1 /* 2 * Access to user system call parameters and results 3 * 4 * Copyright (C) 2008 Red Hat, Inc. All rights reserved. 5 * 6 * This copyrighted material is made available to anyone wishing to use, 7 * modify, copy, or redistribute it subject to the terms and conditions 8 * of the GNU General Public License v.2. 9 * 10 * See asm-generic/syscall.h for descriptions of what we must do here. 11 */ 12 13 #ifndef _ASM_SYSCALL_H 14 #define _ASM_SYSCALL_H 1 15 16 #include <linux/sched.h> 17 18 /* ftrace syscalls requires exporting the sys_call_table */ 19 #ifdef CONFIG_FTRACE_SYSCALLS 20 extern const unsigned long *sys_call_table; 21 #endif /* CONFIG_FTRACE_SYSCALLS */ 22 23 static inline long syscall_get_nr(struct task_struct *task, 24 struct pt_regs *regs) 25 { 26 return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1L; 27 } 28 29 static inline void syscall_rollback(struct task_struct *task, 30 struct pt_regs *regs) 31 { 32 regs->gpr[3] = regs->orig_gpr3; 33 } 34 35 static inline long syscall_get_error(struct task_struct *task, 36 struct pt_regs *regs) 37 { 38 return (regs->ccr & 0x10000000) ? -regs->gpr[3] : 0; 39 } 40 41 static inline long syscall_get_return_value(struct task_struct *task, 42 struct pt_regs *regs) 43 { 44 return regs->gpr[3]; 45 } 46 47 static inline void syscall_set_return_value(struct task_struct *task, 48 struct pt_regs *regs, 49 int error, long val) 50 { 51 if (error) { 52 regs->ccr |= 0x10000000L; 53 regs->gpr[3] = -error; 54 } else { 55 regs->ccr &= ~0x10000000L; 56 regs->gpr[3] = val; 57 } 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 BUG_ON(i + n > 6); 66 #ifdef CONFIG_PPC64 67 if (test_tsk_thread_flag(task, TIF_32BIT)) { 68 /* 69 * Zero-extend 32-bit argument values. The high bits are 70 * garbage ignored by the actual syscall dispatch. 71 */ 72 while (n-- > 0) 73 args[n] = (u32) regs->gpr[3 + i + n]; 74 return; 75 } 76 #endif 77 memcpy(args, ®s->gpr[3 + i], n * sizeof(args[0])); 78 } 79 80 static inline void syscall_set_arguments(struct task_struct *task, 81 struct pt_regs *regs, 82 unsigned int i, unsigned int n, 83 const unsigned long *args) 84 { 85 BUG_ON(i + n > 6); 86 memcpy(®s->gpr[3 + i], args, n * sizeof(args[0])); 87 } 88 89 #endif /* _ASM_SYSCALL_H */ 90