1f27bb139SMarc Zyngier /* 2f27bb139SMarc Zyngier * Copyright (C) 2012 ARM Ltd. 3f27bb139SMarc Zyngier * 4f27bb139SMarc Zyngier * This program is free software; you can redistribute it and/or modify 5f27bb139SMarc Zyngier * it under the terms of the GNU General Public License version 2 as 6f27bb139SMarc Zyngier * published by the Free Software Foundation. 7f27bb139SMarc Zyngier * 8f27bb139SMarc Zyngier * This program is distributed in the hope that it will be useful, 9f27bb139SMarc Zyngier * but WITHOUT ANY WARRANTY; without even the implied warranty of 10f27bb139SMarc Zyngier * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11f27bb139SMarc Zyngier * GNU General Public License for more details. 12f27bb139SMarc Zyngier * 13f27bb139SMarc Zyngier * You should have received a copy of the GNU General Public License 14f27bb139SMarc Zyngier * along with this program. If not, see <http://www.gnu.org/licenses/>. 15f27bb139SMarc Zyngier */ 16f27bb139SMarc Zyngier #ifndef __ASM_SYSCALL_H 17f27bb139SMarc Zyngier #define __ASM_SYSCALL_H 18f27bb139SMarc Zyngier 19f27bb139SMarc Zyngier #include <linux/err.h> 20f27bb139SMarc Zyngier 21f27bb139SMarc Zyngier 22f27bb139SMarc Zyngier static inline int syscall_get_nr(struct task_struct *task, 23f27bb139SMarc Zyngier struct pt_regs *regs) 24f27bb139SMarc Zyngier { 25f27bb139SMarc Zyngier return regs->syscallno; 26f27bb139SMarc Zyngier } 27f27bb139SMarc Zyngier 28f27bb139SMarc Zyngier static inline void syscall_rollback(struct task_struct *task, 29f27bb139SMarc Zyngier struct pt_regs *regs) 30f27bb139SMarc Zyngier { 31f27bb139SMarc Zyngier regs->regs[0] = regs->orig_x0; 32f27bb139SMarc Zyngier } 33f27bb139SMarc Zyngier 34f27bb139SMarc Zyngier 35f27bb139SMarc Zyngier static inline long syscall_get_error(struct task_struct *task, 36f27bb139SMarc Zyngier struct pt_regs *regs) 37f27bb139SMarc Zyngier { 38f27bb139SMarc Zyngier unsigned long error = regs->regs[0]; 39f27bb139SMarc Zyngier return IS_ERR_VALUE(error) ? error : 0; 40f27bb139SMarc Zyngier } 41f27bb139SMarc Zyngier 42f27bb139SMarc Zyngier static inline long syscall_get_return_value(struct task_struct *task, 43f27bb139SMarc Zyngier struct pt_regs *regs) 44f27bb139SMarc Zyngier { 45f27bb139SMarc Zyngier return regs->regs[0]; 46f27bb139SMarc Zyngier } 47f27bb139SMarc Zyngier 48f27bb139SMarc Zyngier static inline void syscall_set_return_value(struct task_struct *task, 49f27bb139SMarc Zyngier struct pt_regs *regs, 50f27bb139SMarc Zyngier int error, long val) 51f27bb139SMarc Zyngier { 52f27bb139SMarc Zyngier regs->regs[0] = (long) error ? error : val; 53f27bb139SMarc Zyngier } 54f27bb139SMarc Zyngier 55f27bb139SMarc Zyngier #define SYSCALL_MAX_ARGS 6 56f27bb139SMarc Zyngier 57f27bb139SMarc Zyngier static inline void syscall_get_arguments(struct task_struct *task, 58f27bb139SMarc Zyngier struct pt_regs *regs, 59f27bb139SMarc Zyngier unsigned int i, unsigned int n, 60f27bb139SMarc Zyngier unsigned long *args) 61f27bb139SMarc Zyngier { 627b22c035SAKASHI Takahiro if (n == 0) 637b22c035SAKASHI Takahiro return; 647b22c035SAKASHI Takahiro 65f27bb139SMarc Zyngier if (i + n > SYSCALL_MAX_ARGS) { 66f27bb139SMarc Zyngier unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i; 67f27bb139SMarc Zyngier unsigned int n_bad = n + i - SYSCALL_MAX_ARGS; 68f27bb139SMarc Zyngier pr_warning("%s called with max args %d, handling only %d\n", 69f27bb139SMarc Zyngier __func__, i + n, SYSCALL_MAX_ARGS); 70f27bb139SMarc Zyngier memset(args_bad, 0, n_bad * sizeof(args[0])); 71f27bb139SMarc Zyngier } 72f27bb139SMarc Zyngier 73f27bb139SMarc Zyngier if (i == 0) { 74f27bb139SMarc Zyngier args[0] = regs->orig_x0; 75f27bb139SMarc Zyngier args++; 76f27bb139SMarc Zyngier i++; 77f27bb139SMarc Zyngier n--; 78f27bb139SMarc Zyngier } 79f27bb139SMarc Zyngier 80f27bb139SMarc Zyngier memcpy(args, ®s->regs[i], n * sizeof(args[0])); 81f27bb139SMarc Zyngier } 82f27bb139SMarc Zyngier 83f27bb139SMarc Zyngier static inline void syscall_set_arguments(struct task_struct *task, 84f27bb139SMarc Zyngier struct pt_regs *regs, 85f27bb139SMarc Zyngier unsigned int i, unsigned int n, 86f27bb139SMarc Zyngier const unsigned long *args) 87f27bb139SMarc Zyngier { 887b22c035SAKASHI Takahiro if (n == 0) 897b22c035SAKASHI Takahiro return; 907b22c035SAKASHI Takahiro 91f27bb139SMarc Zyngier if (i + n > SYSCALL_MAX_ARGS) { 92f27bb139SMarc Zyngier pr_warning("%s called with max args %d, handling only %d\n", 93f27bb139SMarc Zyngier __func__, i + n, SYSCALL_MAX_ARGS); 94f27bb139SMarc Zyngier n = SYSCALL_MAX_ARGS - i; 95f27bb139SMarc Zyngier } 96f27bb139SMarc Zyngier 97f27bb139SMarc Zyngier if (i == 0) { 98f27bb139SMarc Zyngier regs->orig_x0 = args[0]; 99f27bb139SMarc Zyngier args++; 100f27bb139SMarc Zyngier i++; 101f27bb139SMarc Zyngier n--; 102f27bb139SMarc Zyngier } 103f27bb139SMarc Zyngier 104f27bb139SMarc Zyngier memcpy(®s->regs[i], args, n * sizeof(args[0])); 105f27bb139SMarc Zyngier } 106f27bb139SMarc Zyngier 107f27bb139SMarc Zyngier #endif /* __ASM_SYSCALL_H */ 108