_only(unsigned long start, int nr_pages,

			     unsigned int gup_flags, struct page **pages);



static inline bool get_user_page_fast_only(unsigned long addr,

			unsigned int gup_flags, struct page **pagep)

{

	return get_user_pages_fast_only(addr, 1, gup_flags, pagep) == 1;

}

/*

 * per-process(per-mm_struct) statistics.

 */

kernel/events/core.c

+2 −2
Original line number Diff line number Diff line
@@ -6934,12 +6934,12 @@ static u64 perf_virt_to_phys(u64 virt) 
		 * Walking the pages tables for user address.

		 * Interrupts are disabled, so it prevents any tear down

		 * of the page tables.

		 * Try IRQ-safe __get_user_pages_fast first.

		 * Try IRQ-safe get_user_page_fast_only first.

		 * If failed, leave phys_addr as 0.

		 */

		if (current->mm != NULL) {

			pagefault_disable();

			if (__get_user_pages_fast(virt, 1, 0, &p) == 1)

			if (get_user_page_fast_only(virt, 0, &p))

				phys_addr = page_to_phys(p) + virt % PAGE_SIZE;

			pagefault_enable();

		}