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source: trunk/hal/tsar_mips32/core/hal_exception.c @ 435

Last change on this file since 435 was 435, checked in by alain, 6 years ago
Fix a bad bug in scheduler...
File size: 17.0 KB

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1	/*
2	* hal_exception.c - implementation of exception handler for TSAR-MIPS32.
3	*
4	* Author Alain Greiner (2016, 2017)
5	*
6	* Copyright (c) UPMC Sorbonne Universites
7	*
8	* This file is part of ALMOS-MKH.
9	*
10	* ALMOS-MKH is free software; you can redistribute it and/or modify it
11	* under the terms of the GNU General Public License as published by
12	* the Free Software Foundation; version 2.0 of the License.
13	*
14	* ALMOS-MKH is distributed in the hope that it will be useful, but
15	* WITHOUT ANY WARRANTY; without even the implied warranty of
16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17	* General Public License for more details.
18	*
19	* You should have received a copy of the GNU General Public License
20	* along with ALMOS-MKH; if not, write to the Free Software Foundation,
21	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22	*/
23
24	#include <hal_types.h>
25	#include <hal_irqmask.h>
26	#include <hal_special.h>
27	#include <hal_exception.h>
28	#include <thread.h>
29	#include <printk.h>
30	#include <chdev.h>
31	#include <vmm.h>
32	#include <errno.h>
33	#include <scheduler.h>
34	#include <core.h>
35	#include <syscalls.h>
36	#include <remote_spinlock.h>
37	#include <hal_kentry.h>
38
39
40	//////////////////////////////////////////////////////////////////////////////////////////
41	// Extern global variables
42	//////////////////////////////////////////////////////////////////////////////////////////
43
44	extern chdev_directory_t chdev_dir; // allocated in the kernel_init.c file.
45
46	//////////////////////////////////////////////////////////////////////////////////////////
47	// This enum defines the global exception types after analysis by the exception handler.
48	//////////////////////////////////////////////////////////////////////////////////////////
49
50	typedef enum
51	{
52	EXCP_NON_FATAL,
53	EXCP_USER_ERROR,
54	EXCP_KERNEL_PANIC,
55	}
56	exception_handling_type_t;
57
58	//////////////////////////////////////////////////////////////////////////////////////////
59	// This enum defines the mask values for an MMU exception code reported by the mips32.
60	//////////////////////////////////////////////////////////////////////////////////////////
61
62	typedef enum
63	{
64	MMU_WRITE_PT1_UNMAPPED = 0x0001,
65	MMU_WRITE_PT2_UNMAPPED = 0x0002,
66	MMU_WRITE_PRIVILEGE_VIOLATION = 0x0004,
67	MMU_WRITE_ACCESS_VIOLATION = 0x0008,
68	MMU_WRITE_UNDEFINED_XTN = 0x0020,
69	MMU_WRITE_PT1_ILLEGAL_ACCESS = 0x0040,
70	MMU_WRITE_PT2_ILLEGAL_ACCESS = 0x0080,
71	MMU_WRITE_DATA_ILLEGAL_ACCESS = 0x0100,
72
73	MMU_READ_PT1_UNMAPPED = 0x1001,
74	MMU_READ_PT2_UNMAPPED = 0x1002,
75	MMU_READ_PRIVILEGE_VIOLATION = 0x1004,
76	MMU_READ_EXEC_VIOLATION = 0x1010,
77	MMU_READ_UNDEFINED_XTN = 0x1020,
78	MMU_READ_PT1_ILLEGAL_ACCESS = 0x1040,
79	MMU_READ_PT2_ILLEGAL_ACCESS = 0x1080,
80	MMU_READ_DATA_ILLEGAL_ACCESS = 0x1100,
81	}
82	mmu_exception_subtype_t;
83
84	//////////////////////////////////////////////////////////////////////////////////////////
85	// This enum defines the relevant values for XCODE field in mips32 CP0_CR register.
86	//////////////////////////////////////////////////////////////////////////////////////////
87
88	typedef enum
89	{
90	XCODE_ADEL = 0x4, // Illegal address for data load
91	XCODE_ADES = 0x5, // Illegal address for data store
92	XCODE_IBE = 0x6, // Instruction MMU exception (can be NON-FATAL)
93	XCODE_DBE = 0x7, // Data MMU exception (can be NON-FATAL)
94	XCODE_RI = 0xA, // Reserved instruction exception
95	XCODE_CPU = 0xB, // Coprocessor unusable exception (can be NON-FATAl)
96	XCODE_OVR = 0xC, // Arithmetic Overflow exception
97	}
98	xcode_values_t;
99
100	/////////////////////////////////////////////
101	char * hal_mmu_exception_str( uint32_t code )
102	{
103	if ( code == MMU_WRITE_PT1_UNMAPPED ) return "WRITE_PT1_UNMAPPED";
104	else if( code == MMU_WRITE_PT2_UNMAPPED ) return "WRITE_PT2_UNMAPPED";
105	else if( code == MMU_WRITE_PRIVILEGE_VIOLATION ) return "WRITE_PRIVILEGE_VIOLATION";
106	else if( code == MMU_WRITE_ACCESS_VIOLATION ) return "WRITE_ACCESS_VIOLATION";
107	else if( code == MMU_WRITE_UNDEFINED_XTN ) return "WRITE_UNDEFINED_XTN";
108	else if( code == MMU_WRITE_PT1_ILLEGAL_ACCESS ) return "WRITE_PT1_ILLEGAL_ACCESS";
109	else if( code == MMU_WRITE_PT2_ILLEGAL_ACCESS ) return "WRITE_PT2_ILLEGAL_ACCESS";
110	else if( code == MMU_WRITE_DATA_ILLEGAL_ACCESS ) return "WRITE_DATA_ILLEGAL_ACCESS";
111	else if( code == MMU_READ_PT1_UNMAPPED ) return "READ_PT1_UNMAPPED";
112	else if( code == MMU_READ_PT2_UNMAPPED ) return "READ_PT2_UNMAPPED";
113	else if( code == MMU_READ_PRIVILEGE_VIOLATION ) return "READ_PRIVILEGE_VIOLATION";
114	else if( code == MMU_READ_EXEC_VIOLATION ) return "READ_EXEC_VIOLATION";
115	else if( code == MMU_READ_UNDEFINED_XTN ) return "READ_UNDEFINED_XTN";
116	else if( code == MMU_READ_PT1_ILLEGAL_ACCESS ) return "READ_PT1_ILLEGAL_ACCESS";
117	else if( code == MMU_READ_PT2_ILLEGAL_ACCESS ) return "READ_PT2_ILLEGAL_ACCESS";
118	else if( code == MMU_READ_DATA_ILLEGAL_ACCESS ) return "READ_DATA_ILLEGAL_ACCESS";
119	else return "undefined";
120	}
121
122	//////////////////////////////////////////////////////////////////////////////////////////
123	// This function is called when a FPU Coprocessor Unavailable exception has been
124	// detected for the calling thread.
125	// It enables the FPU, It saves the current FPU context in the current owner thread
126	// descriptor if required, and restore the FPU context from the calling thread descriptor.
127	//////////////////////////////////////////////////////////////////////////////////////////
128	// @ this : pointer on faulty thread descriptor.
129	// @ return always EXCP_NON_FATAL
130	//////////////////////////////////////////////////////////////////////////////////////////
131	error_t hal_fpu_exception( thread_t * this )
132	{
133	core_t * core = this->core;
134
135	// enable FPU
136	hal_fpu_enable();
137
138	// save FPU context in current owner thread if required
139	if( core->fpu_owner != NULL )
140	{
141	if( core->fpu_owner != this )
142	{
143	hal_fpu_context_save( XPTR( local_cxy , core->fpu_owner ) );
144	}
145	}
146
147	// attach the FPU to the requesting thread
148	hal_fpu_context_restore( this->fpu_context );
149	core->fpu_owner = this;
150
151	return EXCP_NON_FATAL;
152
153	} // end hal_fpu_exception()
154
155	//////////////////////////////////////////////////////////////////////////////////////////
156	// This function is called when an MMU exception has been detected.
157	// It get the relevant exception arguments from the MMU.
158	// It signal a fatal error in case of illegal access. In case of page unmapped
159	// it checks that the faulty address belongs to a registered vseg. It update the local
160	// vseg list from the reference cluster if required, and signal a fatal user error
161	// in case of illegal virtual address. Finally, it updates the local page table from the
162	// reference cluster.
163	//////////////////////////////////////////////////////////////////////////////////////////
164	// @ this : pointer on faulty thread descriptor.
165	// @ is_ins : IBE if true / DBE if false.
166	// @ return EXCP_NON_FATAL / EXCP_USER_ERROR / EXCP_KERNEL_PANIC
167	//////////////////////////////////////////////////////////////////////////////////////////
168	error_t hal_mmu_exception( thread_t * this,
169	bool_t is_ins )
170	{
171	process_t * process;
172	error_t error;
173
174	uint32_t mmu_ins_excp_code;
175	uint32_t mmu_ins_bad_vaddr;
176	uint32_t mmu_dat_excp_code;
177	uint32_t mmu_dat_bad_vaddr;
178
179	uint32_t bad_vaddr;
180	uint32_t excp_code;
181
182	process = this->process;
183
184	// get relevant values from MMU
185	hal_get_mmu_excp( &mmu_ins_excp_code,
186	&mmu_ins_bad_vaddr,
187	&mmu_dat_excp_code,
188	&mmu_dat_bad_vaddr );
189
190	// get exception code and faulty vaddr, depending on IBE/DBE
191	if( is_ins )
192	{
193	excp_code = mmu_ins_excp_code;
194	bad_vaddr = mmu_ins_bad_vaddr;
195	}
196	else
197	{
198	excp_code = mmu_dat_excp_code;
199	bad_vaddr = mmu_dat_bad_vaddr;
200	}
201
202	#if CONFIG_DEBUG_HAL_EXCEPTIONS
203	uint32_t cycle = (uint32_t)hal_get_cycles();
204	if( CONFIG_DEBUG_HAL_EXCEPTIONS < cycle )
205	printk("\n[DBG] %s : thread %x enter / is_ins %d / %s / vaddr %x / cycle %d\n",
206	__FUNCTION__, this, is_ins, hal_mmu_exception_str(excp_code), bad_vaddr, cycle );
207	#endif
208
209	// analyse exception code
210	switch( excp_code )
211	{
212	case MMU_WRITE_PT1_UNMAPPED: // non fatal
213	case MMU_WRITE_PT2_UNMAPPED:
214	case MMU_READ_PT1_UNMAPPED:
215	case MMU_READ_PT2_UNMAPPED:
216	{
217	// try to map the unmapped PTE
218	error = vmm_handle_page_fault( process,
219	bad_vaddr >> CONFIG_PPM_PAGE_SHIFT ); // vpn
220	if( error )
221	{
222	printk("\n[ERROR] in %s for thread %x : cannot map vaddr = %x\n",
223	__FUNCTION__ , this->trdid , bad_vaddr );
224
225	return EXCP_USER_ERROR;
226	}
227	else // page fault successfull
228	{
229
230	#if CONFIG_DEBUG_HAL_EXCEPTIONS
231	cycle = (uint32_t)hal_get_cycles();
232	if( CONFIG_DEBUG_HAL_EXCEPTIONS < cycle )
233	printk("\n[DBG] %s : thread %x exit / page-fault handled for vaddr = %x\n",
234	__FUNCTION__ , this , bad_vaddr );
235	#endif
236
237	return EXCP_NON_FATAL;
238	}
239	}
240	case MMU_WRITE_PRIVILEGE_VIOLATION: // illegal access user error
241	case MMU_READ_PRIVILEGE_VIOLATION:
242	{
243	printk("\n[ERROR] in %s for thread %x : illegal user access to vaddr = %x\n",
244	__FUNCTION__ , this->trdid , bad_vaddr );
245
246	return EXCP_USER_ERROR;
247	}
248	case MMU_WRITE_ACCESS_VIOLATION: // user error, or Copy-on-Write
249	{
250	// access page table to get GPT_COW flag
251	bool_t cow = hal_gpt_pte_is_cow( &(process->vmm.gpt),
252	bad_vaddr >> CONFIG_PPM_PAGE_SHIFT );
253
254	if( cow ) // Copy-on-Write
255	{
256	// try to allocate and copy the page
257	error = vmm_handle_cow( process,
258	bad_vaddr >> CONFIG_PPM_PAGE_SHIFT );
259	if( error )
260	{
261	printk("\n[ERROR] in %s for thread %x : cannot cow vaddr = %x\n",
262	__FUNCTION__ , this->trdid , bad_vaddr );
263
264	return EXCP_USER_ERROR;
265	}
266	else // Copy on write successfull
267	{
268
269	#if CONFIG_DEBUG_HAL_EXCEPTIONS
270	cycle = (uint32_t)hal_get_cycles();
271	if( CONFIG_DEBUG_HAL_EXCEPTIONS < cycle )
272	printk("\n[DBG] %s : thread %x exit / copy-on-write handled for vaddr = %x\n",
273	__FUNCTION__ , this , bad_vaddr );
274	#endif
275
276	return EXCP_NON_FATAL;
277	}
278	}
279	else // non writable user error
280	{
281	printk("\n[ERROR] in %s for thread %x : non-writable vaddr = %x\n",
282	__FUNCTION__ , this->trdid , bad_vaddr );
283
284	return EXCP_USER_ERROR;
285	}
286	}
287	case MMU_READ_EXEC_VIOLATION: // user error
288	{
289	printk("\n[ERROR] in %s for thread %x : read to non-executable vaddr = %x\n",
290	__FUNCTION__ , this->trdid , bad_vaddr );
291
292	return EXCP_USER_ERROR;
293	}
294	default: // this is a kernel error => panic
295	{
296	assert( false , __FUNCTION__ , "thread %x / excp_code = %x / vaddr = %x\n",
297	this->trdid , excp_code , bad_vaddr );
298
299	return EXCP_KERNEL_PANIC;
300	}
301	}
302	} // end hal_mmu_exception()
303
304	//////////////////////////////////////////////////////////////////////////////////////////
305	// This static function prints on the kernel terminal the saved context (core registers)
306	// and the thread state of a faulty thread.
307	//////////////////////////////////////////////////////////////////////////////////////////
308	// @ this : pointer on faulty thread descriptor.
309	// @ uzone : pointer on register array.
310	// @ error : EXCP_USER_ERROR or EXCP_KERNEL_PANIC
311	//////////////////////////////////////////////////////////////////////////////////////////
312	static void hal_exception_dump( thread_t * this,
313	reg_t * uzone,
314	error_t error )
315	{
316	uint32_t save_sr;
317	core_t * core = this->core;
318	process_t * process = this->process;
319
320	// get pointers on TXT0 chdev
321	xptr_t txt0_xp = chdev_dir.txt_tx[0];
322	cxy_t txt0_cxy = GET_CXY( txt0_xp );
323	chdev_t * txt0_ptr = GET_PTR( txt0_xp );
324
325	// get extended pointer on remote TXT0 chdev lock
326	xptr_t lock_xp = XPTR( txt0_cxy , &txt0_ptr->wait_lock );
327
328	// get TXT0 lock in busy waiting mode
329	remote_spinlock_lock_busy( lock_xp , &save_sr );
330
331	if( error == EXCP_USER_ERROR )
332	{
333	nolock_printk("\n=== USER ERROR / trdid %x / pid %x / core[%x,%d] / cycle %d ===\n",
334	this->trdid, process->pid, local_cxy, core->lid , (uint32_t)hal_get_cycles() );
335	}
336	else
337	{
338	nolock_printk("\n=== KERNEL PANIC / trdid %x / pid %x / core[%x,%d] / cycle %d ===\n",
339	this->trdid, process->pid, local_cxy, core->lid , (uint32_t)hal_get_cycles() );
340	}
341
342	nolock_printk("local locks = %d / remote locks = %d / blocked_vector = %X\n\n",
343	this->local_locks, this->remote_locks, this->blocked );
344
345	nolock_printk("c0_cr %X c0_epc %X c0_sr %X c0_th %X\n",
346	uzone[UZ_CR], uzone[UZ_EPC], uzone[UZ_SR], uzone[UZ_TH] );
347
348	nolock_printk("c2_mode %X c2_ptpr %X\n",
349	uzone[UZ_MODE], uzone[UZ_PTPR] );
350
351	nolock_printk("at_01 %X v0_2 %X v1_3 %X a0_4 %X a1_5 %X\n",
352	uzone[UZ_AT], uzone[UZ_V0], uzone[UZ_V1], uzone[UZ_A0], uzone[UZ_A1] );
353
354	nolock_printk("a2_6 %X a3_7 %X t0_8 %X t1_9 %X t2_10 %X\n",
355	uzone[UZ_A2], uzone[UZ_A3], uzone[UZ_T0], uzone[UZ_T1], uzone[UZ_T2] );
356
357	nolock_printk("t3_11 %X t4_12 %X t5_13 %X t6_14 %X t7_15 %X\n",
358	uzone[UZ_T3], uzone[UZ_T4], uzone[UZ_T5], uzone[UZ_T6], uzone[UZ_T7] );
359
360	nolock_printk("s0_16 %X s1_17 %X s2_18 %X s3_19 %X s4_20 %X\n",
361	uzone[UZ_S0], uzone[UZ_S1], uzone[UZ_S2], uzone[UZ_S3], uzone[UZ_S4] );
362
363	nolock_printk("s5_21 %X s6_22 %X s7_23 %X s8_24 %X ra_25 %X\n",
364	uzone[UZ_S5], uzone[UZ_S6], uzone[UZ_S7], uzone[UZ_T8], uzone[UZ_T9] );
365
366	nolock_printk("gp_28 %X sp_29 %X S8_30 %X ra_31 %X\n",
367	uzone[UZ_GP], uzone[UZ_SP], uzone[UZ_S8], uzone[UZ_RA] );
368
369	// release the lock
370	remote_spinlock_unlock_busy( lock_xp , save_sr );
371
372	} // end hal_exception_dump()
373
374	///////////////////////
375	void hal_do_exception()
376	{
377	uint32_t * uzone;
378	thread_t * this;
379	error_t error;
380	uint32_t excCode; // 4 bits XCODE from CP0_CR
381
382	// get pointer on faulty thread uzone
383	this = CURRENT_THREAD;
384	uzone = (uint32_t *)CURRENT_THREAD->uzone_current;
385
386	// get 4 bits XCODE from CP0_CR register
387	excCode = (uzone[UZ_CR] >> 2) & 0xF;
388
389	#if CONFIG_DEBUG_HAL_EXCEPTIONS
390	uint32_t cycle = (uint32_t)hal_get_cycles();
391	if( CONFIG_DEBUG_HAL_EXCEPTIONS < cycle )
392	printk("\n[DBG] %s : thread %x on core[%x,%d] enter / process %x / xcode %x / cycle %d\n",
393	__FUNCTION__, this, local_cxy, this->core->lid, this->process->pid, excCode, cycle );
394	#endif
395
396	switch(excCode)
397	{
398	case XCODE_DBE: // can be non fatal
399	{
400	error = hal_mmu_exception( this , false ); // data MMU exception
401	break;
402	}
403	case XCODE_IBE: // can be non fatal
404	{
405	error = hal_mmu_exception( this , true ); // ins MMU exception
406	break;
407	}
408	case XCODE_CPU: // can be non fatal
409	{
410	if( ((uzone[UZ_CR] >> 28) & 0x3) == 1 ) // unavailable FPU
411	{
412	error = hal_fpu_exception( this );
413	}
414	else
415	{
416	error = EXCP_USER_ERROR;
417	}
418	break;
419	}
420	case XCODE_OVR: // user fatal error
421	case XCODE_RI: // user fatal error
422	case XCODE_ADEL: // user fatal error
423	case XCODE_ADES: // user fatal error
424	{
425	error = EXCP_USER_ERROR;
426	break;
427	}
428	default:
429	{
430	error = EXCP_KERNEL_PANIC;
431	}
432	}
433
434	// analyse error code
435	if( error == EXCP_USER_ERROR ) // user error => kill user process
436	{
437	hal_exception_dump( this , uzone , error );
438
439	sys_kill( this->process->pid , SIGKILL );
440	}
441	else if( error == EXCP_KERNEL_PANIC ) // kernel error => kernel panic
442	{
443	hal_exception_dump( this , uzone , error );
444
445	assert( false , __FUNCTION__ , "thread %x in process %x on core [%x,%d]",
446	this->trdid , this->process->pid , local_cxy , this->core->lid );
447	}
448
449	#if CONFIG_DEBUG_HAL_EXCEPTIONS
450	cycle = (uint32_t)hal_get_cycles();
451	if( CONFIG_DEBUG_HAL_EXCEPTIONS < cycle )
452	printk("\n[DBG] %s : thread %x on core[%x,%d] exit / process %x / xcode %x / cycle %d\n",
453	__FUNCTION__, this, local_cxy, this->core->lid, this->process->pid, excCode, cycle );
454	#endif
455
456	} // end hal_do_exception()
457
458

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