1 /* 2 * Access to user system call parameters and results 3 * 4 * See asm-generic/syscall.h for descriptions of what we must do here. 5 */ 6 7 #ifndef _ASM_ARM_SYSCALL_H 8 #define _ASM_ARM_SYSCALL_H 9 10 #include <linux/err.h> 11 #include <linux/sched.h> 12 13 #include <asm/unistd.h> 14 15 #define NR_syscalls (__NR_syscalls) 16 17 extern const unsigned long sys_call_table[]; 18 19 static inline int syscall_get_nr(struct task_struct *task, 20 struct pt_regs *regs) 21 { 22 return task_thread_info(task)->syscall; 23 } 24 25 static inline void syscall_rollback(struct task_struct *task, 26 struct pt_regs *regs) 27 { 28 regs->ARM_r0 = regs->ARM_ORIG_r0; 29 } 30 31 static inline long syscall_get_error(struct task_struct *task, 32 struct pt_regs *regs) 33 { 34 unsigned long error = regs->ARM_r0; 35 return IS_ERR_VALUE(error) ? error : 0; 36 } 37 38 static inline long syscall_get_return_value(struct task_struct *task, 39 struct pt_regs *regs) 40 { 41 return regs->ARM_r0; 42 } 43 44 static inline void syscall_set_return_value(struct task_struct *task, 45 struct pt_regs *regs, 46 int error, long val) 47 { 48 regs->ARM_r0 = (long) error ? error : val; 49 } 50 51 #define SYSCALL_MAX_ARGS 7 52 53 static inline void syscall_get_arguments(struct task_struct *task, 54 struct pt_regs *regs, 55 unsigned int i, unsigned int n, 56 unsigned long *args) 57 { 58 if (i + n > SYSCALL_MAX_ARGS) { 59 unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i; 60 unsigned int n_bad = n + i - SYSCALL_MAX_ARGS; 61 pr_warning("%s called with max args %d, handling only %d\n", 62 __func__, i + n, SYSCALL_MAX_ARGS); 63 memset(args_bad, 0, n_bad * sizeof(args[0])); 64 n = SYSCALL_MAX_ARGS - i; 65 } 66 67 if (i == 0) { 68 args[0] = regs->ARM_ORIG_r0; 69 args++; 70 i++; 71 n--; 72 } 73 74 memcpy(args, ®s->ARM_r0 + i, n * sizeof(args[0])); 75 } 76 77 static inline void syscall_set_arguments(struct task_struct *task, 78 struct pt_regs *regs, 79 unsigned int i, unsigned int n, 80 const unsigned long *args) 81 { 82 if (i + n > SYSCALL_MAX_ARGS) { 83 pr_warning("%s called with max args %d, handling only %d\n", 84 __func__, i + n, SYSCALL_MAX_ARGS); 85 n = SYSCALL_MAX_ARGS - i; 86 } 87 88 if (i == 0) { 89 regs->ARM_ORIG_r0 = args[0]; 90 args++; 91 i++; 92 n--; 93 } 94 95 memcpy(®s->ARM_r0 + i, args, n * sizeof(args[0])); 96 } 97 98 #endif /* _ASM_ARM_SYSCALL_H */ 99