Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
cbdc2292 | 2 | * This file handles the architecture dependent parts of process handling. |
1da177e4 | 3 | * |
a53c8fab | 4 | * Copyright IBM Corp. 1999, 2009 |
cbdc2292 HC |
5 | * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>, |
6 | * Hartmut Penner <hp@de.ibm.com>, | |
7 | * Denis Joseph Barrow, | |
1da177e4 LT |
8 | */ |
9 | ||
1da177e4 LT |
10 | #include <linux/compiler.h> |
11 | #include <linux/cpu.h> | |
1da177e4 LT |
12 | #include <linux/sched.h> |
13 | #include <linux/kernel.h> | |
14 | #include <linux/mm.h> | |
638ad34a | 15 | #include <linux/elfcore.h> |
1da177e4 | 16 | #include <linux/smp.h> |
5a0e3ad6 | 17 | #include <linux/slab.h> |
1da177e4 | 18 | #include <linux/interrupt.h> |
5a62b192 | 19 | #include <linux/tick.h> |
9887a1fc | 20 | #include <linux/personality.h> |
26689452 | 21 | #include <linux/syscalls.h> |
3e86a8c6 | 22 | #include <linux/compat.h> |
860dba45 | 23 | #include <linux/kprobes.h> |
9887a1fc | 24 | #include <linux/random.h> |
3af6fb68 | 25 | #include <linux/module.h> |
1da177e4 LT |
26 | #include <asm/io.h> |
27 | #include <asm/processor.h> | |
27f6b416 | 28 | #include <asm/vtimer.h> |
f6e38691 | 29 | #include <asm/exec.h> |
1da177e4 | 30 | #include <asm/irq.h> |
f5daba1d | 31 | #include <asm/nmi.h> |
da7f51c1 | 32 | #include <asm/smp.h> |
a0616cde | 33 | #include <asm/switch_to.h> |
e4b8b3f3 | 34 | #include <asm/runtime_instr.h> |
a806170e | 35 | #include "entry.h" |
1da177e4 | 36 | |
94c12cc7 | 37 | asmlinkage void ret_from_fork(void) asm ("ret_from_fork"); |
1da177e4 LT |
38 | |
39 | /* | |
40 | * Return saved PC of a blocked thread. used in kernel/sched. | |
41 | * resume in entry.S does not create a new stack frame, it | |
42 | * just stores the registers %r6-%r15 to the frame given by | |
43 | * schedule. We want to return the address of the caller of | |
44 | * schedule, so we have to walk the backchain one time to | |
45 | * find the frame schedule() store its return address. | |
46 | */ | |
47 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
48 | { | |
eb33c190 | 49 | struct stack_frame *sf, *low, *high; |
1da177e4 | 50 | |
eb33c190 HC |
51 | if (!tsk || !task_stack_page(tsk)) |
52 | return 0; | |
53 | low = task_stack_page(tsk); | |
54 | high = (struct stack_frame *) task_pt_regs(tsk); | |
55 | sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN); | |
56 | if (sf <= low || sf > high) | |
57 | return 0; | |
58 | sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); | |
59 | if (sf <= low || sf > high) | |
60 | return 0; | |
1da177e4 LT |
61 | return sf->gprs[8]; |
62 | } | |
63 | ||
1da177e4 LT |
64 | /* |
65 | * The idle loop on a S390... | |
66 | */ | |
cdb04527 | 67 | static void default_idle(void) |
1da177e4 | 68 | { |
da7f51c1 | 69 | if (cpu_is_offline(smp_processor_id())) |
1da177e4 | 70 | cpu_die(); |
6931be08 HC |
71 | local_irq_disable(); |
72 | if (need_resched()) { | |
73 | local_irq_enable(); | |
74 | return; | |
75 | } | |
77fa2245 HC |
76 | local_mcck_disable(); |
77 | if (test_thread_flag(TIF_MCCK_PENDING)) { | |
78 | local_mcck_enable(); | |
79 | local_irq_enable(); | |
77fa2245 HC |
80 | return; |
81 | } | |
4c1051e3 | 82 | /* Halt the cpu and keep track of cpu time accounting. */ |
9cfb9b3c | 83 | vtime_stop_cpu(); |
1da177e4 LT |
84 | } |
85 | ||
86 | void cpu_idle(void) | |
87 | { | |
5bfb5d69 | 88 | for (;;) { |
1268fbc7 FW |
89 | tick_nohz_idle_enter(); |
90 | rcu_idle_enter(); | |
f3612304 | 91 | while (!need_resched() && !test_thread_flag(TIF_MCCK_PENDING)) |
5bfb5d69 | 92 | default_idle(); |
1268fbc7 FW |
93 | rcu_idle_exit(); |
94 | tick_nohz_idle_exit(); | |
f3612304 HC |
95 | if (test_thread_flag(TIF_MCCK_PENDING)) |
96 | s390_handle_mcck(); | |
bd2f5536 | 97 | schedule_preempt_disabled(); |
5bfb5d69 | 98 | } |
1da177e4 LT |
99 | } |
100 | ||
860dba45 | 101 | extern void __kprobes kernel_thread_starter(void); |
1da177e4 | 102 | |
1da177e4 LT |
103 | /* |
104 | * Free current thread data structures etc.. | |
105 | */ | |
106 | void exit_thread(void) | |
107 | { | |
e4b8b3f3 | 108 | exit_thread_runtime_instr(); |
1da177e4 LT |
109 | } |
110 | ||
111 | void flush_thread(void) | |
112 | { | |
1da177e4 LT |
113 | } |
114 | ||
115 | void release_thread(struct task_struct *dead_task) | |
116 | { | |
117 | } | |
118 | ||
6f2c55b8 | 119 | int copy_thread(unsigned long clone_flags, unsigned long new_stackp, |
afa86fc4 | 120 | unsigned long arg, struct task_struct *p) |
1da177e4 | 121 | { |
5168ce2c | 122 | struct thread_info *ti; |
cbdc2292 HC |
123 | struct fake_frame |
124 | { | |
125 | struct stack_frame sf; | |
126 | struct pt_regs childregs; | |
127 | } *frame; | |
128 | ||
129 | frame = container_of(task_pt_regs(p), struct fake_frame, childregs); | |
130 | p->thread.ksp = (unsigned long) frame; | |
f9a7e025 AV |
131 | /* Save access registers to new thread structure. */ |
132 | save_access_regs(&p->thread.acrs[0]); | |
133 | /* start new process with ar4 pointing to the correct address space */ | |
134 | p->thread.mm_segment = get_fs(); | |
135 | /* Don't copy debug registers */ | |
136 | memset(&p->thread.per_user, 0, sizeof(p->thread.per_user)); | |
137 | memset(&p->thread.per_event, 0, sizeof(p->thread.per_event)); | |
138 | clear_tsk_thread_flag(p, TIF_SINGLE_STEP); | |
139 | clear_tsk_thread_flag(p, TIF_PER_TRAP); | |
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; | |
1da177e4 | 144 | |
f9a7e025 | 145 | frame->sf.back_chain = 0; |
cbdc2292 HC |
146 | /* new return point is ret_from_fork */ |
147 | frame->sf.gprs[8] = (unsigned long) ret_from_fork; | |
cbdc2292 HC |
148 | /* fake return stack for resume(), don't go back to schedule */ |
149 | frame->sf.gprs[9] = (unsigned long) frame; | |
1da177e4 | 150 | |
f9a7e025 | 151 | /* Store access registers to kernel stack of new process. */ |
87f1ca8f | 152 | if (unlikely(p->flags & PF_KTHREAD)) { |
f9a7e025 AV |
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 = PSW_ADDR_AMODE | | |
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 | } | |
87f1ca8f | 166 | frame->childregs = *current_pt_regs(); |
f9a7e025 | 167 | frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */ |
87f1ca8f AV |
168 | if (new_stackp) |
169 | frame->childregs.gprs[15] = new_stackp; | |
1da177e4 | 170 | |
e4b8b3f3 JG |
171 | /* Don't copy runtime instrumentation info */ |
172 | p->thread.ri_cb = NULL; | |
173 | p->thread.ri_signum = 0; | |
174 | frame->childregs.psw.mask &= ~PSW_MASK_RI; | |
175 | ||
347a8dc3 | 176 | #ifndef CONFIG_64BIT |
cbdc2292 | 177 | /* |
1da177e4 LT |
178 | * save fprs to current->thread.fp_regs to merge them with |
179 | * the emulated registers and then copy the result to the child. | |
180 | */ | |
181 | save_fp_regs(¤t->thread.fp_regs); | |
182 | memcpy(&p->thread.fp_regs, ¤t->thread.fp_regs, | |
183 | sizeof(s390_fp_regs)); | |
1da177e4 LT |
184 | /* Set a new TLS ? */ |
185 | if (clone_flags & CLONE_SETTLS) | |
87f1ca8f | 186 | p->thread.acrs[0] = frame->childregs.gprs[6]; |
347a8dc3 | 187 | #else /* CONFIG_64BIT */ |
1da177e4 LT |
188 | /* Save the fpu registers to new thread structure. */ |
189 | save_fp_regs(&p->thread.fp_regs); | |
1da177e4 LT |
190 | /* Set a new TLS ? */ |
191 | if (clone_flags & CLONE_SETTLS) { | |
87f1ca8f | 192 | unsigned long tls = frame->childregs.gprs[6]; |
7757591a | 193 | if (is_compat_task()) { |
87f1ca8f | 194 | p->thread.acrs[0] = (unsigned int)tls; |
1da177e4 | 195 | } else { |
87f1ca8f AV |
196 | p->thread.acrs[0] = (unsigned int)(tls >> 32); |
197 | p->thread.acrs[1] = (unsigned int)tls; | |
1da177e4 LT |
198 | } |
199 | } | |
347a8dc3 | 200 | #endif /* CONFIG_64BIT */ |
cbdc2292 | 201 | return 0; |
1da177e4 LT |
202 | } |
203 | ||
03ff9a23 MS |
204 | asmlinkage void execve_tail(void) |
205 | { | |
03ff9a23 MS |
206 | current->thread.fp_regs.fpc = 0; |
207 | if (MACHINE_HAS_IEEE) | |
208 | asm volatile("sfpc %0,%0" : : "d" (0)); | |
1da177e4 LT |
209 | } |
210 | ||
1da177e4 LT |
211 | /* |
212 | * fill in the FPU structure for a core dump. | |
213 | */ | |
214 | int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs) | |
215 | { | |
347a8dc3 | 216 | #ifndef CONFIG_64BIT |
cbdc2292 | 217 | /* |
1da177e4 LT |
218 | * save fprs to current->thread.fp_regs to merge them with |
219 | * the emulated registers and then copy the result to the dump. | |
220 | */ | |
221 | save_fp_regs(¤t->thread.fp_regs); | |
222 | memcpy(fpregs, ¤t->thread.fp_regs, sizeof(s390_fp_regs)); | |
347a8dc3 | 223 | #else /* CONFIG_64BIT */ |
1da177e4 | 224 | save_fp_regs(fpregs); |
347a8dc3 | 225 | #endif /* CONFIG_64BIT */ |
1da177e4 LT |
226 | return 1; |
227 | } | |
1485c5c8 | 228 | EXPORT_SYMBOL(dump_fpu); |
1da177e4 | 229 | |
1da177e4 LT |
230 | unsigned long get_wchan(struct task_struct *p) |
231 | { | |
232 | struct stack_frame *sf, *low, *high; | |
233 | unsigned long return_address; | |
234 | int count; | |
235 | ||
30af7120 | 236 | if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p)) |
1da177e4 | 237 | return 0; |
30af7120 AV |
238 | low = task_stack_page(p); |
239 | high = (struct stack_frame *) task_pt_regs(p); | |
1da177e4 LT |
240 | sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN); |
241 | if (sf <= low || sf > high) | |
242 | return 0; | |
243 | for (count = 0; count < 16; count++) { | |
244 | sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); | |
245 | if (sf <= low || sf > high) | |
246 | return 0; | |
247 | return_address = sf->gprs[8] & PSW_ADDR_INSN; | |
248 | if (!in_sched_functions(return_address)) | |
249 | return return_address; | |
250 | } | |
251 | return 0; | |
252 | } | |
9887a1fc HC |
253 | |
254 | unsigned long arch_align_stack(unsigned long sp) | |
255 | { | |
256 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) | |
257 | sp -= get_random_int() & ~PAGE_MASK; | |
258 | return sp & ~0xf; | |
259 | } | |
33519182 HC |
260 | |
261 | static inline unsigned long brk_rnd(void) | |
262 | { | |
263 | /* 8MB for 32bit, 1GB for 64bit */ | |
264 | if (is_32bit_task()) | |
265 | return (get_random_int() & 0x7ffUL) << PAGE_SHIFT; | |
266 | else | |
267 | return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT; | |
268 | } | |
269 | ||
270 | unsigned long arch_randomize_brk(struct mm_struct *mm) | |
271 | { | |
272 | unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd()); | |
273 | ||
274 | if (ret < mm->brk) | |
275 | return mm->brk; | |
276 | return ret; | |
277 | } | |
d2c9dfcc HC |
278 | |
279 | unsigned long randomize_et_dyn(unsigned long base) | |
280 | { | |
281 | unsigned long ret = PAGE_ALIGN(base + brk_rnd()); | |
282 | ||
283 | if (!(current->flags & PF_RANDOMIZE)) | |
284 | return base; | |
285 | if (ret < base) | |
286 | return base; | |
287 | return ret; | |
288 | } |