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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Access to user system call parameters and results
*
* Copyright IBM Corp. 2008
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
*/
#ifndef _ASM_SYSCALL_H
#define _ASM_SYSCALL_H 1
#include <uapi/linux/audit.h>
#include <linux/sched.h>
#include <linux/err.h>
#include <asm/ptrace.h>
extern const sys_call_ptr_t sys_call_table[];
extern const sys_call_ptr_t sys_call_table_emu[];
static inline long syscall_get_nr(struct task_struct *task,
struct pt_regs *regs)
{
return test_pt_regs_flag(regs, PIF_SYSCALL) ?
(regs->int_code & 0xffff) : -1;
}
static inline void syscall_rollback(struct task_struct *task,
struct pt_regs *regs)
{
regs->gprs[2] = regs->orig_gpr2;
}
static inline long syscall_get_error(struct task_struct *task,
struct pt_regs *regs)
{
unsigned long error = regs->gprs[2];
#ifdef CONFIG_COMPAT
if (test_tsk_thread_flag(task, TIF_31BIT)) {
/*
* 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->gprs[2];
}
static inline void syscall_set_return_value(struct task_struct *task,
struct pt_regs *regs,
int error, long val)
{
set_pt_regs_flag(regs, PIF_SYSCALL_RET_SET);
regs->gprs[2] = error ? error : val;
}
static inline void syscall_get_arguments(struct task_struct *task,
struct pt_regs *regs,
unsigned long *args)
{
unsigned long mask = -1UL;
unsigned int n = 6;
#ifdef CONFIG_COMPAT
if (test_tsk_thread_flag(task, TIF_31BIT))
mask = 0xffffffff;
#endif
while (n-- > 0)
if (n > 0)
args[n] = regs->gprs[2 + n] & mask;
args[0] = regs->orig_gpr2 & mask;
}
static inline void syscall_set_arguments(struct task_struct *task,
struct pt_regs *regs,
const unsigned long *args)
{
unsigned int n = 6;
while (n-- > 0)
if (n > 0)
regs->gprs[2 + n] = args[n];
regs->orig_gpr2 = args[0];
}
static inline int syscall_get_arch(struct task_struct *task)
{
#ifdef CONFIG_COMPAT
if (test_tsk_thread_flag(task, TIF_31BIT))
return AUDIT_ARCH_S390;
#endif
return AUDIT_ARCH_S390X;
}
static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
{
return false;
}
#define SYSCALL_FMT_0
#define SYSCALL_FMT_1 , "0" (r2)
#define SYSCALL_FMT_2 , "d" (r3) SYSCALL_FMT_1
#define SYSCALL_FMT_3 , "d" (r4) SYSCALL_FMT_2
#define SYSCALL_FMT_4 , "d" (r5) SYSCALL_FMT_3
#define SYSCALL_FMT_5 , "d" (r6) SYSCALL_FMT_4
#define SYSCALL_FMT_6 , "d" (r7) SYSCALL_FMT_5
#define SYSCALL_PARM_0
#define SYSCALL_PARM_1 , long arg1
#define SYSCALL_PARM_2 SYSCALL_PARM_1, long arg2
#define SYSCALL_PARM_3 SYSCALL_PARM_2, long arg3
#define SYSCALL_PARM_4 SYSCALL_PARM_3, long arg4
#define SYSCALL_PARM_5 SYSCALL_PARM_4, long arg5
#define SYSCALL_PARM_6 SYSCALL_PARM_5, long arg6
#define SYSCALL_REGS_0
#define SYSCALL_REGS_1 \
register long r2 asm("2") = arg1
#define SYSCALL_REGS_2 \
SYSCALL_REGS_1; \
register long r3 asm("3") = arg2
#define SYSCALL_REGS_3 \
SYSCALL_REGS_2; \
register long r4 asm("4") = arg3
#define SYSCALL_REGS_4 \
SYSCALL_REGS_3; \
register long r5 asm("5") = arg4
#define SYSCALL_REGS_5 \
SYSCALL_REGS_4; \
register long r6 asm("6") = arg5
#define SYSCALL_REGS_6 \
SYSCALL_REGS_5; \
register long r7 asm("7") = arg6
#define GENERATE_SYSCALL_FUNC(nr) \
static __always_inline \
long syscall##nr(unsigned long syscall SYSCALL_PARM_##nr) \
{ \
register unsigned long r1 asm ("1") = syscall; \
register long rc asm ("2"); \
SYSCALL_REGS_##nr; \
\
asm volatile ( \
" svc 0\n" \
: "=d" (rc) \
: "d" (r1) SYSCALL_FMT_##nr \
: "memory"); \
return rc; \
}
GENERATE_SYSCALL_FUNC(0)
GENERATE_SYSCALL_FUNC(1)
GENERATE_SYSCALL_FUNC(2)
GENERATE_SYSCALL_FUNC(3)
GENERATE_SYSCALL_FUNC(4)
GENERATE_SYSCALL_FUNC(5)
GENERATE_SYSCALL_FUNC(6)
#endif /* _ASM_SYSCALL_H */