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authorHeiko Carstens <heiko.carstens@de.ibm.com>2013-11-14 15:01:43 +1100
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-11-21 10:33:37 +1100
commit95f715b08fa4a953771398d20cbe35a6803ea41d (patch)
tree6ccc7e13cb8a501232b3d5b153222fe5cb3c4b7b
parent0b5381a61821d1c074c76e01b27bf5f69cf2dd01 (diff)
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: Heiko Carstens <heiko.carstens@de.ibm.com> CC: <stable@vger.kernel.org> [v3.12] Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r--arch/powerpc/mm/gup.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/powerpc/mm/gup.c b/arch/powerpc/mm/gup.c
index 6936547018b8..c5f734e20b0f 100644
--- a/arch/powerpc/mm/gup.c
+++ b/arch/powerpc/mm/gup.c
@@ -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;
}