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 unsigned long sys_call_table[]; 18 extern const unsigned long 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 regs->gprs[2] = error ? error : val; 60 } 61 62 static inline void syscall_get_arguments(struct task_struct *task, 63 struct pt_regs *regs, 64 unsigned long *args) 65 { 66 unsigned long mask = -1UL; 67 unsigned int n = 6; 68 69 #ifdef CONFIG_COMPAT 70 if (test_tsk_thread_flag(task, TIF_31BIT)) 71 mask = 0xffffffff; 72 #endif 73 while (n-- > 0) 74 if (n > 0) 75 args[n] = regs->gprs[2 + n] & mask; 76 77 args[0] = regs->orig_gpr2 & mask; 78 } 79 80 static inline void syscall_set_arguments(struct task_struct *task, 81 struct pt_regs *regs, 82 const unsigned long *args) 83 { 84 unsigned int n = 6; 85 86 while (n-- > 0) 87 if (n > 0) 88 regs->gprs[2 + n] = args[n]; 89 regs->orig_gpr2 = args[0]; 90 } 91 92 static inline int syscall_get_arch(struct task_struct *task) 93 { 94 #ifdef CONFIG_COMPAT 95 if (test_tsk_thread_flag(task, TIF_31BIT)) 96 return AUDIT_ARCH_S390; 97 #endif 98 return AUDIT_ARCH_S390X; 99 } 100 #endif /* _ASM_SYSCALL_H */ 101