1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * Access to user system call parameters and results
5 * Copyright (C) 2008 Red Hat, Inc. All rights reserved.
7 * See asm-generic/syscall.h for descriptions of what we must do here.
10 #ifndef _ASM_SYSCALL_H
11 #define _ASM_SYSCALL_H 1
13 #include <uapi/linux/audit.h>
14 #include <linux/sched.h>
15 #include <linux/thread_info.h>
17 /* ftrace syscalls requires exporting the sys_call_table */
18 extern const unsigned long sys_call_table[];
19 extern const unsigned long compat_sys_call_table[];
21 static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
24 * Note that we are returning an int here. That means 0xffffffff, ie.
25 * 32-bit negative 1, will be interpreted as -1 on a 64-bit kernel.
26 * This is important for seccomp so that compat tasks can set r0 = -1
27 * to reject the syscall.
29 if (trap_is_syscall(regs))
35 static inline void syscall_rollback(struct task_struct *task,
38 regs->gpr[3] = regs->orig_gpr3;
41 static inline long syscall_get_error(struct task_struct *task,
44 if (trap_is_scv(regs)) {
45 unsigned long error = regs->gpr[3];
47 return IS_ERR_VALUE(error) ? error : 0;
50 * If the system call failed,
51 * regs->gpr[3] contains a positive ERRORCODE.
53 return (regs->ccr & 0x10000000UL) ? -regs->gpr[3] : 0;
57 static inline long syscall_get_return_value(struct task_struct *task,
63 static inline void syscall_set_return_value(struct task_struct *task,
67 if (trap_is_scv(regs)) {
68 regs->gpr[3] = (long) error ?: val;
71 * In the general case it's not obvious that we must deal with
72 * CCR here, as the syscall exit path will also do that for us.
73 * However there are some places, eg. the signal code, which
74 * check ccr to decide if the value in r3 is actually an error.
77 regs->ccr |= 0x10000000L;
80 regs->ccr &= ~0x10000000L;
86 static inline void syscall_get_arguments(struct task_struct *task,
90 unsigned long val, mask = -1UL;
94 if (test_tsk_thread_flag(task, TIF_32BIT))
99 val = regs->orig_gpr3;
101 val = regs->gpr[3 + n];
103 args[n] = val & mask;
107 static inline void syscall_set_arguments(struct task_struct *task,
108 struct pt_regs *regs,
109 const unsigned long *args)
111 memcpy(®s->gpr[3], args, 6 * sizeof(args[0]));
113 /* Also copy the first argument into orig_gpr3 */
114 regs->orig_gpr3 = args[0];
117 static inline int syscall_get_arch(struct task_struct *task)
121 if (IS_ENABLED(CONFIG_PPC64) && !test_tsk_thread_flag(task, TIF_32BIT))
122 arch = AUDIT_ARCH_PPC64;
124 arch = AUDIT_ARCH_PPC;
126 #ifdef __LITTLE_ENDIAN__
127 arch |= __AUDIT_ARCH_LE;
131 #endif /* _ASM_SYSCALL_H */