uprobes: __replace_page() needs munlock_vma_page() (194f8dcb) · Commits · 戴 / test

Like do_wp_page(), __replace_page() should do munlock_vma_page() for the case when the old page still has other !VM_LOCKED mappings. Unfortunately this needs mm/internal.h. Also, move put_page() outside of ptl lock. This doesn't really matter but looks a bit better. Signed-off-by:

Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182249.GA20372@redhat.com Signed-off-by:

Ingo Molnar <mingo@kernel.org>

kernel/events/uprobes.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -32,6 +32,7 @@
		#include <linux/swap.h> /* try_to_free_swap */
		#include <linux/ptrace.h> /* user_enable_single_step */
		#include <linux/kdebug.h> /* notifier mechanism */
		#include "../../mm/internal.h" /* munlock_vma_page */

		#include <linux/uprobes.h>

		@@ -141,7 +142,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
		pte_t *ptep;
		int err;

		/* freeze PageSwapCache() for try_to_free_swap() below */
		/* For try_to_free_swap() and munlock_vma_page() below */
		lock_page(page);

		err = -EAGAIN;
		@@ -164,9 +165,12 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
		page_remove_rmap(page);
		if (!page_mapped(page))
		try_to_free_swap(page);
		put_page(page);
		pte_unmap_unlock(ptep, ptl);

		if (vma->vm_flags & VM_LOCKED)
		munlock_vma_page(page);
		put_page(page);

		err = 0;
		unlock:
		unlock_page(page);

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