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 if (IS_ENABLED(CONFIG_AEABI) && !IS_ENABLED(CONFIG_OABI_COMPAT)) 26 return task_thread_info(task)->abi_syscall; 27 28 if (task_thread_info(task)->abi_syscall == -1) 29 return -1; 30 31 return task_thread_info(task)->abi_syscall & __NR_SYSCALL_MASK; 32 } 33 34 static inline bool __in_oabi_syscall(struct task_struct *task) 35 { 36 return IS_ENABLED(CONFIG_OABI_COMPAT) && 37 (task_thread_info(task)->abi_syscall & __NR_OABI_SYSCALL_BASE); 38 } 39 40 static inline bool in_oabi_syscall(void) 41 { 42 return __in_oabi_syscall(current); 43 } 44 45 static inline void syscall_rollback(struct task_struct *task, 46 struct pt_regs *regs) 47 { 48 regs->ARM_r0 = regs->ARM_ORIG_r0; 49 } 50 51 static inline long syscall_get_error(struct task_struct *task, 52 struct pt_regs *regs) 53 { 54 unsigned long error = regs->ARM_r0; 55 return IS_ERR_VALUE(error) ? error : 0; 56 } 57 58 static inline long syscall_get_return_value(struct task_struct *task, 59 struct pt_regs *regs) 60 { 61 return regs->ARM_r0; 62 } 63 64 static inline void syscall_set_return_value(struct task_struct *task, 65 struct pt_regs *regs, 66 int error, long val) 67 { 68 regs->ARM_r0 = (long) error ? error : val; 69 } 70 71 static inline void syscall_set_nr(struct task_struct *task, 72 struct pt_regs *regs, 73 int nr) 74 { 75 if (nr == -1) { 76 task_thread_info(task)->abi_syscall = -1; 77 /* 78 * When the syscall number is set to -1, the syscall will be 79 * skipped. In this case the syscall return value has to be 80 * set explicitly, otherwise the first syscall argument is 81 * returned as the syscall return value. 82 */ 83 syscall_set_return_value(task, regs, -ENOSYS, 0); 84 return; 85 } 86 if ((IS_ENABLED(CONFIG_AEABI) && !IS_ENABLED(CONFIG_OABI_COMPAT))) { 87 task_thread_info(task)->abi_syscall = nr; 88 return; 89 } 90 task_thread_info(task)->abi_syscall = 91 (task_thread_info(task)->abi_syscall & ~__NR_SYSCALL_MASK) | 92 (nr & __NR_SYSCALL_MASK); 93 } 94 95 static inline void syscall_get_arguments(struct task_struct *task, 96 struct pt_regs *regs, 97 unsigned long *args) 98 { 99 args[0] = regs->ARM_ORIG_r0; 100 args++; 101 102 memcpy(args, ®s->ARM_r0 + 1, 5 * sizeof(args[0])); 103 } 104 105 static inline void syscall_set_arguments(struct task_struct *task, 106 struct pt_regs *regs, 107 const unsigned long *args) 108 { 109 memcpy(®s->ARM_r0, args, 6 * sizeof(args[0])); 110 /* 111 * Also copy the first argument into ARM_ORIG_r0 112 * so that syscall_get_arguments() would return it 113 * instead of the previous value. 114 */ 115 regs->ARM_ORIG_r0 = regs->ARM_r0; 116 } 117 118 static inline int syscall_get_arch(struct task_struct *task) 119 { 120 /* ARM tasks don't change audit architectures on the fly. */ 121 return AUDIT_ARCH_ARM; 122 } 123 124 #endif /* _ASM_ARM_SYSCALL_H */ 125