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Commit | Line | Data |
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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> | |
28 | #include <asm/irq.h> | |
29 | #include <asm/timer.h> | |
f5daba1d | 30 | #include <asm/nmi.h> |
da7f51c1 | 31 | #include <asm/smp.h> |
a0616cde | 32 | #include <asm/switch_to.h> |
a806170e | 33 | #include "entry.h" |
1da177e4 | 34 | |
94c12cc7 | 35 | asmlinkage void ret_from_fork(void) asm ("ret_from_fork"); |
1da177e4 LT |
36 | |
37 | /* | |
38 | * Return saved PC of a blocked thread. used in kernel/sched. | |
39 | * resume in entry.S does not create a new stack frame, it | |
40 | * just stores the registers %r6-%r15 to the frame given by | |
41 | * schedule. We want to return the address of the caller of | |
42 | * schedule, so we have to walk the backchain one time to | |
43 | * find the frame schedule() store its return address. | |
44 | */ | |
45 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
46 | { | |
eb33c190 | 47 | struct stack_frame *sf, *low, *high; |
1da177e4 | 48 | |
eb33c190 HC |
49 | if (!tsk || !task_stack_page(tsk)) |
50 | return 0; | |
51 | low = task_stack_page(tsk); | |
52 | high = (struct stack_frame *) task_pt_regs(tsk); | |
53 | sf = (struct stack_frame *) (tsk->thread.ksp & PSW_ADDR_INSN); | |
54 | if (sf <= low || sf > high) | |
55 | return 0; | |
56 | sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); | |
57 | if (sf <= low || sf > high) | |
58 | return 0; | |
1da177e4 LT |
59 | return sf->gprs[8]; |
60 | } | |
61 | ||
1da177e4 LT |
62 | /* |
63 | * The idle loop on a S390... | |
64 | */ | |
cdb04527 | 65 | static void default_idle(void) |
1da177e4 | 66 | { |
da7f51c1 | 67 | if (cpu_is_offline(smp_processor_id())) |
1da177e4 | 68 | cpu_die(); |
6931be08 HC |
69 | local_irq_disable(); |
70 | if (need_resched()) { | |
71 | local_irq_enable(); | |
72 | return; | |
73 | } | |
77fa2245 HC |
74 | local_mcck_disable(); |
75 | if (test_thread_flag(TIF_MCCK_PENDING)) { | |
76 | local_mcck_enable(); | |
77 | local_irq_enable(); | |
77fa2245 HC |
78 | return; |
79 | } | |
4c1051e3 | 80 | /* Halt the cpu and keep track of cpu time accounting. */ |
9cfb9b3c | 81 | vtime_stop_cpu(); |
1da177e4 LT |
82 | } |
83 | ||
84 | void cpu_idle(void) | |
85 | { | |
5bfb5d69 | 86 | for (;;) { |
1268fbc7 FW |
87 | tick_nohz_idle_enter(); |
88 | rcu_idle_enter(); | |
f3612304 | 89 | while (!need_resched() && !test_thread_flag(TIF_MCCK_PENDING)) |
5bfb5d69 | 90 | default_idle(); |
1268fbc7 FW |
91 | rcu_idle_exit(); |
92 | tick_nohz_idle_exit(); | |
f3612304 HC |
93 | if (test_thread_flag(TIF_MCCK_PENDING)) |
94 | s390_handle_mcck(); | |
bd2f5536 | 95 | schedule_preempt_disabled(); |
5bfb5d69 | 96 | } |
1da177e4 LT |
97 | } |
98 | ||
860dba45 | 99 | extern void __kprobes kernel_thread_starter(void); |
1da177e4 | 100 | |
94c12cc7 | 101 | asm( |
860dba45 MS |
102 | ".section .kprobes.text, \"ax\"\n" |
103 | ".global kernel_thread_starter\n" | |
1da177e4 LT |
104 | "kernel_thread_starter:\n" |
105 | " la 2,0(10)\n" | |
106 | " basr 14,9\n" | |
107 | " la 2,0\n" | |
860dba45 MS |
108 | " br 11\n" |
109 | ".previous\n"); | |
1da177e4 LT |
110 | |
111 | int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
112 | { | |
113 | struct pt_regs regs; | |
114 | ||
115 | memset(®s, 0, sizeof(regs)); | |
b50511e4 MS |
116 | regs.psw.mask = psw_kernel_bits | |
117 | PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK; | |
1da177e4 LT |
118 | regs.psw.addr = (unsigned long) kernel_thread_starter | PSW_ADDR_AMODE; |
119 | regs.gprs[9] = (unsigned long) fn; | |
120 | regs.gprs[10] = (unsigned long) arg; | |
121 | regs.gprs[11] = (unsigned long) do_exit; | |
122 | regs.orig_gpr2 = -1; | |
123 | ||
124 | /* Ok, create the new process.. */ | |
125 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, | |
126 | 0, ®s, 0, NULL, NULL); | |
127 | } | |
1485c5c8 | 128 | EXPORT_SYMBOL(kernel_thread); |
1da177e4 LT |
129 | |
130 | /* | |
131 | * Free current thread data structures etc.. | |
132 | */ | |
133 | void exit_thread(void) | |
134 | { | |
135 | } | |
136 | ||
137 | void flush_thread(void) | |
138 | { | |
1da177e4 LT |
139 | } |
140 | ||
141 | void release_thread(struct task_struct *dead_task) | |
142 | { | |
143 | } | |
144 | ||
6f2c55b8 | 145 | int copy_thread(unsigned long clone_flags, unsigned long new_stackp, |
cbdc2292 HC |
146 | unsigned long unused, |
147 | struct task_struct *p, struct pt_regs *regs) | |
1da177e4 | 148 | { |
5168ce2c | 149 | struct thread_info *ti; |
cbdc2292 HC |
150 | struct fake_frame |
151 | { | |
152 | struct stack_frame sf; | |
153 | struct pt_regs childregs; | |
154 | } *frame; | |
155 | ||
156 | frame = container_of(task_pt_regs(p), struct fake_frame, childregs); | |
157 | p->thread.ksp = (unsigned long) frame; | |
1da177e4 | 158 | /* Store access registers to kernel stack of new process. */ |
cbdc2292 | 159 | frame->childregs = *regs; |
1da177e4 | 160 | frame->childregs.gprs[2] = 0; /* child returns 0 on fork. */ |
cbdc2292 HC |
161 | frame->childregs.gprs[15] = new_stackp; |
162 | frame->sf.back_chain = 0; | |
1da177e4 | 163 | |
cbdc2292 HC |
164 | /* new return point is ret_from_fork */ |
165 | frame->sf.gprs[8] = (unsigned long) ret_from_fork; | |
1da177e4 | 166 | |
cbdc2292 HC |
167 | /* fake return stack for resume(), don't go back to schedule */ |
168 | frame->sf.gprs[9] = (unsigned long) frame; | |
1da177e4 LT |
169 | |
170 | /* Save access registers to new thread structure. */ | |
171 | save_access_regs(&p->thread.acrs[0]); | |
172 | ||
347a8dc3 | 173 | #ifndef CONFIG_64BIT |
cbdc2292 | 174 | /* |
1da177e4 LT |
175 | * save fprs to current->thread.fp_regs to merge them with |
176 | * the emulated registers and then copy the result to the child. | |
177 | */ | |
178 | save_fp_regs(¤t->thread.fp_regs); | |
179 | memcpy(&p->thread.fp_regs, ¤t->thread.fp_regs, | |
180 | sizeof(s390_fp_regs)); | |
1da177e4 LT |
181 | /* Set a new TLS ? */ |
182 | if (clone_flags & CLONE_SETTLS) | |
183 | p->thread.acrs[0] = regs->gprs[6]; | |
347a8dc3 | 184 | #else /* CONFIG_64BIT */ |
1da177e4 LT |
185 | /* Save the fpu registers to new thread structure. */ |
186 | save_fp_regs(&p->thread.fp_regs); | |
1da177e4 LT |
187 | /* Set a new TLS ? */ |
188 | if (clone_flags & CLONE_SETTLS) { | |
7757591a | 189 | if (is_compat_task()) { |
1da177e4 LT |
190 | p->thread.acrs[0] = (unsigned int) regs->gprs[6]; |
191 | } else { | |
192 | p->thread.acrs[0] = (unsigned int)(regs->gprs[6] >> 32); | |
193 | p->thread.acrs[1] = (unsigned int) regs->gprs[6]; | |
194 | } | |
195 | } | |
347a8dc3 | 196 | #endif /* CONFIG_64BIT */ |
1da177e4 LT |
197 | /* start new process with ar4 pointing to the correct address space */ |
198 | p->thread.mm_segment = get_fs(); | |
cbdc2292 | 199 | /* Don't copy debug registers */ |
5e9a2692 MS |
200 | memset(&p->thread.per_user, 0, sizeof(p->thread.per_user)); |
201 | memset(&p->thread.per_event, 0, sizeof(p->thread.per_event)); | |
f8d5faf7 | 202 | clear_tsk_thread_flag(p, TIF_SINGLE_STEP); |
5e9a2692 | 203 | clear_tsk_thread_flag(p, TIF_PER_TRAP); |
5168ce2c HC |
204 | /* Initialize per thread user and system timer values */ |
205 | ti = task_thread_info(p); | |
206 | ti->user_timer = 0; | |
207 | ti->system_timer = 0; | |
cbdc2292 | 208 | return 0; |
1da177e4 LT |
209 | } |
210 | ||
26689452 | 211 | SYSCALL_DEFINE0(fork) |
1da177e4 | 212 | { |
03ff9a23 MS |
213 | struct pt_regs *regs = task_pt_regs(current); |
214 | return do_fork(SIGCHLD, regs->gprs[15], regs, 0, NULL, NULL); | |
1da177e4 LT |
215 | } |
216 | ||
2d70ca23 HC |
217 | SYSCALL_DEFINE4(clone, unsigned long, newsp, unsigned long, clone_flags, |
218 | int __user *, parent_tidptr, int __user *, child_tidptr) | |
1da177e4 | 219 | { |
03ff9a23 | 220 | struct pt_regs *regs = task_pt_regs(current); |
1da177e4 | 221 | |
03ff9a23 MS |
222 | if (!newsp) |
223 | newsp = regs->gprs[15]; | |
224 | return do_fork(clone_flags, newsp, regs, 0, | |
1da177e4 LT |
225 | parent_tidptr, child_tidptr); |
226 | } | |
227 | ||
228 | /* | |
229 | * This is trivial, and on the face of it looks like it | |
230 | * could equally well be done in user mode. | |
231 | * | |
232 | * Not so, for quite unobvious reasons - register pressure. | |
233 | * In user mode vfork() cannot have a stack frame, and if | |
234 | * done by calling the "clone()" system call directly, you | |
235 | * do not have enough call-clobbered registers to hold all | |
236 | * the information you need. | |
237 | */ | |
26689452 | 238 | SYSCALL_DEFINE0(vfork) |
1da177e4 | 239 | { |
03ff9a23 | 240 | struct pt_regs *regs = task_pt_regs(current); |
1da177e4 | 241 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, |
03ff9a23 MS |
242 | regs->gprs[15], regs, 0, NULL, NULL); |
243 | } | |
244 | ||
245 | asmlinkage void execve_tail(void) | |
246 | { | |
03ff9a23 MS |
247 | current->thread.fp_regs.fpc = 0; |
248 | if (MACHINE_HAS_IEEE) | |
249 | asm volatile("sfpc %0,%0" : : "d" (0)); | |
1da177e4 LT |
250 | } |
251 | ||
252 | /* | |
253 | * sys_execve() executes a new program. | |
254 | */ | |
d7627467 DH |
255 | SYSCALL_DEFINE3(execve, const char __user *, name, |
256 | const char __user *const __user *, argv, | |
257 | const char __user *const __user *, envp) | |
1da177e4 | 258 | { |
03ff9a23 MS |
259 | struct pt_regs *regs = task_pt_regs(current); |
260 | char *filename; | |
3e86a8c6 | 261 | long rc; |
03ff9a23 | 262 | |
3e86a8c6 HC |
263 | filename = getname(name); |
264 | rc = PTR_ERR(filename); | |
265 | if (IS_ERR(filename)) | |
266 | return rc; | |
267 | rc = do_execve(filename, argv, envp, regs); | |
268 | if (rc) | |
03ff9a23 | 269 | goto out; |
03ff9a23 | 270 | execve_tail(); |
3e86a8c6 | 271 | rc = regs->gprs[2]; |
1da177e4 | 272 | out: |
3e86a8c6 HC |
273 | putname(filename); |
274 | return rc; | |
1da177e4 LT |
275 | } |
276 | ||
1da177e4 LT |
277 | /* |
278 | * fill in the FPU structure for a core dump. | |
279 | */ | |
280 | int dump_fpu (struct pt_regs * regs, s390_fp_regs *fpregs) | |
281 | { | |
347a8dc3 | 282 | #ifndef CONFIG_64BIT |
cbdc2292 | 283 | /* |
1da177e4 LT |
284 | * save fprs to current->thread.fp_regs to merge them with |
285 | * the emulated registers and then copy the result to the dump. | |
286 | */ | |
287 | save_fp_regs(¤t->thread.fp_regs); | |
288 | memcpy(fpregs, ¤t->thread.fp_regs, sizeof(s390_fp_regs)); | |
347a8dc3 | 289 | #else /* CONFIG_64BIT */ |
1da177e4 | 290 | save_fp_regs(fpregs); |
347a8dc3 | 291 | #endif /* CONFIG_64BIT */ |
1da177e4 LT |
292 | return 1; |
293 | } | |
1485c5c8 | 294 | EXPORT_SYMBOL(dump_fpu); |
1da177e4 | 295 | |
1da177e4 LT |
296 | unsigned long get_wchan(struct task_struct *p) |
297 | { | |
298 | struct stack_frame *sf, *low, *high; | |
299 | unsigned long return_address; | |
300 | int count; | |
301 | ||
30af7120 | 302 | if (!p || p == current || p->state == TASK_RUNNING || !task_stack_page(p)) |
1da177e4 | 303 | return 0; |
30af7120 AV |
304 | low = task_stack_page(p); |
305 | high = (struct stack_frame *) task_pt_regs(p); | |
1da177e4 LT |
306 | sf = (struct stack_frame *) (p->thread.ksp & PSW_ADDR_INSN); |
307 | if (sf <= low || sf > high) | |
308 | return 0; | |
309 | for (count = 0; count < 16; count++) { | |
310 | sf = (struct stack_frame *) (sf->back_chain & PSW_ADDR_INSN); | |
311 | if (sf <= low || sf > high) | |
312 | return 0; | |
313 | return_address = sf->gprs[8] & PSW_ADDR_INSN; | |
314 | if (!in_sched_functions(return_address)) | |
315 | return return_address; | |
316 | } | |
317 | return 0; | |
318 | } | |
9887a1fc HC |
319 | |
320 | unsigned long arch_align_stack(unsigned long sp) | |
321 | { | |
322 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) | |
323 | sp -= get_random_int() & ~PAGE_MASK; | |
324 | return sp & ~0xf; | |
325 | } | |
33519182 HC |
326 | |
327 | static inline unsigned long brk_rnd(void) | |
328 | { | |
329 | /* 8MB for 32bit, 1GB for 64bit */ | |
330 | if (is_32bit_task()) | |
331 | return (get_random_int() & 0x7ffUL) << PAGE_SHIFT; | |
332 | else | |
333 | return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT; | |
334 | } | |
335 | ||
336 | unsigned long arch_randomize_brk(struct mm_struct *mm) | |
337 | { | |
338 | unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd()); | |
339 | ||
340 | if (ret < mm->brk) | |
341 | return mm->brk; | |
342 | return ret; | |
343 | } | |
d2c9dfcc HC |
344 | |
345 | unsigned long randomize_et_dyn(unsigned long base) | |
346 | { | |
347 | unsigned long ret = PAGE_ALIGN(base + brk_rnd()); | |
348 | ||
349 | if (!(current->flags & PF_RANDOMIZE)) | |
350 | return base; | |
351 | if (ret < base) | |
352 | return base; | |
353 | return ret; | |
354 | } |