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1 // SPDX-License-Identifier: GPL-2.0
3 * This file handles the architecture dependent parts of process handling.
5 * Copyright IBM Corp. 1999, 2009
6 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
7 * Hartmut Penner <hp@de.ibm.com>,
11 #include <linux/elf-randomize.h>
12 #include <linux/compiler.h>
13 #include <linux/cpu.h>
14 #include <linux/sched.h>
15 #include <linux/sched/debug.h>
16 #include <linux/sched/task.h>
17 #include <linux/sched/task_stack.h>
18 #include <linux/kernel.h>
20 #include <linux/elfcore.h>
21 #include <linux/smp.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24 #include <linux/tick.h>
25 #include <linux/personality.h>
26 #include <linux/syscalls.h>
27 #include <linux/compat.h>
28 #include <linux/kprobes.h>
29 #include <linux/random.h>
30 #include <linux/export.h>
31 #include <linux/init_task.h>
32 #include <asm/cpu_mf.h>
34 #include <asm/processor.h>
35 #include <asm/vtimer.h>
40 #include <asm/switch_to.h>
41 #include <asm/runtime_instr.h>
44 asmlinkage
void ret_from_fork(void) asm ("ret_from_fork");
46 extern void kernel_thread_starter(void);
48 void flush_thread(void)
52 void arch_setup_new_exec(void)
54 if (S390_lowcore
.current_pid
!= current
->pid
) {
55 S390_lowcore
.current_pid
= current
->pid
;
56 if (test_facility(40))
57 lpp(&S390_lowcore
.lpp
);
61 void arch_release_task_struct(struct task_struct
*tsk
)
63 runtime_instr_release(tsk
);
64 guarded_storage_release(tsk
);
67 int arch_dup_task_struct(struct task_struct
*dst
, struct task_struct
*src
)
70 * Save the floating-point or vector register state of the current
71 * task and set the CIF_FPU flag to lazy restore the FPU register
72 * state when returning to user space.
76 memcpy(dst
, src
, arch_task_struct_size
);
77 dst
->thread
.fpu
.regs
= dst
->thread
.fpu
.fprs
;
81 int copy_thread_tls(unsigned long clone_flags
, unsigned long new_stackp
,
82 unsigned long arg
, struct task_struct
*p
, unsigned long tls
)
86 struct stack_frame sf
;
87 struct pt_regs childregs
;
90 frame
= container_of(task_pt_regs(p
), struct fake_frame
, childregs
);
91 p
->thread
.ksp
= (unsigned long) frame
;
92 /* Save access registers to new thread structure. */
93 save_access_regs(&p
->thread
.acrs
[0]);
94 /* start new process with ar4 pointing to the correct address space */
95 p
->thread
.mm_segment
= get_fs();
96 /* Don't copy debug registers */
97 memset(&p
->thread
.per_user
, 0, sizeof(p
->thread
.per_user
));
98 memset(&p
->thread
.per_event
, 0, sizeof(p
->thread
.per_event
));
99 clear_tsk_thread_flag(p
, TIF_SINGLE_STEP
);
100 p
->thread
.per_flags
= 0;
101 /* Initialize per thread user and system timer values */
102 p
->thread
.user_timer
= 0;
103 p
->thread
.guest_timer
= 0;
104 p
->thread
.system_timer
= 0;
105 p
->thread
.hardirq_timer
= 0;
106 p
->thread
.softirq_timer
= 0;
108 frame
->sf
.back_chain
= 0;
109 /* new return point is ret_from_fork */
110 frame
->sf
.gprs
[8] = (unsigned long) ret_from_fork
;
111 /* fake return stack for resume(), don't go back to schedule */
112 frame
->sf
.gprs
[9] = (unsigned long) frame
;
114 /* Store access registers to kernel stack of new process. */
115 if (unlikely(p
->flags
& PF_KTHREAD
)) {
117 memset(&frame
->childregs
, 0, sizeof(struct pt_regs
));
118 frame
->childregs
.psw
.mask
= PSW_KERNEL_BITS
| PSW_MASK_DAT
|
119 PSW_MASK_IO
| PSW_MASK_EXT
| PSW_MASK_MCHECK
;
120 frame
->childregs
.psw
.addr
=
121 (unsigned long) kernel_thread_starter
;
122 frame
->childregs
.gprs
[9] = new_stackp
; /* function */
123 frame
->childregs
.gprs
[10] = arg
;
124 frame
->childregs
.gprs
[11] = (unsigned long) do_exit
;
125 frame
->childregs
.orig_gpr2
= -1;
129 frame
->childregs
= *current_pt_regs();
130 frame
->childregs
.gprs
[2] = 0; /* child returns 0 on fork. */
131 frame
->childregs
.flags
= 0;
133 frame
->childregs
.gprs
[15] = new_stackp
;
135 /* Don't copy runtime instrumentation info */
136 p
->thread
.ri_cb
= NULL
;
137 frame
->childregs
.psw
.mask
&= ~PSW_MASK_RI
;
138 /* Don't copy guarded storage control block */
139 p
->thread
.gs_cb
= NULL
;
140 p
->thread
.gs_bc_cb
= NULL
;
142 /* Set a new TLS ? */
143 if (clone_flags
& CLONE_SETTLS
) {
144 if (is_compat_task()) {
145 p
->thread
.acrs
[0] = (unsigned int)tls
;
147 p
->thread
.acrs
[0] = (unsigned int)(tls
>> 32);
148 p
->thread
.acrs
[1] = (unsigned int)tls
;
154 asmlinkage
void execve_tail(void)
156 current
->thread
.fpu
.fpc
= 0;
157 asm volatile("sfpc %0" : : "d" (0));
161 * fill in the FPU structure for a core dump.
163 int dump_fpu (struct pt_regs
* regs
, s390_fp_regs
*fpregs
)
166 fpregs
->fpc
= current
->thread
.fpu
.fpc
;
169 convert_vx_to_fp((freg_t
*)&fpregs
->fprs
,
170 current
->thread
.fpu
.vxrs
);
172 memcpy(&fpregs
->fprs
, current
->thread
.fpu
.fprs
,
173 sizeof(fpregs
->fprs
));
176 EXPORT_SYMBOL(dump_fpu
);
178 unsigned long get_wchan(struct task_struct
*p
)
180 struct stack_frame
*sf
, *low
, *high
;
181 unsigned long return_address
;
184 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
|| !task_stack_page(p
))
186 low
= task_stack_page(p
);
187 high
= (struct stack_frame
*) task_pt_regs(p
);
188 sf
= (struct stack_frame
*) p
->thread
.ksp
;
189 if (sf
<= low
|| sf
> high
)
191 for (count
= 0; count
< 16; count
++) {
192 sf
= (struct stack_frame
*) sf
->back_chain
;
193 if (sf
<= low
|| sf
> high
)
195 return_address
= sf
->gprs
[8];
196 if (!in_sched_functions(return_address
))
197 return return_address
;
202 unsigned long arch_align_stack(unsigned long sp
)
204 if (!(current
->personality
& ADDR_NO_RANDOMIZE
) && randomize_va_space
)
205 sp
-= get_random_int() & ~PAGE_MASK
;
209 static inline unsigned long brk_rnd(void)
211 return (get_random_int() & BRK_RND_MASK
) << PAGE_SHIFT
;
214 unsigned long arch_randomize_brk(struct mm_struct
*mm
)
218 ret
= PAGE_ALIGN(mm
->brk
+ brk_rnd());
219 return (ret
> mm
->brk
) ? ret
: mm
->brk
;
222 void set_fs_fixup(void)
224 struct pt_regs
*regs
= current_pt_regs();
230 WARN(1, "Unbalanced set_fs - int code: 0x%x\n", regs
->int_code
);
231 show_registers(regs
);