1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
|
// SPDX-License-Identifier: GPL-2.0
/*
* S390 version
* Copyright IBM Corp. 1999, 2000
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
* Thomas Spatzier (tspat@de.ibm.com)
*
* Derived from "arch/i386/kernel/sys_i386.c"
*
* This file contains various random system calls that
* have a non-standard calling sequence on the Linux/s390
* platform.
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/syscalls.h>
#include <linux/mman.h>
#include <linux/file.h>
#include <linux/utsname.h>
#include <linux/personality.h>
#include <linux/unistd.h>
#include <linux/ipc.h>
#include <linux/uaccess.h>
#include <linux/string.h>
#include <linux/thread_info.h>
#include <linux/entry-common.h>
#include <asm/ptrace.h>
#include <asm/vtime.h>
#include "entry.h"
/*
* Perform the mmap() system call. Linux for S/390 isn't able to handle more
* than 5 system call parameters, so this system call uses a memory block
* for parameter passing.
*/
struct s390_mmap_arg_struct {
unsigned long addr;
unsigned long len;
unsigned long prot;
unsigned long flags;
unsigned long fd;
unsigned long offset;
};
SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg)
{
struct s390_mmap_arg_struct a;
int error = -EFAULT;
if (copy_from_user(&a, arg, sizeof(a)))
goto out;
error = ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
out:
return error;
}
#ifdef CONFIG_SYSVIPC
/*
* sys_ipc() is the de-multiplexer for the SysV IPC calls.
*/
SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second,
unsigned long, third, void __user *, ptr)
{
if (call >> 16)
return -EINVAL;
/* The s390 sys_ipc variant has only five parameters instead of six
* like the generic variant. The only difference is the handling of
* the SEMTIMEDOP subcall where on s390 the third parameter is used
* as a pointer to a struct timespec where the generic variant uses
* the fifth parameter.
* Therefore we can call the generic variant by simply passing the
* third parameter also as fifth parameter.
*/
return ksys_ipc(call, first, second, third, ptr, third);
}
#endif /* CONFIG_SYSVIPC */
SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
{
unsigned int ret = current->personality;
if (personality(current->personality) == PER_LINUX32 &&
personality(personality) == PER_LINUX)
personality |= PER_LINUX32;
if (personality != 0xffffffff)
set_personality(personality);
if (personality(ret) == PER_LINUX32)
ret &= ~PER_LINUX32;
return ret;
}
SYSCALL_DEFINE0(ni_syscall)
{
return -ENOSYS;
}
static void do_syscall(struct pt_regs *regs)
{
unsigned long nr;
nr = regs->int_code & 0xffff;
if (!nr) {
nr = regs->gprs[1] & 0xffff;
regs->int_code &= ~0xffffUL;
regs->int_code |= nr;
}
regs->gprs[2] = nr;
if (nr == __NR_restart_syscall && !(current->restart_block.arch_data & 1)) {
regs->psw.addr = current->restart_block.arch_data;
current->restart_block.arch_data = 1;
}
nr = syscall_enter_from_user_mode_work(regs, nr);
/*
* In the s390 ptrace ABI, both the syscall number and the return value
* use gpr2. However, userspace puts the syscall number either in the
* svc instruction itself, or uses gpr1. To make at least skipping syscalls
* work, the ptrace code sets PIF_SYSCALL_RET_SET, which is checked here
* and if set, the syscall will be skipped.
*/
if (unlikely(test_and_clear_pt_regs_flag(regs, PIF_SYSCALL_RET_SET)))
goto out;
regs->gprs[2] = -ENOSYS;
if (likely(nr >= NR_syscalls))
goto out;
do {
regs->gprs[2] = current->thread.sys_call_table[nr](regs);
} while (test_and_clear_pt_regs_flag(regs, PIF_EXECVE_PGSTE_RESTART));
out:
syscall_exit_to_user_mode_work(regs);
}
void noinstr __do_syscall(struct pt_regs *regs, int per_trap)
{
add_random_kstack_offset();
enter_from_user_mode(regs);
regs->psw = S390_lowcore.svc_old_psw;
regs->int_code = S390_lowcore.svc_int_code;
update_timer_sys();
if (static_branch_likely(&cpu_has_bear))
current->thread.last_break = regs->last_break;
local_irq_enable();
regs->orig_gpr2 = regs->gprs[2];
if (per_trap)
set_thread_flag(TIF_PER_TRAP);
regs->flags = 0;
set_pt_regs_flag(regs, PIF_SYSCALL);
do_syscall(regs);
exit_to_user_mode();
}
|
