1 /* 2 * Copyright (C) 2012 ARM Ltd. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program. If not, see <http://www.gnu.org/licenses/>. 15 */ 16 #ifndef __ASM_SYSCALL_H 17 #define __ASM_SYSCALL_H 18 19 #include <uapi/linux/audit.h> 20 #include <linux/compat.h> 21 #include <linux/err.h> 22 23 typedef long (*syscall_fn_t)(struct pt_regs *regs); 24 25 extern const syscall_fn_t sys_call_table[]; 26 27 #ifdef CONFIG_COMPAT 28 extern const syscall_fn_t compat_sys_call_table[]; 29 #endif 30 31 static inline int syscall_get_nr(struct task_struct *task, 32 struct pt_regs *regs) 33 { 34 return regs->syscallno; 35 } 36 37 static inline void syscall_rollback(struct task_struct *task, 38 struct pt_regs *regs) 39 { 40 regs->regs[0] = regs->orig_x0; 41 } 42 43 44 static inline long syscall_get_error(struct task_struct *task, 45 struct pt_regs *regs) 46 { 47 unsigned long error = regs->regs[0]; 48 return IS_ERR_VALUE(error) ? error : 0; 49 } 50 51 static inline long syscall_get_return_value(struct task_struct *task, 52 struct pt_regs *regs) 53 { 54 return regs->regs[0]; 55 } 56 57 static inline void syscall_set_return_value(struct task_struct *task, 58 struct pt_regs *regs, 59 int error, long val) 60 { 61 regs->regs[0] = (long) error ? error : val; 62 } 63 64 #define SYSCALL_MAX_ARGS 6 65 66 static inline void syscall_get_arguments(struct task_struct *task, 67 struct pt_regs *regs, 68 unsigned long *args) 69 { 70 args[0] = regs->orig_x0; 71 args++; 72 73 memcpy(args, ®s->regs[1], 5 * sizeof(args[0])); 74 } 75 76 static inline void syscall_set_arguments(struct task_struct *task, 77 struct pt_regs *regs, 78 const unsigned long *args) 79 { 80 regs->orig_x0 = args[0]; 81 args++; 82 83 memcpy(®s->regs[1], args, 5 * sizeof(args[0])); 84 } 85 86 /* 87 * We don't care about endianness (__AUDIT_ARCH_LE bit) here because 88 * AArch64 has the same system calls both on little- and big- endian. 89 */ 90 static inline int syscall_get_arch(struct task_struct *task) 91 { 92 if (is_compat_thread(task_thread_info(task))) 93 return AUDIT_ARCH_ARM; 94 95 return AUDIT_ARCH_AARCH64; 96 } 97 98 #endif /* __ASM_SYSCALL_H */ 99