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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}
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/compiler.h>
11#include <linux/cpu.h>
12#include <linux/sched.h>
13#include <linux/kernel.h>
14#include <linux/mm.h>
15#include <linux/elfcore.h>
16#include <linux/smp.h>
17#include <linux/slab.h>
18#include <linux/interrupt.h>
19#include <linux/tick.h>
20#include <linux/personality.h>
21#include <linux/syscalls.h>
22#include <linux/compat.h>
23#include <linux/kprobes.h>
24#include <linux/random.h>
25#include <linux/module.h>
26#include <linux/init_task.h>
27#include <asm/io.h>
28#include <asm/processor.h>
29#include <asm/vtimer.h>
30#include <asm/exec.h>
31#include <asm/irq.h>
32#include <asm/nmi.h>
33#include <asm/smp.h>
34#include <asm/switch_to.h>
35#include <asm/runtime_instr.h>
36#include "entry.h"
37
38asmlinkage void ret_from_fork(void) asm ("ret_from_fork");
39
40/* FPU save area for the init task */
41__vector128 init_task_fpu_regs[__NUM_VXRS] __init_task_data;
42
43/*
44 * Return saved PC of a blocked thread. used in kernel/sched.
45 * resume in entry.S does not create a new stack frame, it
46 * just stores the registers %r6-%r15 to the frame given by
47 * schedule. We want to return the address of the caller of
48 * schedule, so we have to walk the backchain one time to
49 * find the frame schedule() store its return address.
50 */
51unsigned long thread_saved_pc(struct task_struct *tsk)
52{
53 struct stack_frame *sf, *low, *high;
54
55 if (!tsk || !task_stack_page(tsk))
56 return 0;
57 low = task_stack_page(tsk);
58 high = (struct stack_frame *) task_pt_regs(tsk);
59 sf = (struct stack_frame *) tsk->thread.ksp;
60 if (sf <= low || sf > high)
61 return 0;
62 sf = (struct stack_frame *) sf->back_chain;
63 if (sf <= low || sf > high)
64 return 0;
65 return sf->gprs[8];
66}
67
68extern void kernel_thread_starter(void);
69
70/*
71 * Free current thread data structures etc..
72 */
73void exit_thread(void)
74{
75 exit_thread_runtime_instr();
76}
77
78void flush_thread(void)
79{
80}
81
82void release_thread(struct task_struct *dead_task)
83{
84}
85
86void arch_release_task_struct(struct task_struct *tsk)
87{
88 /* Free either the floating-point or the vector register save area */
89 kfree(tsk->thread.fpu.regs);
90}
91
92int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
93{
94 size_t fpu_regs_size;
95
96 *dst = *src;
97
98 /*
99 * If the vector extension is available, it is enabled for all tasks,
100 * and, thus, the FPU register save area must be allocated accordingly.
101 */
102 fpu_regs_size = MACHINE_HAS_VX ? sizeof(__vector128) * __NUM_VXRS
103 : sizeof(freg_t) * __NUM_FPRS;
104 dst->thread.fpu.regs = kzalloc(fpu_regs_size, GFP_KERNEL|__GFP_REPEAT);
105 if (!dst->thread.fpu.regs)
106 return -ENOMEM;
107
108 /*
109 * Save the floating-point or vector register state of the current
110 * task and set the CIF_FPU flag to lazy restore the FPU register
111 * state when returning to user space.
112 */
113 save_fpu_regs();
114 dst->thread.fpu.fpc = current->thread.fpu.fpc;
115 memcpy(dst->thread.fpu.regs, current->thread.fpu.regs, fpu_regs_size);
116
117 return 0;
118}
119
120int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
121 unsigned long arg, struct task_struct *p)
122{
123 struct thread_info *ti;
124 struct fake_frame
125 {
126 struct stack_frame sf;
127 struct pt_regs childregs;
128 } *frame;
129
130 frame = container_of(task_pt_regs(p), struct fake_frame, childregs);
131 p->thread.ksp = (unsigned long) frame;
132 /* Save access registers to new thread structure. */
133 save_access_regs(&p->thread.acrs[0]);
134 /* start new process with ar4 pointing to the correct address space */
135 p->thread.mm_segment = get_fs();
136 /* Don't copy debug registers */
137 memset(&p->thread.per_user, 0, sizeof(p->thread.per_user));
138 memset(&p->thread.per_event, 0, sizeof(p->thread.per_event));
139 clear_tsk_thread_flag(p, TIF_SINGLE_STEP);
140 /* Initialize per thread user and system timer values */
141 ti = task_thread_info(p);
142 ti->user_timer = 0;
143 ti->system_timer = 0;
144
145 frame->sf.back_chain = 0;
146 /* new return point is ret_from_fork */
147 frame->sf.gprs[8] = (unsigned long) ret_from_fork;
148 /* fake return stack for resume(), don't go back to schedule */
149 frame->sf.gprs[9] = (unsigned long) frame;
150
151 /* Store access registers to kernel stack of new process. */
152 if (unlikely(p->flags & PF_KTHREAD)) {
153 /* kernel thread */
154 memset(&frame->childregs, 0, sizeof(struct pt_regs));
155 frame->childregs.psw.mask = PSW_KERNEL_BITS | PSW_MASK_DAT |
156 PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
157 frame->childregs.psw.addr =
158 (unsigned long) kernel_thread_starter;
159 frame->childregs.gprs[9] = new_stackp; /* function */
160 frame->childregs.gprs[10] = arg;
161 frame->childregs.gprs[11] = (unsigned long) do_exit;
162 frame->childregs.orig_gpr2 = -1;
163
164 return 0;
165 }
166 frame->childregs = *current_pt_regs();
167 frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */
168 frame->childregs.flags = 0;
169 if (new_stackp)
170 frame->childregs.gprs[15] = new_stackp;
171
172 /* Don't copy runtime instrumentation info */
173 p->thread.ri_cb = NULL;
174 frame->childregs.psw.mask &= ~PSW_MASK_RI;
175
176 /* Set a new TLS ? */
177 if (clone_flags & CLONE_SETTLS) {
178 unsigned long tls = frame->childregs.gprs[6];
179 if (is_compat_task()) {
180 p->thread.acrs[0] = (unsigned int)tls;
181 } else {
182 p->thread.acrs[0] = (unsigned int)(tls >> 32);
183 p->thread.acrs[1] = (unsigned int)tls;
184 }
185 }
186 return 0;
187}
188
189asmlinkage void execve_tail(void)
190{
191 current->thread.fpu.fpc = 0;
192 asm volatile("sfpc %0" : : "d" (0));
193}
194
195/*
196 * fill in the FPU structure for a core dump.
197 */
198int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs)
199{
200 save_fpu_regs();
201 fpregs->fpc = current->thread.fpu.fpc;
202 fpregs->pad = 0;
203 if (MACHINE_HAS_VX)
204 convert_vx_to_fp((freg_t *)&fpregs->fprs,
205 current->thread.fpu.vxrs);
206 else
207 memcpy(&fpregs->fprs, current->thread.fpu.fprs,
208 sizeof(fpregs->fprs));
209 return 1;
210}
211EXPORT_SYMBOL(dump_fpu);
212
213unsigned long get_wchan(struct task_struct *p)
214{
215 struct stack_frame *sf, *low, *high;
216 unsigned long return_address;
217 int count;
218
219 if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p))
220 return 0;
221 low = task_stack_page(p);
222 high = (struct stack_frame *) task_pt_regs(p);
223 sf = (struct stack_frame *) p->thread.ksp;
224 if (sf <= low || sf > high)
225 return 0;
226 for (count = 0; count < 16; count++) {
227 sf = (struct stack_frame *) sf->back_chain;
228 if (sf <= low || sf > high)
229 return 0;
230 return_address = sf->gprs[8];
231 if (!in_sched_functions(return_address))
232 return return_address;
233 }
234 return 0;
235}
236
237unsigned long arch_align_stack(unsigned long sp)
238{
239 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
240 sp -= get_random_int() & ~PAGE_MASK;
241 return sp & ~0xf;
242}
243
244static inline unsigned long brk_rnd(void)
245{
246 return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
247}
248
249unsigned long arch_randomize_brk(struct mm_struct *mm)
250{
251 unsigned long ret;
252
253 ret = PAGE_ALIGN(mm->brk + brk_rnd());
254 return (ret > mm->brk) ? ret : mm->brk;
255}