1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef ARCH_S390_ENTRY_COMMON_H
3 #define ARCH_S390_ENTRY_COMMON_H
4 
5 #include <linux/sched.h>
6 #include <linux/audit.h>
7 #include <linux/randomize_kstack.h>
8 #include <linux/tracehook.h>
9 #include <linux/processor.h>
10 #include <linux/uaccess.h>
11 #include <asm/timex.h>
12 #include <asm/fpu/api.h>
13 
14 #define ARCH_EXIT_TO_USER_MODE_WORK (_TIF_GUARDED_STORAGE | _TIF_PER_TRAP)
15 
16 void do_per_trap(struct pt_regs *regs);
17 
18 #ifdef CONFIG_DEBUG_ENTRY
19 static __always_inline void arch_check_user_regs(struct pt_regs *regs)
20 {
21 	debug_user_asce(0);
22 }
23 
24 #define arch_check_user_regs arch_check_user_regs
25 #endif /* CONFIG_DEBUG_ENTRY */
26 
27 static __always_inline void arch_exit_to_user_mode_work(struct pt_regs *regs,
28 							unsigned long ti_work)
29 {
30 	if (ti_work & _TIF_PER_TRAP) {
31 		clear_thread_flag(TIF_PER_TRAP);
32 		do_per_trap(regs);
33 	}
34 
35 	if (ti_work & _TIF_GUARDED_STORAGE)
36 		gs_load_bc_cb(regs);
37 }
38 
39 #define arch_exit_to_user_mode_work arch_exit_to_user_mode_work
40 
41 static __always_inline void arch_exit_to_user_mode(void)
42 {
43 	if (test_cpu_flag(CIF_FPU))
44 		__load_fpu_regs();
45 
46 	if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
47 		debug_user_asce(1);
48 }
49 
50 #define arch_exit_to_user_mode arch_exit_to_user_mode
51 
52 static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
53 						  unsigned long ti_work)
54 {
55 	choose_random_kstack_offset(get_tod_clock_fast() & 0xff);
56 }
57 
58 #define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare
59 
60 static inline bool on_thread_stack(void)
61 {
62 	return !(((unsigned long)(current->stack) ^ current_stack_pointer()) & ~(THREAD_SIZE - 1));
63 }
64 
65 #endif
66