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arch/tile: fix formatting bug in register dumps
[net-next-2.6.git] / arch / tile / kernel / process.c
CommitLineData
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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>
0707ad30 27#include <linux/kernel.h>
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28#include <asm/system.h>
29#include <asm/stack.h>
30#include <asm/homecache.h>
0707ad30
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31#include <asm/syscalls.h>
32#ifdef CONFIG_HARDWALL
33#include <asm/hardwall.h>
34#endif
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35#include <arch/chip.h>
36#include <arch/abi.h>
37
38
39/*
40 * Use the (x86) "idle=poll" option to prefer low latency when leaving the
41 * idle loop over low power while in the idle loop, e.g. if we have
42 * one thread per core and we want to get threads out of futex waits fast.
43 */
44static int no_idle_nap;
45static int __init idle_setup(char *str)
46{
47 if (!str)
48 return -EINVAL;
49
50 if (!strcmp(str, "poll")) {
0707ad30 51 pr_info("using polling idle threads.\n");
867e359b
CM
52 no_idle_nap = 1;
53 } else if (!strcmp(str, "halt"))
54 no_idle_nap = 0;
55 else
56 return -1;
57
58 return 0;
59}
60early_param("idle", idle_setup);
61
62/*
63 * The idle thread. There's no useful work to be
64 * done, so just try to conserve power and have a
65 * low exit latency (ie sit in a loop waiting for
66 * somebody to say that they'd like to reschedule)
67 */
68void cpu_idle(void)
69{
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70 int cpu = smp_processor_id();
71
72
73 current_thread_info()->status |= TS_POLLING;
74
75 if (no_idle_nap) {
76 while (1) {
77 while (!need_resched())
78 cpu_relax();
79 schedule();
80 }
81 }
82
83 /* endless idle loop with no priority at all */
84 while (1) {
85 tick_nohz_stop_sched_tick(1);
86 while (!need_resched()) {
87 if (cpu_is_offline(cpu))
88 BUG(); /* no HOTPLUG_CPU */
89
90 local_irq_disable();
91 __get_cpu_var(irq_stat).idle_timestamp = jiffies;
92 current_thread_info()->status &= ~TS_POLLING;
93 /*
94 * TS_POLLING-cleared state must be visible before we
95 * test NEED_RESCHED:
96 */
97 smp_mb();
98
99 if (!need_resched())
100 _cpu_idle();
101 else
102 local_irq_enable();
103 current_thread_info()->status |= TS_POLLING;
104 }
105 tick_nohz_restart_sched_tick();
106 preempt_enable_no_resched();
107 schedule();
108 preempt_disable();
109 }
110}
111
112struct thread_info *alloc_thread_info(struct task_struct *task)
113{
114 struct page *page;
0707ad30 115 gfp_t flags = GFP_KERNEL;
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116
117#ifdef CONFIG_DEBUG_STACK_USAGE
118 flags |= __GFP_ZERO;
119#endif
120
121 page = alloc_pages(flags, THREAD_SIZE_ORDER);
122 if (!page)
0707ad30 123 return NULL;
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124
125 return (struct thread_info *)page_address(page);
126}
127
128/*
129 * Free a thread_info node, and all of its derivative
130 * data structures.
131 */
132void free_thread_info(struct thread_info *info)
133{
134 struct single_step_state *step_state = info->step_state;
135
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136#ifdef CONFIG_HARDWALL
137 /*
138 * We free a thread_info from the context of the task that has
139 * been scheduled next, so the original task is already dead.
140 * Calling deactivate here just frees up the data structures.
141 * If the task we're freeing held the last reference to a
142 * hardwall fd, it would have been released prior to this point
143 * anyway via exit_files(), and "hardwall" would be NULL by now.
144 */
145 if (info->task->thread.hardwall)
146 hardwall_deactivate(info->task);
147#endif
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148
149 if (step_state) {
150
151 /*
152 * FIXME: we don't munmap step_state->buffer
153 * because the mm_struct for this process (info->task->mm)
154 * has already been zeroed in exit_mm(). Keeping a
155 * reference to it here seems like a bad move, so this
156 * means we can't munmap() the buffer, and therefore if we
157 * ptrace multiple threads in a process, we will slowly
158 * leak user memory. (Note that as soon as the last
159 * thread in a process dies, we will reclaim all user
160 * memory including single-step buffers in the usual way.)
161 * We should either assign a kernel VA to this buffer
162 * somehow, or we should associate the buffer(s) with the
163 * mm itself so we can clean them up that way.
164 */
165 kfree(step_state);
166 }
167
168 free_page((unsigned long)info);
169}
170
171static void save_arch_state(struct thread_struct *t);
172
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173int copy_thread(unsigned long clone_flags, unsigned long sp,
174 unsigned long stack_size,
175 struct task_struct *p, struct pt_regs *regs)
176{
177 struct pt_regs *childregs;
178 unsigned long ksp;
179
180 /*
181 * When creating a new kernel thread we pass sp as zero.
182 * Assign it to a reasonable value now that we have the stack.
183 */
184 if (sp == 0 && regs->ex1 == PL_ICS_EX1(KERNEL_PL, 0))
185 sp = KSTK_TOP(p);
186
187 /*
188 * Do not clone step state from the parent; each thread
189 * must make its own lazily.
190 */
191 task_thread_info(p)->step_state = NULL;
192
193 /*
194 * Start new thread in ret_from_fork so it schedules properly
195 * and then return from interrupt like the parent.
196 */
197 p->thread.pc = (unsigned long) ret_from_fork;
198
199 /* Save user stack top pointer so we can ID the stack vm area later. */
200 p->thread.usp0 = sp;
201
202 /* Record the pid of the process that created this one. */
203 p->thread.creator_pid = current->pid;
204
205 /*
206 * Copy the registers onto the kernel stack so the
207 * return-from-interrupt code will reload it into registers.
208 */
209 childregs = task_pt_regs(p);
210 *childregs = *regs;
211 childregs->regs[0] = 0; /* return value is zero */
212 childregs->sp = sp; /* override with new user stack pointer */
213
214 /*
215 * Copy the callee-saved registers from the passed pt_regs struct
216 * into the context-switch callee-saved registers area.
217 * We have to restore the callee-saved registers since we may
218 * be cloning a userspace task with userspace register state,
219 * and we won't be unwinding the same kernel frames to restore them.
220 * Zero out the C ABI save area to mark the top of the stack.
221 */
222 ksp = (unsigned long) childregs;
223 ksp -= C_ABI_SAVE_AREA_SIZE; /* interrupt-entry save area */
224 ((long *)ksp)[0] = ((long *)ksp)[1] = 0;
225 ksp -= CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long);
226 memcpy((void *)ksp, &regs->regs[CALLEE_SAVED_FIRST_REG],
227 CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long));
228 ksp -= C_ABI_SAVE_AREA_SIZE; /* __switch_to() save area */
229 ((long *)ksp)[0] = ((long *)ksp)[1] = 0;
230 p->thread.ksp = ksp;
231
232#if CHIP_HAS_TILE_DMA()
233 /*
234 * No DMA in the new thread. We model this on the fact that
235 * fork() clears the pending signals, alarms, and aio for the child.
236 */
237 memset(&p->thread.tile_dma_state, 0, sizeof(struct tile_dma_state));
238 memset(&p->thread.dma_async_tlb, 0, sizeof(struct async_tlb));
239#endif
240
241#if CHIP_HAS_SN_PROC()
242 /* Likewise, the new thread is not running static processor code. */
243 p->thread.sn_proc_running = 0;
244 memset(&p->thread.sn_async_tlb, 0, sizeof(struct async_tlb));
245#endif
246
247#if CHIP_HAS_PROC_STATUS_SPR()
248 /* New thread has its miscellaneous processor state bits clear. */
249 p->thread.proc_status = 0;
250#endif
251
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252#ifdef CONFIG_HARDWALL
253 /* New thread does not own any networks. */
254 p->thread.hardwall = NULL;
255#endif
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256
257
258 /*
259 * Start the new thread with the current architecture state
260 * (user interrupt masks, etc.).
261 */
262 save_arch_state(&p->thread);
263
264 return 0;
265}
266
267/*
268 * Return "current" if it looks plausible, or else a pointer to a dummy.
269 * This can be helpful if we are just trying to emit a clean panic.
270 */
271struct task_struct *validate_current(void)
272{
273 static struct task_struct corrupt = { .comm = "<corrupt>" };
274 struct task_struct *tsk = current;
275 if (unlikely((unsigned long)tsk < PAGE_OFFSET ||
276 (void *)tsk > high_memory ||
277 ((unsigned long)tsk & (__alignof__(*tsk) - 1)) != 0)) {
0707ad30 278 pr_err("Corrupt 'current' %p (sp %#lx)\n", tsk, stack_pointer);
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279 tsk = &corrupt;
280 }
281 return tsk;
282}
283
284/* Take and return the pointer to the previous task, for schedule_tail(). */
285struct task_struct *sim_notify_fork(struct task_struct *prev)
286{
287 struct task_struct *tsk = current;
288 __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK_PARENT |
289 (tsk->thread.creator_pid << _SIM_CONTROL_OPERATOR_BITS));
290 __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_OS_FORK |
291 (tsk->pid << _SIM_CONTROL_OPERATOR_BITS));
292 return prev;
293}
294
295int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
296{
297 struct pt_regs *ptregs = task_pt_regs(tsk);
298 elf_core_copy_regs(regs, ptregs);
299 return 1;
300}
301
302#if CHIP_HAS_TILE_DMA()
303
304/* Allow user processes to access the DMA SPRs */
305void grant_dma_mpls(void)
306{
307 __insn_mtspr(SPR_MPL_DMA_CPL_SET_0, 1);
308 __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_0, 1);
309}
310
311/* Forbid user processes from accessing the DMA SPRs */
312void restrict_dma_mpls(void)
313{
314 __insn_mtspr(SPR_MPL_DMA_CPL_SET_1, 1);
315 __insn_mtspr(SPR_MPL_DMA_NOTIFY_SET_1, 1);
316}
317
318/* Pause the DMA engine, then save off its state registers. */
319static void save_tile_dma_state(struct tile_dma_state *dma)
320{
321 unsigned long state = __insn_mfspr(SPR_DMA_USER_STATUS);
322 unsigned long post_suspend_state;
323
324 /* If we're running, suspend the engine. */
325 if ((state & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK)
326 __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__SUSPEND_MASK);
327
328 /*
329 * Wait for the engine to idle, then save regs. Note that we
330 * want to record the "running" bit from before suspension,
331 * and the "done" bit from after, so that we can properly
332 * distinguish a case where the user suspended the engine from
333 * the case where the kernel suspended as part of the context
334 * swap.
335 */
336 do {
337 post_suspend_state = __insn_mfspr(SPR_DMA_USER_STATUS);
338 } while (post_suspend_state & SPR_DMA_STATUS__BUSY_MASK);
339
340 dma->src = __insn_mfspr(SPR_DMA_SRC_ADDR);
341 dma->src_chunk = __insn_mfspr(SPR_DMA_SRC_CHUNK_ADDR);
342 dma->dest = __insn_mfspr(SPR_DMA_DST_ADDR);
343 dma->dest_chunk = __insn_mfspr(SPR_DMA_DST_CHUNK_ADDR);
344 dma->strides = __insn_mfspr(SPR_DMA_STRIDE);
345 dma->chunk_size = __insn_mfspr(SPR_DMA_CHUNK_SIZE);
346 dma->byte = __insn_mfspr(SPR_DMA_BYTE);
347 dma->status = (state & SPR_DMA_STATUS__RUNNING_MASK) |
348 (post_suspend_state & SPR_DMA_STATUS__DONE_MASK);
349}
350
351/* Restart a DMA that was running before we were context-switched out. */
352static void restore_tile_dma_state(struct thread_struct *t)
353{
354 const struct tile_dma_state *dma = &t->tile_dma_state;
355
356 /*
357 * The only way to restore the done bit is to run a zero
358 * length transaction.
359 */
360 if ((dma->status & SPR_DMA_STATUS__DONE_MASK) &&
361 !(__insn_mfspr(SPR_DMA_USER_STATUS) & SPR_DMA_STATUS__DONE_MASK)) {
362 __insn_mtspr(SPR_DMA_BYTE, 0);
363 __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK);
364 while (__insn_mfspr(SPR_DMA_USER_STATUS) &
365 SPR_DMA_STATUS__BUSY_MASK)
366 ;
367 }
368
369 __insn_mtspr(SPR_DMA_SRC_ADDR, dma->src);
370 __insn_mtspr(SPR_DMA_SRC_CHUNK_ADDR, dma->src_chunk);
371 __insn_mtspr(SPR_DMA_DST_ADDR, dma->dest);
372 __insn_mtspr(SPR_DMA_DST_CHUNK_ADDR, dma->dest_chunk);
373 __insn_mtspr(SPR_DMA_STRIDE, dma->strides);
374 __insn_mtspr(SPR_DMA_CHUNK_SIZE, dma->chunk_size);
375 __insn_mtspr(SPR_DMA_BYTE, dma->byte);
376
377 /*
378 * Restart the engine if we were running and not done.
379 * Clear a pending async DMA fault that we were waiting on return
380 * to user space to execute, since we expect the DMA engine
381 * to regenerate those faults for us now. Note that we don't
382 * try to clear the TIF_ASYNC_TLB flag, since it's relatively
383 * harmless if set, and it covers both DMA and the SN processor.
384 */
385 if ((dma->status & DMA_STATUS_MASK) == SPR_DMA_STATUS__RUNNING_MASK) {
386 t->dma_async_tlb.fault_num = 0;
387 __insn_mtspr(SPR_DMA_CTR, SPR_DMA_CTR__REQUEST_MASK);
388 }
389}
390
391#endif
392
393static void save_arch_state(struct thread_struct *t)
394{
395#if CHIP_HAS_SPLIT_INTR_MASK()
396 t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0_0) |
397 ((u64)__insn_mfspr(SPR_INTERRUPT_MASK_0_1) << 32);
398#else
399 t->interrupt_mask = __insn_mfspr(SPR_INTERRUPT_MASK_0);
400#endif
401 t->ex_context[0] = __insn_mfspr(SPR_EX_CONTEXT_0_0);
402 t->ex_context[1] = __insn_mfspr(SPR_EX_CONTEXT_0_1);
403 t->system_save[0] = __insn_mfspr(SPR_SYSTEM_SAVE_0_0);
404 t->system_save[1] = __insn_mfspr(SPR_SYSTEM_SAVE_0_1);
405 t->system_save[2] = __insn_mfspr(SPR_SYSTEM_SAVE_0_2);
406 t->system_save[3] = __insn_mfspr(SPR_SYSTEM_SAVE_0_3);
407 t->intctrl_0 = __insn_mfspr(SPR_INTCTRL_0_STATUS);
408#if CHIP_HAS_PROC_STATUS_SPR()
409 t->proc_status = __insn_mfspr(SPR_PROC_STATUS);
410#endif
a802fc68
CM
411#if !CHIP_HAS_FIXED_INTVEC_BASE()
412 t->interrupt_vector_base = __insn_mfspr(SPR_INTERRUPT_VECTOR_BASE_0);
413#endif
414#if CHIP_HAS_TILE_RTF_HWM()
415 t->tile_rtf_hwm = __insn_mfspr(SPR_TILE_RTF_HWM);
416#endif
417#if CHIP_HAS_DSTREAM_PF()
418 t->dstream_pf = __insn_mfspr(SPR_DSTREAM_PF);
419#endif
867e359b
CM
420}
421
422static void restore_arch_state(const struct thread_struct *t)
423{
424#if CHIP_HAS_SPLIT_INTR_MASK()
425 __insn_mtspr(SPR_INTERRUPT_MASK_0_0, (u32) t->interrupt_mask);
426 __insn_mtspr(SPR_INTERRUPT_MASK_0_1, t->interrupt_mask >> 32);
427#else
428 __insn_mtspr(SPR_INTERRUPT_MASK_0, t->interrupt_mask);
429#endif
430 __insn_mtspr(SPR_EX_CONTEXT_0_0, t->ex_context[0]);
431 __insn_mtspr(SPR_EX_CONTEXT_0_1, t->ex_context[1]);
432 __insn_mtspr(SPR_SYSTEM_SAVE_0_0, t->system_save[0]);
433 __insn_mtspr(SPR_SYSTEM_SAVE_0_1, t->system_save[1]);
434 __insn_mtspr(SPR_SYSTEM_SAVE_0_2, t->system_save[2]);
435 __insn_mtspr(SPR_SYSTEM_SAVE_0_3, t->system_save[3]);
436 __insn_mtspr(SPR_INTCTRL_0_STATUS, t->intctrl_0);
437#if CHIP_HAS_PROC_STATUS_SPR()
438 __insn_mtspr(SPR_PROC_STATUS, t->proc_status);
439#endif
a802fc68
CM
440#if !CHIP_HAS_FIXED_INTVEC_BASE()
441 __insn_mtspr(SPR_INTERRUPT_VECTOR_BASE_0, t->interrupt_vector_base);
442#endif
867e359b 443#if CHIP_HAS_TILE_RTF_HWM()
a802fc68
CM
444 __insn_mtspr(SPR_TILE_RTF_HWM, t->tile_rtf_hwm);
445#endif
446#if CHIP_HAS_DSTREAM_PF()
447 __insn_mtspr(SPR_DSTREAM_PF, t->dstream_pf);
867e359b
CM
448#endif
449}
450
451
452void _prepare_arch_switch(struct task_struct *next)
453{
454#if CHIP_HAS_SN_PROC()
455 int snctl;
456#endif
457#if CHIP_HAS_TILE_DMA()
458 struct tile_dma_state *dma = &current->thread.tile_dma_state;
459 if (dma->enabled)
460 save_tile_dma_state(dma);
461#endif
462#if CHIP_HAS_SN_PROC()
463 /*
464 * Suspend the static network processor if it was running.
465 * We do not suspend the fabric itself, just like we don't
466 * try to suspend the UDN.
467 */
468 snctl = __insn_mfspr(SPR_SNCTL);
469 current->thread.sn_proc_running =
470 (snctl & SPR_SNCTL__FRZPROC_MASK) == 0;
471 if (current->thread.sn_proc_running)
472 __insn_mtspr(SPR_SNCTL, snctl | SPR_SNCTL__FRZPROC_MASK);
473#endif
474}
475
476
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477struct task_struct *__sched _switch_to(struct task_struct *prev,
478 struct task_struct *next)
479{
480 /* DMA state is already saved; save off other arch state. */
481 save_arch_state(&prev->thread);
482
483#if CHIP_HAS_TILE_DMA()
484 /*
485 * Restore DMA in new task if desired.
486 * Note that it is only safe to restart here since interrupts
487 * are disabled, so we can't take any DMATLB miss or access
488 * interrupts before we have finished switching stacks.
489 */
490 if (next->thread.tile_dma_state.enabled) {
491 restore_tile_dma_state(&next->thread);
492 grant_dma_mpls();
493 } else {
494 restrict_dma_mpls();
495 }
496#endif
497
498 /* Restore other arch state. */
499 restore_arch_state(&next->thread);
500
501#if CHIP_HAS_SN_PROC()
502 /*
503 * Restart static network processor in the new process
504 * if it was running before.
505 */
506 if (next->thread.sn_proc_running) {
507 int snctl = __insn_mfspr(SPR_SNCTL);
508 __insn_mtspr(SPR_SNCTL, snctl & ~SPR_SNCTL__FRZPROC_MASK);
509 }
510#endif
511
0707ad30
CM
512#ifdef CONFIG_HARDWALL
513 /* Enable or disable access to the network registers appropriately. */
514 if (prev->thread.hardwall != NULL) {
515 if (next->thread.hardwall == NULL)
516 restrict_network_mpls();
517 } else if (next->thread.hardwall != NULL) {
518 grant_network_mpls();
519 }
520#endif
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CM
521
522 /*
523 * Switch kernel SP, PC, and callee-saved registers.
524 * In the context of the new task, return the old task pointer
525 * (i.e. the task that actually called __switch_to).
526 * Pass the value to use for SYSTEM_SAVE_1_0 when we reset our sp.
527 */
528 return __switch_to(prev, next, next_current_ksp0(next));
529}
530
0707ad30 531long _sys_fork(struct pt_regs *regs)
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532{
533 return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
534}
535
0707ad30
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536long _sys_clone(unsigned long clone_flags, unsigned long newsp,
537 void __user *parent_tidptr, void __user *child_tidptr,
538 struct pt_regs *regs)
867e359b
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539{
540 if (!newsp)
541 newsp = regs->sp;
542 return do_fork(clone_flags, newsp, regs, 0,
543 parent_tidptr, child_tidptr);
544}
545
0707ad30 546long _sys_vfork(struct pt_regs *regs)
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CM
547{
548 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp,
549 regs, 0, NULL, NULL);
550}
551
552/*
553 * sys_execve() executes a new program.
554 */
d7627467
DH
555long _sys_execve(const char __user *path,
556 const char __user *const __user *argv,
557 const char __user *const __user *envp, struct pt_regs *regs)
867e359b 558{
0707ad30 559 long error;
867e359b
CM
560 char *filename;
561
562 filename = getname(path);
563 error = PTR_ERR(filename);
564 if (IS_ERR(filename))
565 goto out;
566 error = do_execve(filename, argv, envp, regs);
567 putname(filename);
568out:
569 return error;
570}
571
572#ifdef CONFIG_COMPAT
e6e6c46d
CM
573long _compat_sys_execve(const char __user *path,
574 const compat_uptr_t __user *argv,
575 const compat_uptr_t __user *envp, struct pt_regs *regs)
867e359b 576{
0707ad30 577 long error;
867e359b
CM
578 char *filename;
579
580 filename = getname(path);
581 error = PTR_ERR(filename);
582 if (IS_ERR(filename))
583 goto out;
584 error = compat_do_execve(filename, argv, envp, regs);
585 putname(filename);
586out:
587 return error;
588}
589#endif
590
591unsigned long get_wchan(struct task_struct *p)
592{
593 struct KBacktraceIterator kbt;
594
595 if (!p || p == current || p->state == TASK_RUNNING)
596 return 0;
597
598 for (KBacktraceIterator_init(&kbt, p, NULL);
599 !KBacktraceIterator_end(&kbt);
600 KBacktraceIterator_next(&kbt)) {
601 if (!in_sched_functions(kbt.it.pc))
602 return kbt.it.pc;
603 }
604
605 return 0;
606}
607
608/*
609 * We pass in lr as zero (cleared in kernel_thread) and the caller
610 * part of the backtrace ABI on the stack also zeroed (in copy_thread)
611 * so that backtraces will stop with this function.
612 * Note that we don't use r0, since copy_thread() clears it.
613 */
614static void start_kernel_thread(int dummy, int (*fn)(int), int arg)
615{
616 do_exit(fn(arg));
617}
618
619/*
620 * Create a kernel thread
621 */
622int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
623{
624 struct pt_regs regs;
625
626 memset(&regs, 0, sizeof(regs));
627 regs.ex1 = PL_ICS_EX1(KERNEL_PL, 0); /* run at kernel PL, no ICS */
628 regs.pc = (long) start_kernel_thread;
629 regs.flags = PT_FLAGS_CALLER_SAVES; /* need to restore r1 and r2 */
630 regs.regs[1] = (long) fn; /* function pointer */
631 regs.regs[2] = (long) arg; /* parameter register */
632
633 /* Ok, create the new process.. */
634 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs,
635 0, NULL, NULL);
636}
637EXPORT_SYMBOL(kernel_thread);
638
639/* Flush thread state. */
640void flush_thread(void)
641{
642 /* Nothing */
643}
644
645/*
646 * Free current thread data structures etc..
647 */
648void exit_thread(void)
649{
650 /* Nothing */
651}
652
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653void show_regs(struct pt_regs *regs)
654{
655 struct task_struct *tsk = validate_current();
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656 int i;
657
658 pr_err("\n");
659 pr_err(" Pid: %d, comm: %20s, CPU: %d\n",
867e359b 660 tsk->pid, tsk->comm, smp_processor_id());
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661#ifdef __tilegx__
662 for (i = 0; i < 51; i += 3)
663 pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT" r%-2d: "REGFMT"\n",
664 i, regs->regs[i], i+1, regs->regs[i+1],
665 i+2, regs->regs[i+2]);
666 pr_err(" r51: "REGFMT" r52: "REGFMT" tp : "REGFMT"\n",
667 regs->regs[51], regs->regs[52], regs->tp);
668 pr_err(" sp : "REGFMT" lr : "REGFMT"\n", regs->sp, regs->lr);
669#else
7040dea4 670 for (i = 0; i < 52; i += 4)
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671 pr_err(" r%-2d: "REGFMT" r%-2d: "REGFMT
672 " r%-2d: "REGFMT" r%-2d: "REGFMT"\n",
673 i, regs->regs[i], i+1, regs->regs[i+1],
674 i+2, regs->regs[i+2], i+3, regs->regs[i+3]);
675 pr_err(" r52: "REGFMT" tp : "REGFMT" sp : "REGFMT" lr : "REGFMT"\n",
676 regs->regs[52], regs->tp, regs->sp, regs->lr);
677#endif
678 pr_err(" pc : "REGFMT" ex1: %ld faultnum: %ld\n",
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679 regs->pc, regs->ex1, regs->faultnum);
680
681 dump_stack_regs(regs);
682}