[apple/xnu.git] / libkern / gen / OSDebug.cpp

/*
 * Copyright (c) 2005 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

// NOTE:  This file is only c++ so I can get static initialisers going
#include <libkern/OSDebug.h>

#include <sys/cdefs.h>

#include <stdarg.h>
#include <mach/mach_types.h>
#include <mach/kmod.h>
#include <kern/lock.h>

#include <libkern/libkern.h>	// From bsd's libkern directory
#include <mach/vm_param.h>

#include <sys/kdebug.h>
extern int etext;
__BEGIN_DECLS
// From osmfk/kern/thread.h but considered to be private
extern vm_offset_t min_valid_stack_address(void);
extern vm_offset_t max_valid_stack_address(void);

// From osfmk/kmod.c
extern void kmod_dump_log(vm_offset_t *addr, unsigned int cnt);

extern addr64_t kvtophys(vm_offset_t va);

__END_DECLS

static mutex_t *sOSReportLock = mutex_alloc(0);

/* Use kernel_debug() to log a backtrace */ 
void
trace_backtrace(unsigned int debugid, unsigned int debugid2, int size, int data) {
	void *bt[16];
	const unsigned cnt = sizeof(bt) / sizeof(bt[0]);
  	unsigned i;
	int found = 0;

	OSBacktrace(bt, cnt);	
  
	/* find first non-kernel frame */
  	for (i = 3; i < cnt && bt[i]; i++) {
 		if (bt[i] > (void*)&etext) {
			found = 1;
  			break;
		}
	}
	/* 
	 * if there are non-kernel frames, only log these
	 * otherwise, log everything but the first two
	 */
	if (!found) i=2;

#define safe_bt(a) (int)(a<cnt ? bt[a] : 0)
	kernel_debug(debugid, data, size, safe_bt(i), safe_bt(i+1), 0);
	kernel_debug(debugid2, safe_bt(i+2), safe_bt(i+3), safe_bt(i+4), safe_bt(i+5), 0);
}

/* Report a message with a 4 entry backtrace - very slow */
void
OSReportWithBacktrace(const char *str, ...)
{
    char buf[128];
    void *bt[9];
    const unsigned cnt = sizeof(bt) / sizeof(bt[0]);
    va_list listp;

    // Ignore the our and our callers stackframes, skipping frames 0 & 1
    (void) OSBacktrace(bt, cnt);

    va_start(listp, str);
    vsnprintf(buf, sizeof(buf), str, listp);
    va_end(listp);

    mutex_lock(sOSReportLock);
    {
	printf("%s\nBacktrace %p %p %p %p %p %p %p\n",
		buf, bt[2], bt[3], bt[4], bt[5], bt[6], bt[7], bt[8]);
	kmod_dump_log((vm_offset_t *) &bt[2], cnt - 2);
    }
    mutex_unlock(sOSReportLock);
}

static vm_offset_t minstackaddr = min_valid_stack_address();
static vm_offset_t maxstackaddr = max_valid_stack_address();

#if __i386__
#define i386_RETURN_OFFSET 4

static unsigned int
i386_validate_stackptr(vm_offset_t stackptr)
{
	/* Existence and alignment check
	 */
	if (!stackptr || (stackptr & 0x3))
		return 0;
  
	/* Is a virtual->physical translation present?
	 */
	if (!kvtophys(stackptr))
		return 0;
  
	/* Check if the return address lies on the same page;
	 * If not, verify that a translation exists.
	 */
	if (((PAGE_SIZE - (stackptr & PAGE_MASK)) < i386_RETURN_OFFSET) &&
	    !kvtophys(stackptr + i386_RETURN_OFFSET))
		return 0;
	return 1;
}

static unsigned int
i386_validate_raddr(vm_offset_t raddr)
{
	return ((raddr > VM_MIN_KERNEL_ADDRESS) &&
	    (raddr < VM_MAX_KERNEL_ADDRESS));
}
#endif

unsigned OSBacktrace(void **bt, unsigned maxAddrs)
{
    unsigned frame;

#if __ppc__
    vm_offset_t stackptr, stackptr_prev;
    const vm_offset_t * const mem = (vm_offset_t *) 0;
    unsigned i = 0;

    __asm__ volatile("mflr %0" : "=r" (stackptr)); 
    bt[i++] = (void *) stackptr;

    __asm__ volatile("mr %0,r1" : "=r" (stackptr)); 
    for ( ; i < maxAddrs; i++) {
	// Validate we have a reasonable stackptr
	if ( !(minstackaddr <= stackptr && stackptr < maxstackaddr)
	|| (stackptr & 3))
	    break;

	stackptr_prev = stackptr;
	stackptr = mem[stackptr_prev >> 2];
	if ((stackptr_prev ^ stackptr) > 8 * 1024)	// Sanity check
	    break;

	vm_offset_t addr = mem[(stackptr >> 2) + 2]; 
	if ((addr & 3) || (addr < 0x8000))	// More sanity checks
	    break;
	bt[i] = (void *) addr;
    }
    frame = i;

    for ( ; i < maxAddrs; i++)
	    bt[i] = (void *) 0;
#elif __i386__
#define SANE_i386_FRAME_SIZE 8*1024
    vm_offset_t stackptr, stackptr_prev, raddr;
    unsigned frame_index = 0;
/* Obtain current frame pointer */
    __asm__ volatile("movl %%ebp, %0" : "=m" (stackptr)); 

    if (!i386_validate_stackptr(stackptr))
	    goto pad;

    raddr = *((vm_offset_t *) (stackptr + i386_RETURN_OFFSET));

    if (!i386_validate_raddr(raddr))
	    goto pad;

    bt[frame_index++] = (void *) raddr;

    for ( ; frame_index < maxAddrs; frame_index++) {
	    stackptr_prev = stackptr;
	    stackptr = *((vm_offset_t *) stackptr_prev);

	    if (!i386_validate_stackptr(stackptr))
		    break;
	/* Stack grows downwards */
	    if (stackptr < stackptr_prev)
		    break;

	    if ((stackptr_prev ^ stackptr) > SANE_i386_FRAME_SIZE)
		    break;

	    raddr = *((vm_offset_t *) (stackptr + i386_RETURN_OFFSET));

	    if (!i386_validate_raddr(raddr))
		    break;

	    bt[frame_index] = (void *) raddr;
    }
pad:
    frame = frame_index;

    for ( ; frame_index < maxAddrs; frame_index++)
	    bt[frame_index] = (void *) 0;
#else
#error arch
#endif
    return frame;
}
Commit	Line	Data
91447636 A	1	/*
	2	* Copyright (c) 2005 Apple Computer, Inc. All rights reserved.
	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
91447636	5	*
2d21ac55 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
8f6c56a5	14	*
2d21ac55 A	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
8f6c56a5 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
8f6c56a5 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
8f6c56a5	25	*
2d21ac55	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
91447636 A	27	*/
	28
	29	// NOTE: This file is only c++ so I can get static initialisers going
	30	#include <libkern/OSDebug.h>
	31
	32	#include <sys/cdefs.h>
	33
	34	#include <stdarg.h>
	35	#include <mach/mach_types.h>
	36	#include <mach/kmod.h>
	37	#include <kern/lock.h>
	38
	39	#include <libkern/libkern.h> // From bsd's libkern directory
0c530ab8	40	#include <mach/vm_param.h>
91447636	41
2d21ac55 A	42	#include <sys/kdebug.h>
2d21ac55 A	43	extern int etext;
91447636 A	44	__BEGIN_DECLS
	45	// From osmfk/kern/thread.h but considered to be private
	46	extern vm_offset_t min_valid_stack_address(void);
	47	extern vm_offset_t max_valid_stack_address(void);
	48
	49	// From osfmk/kmod.c
	50	extern void kmod_dump_log(vm_offset_t *addr, unsigned int cnt);
0c530ab8 A	51
0c530ab8 A	52	extern addr64_t kvtophys(vm_offset_t va);
2d21ac55	53
91447636 A	54	__END_DECLS
	55
	56	static mutex_t *sOSReportLock = mutex_alloc(0);
	57
2d21ac55 A	58	/* Use kernel_debug() to log a backtrace */
	59	void
	60	trace_backtrace(unsigned int debugid, unsigned int debugid2, int size, int data) {
	61	void *bt[16];
	62	const unsigned cnt = sizeof(bt) / sizeof(bt[0]);
	63	unsigned i;
	64	int found = 0;
	65
	66	OSBacktrace(bt, cnt);
	67
	68	/* find first non-kernel frame */
	69	for (i = 3; i < cnt && bt[i]; i++) {
	70	if (bt[i] > (void*)&etext) {
	71	found = 1;
	72	break;
	73	}
	74	}
	75	/*
	76	* if there are non-kernel frames, only log these
	77	* otherwise, log everything but the first two
	78	*/
	79	if (!found) i=2;
	80
	81	#define safe_bt(a) (int)(a<cnt ? bt[a] : 0)
	82	kernel_debug(debugid, data, size, safe_bt(i), safe_bt(i+1), 0);
	83	kernel_debug(debugid2, safe_bt(i+2), safe_bt(i+3), safe_bt(i+4), safe_bt(i+5), 0);
	84	}
	85
91447636 A	86	/* Report a message with a 4 entry backtrace - very slow */
	87	void
	88	OSReportWithBacktrace(const char *str, ...)
	89	{
	90	char buf[128];
	91	void *bt[9];
	92	const unsigned cnt = sizeof(bt) / sizeof(bt[0]);
	93	va_list listp;
	94
	95	// Ignore the our and our callers stackframes, skipping frames 0 & 1
	96	(void) OSBacktrace(bt, cnt);
	97
	98	va_start(listp, str);
	99	vsnprintf(buf, sizeof(buf), str, listp);
	100	va_end(listp);
	101
	102	mutex_lock(sOSReportLock);
	103	{
	104	printf("%s\nBacktrace %p %p %p %p %p %p %p\n",
	105	buf, bt[2], bt[3], bt[4], bt[5], bt[6], bt[7], bt[8]);
	106	kmod_dump_log((vm_offset_t *) &bt[2], cnt - 2);
	107	}
	108	mutex_unlock(sOSReportLock);
	109	}
	110
	111	static vm_offset_t minstackaddr = min_valid_stack_address();
	112	static vm_offset_t maxstackaddr = max_valid_stack_address();
	113
0c530ab8 A	114	#if __i386__
	115	#define i386_RETURN_OFFSET 4
	116
	117	static unsigned int
	118	i386_validate_stackptr(vm_offset_t stackptr)
	119	{
	120	/* Existence and alignment check
	121	*/
	122	if (!stackptr \|\| (stackptr & 0x3))
	123	return 0;
	124
	125	/* Is a virtual->physical translation present?
	126	*/
	127	if (!kvtophys(stackptr))
	128	return 0;
	129
	130	/* Check if the return address lies on the same page;
	131	* If not, verify that a translation exists.
	132	*/
	133	if (((PAGE_SIZE - (stackptr & PAGE_MASK)) < i386_RETURN_OFFSET) &&
	134	!kvtophys(stackptr + i386_RETURN_OFFSET))
	135	return 0;
	136	return 1;
	137	}
	138
	139	static unsigned int
	140	i386_validate_raddr(vm_offset_t raddr)
	141	{
	142	return ((raddr > VM_MIN_KERNEL_ADDRESS) &&
	143	(raddr < VM_MAX_KERNEL_ADDRESS));
	144	}
	145	#endif
	146
91447636 A	147	unsigned OSBacktrace(void **bt, unsigned maxAddrs)
	148	{
	149	unsigned frame;
	150
	151	#if __ppc__
	152	vm_offset_t stackptr, stackptr_prev;
	153	const vm_offset_t * const mem = (vm_offset_t *) 0;
	154	unsigned i = 0;
	155
	156	__asm__ volatile("mflr %0" : "=r" (stackptr));
	157	bt[i++] = (void *) stackptr;
	158
	159	__asm__ volatile("mr %0,r1" : "=r" (stackptr));
	160	for ( ; i < maxAddrs; i++) {
	161	// Validate we have a reasonable stackptr
	162	if ( !(minstackaddr <= stackptr && stackptr < maxstackaddr)
	163	\|\| (stackptr & 3))
	164	break;
	165
	166	stackptr_prev = stackptr;
	167	stackptr = mem[stackptr_prev >> 2];
	168	if ((stackptr_prev ^ stackptr) > 8 * 1024) // Sanity check
	169	break;
	170
	171	vm_offset_t addr = mem[(stackptr >> 2) + 2];
	172	if ((addr & 3) \|\| (addr < 0x8000)) // More sanity checks
	173	break;
	174	bt[i] = (void *) addr;
	175	}
	176	frame = i;
	177
	178	for ( ; i < maxAddrs; i++)
	179	bt[i] = (void *) 0;
0c530ab8 A	180	#elif __i386__
	181	#define SANE_i386_FRAME_SIZE 8*1024
	182	vm_offset_t stackptr, stackptr_prev, raddr;
	183	unsigned frame_index = 0;
	184	/* Obtain current frame pointer */
	185	__asm__ volatile("movl %%ebp, %0" : "=m" (stackptr));
4452a7af	186
0c530ab8 A	187	if (!i386_validate_stackptr(stackptr))
0c530ab8 A	188	goto pad;
4452a7af	189
0c530ab8 A	190	raddr = ((vm_offset_t ) (stackptr + i386_RETURN_OFFSET));
	191
	192	if (!i386_validate_raddr(raddr))
	193	goto pad;
	194
	195	bt[frame_index++] = (void *) raddr;
	196
	197	for ( ; frame_index < maxAddrs; frame_index++) {
	198	stackptr_prev = stackptr;
	199	stackptr = ((vm_offset_t ) stackptr_prev);
	200
	201	if (!i386_validate_stackptr(stackptr))
	202	break;
	203	/* Stack grows downwards */
	204	if (stackptr < stackptr_prev)
	205	break;
4452a7af	206
0c530ab8 A	207	if ((stackptr_prev ^ stackptr) > SANE_i386_FRAME_SIZE)
	208	break;
	209
	210	raddr = ((vm_offset_t ) (stackptr + i386_RETURN_OFFSET));
	211
	212	if (!i386_validate_raddr(raddr))
	213	break;
	214
	215	bt[frame_index] = (void *) raddr;
91447636	216	}
0c530ab8 A	217	pad:
0c530ab8 A	218	frame = frame_index;
91447636	219
0c530ab8 A	220	for ( ; frame_index < maxAddrs; frame_index++)
	221	bt[frame_index] = (void *) 0;
	222	#else
	223	#error arch
91447636	224	#endif
91447636 A	225	return frame;
91447636 A	226	}