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>
33 #include <asm/processor.h>
34 #include <asm/vtimer.h>
39 #include <asm/switch_to.h>
40 #include <asm/runtime_instr.h>
43 asmlinkage
void ret_from_fork(void) asm ("ret_from_fork");
45 extern void kernel_thread_starter(void);
48 * Free current thread data structures etc..
50 void exit_thread(struct task_struct
*tsk
)
56 void flush_thread(void)
60 void release_thread(struct task_struct
*dead_task
)
64 void arch_release_task_struct(struct task_struct
*tsk
)
66 runtime_instr_release(tsk
);
69 int arch_dup_task_struct(struct task_struct
*dst
, struct task_struct
*src
)
72 * Save the floating-point or vector register state of the current
73 * task and set the CIF_FPU flag to lazy restore the FPU register
74 * state when returning to user space.
78 memcpy(dst
, src
, arch_task_struct_size
);
79 dst
->thread
.fpu
.regs
= dst
->thread
.fpu
.fprs
;
83 int copy_thread_tls(unsigned long clone_flags
, unsigned long new_stackp
,
84 unsigned long arg
, struct task_struct
*p
, unsigned long tls
)
88 struct stack_frame sf
;
89 struct pt_regs childregs
;
92 frame
= container_of(task_pt_regs(p
), struct fake_frame
, childregs
);
93 p
->thread
.ksp
= (unsigned long) frame
;
94 /* Save access registers to new thread structure. */
95 save_access_regs(&p
->thread
.acrs
[0]);
96 /* start new process with ar4 pointing to the correct address space */
97 p
->thread
.mm_segment
= get_fs();
98 /* Don't copy debug registers */
99 memset(&p
->thread
.per_user
, 0, sizeof(p
->thread
.per_user
));
100 memset(&p
->thread
.per_event
, 0, sizeof(p
->thread
.per_event
));
101 clear_tsk_thread_flag(p
, TIF_SINGLE_STEP
);
102 p
->thread
.per_flags
= 0;
103 /* Initialize per thread user and system timer values */
104 p
->thread
.user_timer
= 0;
105 p
->thread
.guest_timer
= 0;
106 p
->thread
.system_timer
= 0;
107 p
->thread
.hardirq_timer
= 0;
108 p
->thread
.softirq_timer
= 0;
110 frame
->sf
.back_chain
= 0;
111 /* new return point is ret_from_fork */
112 frame
->sf
.gprs
[8] = (unsigned long) ret_from_fork
;
113 /* fake return stack for resume(), don't go back to schedule */
114 frame
->sf
.gprs
[9] = (unsigned long) frame
;
116 /* Store access registers to kernel stack of new process. */
117 if (unlikely(p
->flags
& PF_KTHREAD
)) {
119 memset(&frame
->childregs
, 0, sizeof(struct pt_regs
));
120 frame
->childregs
.psw
.mask
= PSW_KERNEL_BITS
| PSW_MASK_DAT
|
121 PSW_MASK_IO
| PSW_MASK_EXT
| PSW_MASK_MCHECK
;
122 frame
->childregs
.psw
.addr
=
123 (unsigned long) kernel_thread_starter
;
124 frame
->childregs
.gprs
[9] = new_stackp
; /* function */
125 frame
->childregs
.gprs
[10] = arg
;
126 frame
->childregs
.gprs
[11] = (unsigned long) do_exit
;
127 frame
->childregs
.orig_gpr2
= -1;
131 frame
->childregs
= *current_pt_regs();
132 frame
->childregs
.gprs
[2] = 0; /* child returns 0 on fork. */
133 frame
->childregs
.flags
= 0;
135 frame
->childregs
.gprs
[15] = new_stackp
;
137 /* Don't copy runtime instrumentation info */
138 p
->thread
.ri_cb
= NULL
;
139 frame
->childregs
.psw
.mask
&= ~PSW_MASK_RI
;
140 /* Don't copy guarded storage control block */
141 p
->thread
.gs_cb
= NULL
;
142 p
->thread
.gs_bc_cb
= NULL
;
144 /* Set a new TLS ? */
145 if (clone_flags
& CLONE_SETTLS
) {
146 if (is_compat_task()) {
147 p
->thread
.acrs
[0] = (unsigned int)tls
;
149 p
->thread
.acrs
[0] = (unsigned int)(tls
>> 32);
150 p
->thread
.acrs
[1] = (unsigned int)tls
;
156 asmlinkage
void execve_tail(void)
158 current
->thread
.fpu
.fpc
= 0;
159 asm volatile("sfpc %0" : : "d" (0));
163 * fill in the FPU structure for a core dump.
165 int dump_fpu (struct pt_regs
* regs
, s390_fp_regs
*fpregs
)
168 fpregs
->fpc
= current
->thread
.fpu
.fpc
;
171 convert_vx_to_fp((freg_t
*)&fpregs
->fprs
,
172 current
->thread
.fpu
.vxrs
);
174 memcpy(&fpregs
->fprs
, current
->thread
.fpu
.fprs
,
175 sizeof(fpregs
->fprs
));
178 EXPORT_SYMBOL(dump_fpu
);
180 unsigned long get_wchan(struct task_struct
*p
)
182 struct stack_frame
*sf
, *low
, *high
;
183 unsigned long return_address
;
186 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
|| !task_stack_page(p
))
188 low
= task_stack_page(p
);
189 high
= (struct stack_frame
*) task_pt_regs(p
);
190 sf
= (struct stack_frame
*) p
->thread
.ksp
;
191 if (sf
<= low
|| sf
> high
)
193 for (count
= 0; count
< 16; count
++) {
194 sf
= (struct stack_frame
*) sf
->back_chain
;
195 if (sf
<= low
|| sf
> high
)
197 return_address
= sf
->gprs
[8];
198 if (!in_sched_functions(return_address
))
199 return return_address
;
204 unsigned long arch_align_stack(unsigned long sp
)
206 if (!(current
->personality
& ADDR_NO_RANDOMIZE
) && randomize_va_space
)
207 sp
-= get_random_int() & ~PAGE_MASK
;
211 static inline unsigned long brk_rnd(void)
213 return (get_random_int() & BRK_RND_MASK
) << PAGE_SHIFT
;
216 unsigned long arch_randomize_brk(struct mm_struct
*mm
)
220 ret
= PAGE_ALIGN(mm
->brk
+ brk_rnd());
221 return (ret
> mm
->brk
) ? ret
: mm
->brk
;
224 void set_fs_fixup(void)
226 struct pt_regs
*regs
= current_pt_regs();
232 WARN(1, "Unbalanced set_fs - int code: 0x%x\n", regs
->int_code
);
233 show_registers(regs
);