ARM: Ensure correct might_sleep() check in pagefault path

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 501304f7e30c0bbf5563921d00328a45972c26c3..b8b3bb4423cf433ca2aab05b449db77e08611104 100644 (file)
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -271,6 +271,13 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
                if (!user_mode(regs) && !search_exception_tables(regs->ARM_pc))
                        goto no_context;
                down_read(&mm->mmap_sem);
+       } else {
+               /*
+                * The above down_read_trylock() might have succeeded in
+                * which case, we'll have missed the might_sleep() from
+                * down_read()
+                */
+               might_sleep();
        }
 
        fault = __do_page_fault(mm, addr, fsr, tsk);