1 /* 2 * Access to user system call parameters and results 3 * 4 * Copyright IBM Corp. 2008 5 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License (version 2 only) 9 * as published by the Free Software Foundation. 10 */ 11 12 #ifndef _ASM_SYSCALL_H 13 #define _ASM_SYSCALL_H 1 14 15 #include <linux/audit.h> 16 #include <linux/sched.h> 17 #include <linux/err.h> 18 #include <asm/ptrace.h> 19 20 /* 21 * The syscall table always contains 32 bit pointers since we know that the 22 * address of the function to be called is (way) below 4GB. So the "int" 23 * type here is what we want [need] for both 32 bit and 64 bit systems. 24 */ 25 extern const unsigned int sys_call_table[]; 26 27 static inline long syscall_get_nr(struct task_struct *task, 28 struct pt_regs *regs) 29 { 30 return test_tsk_thread_flag(task, TIF_SYSCALL) ? 31 (regs->int_code & 0xffff) : -1; 32 } 33 34 static inline void syscall_rollback(struct task_struct *task, 35 struct pt_regs *regs) 36 { 37 regs->gprs[2] = regs->orig_gpr2; 38 } 39 40 static inline long syscall_get_error(struct task_struct *task, 41 struct pt_regs *regs) 42 { 43 return IS_ERR_VALUE(regs->gprs[2]) ? regs->gprs[2] : 0; 44 } 45 46 static inline long syscall_get_return_value(struct task_struct *task, 47 struct pt_regs *regs) 48 { 49 return regs->gprs[2]; 50 } 51 52 static inline void syscall_set_return_value(struct task_struct *task, 53 struct pt_regs *regs, 54 int error, long val) 55 { 56 regs->gprs[2] = error ? -error : val; 57 } 58 59 static inline void syscall_get_arguments(struct task_struct *task, 60 struct pt_regs *regs, 61 unsigned int i, unsigned int n, 62 unsigned long *args) 63 { 64 unsigned long mask = -1UL; 65 66 BUG_ON(i + n > 6); 67 #ifdef CONFIG_COMPAT 68 if (test_tsk_thread_flag(task, TIF_31BIT)) 69 mask = 0xffffffff; 70 #endif 71 while (n-- > 0) 72 if (i + n > 0) 73 args[n] = regs->gprs[2 + i + n] & mask; 74 if (i == 0) 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 unsigned int i, unsigned int n, 81 const unsigned long *args) 82 { 83 BUG_ON(i + n > 6); 84 while (n-- > 0) 85 if (i + n > 0) 86 regs->gprs[2 + i + n] = args[n]; 87 if (i == 0) 88 regs->orig_gpr2 = args[0]; 89 } 90 91 static inline int syscall_get_arch(struct task_struct *task, 92 struct pt_regs *regs) 93 { 94 #ifdef CONFIG_COMPAT 95 if (test_tsk_thread_flag(task, TIF_31BIT)) 96 return AUDIT_ARCH_S390; 97 #endif 98 return sizeof(long) == 8 ? AUDIT_ARCH_S390X : AUDIT_ARCH_S390; 99 } 100 #endif /* _ASM_SYSCALL_H */ 101