Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / arch / x86 / entry / common.c

diff --git a/kernel/arch/x86/entry/common.c b/kernel/arch/x86/entry/common.c
index 3ec240f..75a301b 100644 (file)
--- a/kernel/arch/x86/entry/common.c
+++ b/kernel/arch/x86/entry/common.c
@@ -275,6 +275,7 @@ static void exit_to_usermode_loop(struct pt_regs *regs, u32 cached_flags)
 /* Called with IRQs disabled. */
 __visible inline void prepare_exit_to_usermode(struct pt_regs *regs)
 {
+       struct thread_info *ti = pt_regs_to_thread_info(regs);
        u32 cached_flags;
 
        if (IS_ENABLED(CONFIG_PROVE_LOCKING) && WARN_ON(!irqs_disabled()))
@@ -282,12 +283,22 @@ __visible inline void prepare_exit_to_usermode(struct pt_regs *regs)
 
        lockdep_sys_exit();
 
-       cached_flags =
-               READ_ONCE(pt_regs_to_thread_info(regs)->flags);
+       cached_flags = READ_ONCE(ti->flags);
 
        if (unlikely(cached_flags & EXIT_TO_USERMODE_LOOP_FLAGS))
                exit_to_usermode_loop(regs, cached_flags);
 
+#ifdef CONFIG_COMPAT
+       /*
+        * Compat syscalls set TS_COMPAT.  Make sure we clear it before
+        * returning to user mode.  We need to clear it *after* signal
+        * handling, because syscall restart has a fixup for compat
+        * syscalls.  The fixup is exercised by the ptrace_syscall_32
+        * selftest.
+        */
+       ti->status &= ~TS_COMPAT;
+#endif
+
        user_enter();
 }
 
@@ -339,14 +350,6 @@ __visible inline void syscall_return_slowpath(struct pt_regs *regs)
        if (unlikely(cached_flags & SYSCALL_EXIT_WORK_FLAGS))
                syscall_slow_exit_work(regs, cached_flags);
 
-#ifdef CONFIG_COMPAT
-       /*
-        * Compat syscalls set TS_COMPAT.  Make sure we clear it before
-        * returning to user mode.
-        */
-       ti->status &= ~TS_COMPAT;
-#endif
-
        local_irq_disable();
        prepare_exit_to_usermode(regs);
 }