Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
cbdc2292 | 2 | * This file handles the architecture dependent parts of process handling. |
1da177e4 | 3 | * |
cbdc2292 HC |
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, | |
1da177e4 LT |
8 | */ |
9 | ||
1da177e4 LT |
10 | #include <linux/compiler.h> |
11 | #include <linux/cpu.h> | |
12 | #include <linux/errno.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/mm.h> | |
4e950f6f | 16 | #include <linux/fs.h> |
1da177e4 | 17 | #include <linux/smp.h> |
1da177e4 LT |
18 | #include <linux/stddef.h> |
19 | #include <linux/unistd.h> | |
20 | #include <linux/ptrace.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/vmalloc.h> | |
23 | #include <linux/user.h> | |
1da177e4 LT |
24 | #include <linux/interrupt.h> |
25 | #include <linux/delay.h> | |
26 | #include <linux/reboot.h> | |
27 | #include <linux/init.h> | |
28 | #include <linux/module.h> | |
29 | #include <linux/notifier.h> | |
5c699714 | 30 | #include <linux/utsname.h> |
5a62b192 | 31 | #include <linux/tick.h> |
a806170e | 32 | #include <linux/elfcore.h> |
6f430924 | 33 | #include <linux/kernel_stat.h> |
26689452 | 34 | #include <linux/syscalls.h> |
1da177e4 LT |
35 | #include <asm/uaccess.h> |
36 | #include <asm/pgtable.h> | |
37 | #include <asm/system.h> | |
38 | #include <asm/io.h> | |
39 | #include <asm/processor.h> | |
40 | #include <asm/irq.h> | |
41 | #include <asm/timer.h> | |
f5daba1d | 42 | #include <asm/nmi.h> |
a806170e | 43 | #include "entry.h" |
1da177e4 | 44 | |
94c12cc7 | 45 | asmlinkage void ret_from_fork(void) asm ("ret_from_fork"); |
1da177e4 LT |
46 | |
47 | /* | |
48 | * Return saved PC of a blocked thread. used in kernel/sched. | |
49 | * resume in entry.S does not create a new stack frame, it | |
50 | * just stores the registers %r6-%r15 to the frame given by | |
51 | * schedule. We want to return the address of the caller of | |
52 | * schedule, so we have to walk the backchain one time to | |
53 | * find the frame schedule() store its return address. | |
54 | */ | |
55 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
56 | { | |
eb33c190 | 57 | struct stack_frame *sf, *low, *high; |
1da177e4 | 58 | |
eb33c190 HC |
59 | if (!tsk || !task_stack_page(tsk)) |
60 | return 0; | |
61 | low = task_stack_page(tsk); | |
62 | high = (struct stack_frame *) task_pt_regs(tsk); | |
63 | sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN); | |
64 | if (sf <= low || sf > high) | |
65 | return 0; | |
66 | sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); | |
67 | if (sf <= low || sf > high) | |
68 | return 0; | |
1da177e4 LT |
69 | return sf->gprs[8]; |
70 | } | |
71 | ||
1da177e4 LT |
72 | /* |
73 | * The idle loop on a S390... | |
74 | */ | |
cdb04527 | 75 | static void default_idle(void) |
1da177e4 | 76 | { |
64c7c8f8 | 77 | /* CPU is going idle. */ |
1da177e4 | 78 | local_irq_disable(); |
64c7c8f8 | 79 | if (need_resched()) { |
1da177e4 | 80 | local_irq_enable(); |
64c7c8f8 NP |
81 | return; |
82 | } | |
1da177e4 | 83 | #ifdef CONFIG_HOTPLUG_CPU |
43ca5c3a | 84 | if (cpu_is_offline(smp_processor_id())) { |
1fca251f | 85 | preempt_enable_no_resched(); |
1da177e4 | 86 | cpu_die(); |
1fca251f | 87 | } |
1da177e4 | 88 | #endif |
77fa2245 HC |
89 | local_mcck_disable(); |
90 | if (test_thread_flag(TIF_MCCK_PENDING)) { | |
91 | local_mcck_enable(); | |
92 | local_irq_enable(); | |
93 | s390_handle_mcck(); | |
94 | return; | |
95 | } | |
1f194a4c | 96 | trace_hardirqs_on(); |
632448f6 HC |
97 | /* Don't trace preempt off for idle. */ |
98 | stop_critical_timings(); | |
9cfb9b3c MS |
99 | /* Stop virtual timer and halt the cpu. */ |
100 | vtime_stop_cpu(); | |
101 | /* Reenable preemption tracer. */ | |
632448f6 | 102 | start_critical_timings(); |
1da177e4 LT |
103 | } |
104 | ||
105 | void cpu_idle(void) | |
106 | { | |
5bfb5d69 | 107 | for (;;) { |
e338125b | 108 | tick_nohz_stop_sched_tick(1); |
5bfb5d69 NP |
109 | while (!need_resched()) |
110 | default_idle(); | |
5a62b192 | 111 | tick_nohz_restart_sched_tick(); |
5bfb5d69 NP |
112 | preempt_enable_no_resched(); |
113 | schedule(); | |
114 | preempt_disable(); | |
115 | } | |
1da177e4 LT |
116 | } |
117 | ||
1da177e4 LT |
118 | extern void kernel_thread_starter(void); |
119 | ||
94c12cc7 MS |
120 | asm( |
121 | ".align 4\n" | |
1da177e4 LT |
122 | "kernel_thread_starter:\n" |
123 | " la 2,0(10)\n" | |
124 | " basr 14,9\n" | |
125 | " la 2,0\n" | |
126 | " br 11\n"); | |
127 | ||
128 | int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
129 | { | |
130 | struct pt_regs regs; | |
131 | ||
132 | memset(®s, 0, sizeof(regs)); | |
c1821c2e | 133 | regs.psw.mask = psw_kernel_bits | PSW_MASK_IO | PSW_MASK_EXT; |
1da177e4 LT |
134 | regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE; |
135 | regs.gprs[9] = (unsigned long) fn; | |
136 | regs.gprs[10] = (unsigned long) arg; | |
137 | regs.gprs[11] = (unsigned long) do_exit; | |
138 | regs.orig_gpr2 = -1; | |
139 | ||
140 | /* Ok, create the new process.. */ | |
141 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, | |
142 | 0, ®s, 0, NULL, NULL); | |
143 | } | |
1485c5c8 | 144 | EXPORT_SYMBOL(kernel_thread); |
1da177e4 LT |
145 | |
146 | /* | |
147 | * Free current thread data structures etc.. | |
148 | */ | |
149 | void exit_thread(void) | |
150 | { | |
151 | } | |
152 | ||
153 | void flush_thread(void) | |
154 | { | |
155 | clear_used_math(); | |
156 | clear_tsk_thread_flag(current, TIF_USEDFPU); | |
157 | } | |
158 | ||
159 | void release_thread(struct task_struct *dead_task) | |
160 | { | |
161 | } | |
162 | ||
163 | int copy_thread(int nr, unsigned long clone_flags, unsigned long new_stackp, | |
cbdc2292 HC |
164 | unsigned long unused, |
165 | struct task_struct *p, struct pt_regs *regs) | |
1da177e4 | 166 | { |
5168ce2c | 167 | struct thread_info *ti; |
cbdc2292 HC |
168 | struct fake_frame |
169 | { | |
170 | struct stack_frame sf; | |
171 | struct pt_regs childregs; | |
172 | } *frame; | |
173 | ||
174 | frame = container_of(task_pt_regs(p), struct fake_frame, childregs); | |
175 | p->thread.ksp = (unsigned long) frame; | |
1da177e4 | 176 | /* Store access registers to kernel stack of new process. */ |
cbdc2292 | 177 | frame->childregs = *regs; |
1da177e4 | 178 | frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */ |
cbdc2292 HC |
179 | frame->childregs.gprs[15] = new_stackp; |
180 | frame->sf.back_chain = 0; | |
1da177e4 | 181 | |
cbdc2292 HC |
182 | /* new return point is ret_from_fork */ |
183 | frame->sf.gprs[8] = (unsigned long) ret_from_fork; | |
1da177e4 | 184 | |
cbdc2292 HC |
185 | /* fake return stack for resume(), don't go back to schedule */ |
186 | frame->sf.gprs[9] = (unsigned long) frame; | |
1da177e4 LT |
187 | |
188 | /* Save access registers to new thread structure. */ | |
189 | save_access_regs(&p->thread.acrs[0]); | |
190 | ||
347a8dc3 | 191 | #ifndef CONFIG_64BIT |
cbdc2292 | 192 | /* |
1da177e4 LT |
193 | * save fprs to current->thread.fp_regs to merge them with |
194 | * the emulated registers and then copy the result to the child. | |
195 | */ | |
196 | save_fp_regs(¤t->thread.fp_regs); | |
197 | memcpy(&p->thread.fp_regs, ¤t->thread.fp_regs, | |
198 | sizeof(s390_fp_regs)); | |
1da177e4 LT |
199 | /* Set a new TLS ? */ |
200 | if (clone_flags & CLONE_SETTLS) | |
201 | p->thread.acrs[0] = regs->gprs[6]; | |
347a8dc3 | 202 | #else /* CONFIG_64BIT */ |
1da177e4 LT |
203 | /* Save the fpu registers to new thread structure. */ |
204 | save_fp_regs(&p->thread.fp_regs); | |
1da177e4 LT |
205 | /* Set a new TLS ? */ |
206 | if (clone_flags & CLONE_SETTLS) { | |
207 | if (test_thread_flag(TIF_31BIT)) { | |
208 | p->thread.acrs[0] = (unsigned int) regs->gprs[6]; | |
209 | } else { | |
210 | p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32); | |
211 | p->thread.acrs[1] = (unsigned int) regs->gprs[6]; | |
212 | } | |
213 | } | |
347a8dc3 | 214 | #endif /* CONFIG_64BIT */ |
1da177e4 LT |
215 | /* start new process with ar4 pointing to the correct address space */ |
216 | p->thread.mm_segment = get_fs(); | |
cbdc2292 HC |
217 | /* Don't copy debug registers */ |
218 | memset(&p->thread.per_info, 0, sizeof(p->thread.per_info)); | |
5168ce2c HC |
219 | /* Initialize per thread user and system timer values */ |
220 | ti = task_thread_info(p); | |
221 | ti->user_timer = 0; | |
222 | ti->system_timer = 0; | |
cbdc2292 | 223 | return 0; |
1da177e4 LT |
224 | } |
225 | ||
26689452 | 226 | SYSCALL_DEFINE0(fork) |
1da177e4 | 227 | { |
03ff9a23 MS |
228 | struct pt_regs *regs = task_pt_regs(current); |
229 | return do_fork(SIGCHLD, regs->gprs[15], regs, 0, NULL, NULL); | |
1da177e4 LT |
230 | } |
231 | ||
26689452 | 232 | SYSCALL_DEFINE0(clone) |
1da177e4 | 233 | { |
03ff9a23 MS |
234 | struct pt_regs *regs = task_pt_regs(current); |
235 | unsigned long clone_flags; | |
236 | unsigned long newsp; | |
1da177e4 LT |
237 | int __user *parent_tidptr, *child_tidptr; |
238 | ||
03ff9a23 MS |
239 | clone_flags = regs->gprs[3]; |
240 | newsp = regs->orig_gpr2; | |
241 | parent_tidptr = (int __user *) regs->gprs[4]; | |
242 | child_tidptr = (int __user *) regs->gprs[5]; | |
243 | if (!newsp) | |
244 | newsp = regs->gprs[15]; | |
245 | return do_fork(clone_flags, newsp, regs, 0, | |
1da177e4 LT |
246 | parent_tidptr, child_tidptr); |
247 | } | |
248 | ||
249 | /* | |
250 | * This is trivial, and on the face of it looks like it | |
251 | * could equally well be done in user mode. | |
252 | * | |
253 | * Not so, for quite unobvious reasons - register pressure. | |
254 | * In user mode vfork() cannot have a stack frame, and if | |
255 | * done by calling the "clone()" system call directly, you | |
256 | * do not have enough call-clobbered registers to hold all | |
257 | * the information you need. | |
258 | */ | |
26689452 | 259 | SYSCALL_DEFINE0(vfork) |
1da177e4 | 260 | { |
03ff9a23 | 261 | struct pt_regs *regs = task_pt_regs(current); |
1da177e4 | 262 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, |
03ff9a23 MS |
263 | regs->gprs[15], regs, 0, NULL, NULL); |
264 | } | |
265 | ||
266 | asmlinkage void execve_tail(void) | |
267 | { | |
268 | task_lock(current); | |
269 | current->ptrace &= ~PT_DTRACE; | |
270 | task_unlock(current); | |
271 | current->thread.fp_regs.fpc = 0; | |
272 | if (MACHINE_HAS_IEEE) | |
273 | asm volatile("sfpc %0,%0" : : "d" (0)); | |
1da177e4 LT |
274 | } |
275 | ||
276 | /* | |
277 | * sys_execve() executes a new program. | |
278 | */ | |
26689452 | 279 | SYSCALL_DEFINE0(execve) |
1da177e4 | 280 | { |
03ff9a23 MS |
281 | struct pt_regs *regs = task_pt_regs(current); |
282 | char *filename; | |
283 | unsigned long result; | |
284 | int rc; | |
285 | ||
286 | filename = getname((char __user *) regs->orig_gpr2); | |
287 | if (IS_ERR(filename)) { | |
288 | result = PTR_ERR(filename); | |
289 | goto out; | |
1da177e4 | 290 | } |
03ff9a23 MS |
291 | rc = do_execve(filename, (char __user * __user *) regs->gprs[3], |
292 | (char __user * __user *) regs->gprs[4], regs); | |
293 | if (rc) { | |
294 | result = rc; | |
295 | goto out_putname; | |
296 | } | |
297 | execve_tail(); | |
298 | result = regs->gprs[2]; | |
299 | out_putname: | |
300 | putname(filename); | |
1da177e4 | 301 | out: |
03ff9a23 | 302 | return result; |
1da177e4 LT |
303 | } |
304 | ||
1da177e4 LT |
305 | /* |
306 | * fill in the FPU structure for a core dump. | |
307 | */ | |
308 | int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs) | |
309 | { | |
347a8dc3 | 310 | #ifndef CONFIG_64BIT |
cbdc2292 | 311 | /* |
1da177e4 LT |
312 | * save fprs to current->thread.fp_regs to merge them with |
313 | * the emulated registers and then copy the result to the dump. | |
314 | */ | |
315 | save_fp_regs(¤t->thread.fp_regs); | |
316 | memcpy(fpregs, ¤t->thread.fp_regs, sizeof(s390_fp_regs)); | |
347a8dc3 | 317 | #else /* CONFIG_64BIT */ |
1da177e4 | 318 | save_fp_regs(fpregs); |
347a8dc3 | 319 | #endif /* CONFIG_64BIT */ |
1da177e4 LT |
320 | return 1; |
321 | } | |
1485c5c8 | 322 | EXPORT_SYMBOL(dump_fpu); |
1da177e4 | 323 | |
1da177e4 LT |
324 | unsigned long get_wchan(struct task_struct *p) |
325 | { | |
326 | struct stack_frame *sf, *low, *high; | |
327 | unsigned long return_address; | |
328 | int count; | |
329 | ||
30af7120 | 330 | if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p)) |
1da177e4 | 331 | return 0; |
30af7120 AV |
332 | low = task_stack_page(p); |
333 | high = (struct stack_frame *) task_pt_regs(p); | |
1da177e4 LT |
334 | sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN); |
335 | if (sf <= low || sf > high) | |
336 | return 0; | |
337 | for (count = 0; count < 16; count++) { | |
338 | sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); | |
339 | if (sf <= low || sf > high) | |
340 | return 0; | |
341 | return_address = sf->gprs[8] & PSW_ADDR_INSN; | |
342 | if (!in_sched_functions(return_address)) | |
343 | return return_address; | |
344 | } | |
345 | return 0; | |
346 | } |