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 <uapi/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 extern const unsigned int sys_call_table_emu[]; 27 28 static inline long syscall_get_nr(struct task_struct *task, 29 struct pt_regs *regs) 30 { 31 return test_pt_regs_flag(regs, PIF_SYSCALL) ? 32 (regs->int_code & 0xffff) : -1; 33 } 34 35 static inline void syscall_rollback(struct task_struct *task, 36 struct pt_regs *regs) 37 { 38 regs->gprs[2] = regs->orig_gpr2; 39 } 40 41 static inline long syscall_get_error(struct task_struct *task, 42 struct pt_regs *regs) 43 { 44 return IS_ERR_VALUE(regs->gprs[2]) ? regs->gprs[2] : 0; 45 } 46 47 static inline long syscall_get_return_value(struct task_struct *task, 48 struct pt_regs *regs) 49 { 50 return regs->gprs[2]; 51 } 52 53 static inline void syscall_set_return_value(struct task_struct *task, 54 struct pt_regs *regs, 55 int error, long val) 56 { 57 regs->gprs[2] = error ? error : val; 58 } 59 60 static inline void syscall_get_arguments(struct task_struct *task, 61 struct pt_regs *regs, 62 unsigned int i, unsigned int n, 63 unsigned long *args) 64 { 65 unsigned long mask = -1UL; 66 67 /* 68 * No arguments for this syscall, there's nothing to do. 69 */ 70 if (!n) 71 return; 72 73 BUG_ON(i + n > 6); 74 #ifdef CONFIG_COMPAT 75 if (test_tsk_thread_flag(task, TIF_31BIT)) 76 mask = 0xffffffff; 77 #endif 78 while (n-- > 0) 79 if (i + n > 0) 80 args[n] = regs->gprs[2 + i + n] & mask; 81 if (i == 0) 82 args[0] = regs->orig_gpr2 & mask; 83 } 84 85 static inline void syscall_set_arguments(struct task_struct *task, 86 struct pt_regs *regs, 87 unsigned int i, unsigned int n, 88 const unsigned long *args) 89 { 90 BUG_ON(i + n > 6); 91 while (n-- > 0) 92 if (i + n > 0) 93 regs->gprs[2 + i + n] = args[n]; 94 if (i == 0) 95 regs->orig_gpr2 = args[0]; 96 } 97 98 static inline int syscall_get_arch(void) 99 { 100 #ifdef CONFIG_COMPAT 101 if (test_tsk_thread_flag(current, TIF_31BIT)) 102 return AUDIT_ARCH_S390; 103 #endif 104 return AUDIT_ARCH_S390X; 105 } 106 #endif /* _ASM_SYSCALL_H */ 107