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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Access to user system call parameters and results
*
* Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved.
*
* See asm-generic/syscall.h for descriptions of what we must do here.
*/
#ifndef _ASM_X86_SYSCALL_H
#define _ASM_X86_SYSCALL_H
#include <uapi/linux/audit.h>
#include <linux/sched.h>
#include <linux/err.h>
#include <linux/jump_label.h>
#include <asm/thread_info.h> /* for TS_COMPAT */
#include <asm/unistd.h>
/* This is used purely for kernel/trace/trace_syscalls.c */
typedef long (*sys_call_ptr_t)(const struct pt_regs *);
extern const sys_call_ptr_t sys_call_table[];
/*
* These may not exist, but still put the prototypes in so we
* can use IS_ENABLED().
*/
extern long ia32_sys_call(const struct pt_regs *, unsigned int nr);
extern long x32_sys_call(const struct pt_regs *, unsigned int nr);
extern long x64_sys_call(const struct pt_regs *, unsigned int nr);
#if defined(CONFIG_X86_X32_ABI)
#if defined(CONFIG_X86_X32_DISABLED)
DECLARE_STATIC_KEY_FALSE(x32_enabled_skey);
#define x32_enabled static_branch_unlikely(&x32_enabled_skey)
#else
DECLARE_STATIC_KEY_TRUE(x32_enabled_skey);
#define x32_enabled static_branch_likely(&x32_enabled_skey)
#endif
#else
#define x32_enabled 0
#endif
/*
* Only the low 32 bits of orig_ax are meaningful, so we return int.
* This importantly ignores the high bits on 64-bit, so comparisons
* sign-extend the low 32 bits.
*/
static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
{
return regs->orig_ax;
}
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
regs->ax = regs->orig_ax;
}
static inline long syscall_get_error(struct task_struct *task,
struct pt_regs *regs)
{
unsigned long error = regs->ax;
#ifdef CONFIG_IA32_EMULATION
/*
* TS_COMPAT is set for 32-bit syscall entries and then
* remains set until we return to user mode.
*/
if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED))
/*
* Sign-extend the value so (int)-EFOO becomes (long)-EFOO
* and will match correctly in comparisons.
*/
error = (long) (int) error;
#endif
return IS_ERR_VALUE(error) ? error : 0;
}
static inline long syscall_get_return_value(struct task_struct *task,
struct pt_regs *regs)
{
return regs->ax;
}
static inline void syscall_set_return_value(struct task_struct *task,
struct pt_regs *regs,
int error, long val)
{
regs->ax = (long) error ?: val;
}
#ifdef CONFIG_X86_32
static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned long *args)
{
args[0] = regs->bx;
args[1] = regs->cx;
args[2] = regs->dx;
args[3] = regs->si;
args[4] = regs->di;
args[5] = regs->bp;
}
static inline int syscall_get_arch(struct task_struct *task)
{
return AUDIT_ARCH_I386;
}
#else /* CONFIG_X86_64 */
static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned long *args)
{
# ifdef CONFIG_IA32_EMULATION
if (task->thread_info.status & TS_COMPAT) {
*args++ = regs->bx;
*args++ = regs->cx;
*args++ = regs->dx;
*args++ = regs->si;
*args++ = regs->di;
*args = regs->bp;
} else
# endif
{
*args++ = regs->di;
*args++ = regs->si;
*args++ = regs->dx;
*args++ = regs->r10;
*args++ = regs->r8;
*args = regs->r9;
}
}
static inline int syscall_get_arch(struct task_struct *task)
{
/* x32 tasks should be considered AUDIT_ARCH_X86_64. */
return (IS_ENABLED(CONFIG_IA32_EMULATION) &&
task->thread_info.status & TS_COMPAT)
? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
}
void do_syscall_64(struct pt_regs *regs, int nr);
void do_int80_syscall_32(struct pt_regs *regs);
long do_fast_syscall_32(struct pt_regs *regs);
void do_int80_emulation(struct pt_regs *regs);
#endif /* CONFIG_X86_32 */
#endif /* _ASM_X86_SYSCALL_H */
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