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867e359b CM |
1 | /* |
2 | * Copyright 2010 Tilera Corporation. All Rights Reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation, version 2. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but | |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | |
11 | * NON INFRINGEMENT. See the GNU General Public License for | |
12 | * more details. | |
13 | */ | |
14 | ||
15 | #include <linux/sched.h> | |
16 | #include <linux/preempt.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/fs.h> | |
19 | #include <linux/kprobes.h> | |
20 | #include <linux/elfcore.h> | |
21 | #include <linux/tick.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/mm.h> | |
24 | #include <linux/compat.h> | |
25 | #include <linux/hardirq.h> | |
26 | #include <linux/syscalls.h> | |
27 | #include <asm/system.h> | |
28 | #include <asm/stack.h> | |
29 | #include <asm/homecache.h> | |
30 | #include <arch/chip.h> | |
31 | #include <arch/abi.h> | |
32 | ||
33 | ||
34 | /* | |
35 | * Use the (x86) "idle=poll" option to prefer low latency when leaving the | |
36 | * idle loop over low power while in the idle loop, e.g. if we have | |
37 | * one thread per core and we want to get threads out of futex waits fast. | |
38 | */ | |
39 | static int no_idle_nap; | |
40 | static int __init idle_setup(char *str) | |
41 | { | |
42 | if (!str) | |
43 | return -EINVAL; | |
44 | ||
45 | if (!strcmp(str, "poll")) { | |
46 | printk("using polling idle threads.\n"); | |
47 | no_idle_nap = 1; | |
48 | } else if (!strcmp(str, "halt")) | |
49 | no_idle_nap = 0; | |
50 | else | |
51 | return -1; | |
52 | ||
53 | return 0; | |
54 | } | |
55 | early_param("idle", idle_setup); | |
56 | ||
57 | /* | |
58 | * The idle thread. There's no useful work to be | |
59 | * done, so just try to conserve power and have a | |
60 | * low exit latency (ie sit in a loop waiting for | |
61 | * somebody to say that they'd like to reschedule) | |
62 | */ | |
63 | void cpu_idle(void) | |
64 | { | |
65 | extern void _cpu_idle(void); | |
66 | int cpu = smp_processor_id(); | |
67 | ||
68 | ||
69 | current_thread_info()->status |= TS_POLLING; | |
70 | ||
71 | if (no_idle_nap) { | |
72 | while (1) { | |
73 | while (!need_resched()) | |
74 | cpu_relax(); | |
75 | schedule(); | |
76 | } | |
77 | } | |
78 | ||
79 | /* endless idle loop with no priority at all */ | |
80 | while (1) { | |
81 | tick_nohz_stop_sched_tick(1); | |
82 | while (!need_resched()) { | |
83 | if (cpu_is_offline(cpu)) | |
84 | BUG(); /* no HOTPLUG_CPU */ | |
85 | ||
86 | local_irq_disable(); | |
87 | __get_cpu_var(irq_stat).idle_timestamp = jiffies; | |
88 | current_thread_info()->status &= ~TS_POLLING; | |
89 | /* | |
90 | * TS_POLLING-cleared state must be visible before we | |
91 | * test NEED_RESCHED: | |
92 | */ | |
93 | smp_mb(); | |
94 | ||
95 | if (!need_resched()) | |
96 | _cpu_idle(); | |
97 | else | |
98 | local_irq_enable(); | |
99 | current_thread_info()->status |= TS_POLLING; | |
100 | } | |
101 | tick_nohz_restart_sched_tick(); | |
102 | preempt_enable_no_resched(); | |
103 | schedule(); | |
104 | preempt_disable(); | |
105 | } | |
106 | } | |
107 | ||
108 | struct thread_info *alloc_thread_info(struct task_struct *task) | |
109 | { | |
110 | struct page *page; | |
111 | int flags = GFP_KERNEL; | |
112 | ||
113 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
114 | flags |= __GFP_ZERO; | |
115 | #endif | |
116 | ||
117 | page = alloc_pages(flags, THREAD_SIZE_ORDER); | |
118 | if (!page) | |
119 | return 0; | |
120 | ||
121 | return (struct thread_info *)page_address(page); | |
122 | } | |
123 | ||
124 | /* | |
125 | * Free a thread_info node, and all of its derivative | |
126 | * data structures. | |
127 | */ | |
128 | void free_thread_info(struct thread_info *info) | |
129 | { | |
130 | struct single_step_state *step_state = info->step_state; | |
131 | ||
132 | ||
133 | if (step_state) { | |
134 | ||
135 | /* | |
136 | * FIXME: we don't munmap step_state->buffer | |
137 | * because the mm_struct for this process (info->task->mm) | |
138 | * has already been zeroed in exit_mm(). Keeping a | |
139 | * reference to it here seems like a bad move, so this | |
140 | * means we can't munmap() the buffer, and therefore if we | |
141 | * ptrace multiple threads in a process, we will slowly | |
142 | * leak user memory. (Note that as soon as the last | |
143 | * thread in a process dies, we will reclaim all user | |
144 | * memory including single-step buffers in the usual way.) | |
145 | * We should either assign a kernel VA to this buffer | |
146 | * somehow, or we should associate the buffer(s) with the | |
147 | * mm itself so we can clean them up that way. | |
148 | */ | |
149 | kfree(step_state); | |
150 | } | |
151 | ||
152 | free_page((unsigned long)info); | |
153 | } | |
154 | ||
155 | static void save_arch_state(struct thread_struct *t); | |
156 | ||
157 | extern void ret_from_fork(void); | |
158 | ||
159 | int copy_thread(unsigned long clone_flags, unsigned long sp, | |
160 | unsigned long stack_size, | |
161 | struct task_struct *p, struct pt_regs *regs) | |
162 | { | |
163 | struct pt_regs *childregs; | |
164 | unsigned long ksp; | |
165 | ||
166 | /* | |
167 | * When creating a new kernel thread we pass sp as zero. | |
168 | * Assign it to a reasonable value now that we have the stack. | |
169 | */ | |
170 | if (sp == 0 && regs->ex1 == PL_ICS_EX1(KERNEL_PL, 0)) | |
171 | sp = KSTK_TOP(p); | |
172 | ||
173 | /* | |
174 | * Do not clone step state from the parent; each thread | |
175 | * must make its own lazily. | |
176 | */ | |
177 | task_thread_info(p)->step_state = NULL; | |
178 | ||
179 | /* | |
180 | * Start new thread in ret_from_fork so it schedules properly | |
181 | * and then return from interrupt like the parent. | |
182 | */ | |
183 | p->thread.pc = (unsigned long) ret_from_fork; | |
184 | ||
185 | /* Save user stack top pointer so we can ID the stack vm area later. */ | |
186 | p->thread.usp0 = sp; | |
187 | ||
188 | /* Record the pid of the process that created this one. */ | |
189 | p->thread.creator_pid = current->pid; | |
190 | ||
191 | /* | |
192 | * Copy the registers onto the kernel stack so the | |
193 | * return-from-interrupt code will reload it into registers. | |
194 | */ | |
195 | childregs = task_pt_regs(p); | |
196 | *childregs = *regs; | |
197 | childregs->regs[0] = 0; /* return value is zero */ | |
198 | childregs->sp = sp; /* override with new user stack pointer */ | |
199 | ||
200 | /* | |
201 | * Copy the callee-saved registers from the passed pt_regs struct | |
202 | * into the context-switch callee-saved registers area. | |
203 | * We have to restore the callee-saved registers since we may | |
204 | * be cloning a userspace task with userspace register state, | |
205 | * and we won't be unwinding the same kernel frames to restore them. | |
206 | * Zero out the C ABI save area to mark the top of the stack. | |
207 | */ | |
208 | ksp = (unsigned long) childregs; | |
209 | ksp -= C_ABI_SAVE_AREA_SIZE; /* interrupt-entry save area */ | |
210 | ((long *)ksp)[0] = ((long *)ksp)[1] = 0; | |
211 | ksp -= CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long); | |
212 | memcpy((void *)ksp, ®s->regs[CALLEE_SAVED_FIRST_REG], | |
213 | CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long)); | |
214 | ksp -= C_ABI_SAVE_AREA_SIZE; /* __switch_to() save area */ | |
215 | ((long *)ksp)[0] = ((long *)ksp)[1] = 0; | |
216 | p->thread.ksp = ksp; | |
217 | ||
218 | #if CHIP_HAS_TILE_DMA() | |
219 | /* | |
220 | * No DMA in the new thread. We model this on the fact that | |
221 | * fork() clears the pending signals, alarms, and aio for the child. | |
222 | */ | |
223 | memset(&p->thread.tile_dma_state, 0, sizeof(struct tile_dma_state)); | |
224 | memset(&p->thread.dma_async_tlb, 0, sizeof(struct async_tlb)); | |
225 | #endif | |
226 | ||
227 | #if CHIP_HAS_SN_PROC() | |
228 | /* Likewise, the new thread is not running static processor code. */ | |
229 | p->thread.sn_proc_running = 0; | |
230 | memset(&p->thread.sn_async_tlb, 0, sizeof(struct async_tlb)); | |
231 | #endif | |
232 | ||
233 | #if CHIP_HAS_PROC_STATUS_SPR() | |
234 | /* New thread has its miscellaneous processor state bits clear. */ | |
235 | p->thread.proc_status = 0; | |
236 | #endif | |
237 | ||
238 | ||
239 | ||
240 | /* | |
241 | * Start the new thread with the current architecture state | |
242 | * (user interrupt masks, etc.). | |
243 | */ | |
244 | save_arch_state(&p->thread); | |
245 | ||
246 | return 0; | |
247 | } | |
248 | ||
249 | /* | |
250 | * Return "current" if it looks plausible, or else a pointer to a dummy. | |
251 | * This can be helpful if we are just trying to emit a clean panic. | |
252 | */ | |
253 | struct task_struct *validate_current(void) | |
254 | { | |
255 | static struct task_struct corrupt = { .comm = "<corrupt>" }; | |
256 | struct task_struct *tsk = current; | |
257 | if (unlikely((unsigned long)tsk < PAGE_OFFSET || | |
258 | (void *)tsk > high_memory || | |
259 | ((unsigned long)tsk & (__alignof__(*tsk) - 1)) != 0)) { | |
260 | printk("Corrupt 'current' %p (sp %#lx)\n", tsk, stack_pointer); | |
261 | tsk = &corrupt; | |
262 | } | |
263 | return tsk; | |
264 | } | |
265 | ||
266 | /* Take and return the pointer to the previous task, for schedule_tail(). */ | |
267 | struct task_struct *sim_notify_fork(struct task_struct *prev) | |
268 | { | |
269 | struct task_struct *tsk = current; | |
270 | __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK_PARENT | | |
271 | (tsk->thread.creator_pid << _SIM_CONTROL_OPERATOR_BITS)); | |
272 | __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK | | |
273 | (tsk->pid << _SIM_CONTROL_OPERATOR_BITS)); | |
274 | return prev; | |
275 | } | |
276 | ||
277 | int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) | |
278 | { | |
279 | struct pt_regs *ptregs = task_pt_regs(tsk); | |
280 | elf_core_copy_regs(regs, ptregs); | |
281 | return 1; | |
282 | } | |
283 | ||
284 | #if CHIP_HAS_TILE_DMA() | |
285 | ||
286 | /* Allow user processes to access the DMA SPRs */ | |
287 | void grant_dma_mpls(void) | |
288 | { | |
289 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_0, 1); | |
290 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_0, 1); | |
291 | } | |
292 | ||
293 | /* Forbid user processes from accessing the DMA SPRs */ | |
294 | void restrict_dma_mpls(void) | |
295 | { | |
296 | __insn_mtspr(SPR_MPL_DMA_CPL_SET_1, 1); | |
297 | __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1, 1); | |
298 | } | |
299 | ||
300 | /* Pause the DMA engine, then save off its state registers. */ | |
301 | static void save_tile_dma_state(struct tile_dma_state *dma) | |
302 | { | |
303 | unsigned long state = __insn_mfspr(SPR_DMA_USER_STATUS); | |
304 | unsigned long post_suspend_state; | |
305 | ||
306 | /* If we're running, suspend the engine. */ | |
307 | if ((state & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) | |
308 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__SUSPEND_MASK); | |
309 | ||
310 | /* | |
311 | * Wait for the engine to idle, then save regs. Note that we | |
312 | * want to record the "running" bit from before suspension, | |
313 | * and the "done" bit from after, so that we can properly | |
314 | * distinguish a case where the user suspended the engine from | |
315 | * the case where the kernel suspended as part of the context | |
316 | * swap. | |
317 | */ | |
318 | do { | |
319 | post_suspend_state = __insn_mfspr(SPR_DMA_USER_STATUS); | |
320 | } while (post_suspend_state & SPR_DMA_STATUS__BUSY_MASK); | |
321 | ||
322 | dma->src = __insn_mfspr(SPR_DMA_SRC_ADDR); | |
323 | dma->src_chunk = __insn_mfspr(SPR_DMA_SRC_CHUNK_ADDR); | |
324 | dma->dest = __insn_mfspr(SPR_DMA_DST_ADDR); | |
325 | dma->dest_chunk = __insn_mfspr(SPR_DMA_DST_CHUNK_ADDR); | |
326 | dma->strides = __insn_mfspr(SPR_DMA_STRIDE); | |
327 | dma->chunk_size = __insn_mfspr(SPR_DMA_CHUNK_SIZE); | |
328 | dma->byte = __insn_mfspr(SPR_DMA_BYTE); | |
329 | dma->status = (state & SPR_DMA_STATUS__RUNNING_MASK) | | |
330 | (post_suspend_state & SPR_DMA_STATUS__DONE_MASK); | |
331 | } | |
332 | ||
333 | /* Restart a DMA that was running before we were context-switched out. */ | |
334 | static void restore_tile_dma_state(struct thread_struct *t) | |
335 | { | |
336 | const struct tile_dma_state *dma = &t->tile_dma_state; | |
337 | ||
338 | /* | |
339 | * The only way to restore the done bit is to run a zero | |
340 | * length transaction. | |
341 | */ | |
342 | if ((dma->status & SPR_DMA_STATUS__DONE_MASK) && | |
343 | !(__insn_mfspr(SPR_DMA_USER_STATUS) & SPR_DMA_STATUS__DONE_MASK)) { | |
344 | __insn_mtspr(SPR_DMA_BYTE, 0); | |
345 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK); | |
346 | while (__insn_mfspr(SPR_DMA_USER_STATUS) & | |
347 | SPR_DMA_STATUS__BUSY_MASK) | |
348 | ; | |
349 | } | |
350 | ||
351 | __insn_mtspr(SPR_DMA_SRC_ADDR, dma->src); | |
352 | __insn_mtspr(SPR_DMA_SRC_CHUNK_ADDR, dma->src_chunk); | |
353 | __insn_mtspr(SPR_DMA_DST_ADDR, dma->dest); | |
354 | __insn_mtspr(SPR_DMA_DST_CHUNK_ADDR, dma->dest_chunk); | |
355 | __insn_mtspr(SPR_DMA_STRIDE, dma->strides); | |
356 | __insn_mtspr(SPR_DMA_CHUNK_SIZE, dma->chunk_size); | |
357 | __insn_mtspr(SPR_DMA_BYTE, dma->byte); | |
358 | ||
359 | /* | |
360 | * Restart the engine if we were running and not done. | |
361 | * Clear a pending async DMA fault that we were waiting on return | |
362 | * to user space to execute, since we expect the DMA engine | |
363 | * to regenerate those faults for us now. Note that we don't | |
364 | * try to clear the TIF_ASYNC_TLB flag, since it's relatively | |
365 | * harmless if set, and it covers both DMA and the SN processor. | |
366 | */ | |
367 | if ((dma->status & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) { | |
368 | t->dma_async_tlb.fault_num = 0; | |
369 | __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK); | |
370 | } | |
371 | } | |
372 | ||
373 | #endif | |
374 | ||
375 | static void save_arch_state(struct thread_struct *t) | |
376 | { | |
377 | #if CHIP_HAS_SPLIT_INTR_MASK() | |
378 | t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0_0) | | |
379 | ((u64)__insn_mfspr(SPR_INTERRUPT_MASK_0_1) << 32); | |
380 | #else | |
381 | t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0); | |
382 | #endif | |
383 | t->ex_context[0] = __insn_mfspr(SPR_EX_CONTEXT_0_0); | |
384 | t->ex_context[1] = __insn_mfspr(SPR_EX_CONTEXT_0_1); | |
385 | t->system_save[0] = __insn_mfspr(SPR_SYSTEM_SAVE_0_0); | |
386 | t->system_save[1] = __insn_mfspr(SPR_SYSTEM_SAVE_0_1); | |
387 | t->system_save[2] = __insn_mfspr(SPR_SYSTEM_SAVE_0_2); | |
388 | t->system_save[3] = __insn_mfspr(SPR_SYSTEM_SAVE_0_3); | |
389 | t->intctrl_0 = __insn_mfspr(SPR_INTCTRL_0_STATUS); | |
390 | #if CHIP_HAS_PROC_STATUS_SPR() | |
391 | t->proc_status = __insn_mfspr(SPR_PROC_STATUS); | |
392 | #endif | |
393 | } | |
394 | ||
395 | static void restore_arch_state(const struct thread_struct *t) | |
396 | { | |
397 | #if CHIP_HAS_SPLIT_INTR_MASK() | |
398 | __insn_mtspr(SPR_INTERRUPT_MASK_0_0, (u32) t->interrupt_mask); | |
399 | __insn_mtspr(SPR_INTERRUPT_MASK_0_1, t->interrupt_mask >> 32); | |
400 | #else | |
401 | __insn_mtspr(SPR_INTERRUPT_MASK_0, t->interrupt_mask); | |
402 | #endif | |
403 | __insn_mtspr(SPR_EX_CONTEXT_0_0, t->ex_context[0]); | |
404 | __insn_mtspr(SPR_EX_CONTEXT_0_1, t->ex_context[1]); | |
405 | __insn_mtspr(SPR_SYSTEM_SAVE_0_0, t->system_save[0]); | |
406 | __insn_mtspr(SPR_SYSTEM_SAVE_0_1, t->system_save[1]); | |
407 | __insn_mtspr(SPR_SYSTEM_SAVE_0_2, t->system_save[2]); | |
408 | __insn_mtspr(SPR_SYSTEM_SAVE_0_3, t->system_save[3]); | |
409 | __insn_mtspr(SPR_INTCTRL_0_STATUS, t->intctrl_0); | |
410 | #if CHIP_HAS_PROC_STATUS_SPR() | |
411 | __insn_mtspr(SPR_PROC_STATUS, t->proc_status); | |
412 | #endif | |
413 | #if CHIP_HAS_TILE_RTF_HWM() | |
414 | /* | |
415 | * Clear this whenever we switch back to a process in case | |
416 | * the previous process was monkeying with it. Even if enabled | |
417 | * in CBOX_MSR1 via TILE_RTF_HWM_MIN, it's still just a | |
418 | * performance hint, so isn't worth a full save/restore. | |
419 | */ | |
420 | __insn_mtspr(SPR_TILE_RTF_HWM, 0); | |
421 | #endif | |
422 | } | |
423 | ||
424 | ||
425 | void _prepare_arch_switch(struct task_struct *next) | |
426 | { | |
427 | #if CHIP_HAS_SN_PROC() | |
428 | int snctl; | |
429 | #endif | |
430 | #if CHIP_HAS_TILE_DMA() | |
431 | struct tile_dma_state *dma = ¤t->thread.tile_dma_state; | |
432 | if (dma->enabled) | |
433 | save_tile_dma_state(dma); | |
434 | #endif | |
435 | #if CHIP_HAS_SN_PROC() | |
436 | /* | |
437 | * Suspend the static network processor if it was running. | |
438 | * We do not suspend the fabric itself, just like we don't | |
439 | * try to suspend the UDN. | |
440 | */ | |
441 | snctl = __insn_mfspr(SPR_SNCTL); | |
442 | current->thread.sn_proc_running = | |
443 | (snctl & SPR_SNCTL__FRZPROC_MASK) == 0; | |
444 | if (current->thread.sn_proc_running) | |
445 | __insn_mtspr(SPR_SNCTL, snctl | SPR_SNCTL__FRZPROC_MASK); | |
446 | #endif | |
447 | } | |
448 | ||
449 | ||
450 | extern struct task_struct *__switch_to(struct task_struct *prev, | |
451 | struct task_struct *next, | |
452 | unsigned long new_system_save_1_0); | |
453 | ||
454 | struct task_struct *__sched _switch_to(struct task_struct *prev, | |
455 | struct task_struct *next) | |
456 | { | |
457 | /* DMA state is already saved; save off other arch state. */ | |
458 | save_arch_state(&prev->thread); | |
459 | ||
460 | #if CHIP_HAS_TILE_DMA() | |
461 | /* | |
462 | * Restore DMA in new task if desired. | |
463 | * Note that it is only safe to restart here since interrupts | |
464 | * are disabled, so we can't take any DMATLB miss or access | |
465 | * interrupts before we have finished switching stacks. | |
466 | */ | |
467 | if (next->thread.tile_dma_state.enabled) { | |
468 | restore_tile_dma_state(&next->thread); | |
469 | grant_dma_mpls(); | |
470 | } else { | |
471 | restrict_dma_mpls(); | |
472 | } | |
473 | #endif | |
474 | ||
475 | /* Restore other arch state. */ | |
476 | restore_arch_state(&next->thread); | |
477 | ||
478 | #if CHIP_HAS_SN_PROC() | |
479 | /* | |
480 | * Restart static network processor in the new process | |
481 | * if it was running before. | |
482 | */ | |
483 | if (next->thread.sn_proc_running) { | |
484 | int snctl = __insn_mfspr(SPR_SNCTL); | |
485 | __insn_mtspr(SPR_SNCTL, snctl & ~SPR_SNCTL__FRZPROC_MASK); | |
486 | } | |
487 | #endif | |
488 | ||
489 | ||
490 | /* | |
491 | * Switch kernel SP, PC, and callee-saved registers. | |
492 | * In the context of the new task, return the old task pointer | |
493 | * (i.e. the task that actually called __switch_to). | |
494 | * Pass the value to use for SYSTEM_SAVE_1_0 when we reset our sp. | |
495 | */ | |
496 | return __switch_to(prev, next, next_current_ksp0(next)); | |
497 | } | |
498 | ||
499 | int _sys_fork(struct pt_regs *regs) | |
500 | { | |
501 | return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL); | |
502 | } | |
503 | ||
504 | int _sys_clone(unsigned long clone_flags, unsigned long newsp, | |
505 | int __user *parent_tidptr, int __user *child_tidptr, | |
506 | struct pt_regs *regs) | |
507 | { | |
508 | if (!newsp) | |
509 | newsp = regs->sp; | |
510 | return do_fork(clone_flags, newsp, regs, 0, | |
511 | parent_tidptr, child_tidptr); | |
512 | } | |
513 | ||
514 | int _sys_vfork(struct pt_regs *regs) | |
515 | { | |
516 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, | |
517 | regs, 0, NULL, NULL); | |
518 | } | |
519 | ||
520 | /* | |
521 | * sys_execve() executes a new program. | |
522 | */ | |
523 | int _sys_execve(char __user *path, char __user *__user *argv, | |
524 | char __user *__user *envp, struct pt_regs *regs) | |
525 | { | |
526 | int error; | |
527 | char *filename; | |
528 | ||
529 | filename = getname(path); | |
530 | error = PTR_ERR(filename); | |
531 | if (IS_ERR(filename)) | |
532 | goto out; | |
533 | error = do_execve(filename, argv, envp, regs); | |
534 | putname(filename); | |
535 | out: | |
536 | return error; | |
537 | } | |
538 | ||
539 | #ifdef CONFIG_COMPAT | |
540 | int _compat_sys_execve(char __user *path, compat_uptr_t __user *argv, | |
541 | compat_uptr_t __user *envp, struct pt_regs *regs) | |
542 | { | |
543 | int error; | |
544 | char *filename; | |
545 | ||
546 | filename = getname(path); | |
547 | error = PTR_ERR(filename); | |
548 | if (IS_ERR(filename)) | |
549 | goto out; | |
550 | error = compat_do_execve(filename, argv, envp, regs); | |
551 | putname(filename); | |
552 | out: | |
553 | return error; | |
554 | } | |
555 | #endif | |
556 | ||
557 | unsigned long get_wchan(struct task_struct *p) | |
558 | { | |
559 | struct KBacktraceIterator kbt; | |
560 | ||
561 | if (!p || p == current || p->state == TASK_RUNNING) | |
562 | return 0; | |
563 | ||
564 | for (KBacktraceIterator_init(&kbt, p, NULL); | |
565 | !KBacktraceIterator_end(&kbt); | |
566 | KBacktraceIterator_next(&kbt)) { | |
567 | if (!in_sched_functions(kbt.it.pc)) | |
568 | return kbt.it.pc; | |
569 | } | |
570 | ||
571 | return 0; | |
572 | } | |
573 | ||
574 | /* | |
575 | * We pass in lr as zero (cleared in kernel_thread) and the caller | |
576 | * part of the backtrace ABI on the stack also zeroed (in copy_thread) | |
577 | * so that backtraces will stop with this function. | |
578 | * Note that we don't use r0, since copy_thread() clears it. | |
579 | */ | |
580 | static void start_kernel_thread(int dummy, int (*fn)(int), int arg) | |
581 | { | |
582 | do_exit(fn(arg)); | |
583 | } | |
584 | ||
585 | /* | |
586 | * Create a kernel thread | |
587 | */ | |
588 | int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags) | |
589 | { | |
590 | struct pt_regs regs; | |
591 | ||
592 | memset(®s, 0, sizeof(regs)); | |
593 | regs.ex1 = PL_ICS_EX1(KERNEL_PL, 0); /* run at kernel PL, no ICS */ | |
594 | regs.pc = (long) start_kernel_thread; | |
595 | regs.flags = PT_FLAGS_CALLER_SAVES; /* need to restore r1 and r2 */ | |
596 | regs.regs[1] = (long) fn; /* function pointer */ | |
597 | regs.regs[2] = (long) arg; /* parameter register */ | |
598 | ||
599 | /* Ok, create the new process.. */ | |
600 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, | |
601 | 0, NULL, NULL); | |
602 | } | |
603 | EXPORT_SYMBOL(kernel_thread); | |
604 | ||
605 | /* Flush thread state. */ | |
606 | void flush_thread(void) | |
607 | { | |
608 | /* Nothing */ | |
609 | } | |
610 | ||
611 | /* | |
612 | * Free current thread data structures etc.. | |
613 | */ | |
614 | void exit_thread(void) | |
615 | { | |
616 | /* Nothing */ | |
617 | } | |
618 | ||
619 | #ifdef __tilegx__ | |
620 | # define LINECOUNT 3 | |
621 | # define EXTRA_NL "\n" | |
622 | #else | |
623 | # define LINECOUNT 4 | |
624 | # define EXTRA_NL "" | |
625 | #endif | |
626 | ||
627 | void show_regs(struct pt_regs *regs) | |
628 | { | |
629 | struct task_struct *tsk = validate_current(); | |
630 | int i, linebreak; | |
631 | printk("\n"); | |
632 | printk(" Pid: %d, comm: %20s, CPU: %d\n", | |
633 | tsk->pid, tsk->comm, smp_processor_id()); | |
634 | for (i = linebreak = 0; i < 53; ++i) { | |
635 | printk(" r%-2d: "REGFMT, i, regs->regs[i]); | |
636 | if (++linebreak == LINECOUNT) { | |
637 | linebreak = 0; | |
638 | printk("\n"); | |
639 | } | |
640 | } | |
641 | printk(" tp : "REGFMT EXTRA_NL " sp : "REGFMT" lr : "REGFMT"\n", | |
642 | regs->tp, regs->sp, regs->lr); | |
643 | printk(" pc : "REGFMT" ex1: %ld faultnum: %ld\n", | |
644 | regs->pc, regs->ex1, regs->faultnum); | |
645 | ||
646 | dump_stack_regs(regs); | |
647 | } |