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 <linux/err.h> 20 21 extern const void *sys_call_table[]; 22 23 static inline int syscall_get_nr(struct task_struct *task, 24 struct pt_regs *regs) 25 { 26 return regs->syscallno; 27 } 28 29 static inline void syscall_rollback(struct task_struct *task, 30 struct pt_regs *regs) 31 { 32 regs->regs[0] = regs->orig_x0; 33 } 34 35 36 static inline long syscall_get_error(struct task_struct *task, 37 struct pt_regs *regs) 38 { 39 unsigned long error = regs->regs[0]; 40 return IS_ERR_VALUE(error) ? error : 0; 41 } 42 43 static inline long syscall_get_return_value(struct task_struct *task, 44 struct pt_regs *regs) 45 { 46 return regs->regs[0]; 47 } 48 49 static inline void syscall_set_return_value(struct task_struct *task, 50 struct pt_regs *regs, 51 int error, long val) 52 { 53 regs->regs[0] = (long) error ? error : val; 54 } 55 56 #define SYSCALL_MAX_ARGS 6 57 58 static inline void syscall_get_arguments(struct task_struct *task, 59 struct pt_regs *regs, 60 unsigned int i, unsigned int n, 61 unsigned long *args) 62 { 63 if (n == 0) 64 return; 65 66 if (i + n > SYSCALL_MAX_ARGS) { 67 unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i; 68 unsigned int n_bad = n + i - SYSCALL_MAX_ARGS; 69 pr_warning("%s called with max args %d, handling only %d\n", 70 __func__, i + n, SYSCALL_MAX_ARGS); 71 memset(args_bad, 0, n_bad * sizeof(args[0])); 72 } 73 74 if (i == 0) { 75 args[0] = regs->orig_x0; 76 args++; 77 i++; 78 n--; 79 } 80 81 memcpy(args, ®s->regs[i], n * sizeof(args[0])); 82 } 83 84 static inline void syscall_set_arguments(struct task_struct *task, 85 struct pt_regs *regs, 86 unsigned int i, unsigned int n, 87 const unsigned long *args) 88 { 89 if (n == 0) 90 return; 91 92 if (i + n > SYSCALL_MAX_ARGS) { 93 pr_warning("%s called with max args %d, handling only %d\n", 94 __func__, i + n, SYSCALL_MAX_ARGS); 95 n = SYSCALL_MAX_ARGS - i; 96 } 97 98 if (i == 0) { 99 regs->orig_x0 = args[0]; 100 args++; 101 i++; 102 n--; 103 } 104 105 memcpy(®s->regs[i], args, n * sizeof(args[0])); 106 } 107 108 #endif /* __ASM_SYSCALL_H */ 109