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Commit bdfaa2ee authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Ingo Molnar
Browse files

uprobes: Rename the "struct page *" args of __replace_page() 



Purely cosmetic, no changes in the compiled code.

Perhaps it is just me but I can hardly read __replace_page() because I can't
distinguish "page" from "kpage" and because I need to look at the caller to
to ensure that, say, kpage is really the new page and the code is correct.
Rename them to old_page and new_page, this matches the caller.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Brenden Blanco <bblanco@plumgrid.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Link: http://lkml.kernel.org/r/20160817153704.GC29724@redhat.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent bc06f00d

kernel/events/uprobes.c

+18 −18
Original line number Diff line number Diff line
@@ -150,7 +150,7 @@ static loff_t vaddr_to_offset(struct vm_area_struct *vma, unsigned long vaddr) 
 * Returns 0 on success, -EFAULT on failure.

 */

static int __replace_page(struct vm_area_struct *vma, unsigned long addr,

				struct page *page, struct page *kpage)

				struct page *old_page, struct page *new_page)

{

	struct mm_struct *mm = vma->vm_mm;

	spinlock_t *ptl;
@@ -161,49 +161,49 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr, 
	const unsigned long mmun_end   = addr + PAGE_SIZE;

	struct mem_cgroup *memcg;



	err = mem_cgroup_try_charge(kpage, vma->vm_mm, GFP_KERNEL, &memcg,

	err = mem_cgroup_try_charge(new_page, vma->vm_mm, GFP_KERNEL, &memcg,

			false);

	if (err)

		return err;



	/* For try_to_free_swap() and munlock_vma_page() below */

	lock_page(page);

	lock_page(old_page);



	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);

	err = -EAGAIN;

	ptep = page_check_address(page, mm, addr, &ptl, 0);

	ptep = page_check_address(old_page, mm, addr, &ptl, 0);

	if (!ptep) {

		mem_cgroup_cancel_charge(kpage, memcg, false);

		mem_cgroup_cancel_charge(new_page, memcg, false);

		goto unlock;

	}



	get_page(kpage);

	page_add_new_anon_rmap(kpage, vma, addr, false);

	mem_cgroup_commit_charge(kpage, memcg, false, false);

	lru_cache_add_active_or_unevictable(kpage, vma);

	get_page(new_page);

	page_add_new_anon_rmap(new_page, vma, addr, false);

	mem_cgroup_commit_charge(new_page, memcg, false, false);

	lru_cache_add_active_or_unevictable(new_page, vma);



	if (!PageAnon(page)) {

		dec_mm_counter(mm, mm_counter_file(page));

	if (!PageAnon(old_page)) {

		dec_mm_counter(mm, mm_counter_file(old_page));

		inc_mm_counter(mm, MM_ANONPAGES);

	}



	flush_cache_page(vma, addr, pte_pfn(*ptep));

	ptep_clear_flush_notify(vma, addr, ptep);

	set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot));

	set_pte_at_notify(mm, addr, ptep, mk_pte(new_page, vma->vm_page_prot));



	page_remove_rmap(page, false);

	if (!page_mapped(page))

		try_to_free_swap(page);

	page_remove_rmap(old_page, false);

	if (!page_mapped(old_page))

		try_to_free_swap(old_page);

	pte_unmap_unlock(ptep, ptl);



	if (vma->vm_flags & VM_LOCKED)

		munlock_vma_page(page);

	put_page(page);

		munlock_vma_page(old_page);

	put_page(old_page);



	err = 0;

 unlock:

	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);

	unlock_page(page);

	unlock_page(old_page);

	return err;

}