| Marc Zyngier | f27bb13 | 2012-03-05 11:49:33 +0000 | [diff] [blame^] | 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 | |
| 22 | static inline int syscall_get_nr(struct task_struct *task, |
| 23 | struct pt_regs *regs) |
| 24 | { |
| 25 | return regs->syscallno; |
| 26 | } |
| 27 | |
| 28 | static inline void syscall_rollback(struct task_struct *task, |
| 29 | struct pt_regs *regs) |
| 30 | { |
| 31 | regs->regs[0] = regs->orig_x0; |
| 32 | } |
| 33 | |
| 34 | |
| 35 | static inline long syscall_get_error(struct task_struct *task, |
| 36 | struct pt_regs *regs) |
| 37 | { |
| 38 | unsigned long error = regs->regs[0]; |
| 39 | return IS_ERR_VALUE(error) ? error : 0; |
| 40 | } |
| 41 | |
| 42 | static inline long syscall_get_return_value(struct task_struct *task, |
| 43 | struct pt_regs *regs) |
| 44 | { |
| 45 | return regs->regs[0]; |
| 46 | } |
| 47 | |
| 48 | static inline void syscall_set_return_value(struct task_struct *task, |
| 49 | struct pt_regs *regs, |
| 50 | int error, long val) |
| 51 | { |
| 52 | regs->regs[0] = (long) error ? error : val; |
| 53 | } |
| 54 | |
| 55 | #define SYSCALL_MAX_ARGS 6 |
| 56 | |
| 57 | static inline void syscall_get_arguments(struct task_struct *task, |
| 58 | struct pt_regs *regs, |
| 59 | unsigned int i, unsigned int n, |
| 60 | unsigned long *args) |
| 61 | { |
| 62 | if (i + n > SYSCALL_MAX_ARGS) { |
| 63 | unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i; |
| 64 | unsigned int n_bad = n + i - SYSCALL_MAX_ARGS; |
| 65 | pr_warning("%s called with max args %d, handling only %d\n", |
| 66 | __func__, i + n, SYSCALL_MAX_ARGS); |
| 67 | memset(args_bad, 0, n_bad * sizeof(args[0])); |
| 68 | } |
| 69 | |
| 70 | if (i == 0) { |
| 71 | args[0] = regs->orig_x0; |
| 72 | args++; |
| 73 | i++; |
| 74 | n--; |
| 75 | } |
| 76 | |
| 77 | memcpy(args, ®s->regs[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 | if (i + n > SYSCALL_MAX_ARGS) { |
| 86 | pr_warning("%s called with max args %d, handling only %d\n", |
| 87 | __func__, i + n, SYSCALL_MAX_ARGS); |
| 88 | n = SYSCALL_MAX_ARGS - i; |
| 89 | } |
| 90 | |
| 91 | if (i == 0) { |
| 92 | regs->orig_x0 = args[0]; |
| 93 | args++; |
| 94 | i++; |
| 95 | n--; |
| 96 | } |
| 97 | |
| 98 | memcpy(®s->regs[i], args, n * sizeof(args[0])); |
| 99 | } |
| 100 | |
| 101 | #endif /* __ASM_SYSCALL_H */ |