| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | /* |
| 3 | * Access to user system call parameters and results |
| 4 | * |
| 5 | * See asm-generic/syscall.h for descriptions of what we must do here. |
| 6 | */ |
| 7 | |
| 8 | #ifndef _ASM_ARM_SYSCALL_H |
| 9 | #define _ASM_ARM_SYSCALL_H |
| 10 | |
| 11 | #include <uapi/linux/audit.h> /* for AUDIT_ARCH_* */ |
| 12 | #include <linux/elf.h> /* for ELF_EM */ |
| 13 | #include <linux/err.h> |
| 14 | #include <linux/sched.h> |
| 15 | |
| 16 | #include <asm/unistd.h> |
| 17 | |
| 18 | #define NR_syscalls (__NR_syscalls) |
| 19 | |
| 20 | extern const unsigned long sys_call_table[]; |
| 21 | |
| 22 | static inline int syscall_get_nr(struct task_struct *task, |
| 23 | struct pt_regs *regs) |
| 24 | { |
| 25 | return task_thread_info(task)->syscall; |
| 26 | } |
| 27 | |
| 28 | static inline void syscall_rollback(struct task_struct *task, |
| 29 | struct pt_regs *regs) |
| 30 | { |
| 31 | regs->ARM_r0 = regs->ARM_ORIG_r0; |
| 32 | } |
| 33 | |
| 34 | static inline long syscall_get_error(struct task_struct *task, |
| 35 | struct pt_regs *regs) |
| 36 | { |
| 37 | unsigned long error = regs->ARM_r0; |
| 38 | return IS_ERR_VALUE(error) ? error : 0; |
| 39 | } |
| 40 | |
| 41 | static inline long syscall_get_return_value(struct task_struct *task, |
| 42 | struct pt_regs *regs) |
| 43 | { |
| 44 | return regs->ARM_r0; |
| 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 | regs->ARM_r0 = (long) error ? error : val; |
| 52 | } |
| 53 | |
| 54 | #define SYSCALL_MAX_ARGS 7 |
| 55 | |
| 56 | static inline void syscall_get_arguments(struct task_struct *task, |
| 57 | struct pt_regs *regs, |
| 58 | unsigned int i, unsigned int n, |
| 59 | unsigned long *args) |
| 60 | { |
| 61 | if (n == 0) |
| 62 | return; |
| 63 | |
| 64 | if (i + n > SYSCALL_MAX_ARGS) { |
| 65 | unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i; |
| 66 | unsigned int n_bad = n + i - SYSCALL_MAX_ARGS; |
| 67 | pr_warn("%s called with max args %d, handling only %d\n", |
| 68 | __func__, i + n, SYSCALL_MAX_ARGS); |
| 69 | memset(args_bad, 0, n_bad * sizeof(args[0])); |
| 70 | n = SYSCALL_MAX_ARGS - i; |
| 71 | } |
| 72 | |
| 73 | if (i == 0) { |
| 74 | args[0] = regs->ARM_ORIG_r0; |
| 75 | args++; |
| 76 | i++; |
| 77 | n--; |
| 78 | } |
| 79 | |
| 80 | memcpy(args, ®s->ARM_r0 + i, n * sizeof(args[0])); |
| 81 | } |
| 82 | |
| 83 | static inline void syscall_set_arguments(struct task_struct *task, |
| 84 | struct pt_regs *regs, |
| 85 | unsigned int i, unsigned int n, |
| 86 | const unsigned long *args) |
| 87 | { |
| 88 | if (n == 0) |
| 89 | return; |
| 90 | |
| 91 | if (i + n > SYSCALL_MAX_ARGS) { |
| 92 | pr_warn("%s called with max args %d, handling only %d\n", |
| 93 | __func__, i + n, SYSCALL_MAX_ARGS); |
| 94 | n = SYSCALL_MAX_ARGS - i; |
| 95 | } |
| 96 | |
| 97 | if (i == 0) { |
| 98 | regs->ARM_ORIG_r0 = args[0]; |
| 99 | args++; |
| 100 | i++; |
| 101 | n--; |
| 102 | } |
| 103 | |
| 104 | memcpy(®s->ARM_r0 + i, args, n * sizeof(args[0])); |
| 105 | } |
| 106 | |
| 107 | static inline int syscall_get_arch(void) |
| 108 | { |
| 109 | /* ARM tasks don't change audit architectures on the fly. */ |
| 110 | return AUDIT_ARCH_ARM; |
| 111 | } |
| 112 | |
| 113 | #endif /* _ASM_ARM_SYSCALL_H */ |