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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * This file handles the architecture dependent parts of process handling.
4 *
5 * Copyright IBM Corp. 1999, 2009
6 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
7 * Hartmut Penner <hp@de.ibm.com>,
8 * Denis Joseph Barrow,
9 */
10
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>
19#include <linux/mm.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>
33#include <asm/io.h>
34#include <asm/processor.h>
35#include <asm/vtimer.h>
36#include <asm/exec.h>
37#include <asm/irq.h>
38#include <asm/nmi.h>
39#include <asm/smp.h>
40#include <asm/switch_to.h>
41#include <asm/runtime_instr.h>
42#include "entry.h"
43
44asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
45
46extern void kernel_thread_starter(void);
47
48void flush_thread(void)
49{
50}
51
52void arch_setup_new_exec(void)
53{
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);
58 }
59}
60
61void arch_release_task_struct(struct task_struct *tsk)
62{
63 runtime_instr_release(tsk);
64 guarded_storage_release(tsk);
65}
66
67int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
68{
69 /*
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.
73 */
74 save_fpu_regs();
75
76 memcpy(dst, src, arch_task_struct_size);
77 dst->thread.fpu.regs = dst->thread.fpu.fprs;
78 return 0;
79}
80
81int copy_thread_tls(unsigned long clone_flags, unsigned long new_stackp,
82 unsigned long arg, struct task_struct *p, unsigned long tls)
83{
84 struct fake_frame
85 {
86 struct stack_frame sf;
87 struct pt_regs childregs;
88 } *frame;
89
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;
107
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;
113
114 /* Store access registers to kernel stack of new process. */
115 if (unlikely(p->flags & PF_KTHREAD)) {
116 /* kernel thread */
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;
126
127 return 0;
128 }
129 frame->childregs = *current_pt_regs();
130 frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */
131 frame->childregs.flags = 0;
132 if (new_stackp)
133 frame->childregs.gprs[15] = new_stackp;
134
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;
141
142 /* Set a new TLS ? */
143 if (clone_flags & CLONE_SETTLS) {
144 if (is_compat_task()) {
145 p->thread.acrs[0] = (unsigned int)tls;
146 } else {
147 p->thread.acrs[0] = (unsigned int)(tls >> 32);
148 p->thread.acrs[1] = (unsigned int)tls;
149 }
150 }
151 return 0;
152}
153
154asmlinkage void execve_tail(void)
155{
156 current->thread.fpu.fpc = 0;
157 asm volatile("sfpc %0" : : "d" (0));
158}
159
160/*
161 * fill in the FPU structure for a core dump.
162 */
163int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
164{
165 save_fpu_regs();
166 fpregs->fpc = current->thread.fpu.fpc;
167 fpregs->pad = 0;
168 if (MACHINE_HAS_VX)
169 convert_vx_to_fp((freg_t *)&fpregs->fprs,
170 current->thread.fpu.vxrs);
171 else
172 memcpy(&fpregs->fprs, current->thread.fpu.fprs,
173 sizeof(fpregs->fprs));
174 return 1;
175}
176EXPORT_SYMBOL(dump_fpu);
177
178unsigned long get_wchan(struct task_struct *p)
179{
180 struct stack_frame *sf, *low, *high;
181 unsigned long return_address;
182 int count;
183
184 if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p))
185 return 0;
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)
190 return 0;
191 for (count = 0; count < 16; count++) {
192 sf = (struct stack_frame *) sf->back_chain;
193 if (sf <= low || sf > high)
194 return 0;
195 return_address = sf->gprs[8];
196 if (!in_sched_functions(return_address))
197 return return_address;
198 }
199 return 0;
200}
201
202unsigned long arch_align_stack(unsigned long sp)
203{
204 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
205 sp -= get_random_int() & ~PAGE_MASK;
206 return sp & ~0xf;
207}
208
209static inline unsigned long brk_rnd(void)
210{
211 return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
212}
213
214unsigned long arch_randomize_brk(struct mm_struct *mm)
215{
216 unsigned long ret;
217
218 ret = PAGE_ALIGN(mm->brk + brk_rnd());
219 return (ret > mm->brk) ? ret : mm->brk;
220}
221
222void set_fs_fixup(void)
223{
224 struct pt_regs *regs = current_pt_regs();
225 static bool warned;
226
227 set_fs(USER_DS);
228 if (warned)
229 return;
230 WARN(1, "Unbalanced set_fs - int code: 0x%x\n", regs->int_code);
231 show_registers(regs);
232 warned = true;
233}
1/*
2 * This file handles the architecture dependent parts of process handling.
3 *
4 * Copyright IBM Corp. 1999, 2009
5 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
6 * Hartmut Penner <hp@de.ibm.com>,
7 * Denis Joseph Barrow,
8 */
9
10#include <linux/elf-randomize.h>
11#include <linux/compiler.h>
12#include <linux/cpu.h>
13#include <linux/sched.h>
14#include <linux/kernel.h>
15#include <linux/mm.h>
16#include <linux/elfcore.h>
17#include <linux/smp.h>
18#include <linux/slab.h>
19#include <linux/interrupt.h>
20#include <linux/tick.h>
21#include <linux/personality.h>
22#include <linux/syscalls.h>
23#include <linux/compat.h>
24#include <linux/kprobes.h>
25#include <linux/random.h>
26#include <linux/module.h>
27#include <linux/init_task.h>
28#include <asm/io.h>
29#include <asm/processor.h>
30#include <asm/vtimer.h>
31#include <asm/exec.h>
32#include <asm/irq.h>
33#include <asm/nmi.h>
34#include <asm/smp.h>
35#include <asm/switch_to.h>
36#include <asm/runtime_instr.h>
37#include "entry.h"
38
39asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
40
41/*
42 * Return saved PC of a blocked thread. used in kernel/sched.
43 * resume in entry.S does not create a new stack frame, it
44 * just stores the registers %r6-%r15 to the frame given by
45 * schedule. We want to return the address of the caller of
46 * schedule, so we have to walk the backchain one time to
47 * find the frame schedule() store its return address.
48 */
49unsigned long thread_saved_pc(struct task_struct *tsk)
50{
51 struct stack_frame *sf, *low, *high;
52
53 if (!tsk || !task_stack_page(tsk))
54 return 0;
55 low = task_stack_page(tsk);
56 high = (struct stack_frame *) task_pt_regs(tsk);
57 sf = (struct stack_frame *) tsk->thread.ksp;
58 if (sf <= low || sf > high)
59 return 0;
60 sf = (struct stack_frame *) sf->back_chain;
61 if (sf <= low || sf > high)
62 return 0;
63 return sf->gprs[8];
64}
65
66extern void kernel_thread_starter(void);
67
68/*
69 * Free current thread data structures etc..
70 */
71void exit_thread(struct task_struct *tsk)
72{
73 if (tsk == current)
74 exit_thread_runtime_instr();
75}
76
77void flush_thread(void)
78{
79}
80
81void release_thread(struct task_struct *dead_task)
82{
83}
84
85void arch_release_task_struct(struct task_struct *tsk)
86{
87}
88
89int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
90{
91 /*
92 * Save the floating-point or vector register state of the current
93 * task and set the CIF_FPU flag to lazy restore the FPU register
94 * state when returning to user space.
95 */
96 save_fpu_regs();
97
98 memcpy(dst, src, arch_task_struct_size);
99 dst->thread.fpu.regs = dst->thread.fpu.fprs;
100 return 0;
101}
102
103int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
104 unsigned long arg, struct task_struct *p)
105{
106 struct fake_frame
107 {
108 struct stack_frame sf;
109 struct pt_regs childregs;
110 } *frame;
111
112 frame = container_of(task_pt_regs(p), struct fake_frame, childregs);
113 p->thread.ksp = (unsigned long) frame;
114 /* Save access registers to new thread structure. */
115 save_access_regs(&p->thread.acrs[0]);
116 /* start new process with ar4 pointing to the correct address space */
117 p->thread.mm_segment = get_fs();
118 /* Don't copy debug registers */
119 memset(&p->thread.per_user, 0, sizeof(p->thread.per_user));
120 memset(&p->thread.per_event, 0, sizeof(p->thread.per_event));
121 clear_tsk_thread_flag(p, TIF_SINGLE_STEP);
122 /* Initialize per thread user and system timer values */
123 p->thread.user_timer = 0;
124 p->thread.system_timer = 0;
125
126 frame->sf.back_chain = 0;
127 /* new return point is ret_from_fork */
128 frame->sf.gprs[8] = (unsigned long) ret_from_fork;
129 /* fake return stack for resume(), don't go back to schedule */
130 frame->sf.gprs[9] = (unsigned long) frame;
131
132 /* Store access registers to kernel stack of new process. */
133 if (unlikely(p->flags & PF_KTHREAD)) {
134 /* kernel thread */
135 memset(&frame->childregs, 0, sizeof(struct pt_regs));
136 frame->childregs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_DAT |
137 PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
138 frame->childregs.psw.addr =
139 (unsigned long) kernel_thread_starter;
140 frame->childregs.gprs[9] = new_stackp; /* function */
141 frame->childregs.gprs[10] = arg;
142 frame->childregs.gprs[11] = (unsigned long) do_exit;
143 frame->childregs.orig_gpr2 = -1;
144
145 return 0;
146 }
147 frame->childregs = *current_pt_regs();
148 frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */
149 frame->childregs.flags = 0;
150 if (new_stackp)
151 frame->childregs.gprs[15] = new_stackp;
152
153 /* Don't copy runtime instrumentation info */
154 p->thread.ri_cb = NULL;
155 frame->childregs.psw.mask &= ~PSW_MASK_RI;
156
157 /* Set a new TLS ? */
158 if (clone_flags & CLONE_SETTLS) {
159 unsigned long tls = frame->childregs.gprs[6];
160 if (is_compat_task()) {
161 p->thread.acrs[0] = (unsigned int)tls;
162 } else {
163 p->thread.acrs[0] = (unsigned int)(tls >> 32);
164 p->thread.acrs[1] = (unsigned int)tls;
165 }
166 }
167 return 0;
168}
169
170asmlinkage void execve_tail(void)
171{
172 current->thread.fpu.fpc = 0;
173 asm volatile("sfpc %0" : : "d" (0));
174}
175
176/*
177 * fill in the FPU structure for a core dump.
178 */
179int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
180{
181 save_fpu_regs();
182 fpregs->fpc = current->thread.fpu.fpc;
183 fpregs->pad = 0;
184 if (MACHINE_HAS_VX)
185 convert_vx_to_fp((freg_t *)&fpregs->fprs,
186 current->thread.fpu.vxrs);
187 else
188 memcpy(&fpregs->fprs, current->thread.fpu.fprs,
189 sizeof(fpregs->fprs));
190 return 1;
191}
192EXPORT_SYMBOL(dump_fpu);
193
194unsigned long get_wchan(struct task_struct *p)
195{
196 struct stack_frame *sf, *low, *high;
197 unsigned long return_address;
198 int count;
199
200 if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p))
201 return 0;
202 low = task_stack_page(p);
203 high = (struct stack_frame *) task_pt_regs(p);
204 sf = (struct stack_frame *) p->thread.ksp;
205 if (sf <= low || sf > high)
206 return 0;
207 for (count = 0; count < 16; count++) {
208 sf = (struct stack_frame *) sf->back_chain;
209 if (sf <= low || sf > high)
210 return 0;
211 return_address = sf->gprs[8];
212 if (!in_sched_functions(return_address))
213 return return_address;
214 }
215 return 0;
216}
217
218unsigned long arch_align_stack(unsigned long sp)
219{
220 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
221 sp -= get_random_int() & ~PAGE_MASK;
222 return sp & ~0xf;
223}
224
225static inline unsigned long brk_rnd(void)
226{
227 return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
228}
229
230unsigned long arch_randomize_brk(struct mm_struct *mm)
231{
232 unsigned long ret;
233
234 ret = PAGE_ALIGN(mm->brk + brk_rnd());
235 return (ret > mm->brk) ? ret : mm->brk;
236}