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 <uapi/linux/audit.h> /* for AUDIT_ARCH_* */ 11 #include <linux/elf.h> /* for ELF_EM */ 12 #include <linux/err.h> 13 #include <linux/sched.h> 14 15 #include <asm/unistd.h> 16 17 #define NR_syscalls (__NR_syscalls) 18 19 extern const unsigned long sys_call_table[]; 20 21 static inline int syscall_get_nr(struct task_struct *task, 22 struct pt_regs *regs) 23 { 24 return task_thread_info(task)->syscall; 25 } 26 27 static inline void syscall_rollback(struct task_struct *task, 28 struct pt_regs *regs) 29 { 30 regs->ARM_r0 = regs->ARM_ORIG_r0; 31 } 32 33 static inline long syscall_get_error(struct task_struct *task, 34 struct pt_regs *regs) 35 { 36 unsigned long error = regs->ARM_r0; 37 return IS_ERR_VALUE(error) ? error : 0; 38 } 39 40 static inline long syscall_get_return_value(struct task_struct *task, 41 struct pt_regs *regs) 42 { 43 return regs->ARM_r0; 44 } 45 46 static inline void syscall_set_return_value(struct task_struct *task, 47 struct pt_regs *regs, 48 int error, long val) 49 { 50 regs->ARM_r0 = (long) error ? error : val; 51 } 52 53 #define SYSCALL_MAX_ARGS 7 54 55 static inline void syscall_get_arguments(struct task_struct *task, 56 struct pt_regs *regs, 57 unsigned int i, unsigned int n, 58 unsigned long *args) 59 { 60 if (n == 0) 61 return; 62 63 if (i + n > SYSCALL_MAX_ARGS) { 64 unsigned long *args_bad = args + SYSCALL_MAX_ARGS - i; 65 unsigned int n_bad = n + i - SYSCALL_MAX_ARGS; 66 pr_warning("%s called with max args %d, handling only %d\n", 67 __func__, i + n, SYSCALL_MAX_ARGS); 68 memset(args_bad, 0, n_bad * sizeof(args[0])); 69 n = SYSCALL_MAX_ARGS - i; 70 } 71 72 if (i == 0) { 73 args[0] = regs->ARM_ORIG_r0; 74 args++; 75 i++; 76 n--; 77 } 78 79 memcpy(args, ®s->ARM_r0 + i, n * sizeof(args[0])); 80 } 81 82 static inline void syscall_set_arguments(struct task_struct *task, 83 struct pt_regs *regs, 84 unsigned int i, unsigned int n, 85 const unsigned long *args) 86 { 87 if (n == 0) 88 return; 89 90 if (i + n > SYSCALL_MAX_ARGS) { 91 pr_warning("%s called with max args %d, handling only %d\n", 92 __func__, i + n, SYSCALL_MAX_ARGS); 93 n = SYSCALL_MAX_ARGS - i; 94 } 95 96 if (i == 0) { 97 regs->ARM_ORIG_r0 = args[0]; 98 args++; 99 i++; 100 n--; 101 } 102 103 memcpy(®s->ARM_r0 + i, args, n * sizeof(args[0])); 104 } 105 106 static inline int syscall_get_arch(void) 107 { 108 /* ARM tasks don't change audit architectures on the fly. */ 109 return AUDIT_ARCH_ARM; 110 } 111 112 #endif /* _ASM_ARM_SYSCALL_H */ 113