From: Heiko Carstens Date: Thu, 14 Nov 2013 04:01:43 +0000 (+1100) Subject: powerpc: Fix __get_user_pages_fast() irq handling X-Git-Tag: submit/tizen/20160422.055611~1^2~99^2~18^2~2653^2~10 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=95f715b08fa4a953771398d20cbe35a6803ea41d;p=sdk%2Femulator%2Femulator-kernel.git 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 CC: [v3.12] Signed-off-by: Benjamin Herrenschmidt --- 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; }