1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * Access to user system call parameters and results
5 * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved.
7 * See asm-generic/syscall.h for descriptions of what we must do here.
10 #ifndef _ASM_X86_SYSCALL_H
11 #define _ASM_X86_SYSCALL_H
13 #include <uapi/linux/audit.h>
14 #include <linux/sched.h>
15 #include <linux/err.h>
16 #include <asm/thread_info.h> /* for TS_COMPAT */
17 #include <asm/unistd.h>
19 typedef long (*sys_call_ptr_t)(const struct pt_regs *);
20 extern const sys_call_ptr_t sys_call_table[];
22 #if defined(CONFIG_X86_32)
23 #define ia32_sys_call_table sys_call_table
26 #if defined(CONFIG_IA32_EMULATION)
27 extern const sys_call_ptr_t ia32_sys_call_table[];
30 #ifdef CONFIG_X86_X32_ABI
31 extern const sys_call_ptr_t x32_sys_call_table[];
35 * Only the low 32 bits of orig_ax are meaningful, so we return int.
36 * This importantly ignores the high bits on 64-bit, so comparisons
37 * sign-extend the low 32 bits.
39 static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
44 static inline void syscall_rollback(struct task_struct *task,
47 regs->ax = regs->orig_ax;
50 static inline long syscall_get_error(struct task_struct *task,
53 unsigned long error = regs->ax;
54 #ifdef CONFIG_IA32_EMULATION
56 * TS_COMPAT is set for 32-bit syscall entries and then
57 * remains set until we return to user mode.
59 if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED))
61 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
62 * and will match correctly in comparisons.
64 error = (long) (int) error;
66 return IS_ERR_VALUE(error) ? error : 0;
69 static inline long syscall_get_return_value(struct task_struct *task,
75 static inline void syscall_set_return_value(struct task_struct *task,
79 regs->ax = (long) error ?: val;
84 static inline void syscall_get_arguments(struct task_struct *task,
88 memcpy(args, ®s->bx, 6 * sizeof(args[0]));
91 static inline void syscall_set_arguments(struct task_struct *task,
93 unsigned int i, unsigned int n,
94 const unsigned long *args)
97 memcpy(®s->bx + i, args, n * sizeof(args[0]));
100 static inline int syscall_get_arch(struct task_struct *task)
102 return AUDIT_ARCH_I386;
105 #else /* CONFIG_X86_64 */
107 static inline void syscall_get_arguments(struct task_struct *task,
108 struct pt_regs *regs,
111 # ifdef CONFIG_IA32_EMULATION
112 if (task->thread_info.status & TS_COMPAT) {
131 static inline void syscall_set_arguments(struct task_struct *task,
132 struct pt_regs *regs,
133 const unsigned long *args)
135 # ifdef CONFIG_IA32_EMULATION
136 if (task->thread_info.status & TS_COMPAT) {
155 static inline int syscall_get_arch(struct task_struct *task)
157 /* x32 tasks should be considered AUDIT_ARCH_X86_64. */
158 return (IS_ENABLED(CONFIG_IA32_EMULATION) &&
159 task->thread_info.status & TS_COMPAT)
160 ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
163 void do_syscall_64(unsigned long nr, struct pt_regs *regs);
164 void do_int80_syscall_32(struct pt_regs *regs);
165 long do_fast_syscall_32(struct pt_regs *regs);
167 #endif /* CONFIG_X86_32 */
169 #endif /* _ASM_X86_SYSCALL_H */