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 19 static inline long syscall_get_nr(struct task_struct *task, 20 struct pt_regs *regs) 21 { 22 return test_pt_regs_flag(regs, PIF_SYSCALL) ? 23 (regs->int_code & 0xffff) : -1; 24 } 25 26 static inline void syscall_set_nr(struct task_struct *task, 27 struct pt_regs *regs, 28 int nr) 29 { 30 /* 31 * Unlike syscall_get_nr(), syscall_set_nr() can be called only when 32 * the target task is stopped for tracing on entering syscall, so 33 * there is no need to have the same check syscall_get_nr() has. 34 */ 35 regs->int_code = (regs->int_code & ~0xffff) | (nr & 0xffff); 36 } 37 38 static inline void syscall_rollback(struct task_struct *task, 39 struct pt_regs *regs) 40 { 41 regs->gprs[2] = regs->orig_gpr2; 42 } 43 44 static inline long syscall_get_error(struct task_struct *task, 45 struct pt_regs *regs) 46 { 47 unsigned long error = regs->gprs[2]; 48 49 return IS_ERR_VALUE(error) ? error : 0; 50 } 51 52 static inline long syscall_get_return_value(struct task_struct *task, 53 struct pt_regs *regs) 54 { 55 return regs->gprs[2]; 56 } 57 58 static inline void syscall_set_return_value(struct task_struct *task, 59 struct pt_regs *regs, 60 int error, long val) 61 { 62 set_pt_regs_flag(regs, PIF_SYSCALL_RET_SET); 63 regs->gprs[2] = error ? error : val; 64 } 65 66 static inline void syscall_get_arguments(struct task_struct *task, 67 struct pt_regs *regs, 68 unsigned long *args) 69 { 70 unsigned long mask = -1UL; 71 72 for (int i = 1; i < 6; i++) 73 args[i] = regs->gprs[2 + i] & mask; 74 75 args[0] = regs->orig_gpr2 & mask; 76 } 77 78 static inline void syscall_set_arguments(struct task_struct *task, 79 struct pt_regs *regs, 80 const unsigned long *args) 81 { 82 regs->orig_gpr2 = args[0]; 83 for (int n = 1; n < 6; n++) 84 regs->gprs[2 + n] = args[n]; 85 } 86 87 static inline int syscall_get_arch(struct task_struct *task) 88 { 89 return AUDIT_ARCH_S390X; 90 } 91 92 #define SYSCALL_FMT_0 93 #define SYSCALL_FMT_1 , "0" (r2) 94 #define SYSCALL_FMT_2 , "d" (r3) SYSCALL_FMT_1 95 #define SYSCALL_FMT_3 , "d" (r4) SYSCALL_FMT_2 96 #define SYSCALL_FMT_4 , "d" (r5) SYSCALL_FMT_3 97 #define SYSCALL_FMT_5 , "d" (r6) SYSCALL_FMT_4 98 #define SYSCALL_FMT_6 , "d" (r7) SYSCALL_FMT_5 99 100 #define SYSCALL_PARM_0 101 #define SYSCALL_PARM_1 , long arg1 102 #define SYSCALL_PARM_2 SYSCALL_PARM_1, long arg2 103 #define SYSCALL_PARM_3 SYSCALL_PARM_2, long arg3 104 #define SYSCALL_PARM_4 SYSCALL_PARM_3, long arg4 105 #define SYSCALL_PARM_5 SYSCALL_PARM_4, long arg5 106 #define SYSCALL_PARM_6 SYSCALL_PARM_5, long arg6 107 108 #define SYSCALL_REGS_0 109 #define SYSCALL_REGS_1 \ 110 register long r2 asm("2") = arg1 111 #define SYSCALL_REGS_2 \ 112 SYSCALL_REGS_1; \ 113 register long r3 asm("3") = arg2 114 #define SYSCALL_REGS_3 \ 115 SYSCALL_REGS_2; \ 116 register long r4 asm("4") = arg3 117 #define SYSCALL_REGS_4 \ 118 SYSCALL_REGS_3; \ 119 register long r5 asm("5") = arg4 120 #define SYSCALL_REGS_5 \ 121 SYSCALL_REGS_4; \ 122 register long r6 asm("6") = arg5 123 #define SYSCALL_REGS_6 \ 124 SYSCALL_REGS_5; \ 125 register long r7 asm("7") = arg6 126 127 #define GENERATE_SYSCALL_FUNC(nr) \ 128 static __always_inline \ 129 long syscall##nr(unsigned long syscall SYSCALL_PARM_##nr) \ 130 { \ 131 register unsigned long r1 asm ("1") = syscall; \ 132 register long rc asm ("2"); \ 133 SYSCALL_REGS_##nr; \ 134 \ 135 asm volatile ( \ 136 " svc 0" \ 137 : "=d" (rc) \ 138 : "d" (r1) SYSCALL_FMT_##nr \ 139 : "memory"); \ 140 return rc; \ 141 } 142 143 GENERATE_SYSCALL_FUNC(0) 144 GENERATE_SYSCALL_FUNC(1) 145 GENERATE_SYSCALL_FUNC(2) 146 GENERATE_SYSCALL_FUNC(3) 147 GENERATE_SYSCALL_FUNC(4) 148 GENERATE_SYSCALL_FUNC(5) 149 GENERATE_SYSCALL_FUNC(6) 150 151 #endif /* _ASM_SYSCALL_H */ 152