Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 95f715b0 authored by Heiko Carstens's avatar Heiko Carstens Committed by Benjamin Herrenschmidt
Browse files

powerpc: Fix __get_user_pages_fast() irq handling 



__get_user_pages_fast() may be called with interrupts disabled (see e.g.
get_futex_key() in kernel/futex.c) and therefore should use local_irq_save()
and local_irq_restore() instead of local_irq_disable()/enable().

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
CC: <stable@vger.kernel.org> [v3.12]
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 0b5381a6

arch/powerpc/mm/gup.c

+3 −2
Original line number Diff line number Diff line
@@ -123,6 +123,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, 
	struct mm_struct *mm = current->mm;

	unsigned long addr, len, end;

	unsigned long next;

	unsigned long flags;

	pgd_t *pgdp;

	int nr = 0;
@@ -156,7 +157,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, 
	 * So long as we atomically load page table pointers versus teardown,

	 * we can follow the address down to the the page and take a ref on it.

	 */

	local_irq_disable();

	local_irq_save(flags);



	pgdp = pgd_offset(mm, addr);

	do {
@@ -179,7 +180,7 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, 
			break;

	} while (pgdp++, addr = next, addr != end);



	local_irq_enable();

	local_irq_restore(flags);



	return nr;

}