1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Access to user system call parameters and results 4 * 5 * Copyright IBM Corp. 2008 6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) 7 */ 8 9 #ifndef _ASM_SYSCALL_H 10 #define _ASM_SYSCALL_H 1 11 12 #include <uapi/linux/audit.h> 13 #include <linux/sched.h> 14 #include <linux/err.h> 15 #include <asm/ptrace.h> 16 17 extern const sys_call_ptr_t sys_call_table[]; 18 extern const sys_call_ptr_t sys_call_table_emu[]; 19 20 static inline long syscall_get_nr(struct task_struct *task, 21 struct pt_regs *regs) 22 { 23 return test_pt_regs_flag(regs, PIF_SYSCALL) ? 24 (regs->int_code & 0xffff) : -1; 25 } 26 27 static inline void syscall_rollback(struct task_struct *task, 28 struct pt_regs *regs) 29 { 30 regs->gprs[2] = regs->orig_gpr2; 31 } 32 33 static inline long syscall_get_error(struct task_struct *task, 34 struct pt_regs *regs) 35 { 36 unsigned long error = regs->gprs[2]; 37 #ifdef CONFIG_COMPAT 38 if (test_tsk_thread_flag(task, TIF_31BIT)) { 39 /* 40 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO 41 * and will match correctly in comparisons. 42 */ 43 error = (long)(int)error; 44 } 45 #endif 46 return IS_ERR_VALUE(error) ? error : 0; 47 } 48 49 static inline long syscall_get_return_value(struct task_struct *task, 50 struct pt_regs *regs) 51 { 52 return regs->gprs[2]; 53 } 54 55 static inline void syscall_set_return_value(struct task_struct *task, 56 struct pt_regs *regs, 57 int error, long val) 58 { 59 set_pt_regs_flag(regs, PIF_SYSCALL_RET_SET); 60 regs->gprs[2] = error ? error : val; 61 } 62 63 static inline void syscall_get_arguments(struct task_struct *task, 64 struct pt_regs *regs, 65 unsigned long *args) 66 { 67 unsigned long mask = -1UL; 68 69 #ifdef CONFIG_COMPAT 70 if (test_tsk_thread_flag(task, TIF_31BIT)) 71 mask = 0xffffffff; 72 #endif 73 for (int i = 1; i < 6; i++) 74 args[i] = regs->gprs[2 + i] & mask; 75 76 args[0] = regs->orig_gpr2 & mask; 77 } 78 79 static inline int syscall_get_arch(struct task_struct *task) 80 { 81 #ifdef CONFIG_COMPAT 82 if (test_tsk_thread_flag(task, TIF_31BIT)) 83 return AUDIT_ARCH_S390; 84 #endif 85 return AUDIT_ARCH_S390X; 86 } 87 88 static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs) 89 { 90 return false; 91 } 92 93 #define SYSCALL_FMT_0 94 #define SYSCALL_FMT_1 , "0" (r2) 95 #define SYSCALL_FMT_2 , "d" (r3) SYSCALL_FMT_1 96 #define SYSCALL_FMT_3 , "d" (r4) SYSCALL_FMT_2 97 #define SYSCALL_FMT_4 , "d" (r5) SYSCALL_FMT_3 98 #define SYSCALL_FMT_5 , "d" (r6) SYSCALL_FMT_4 99 #define SYSCALL_FMT_6 , "d" (r7) SYSCALL_FMT_5 100 101 #define SYSCALL_PARM_0 102 #define SYSCALL_PARM_1 , long arg1 103 #define SYSCALL_PARM_2 SYSCALL_PARM_1, long arg2 104 #define SYSCALL_PARM_3 SYSCALL_PARM_2, long arg3 105 #define SYSCALL_PARM_4 SYSCALL_PARM_3, long arg4 106 #define SYSCALL_PARM_5 SYSCALL_PARM_4, long arg5 107 #define SYSCALL_PARM_6 SYSCALL_PARM_5, long arg6 108 109 #define SYSCALL_REGS_0 110 #define SYSCALL_REGS_1 \ 111 register long r2 asm("2") = arg1 112 #define SYSCALL_REGS_2 \ 113 SYSCALL_REGS_1; \ 114 register long r3 asm("3") = arg2 115 #define SYSCALL_REGS_3 \ 116 SYSCALL_REGS_2; \ 117 register long r4 asm("4") = arg3 118 #define SYSCALL_REGS_4 \ 119 SYSCALL_REGS_3; \ 120 register long r5 asm("5") = arg4 121 #define SYSCALL_REGS_5 \ 122 SYSCALL_REGS_4; \ 123 register long r6 asm("6") = arg5 124 #define SYSCALL_REGS_6 \ 125 SYSCALL_REGS_5; \ 126 register long r7 asm("7") = arg6 127 128 #define GENERATE_SYSCALL_FUNC(nr) \ 129 static __always_inline \ 130 long syscall##nr(unsigned long syscall SYSCALL_PARM_##nr) \ 131 { \ 132 register unsigned long r1 asm ("1") = syscall; \ 133 register long rc asm ("2"); \ 134 SYSCALL_REGS_##nr; \ 135 \ 136 asm volatile ( \ 137 " svc 0\n" \ 138 : "=d" (rc) \ 139 : "d" (r1) SYSCALL_FMT_##nr \ 140 : "memory"); \ 141 return rc; \ 142 } 143 144 GENERATE_SYSCALL_FUNC(0) 145 GENERATE_SYSCALL_FUNC(1) 146 GENERATE_SYSCALL_FUNC(2) 147 GENERATE_SYSCALL_FUNC(3) 148 GENERATE_SYSCALL_FUNC(4) 149 GENERATE_SYSCALL_FUNC(5) 150 GENERATE_SYSCALL_FUNC(6) 151 152 #endif /* _ASM_SYSCALL_H */ 153