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
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
|
// SPDX-License-Identifier: GPL-2.0
/*
* This file handles the architecture dependent parts of process handling.
*
* Copyright IBM Corp. 1999, 2009
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
* Hartmut Penner <hp@de.ibm.com>,
* Denis Joseph Barrow,
*/
#include <linux/elf-randomize.h>
#include <linux/compiler.h>
#include <linux/cpu.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task.h>
#include <linux/sched/task_stack.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/elfcore.h>
#include <linux/smp.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/tick.h>
#include <linux/personality.h>
#include <linux/syscalls.h>
#include <linux/compat.h>
#include <linux/kprobes.h>
#include <linux/random.h>
#include <linux/export.h>
#include <linux/init_task.h>
#include <linux/entry-common.h>
#include <asm/cpu_mf.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/vtimer.h>
#include <asm/exec.h>
#include <asm/irq.h>
#include <asm/nmi.h>
#include <asm/smp.h>
#include <asm/stacktrace.h>
#include <asm/switch_to.h>
#include <asm/runtime_instr.h>
#include <asm/unwind.h>
#include "entry.h"
void ret_from_fork(void) asm("ret_from_fork");
void __ret_from_fork(struct task_struct *prev, struct pt_regs *regs)
{
void (*func)(void *arg);
schedule_tail(prev);
if (!user_mode(regs)) {
/* Kernel thread */
func = (void *)regs->gprs[9];
func((void *)regs->gprs[10]);
}
clear_pt_regs_flag(regs, PIF_SYSCALL);
syscall_exit_to_user_mode(regs);
}
void flush_thread(void)
{
}
void arch_setup_new_exec(void)
{
if (S390_lowcore.current_pid != current->pid) {
S390_lowcore.current_pid = current->pid;
if (test_facility(40))
lpp(&S390_lowcore.lpp);
}
}
void arch_release_task_struct(struct task_struct *tsk)
{
runtime_instr_release(tsk);
guarded_storage_release(tsk);
}
int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
{
/*
* Save the floating-point or vector register state of the current
* task and set the CIF_FPU flag to lazy restore the FPU register
* state when returning to user space.
*/
save_fpu_regs();
memcpy(dst, src, arch_task_struct_size);
dst->thread.fpu.regs = dst->thread.fpu.fprs;
/*
* Don't transfer over the runtime instrumentation or the guarded
* storage control block pointers. These fields are cleared here instead
* of in copy_thread() to avoid premature freeing of associated memory
* on fork() failure. Wait to clear the RI flag because ->stack still
* refers to the source thread.
*/
dst->thread.ri_cb = NULL;
dst->thread.gs_cb = NULL;
dst->thread.gs_bc_cb = NULL;
return 0;
}
int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
{
unsigned long clone_flags = args->flags;
unsigned long new_stackp = args->stack;
unsigned long tls = args->tls;
struct fake_frame
{
struct stack_frame sf;
struct pt_regs childregs;
} *frame;
frame = container_of(task_pt_regs(p), struct fake_frame, childregs);
p->thread.ksp = (unsigned long) frame;
/* Save access registers to new thread structure. */
save_access_regs(&p->thread.acrs[0]);
/* start new process with ar4 pointing to the correct address space */
/* Don't copy debug registers */
memset(&p->thread.per_user, 0, sizeof(p->thread.per_user));
memset(&p->thread.per_event, 0, sizeof(p->thread.per_event));
clear_tsk_thread_flag(p, TIF_SINGLE_STEP);
p->thread.per_flags = 0;
/* Initialize per thread user and system timer values */
p->thread.user_timer = 0;
p->thread.guest_timer = 0;
p->thread.system_timer = 0;
p->thread.hardirq_timer = 0;
p->thread.softirq_timer = 0;
p->thread.last_break = 1;
frame->sf.back_chain = 0;
frame->sf.gprs[5] = (unsigned long)frame + sizeof(struct stack_frame);
frame->sf.gprs[6] = (unsigned long)p;
/* new return point is ret_from_fork */
frame->sf.gprs[8] = (unsigned long)ret_from_fork;
/* fake return stack for resume(), don't go back to schedule */
frame->sf.gprs[9] = (unsigned long)frame;
/* Store access registers to kernel stack of new process. */
if (unlikely(args->fn)) {
/* kernel thread */
memset(&frame->childregs, 0, sizeof(struct pt_regs));
frame->childregs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_DAT |
PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
frame->childregs.psw.addr =
(unsigned long)__ret_from_fork;
frame->childregs.gprs[9] = (unsigned long)args->fn;
frame->childregs.gprs[10] = (unsigned long)args->fn_arg;
frame->childregs.orig_gpr2 = -1;
frame->childregs.last_break = 1;
return 0;
}
frame->childregs = *current_pt_regs();
frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */
frame->childregs.flags = 0;
if (new_stackp)
frame->childregs.gprs[15] = new_stackp;
/*
* Clear the runtime instrumentation flag after the above childregs
* copy. The CB pointer was already cleared in arch_dup_task_struct().
*/
frame->childregs.psw.mask &= ~PSW_MASK_RI;
/* Set a new TLS ? */
if (clone_flags & CLONE_SETTLS) {
if (is_compat_task()) {
p->thread.acrs[0] = (unsigned int)tls;
} else {
p->thread.acrs[0] = (unsigned int)(tls >> 32);
p->thread.acrs[1] = (unsigned int)tls;
}
}
/*
* s390 stores the svc return address in arch_data when calling
* sigreturn()/restart_syscall() via vdso. 1 means no valid address
* stored.
*/
p->restart_block.arch_data = 1;
return 0;
}
void execve_tail(void)
{
current->thread.fpu.fpc = 0;
asm volatile("sfpc %0" : : "d" (0));
}
unsigned long __get_wchan(struct task_struct *p)
{
struct unwind_state state;
unsigned long ip = 0;
if (!task_stack_page(p))
return 0;
if (!try_get_task_stack(p))
return 0;
unwind_for_each_frame(&state, p, NULL, 0) {
if (state.stack_info.type != STACK_TYPE_TASK) {
ip = 0;
break;
}
ip = unwind_get_return_address(&state);
if (!ip)
break;
if (!in_sched_functions(ip))
break;
}
put_task_stack(p);
return ip;
}
unsigned long arch_align_stack(unsigned long sp)
{
if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
sp -= prandom_u32_max(PAGE_SIZE);
return sp & ~0xf;
}
static inline unsigned long brk_rnd(void)
{
return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
}
unsigned long arch_randomize_brk(struct mm_struct *mm)
{
unsigned long ret;
ret = PAGE_ALIGN(mm->brk + brk_rnd());
return (ret > mm->brk) ? ret : mm->brk;
}
|
