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 unsigned int n = 6; 69 70 #ifdef CONFIG_COMPAT 71 if (test_tsk_thread_flag(task, TIF_31BIT)) 72 mask = 0xffffffff; 73 #endif 74 while (n-- > 0) 75 if (n > 0) 76 args[n] = regs->gprs[2 + n] & mask; 77 78 args[0] = regs->orig_gpr2 & mask; 79 } 80 81 static inline int syscall_get_arch(struct task_struct *task) 82 { 83 #ifdef CONFIG_COMPAT 84 if (test_tsk_thread_flag(task, TIF_31BIT)) 85 return AUDIT_ARCH_S390; 86 #endif 87 return AUDIT_ARCH_S390X; 88 } 89 90 static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs) 91 { 92 return false; 93 } 94 95 #define SYSCALL_FMT_0 96 #define SYSCALL_FMT_1 , "0" (r2) 97 #define SYSCALL_FMT_2 , "d" (r3) SYSCALL_FMT_1 98 #define SYSCALL_FMT_3 , "d" (r4) SYSCALL_FMT_2 99 #define SYSCALL_FMT_4 , "d" (r5) SYSCALL_FMT_3 100 #define SYSCALL_FMT_5 , "d" (r6) SYSCALL_FMT_4 101 #define SYSCALL_FMT_6 , "d" (r7) SYSCALL_FMT_5 102 103 #define SYSCALL_PARM_0 104 #define SYSCALL_PARM_1 , long arg1 105 #define SYSCALL_PARM_2 SYSCALL_PARM_1, long arg2 106 #define SYSCALL_PARM_3 SYSCALL_PARM_2, long arg3 107 #define SYSCALL_PARM_4 SYSCALL_PARM_3, long arg4 108 #define SYSCALL_PARM_5 SYSCALL_PARM_4, long arg5 109 #define SYSCALL_PARM_6 SYSCALL_PARM_5, long arg6 110 111 #define SYSCALL_REGS_0 112 #define SYSCALL_REGS_1 \ 113 register long r2 asm("2") = arg1 114 #define SYSCALL_REGS_2 \ 115 SYSCALL_REGS_1; \ 116 register long r3 asm("3") = arg2 117 #define SYSCALL_REGS_3 \ 118 SYSCALL_REGS_2; \ 119 register long r4 asm("4") = arg3 120 #define SYSCALL_REGS_4 \ 121 SYSCALL_REGS_3; \ 122 register long r5 asm("5") = arg4 123 #define SYSCALL_REGS_5 \ 124 SYSCALL_REGS_4; \ 125 register long r6 asm("6") = arg5 126 #define SYSCALL_REGS_6 \ 127 SYSCALL_REGS_5; \ 128 register long r7 asm("7") = arg6 129 130 #define GENERATE_SYSCALL_FUNC(nr) \ 131 static __always_inline \ 132 long syscall##nr(unsigned long syscall SYSCALL_PARM_##nr) \ 133 { \ 134 register unsigned long r1 asm ("1") = syscall; \ 135 register long rc asm ("2"); \ 136 SYSCALL_REGS_##nr; \ 137 \ 138 asm volatile ( \ 139 " svc 0\n" \ 140 : "=d" (rc) \ 141 : "d" (r1) SYSCALL_FMT_##nr \ 142 : "memory"); \ 143 return rc; \ 144 } 145 146 GENERATE_SYSCALL_FUNC(0) 147 GENERATE_SYSCALL_FUNC(1) 148 GENERATE_SYSCALL_FUNC(2) 149 GENERATE_SYSCALL_FUNC(3) 150 GENERATE_SYSCALL_FUNC(4) 151 GENERATE_SYSCALL_FUNC(5) 152 GENERATE_SYSCALL_FUNC(6) 153 154 #endif /* _ASM_SYSCALL_H */ 155