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

/*
 * Copyright (c) 2005-2012 Apple 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 <IOKit/IOLib.h>

#include <sys/cdefs.h>

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

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

#include <sys/kdebug.h>
#include <kern/thread.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

extern lck_grp_t *IOLockGroup;

static lck_mtx_t *sOSReportLock = lck_mtx_alloc_init(IOLockGroup, LCK_ATTR_NULL);

/* Use kernel_debug() to log a backtrace */ 
void
trace_backtrace(uint32_t debugid, uint32_t debugid2, uintptr_t size, uintptr_t 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) (uintptr_t)(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);

    lck_mtx_lock(sOSReportLock);
    {
        printf("%s\nBacktrace 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", buf, 
            (unsigned long) VM_KERNEL_UNSLIDE(bt[2]), (unsigned long) VM_KERNEL_UNSLIDE(bt[3]), 
            (unsigned long) VM_KERNEL_UNSLIDE(bt[4]), (unsigned long) VM_KERNEL_UNSLIDE(bt[5]), 
            (unsigned long) VM_KERNEL_UNSLIDE(bt[6]), (unsigned long) VM_KERNEL_UNSLIDE(bt[7]), 
            (unsigned long) VM_KERNEL_UNSLIDE(bt[8]));
        kmod_dump_log((vm_offset_t *) &bt[2], cnt - 2);
    }
    lck_mtx_unlock(sOSReportLock);
}

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


#if __x86_64__
#define x86_64_RETURN_OFFSET 8
static unsigned int
x86_64_validate_raddr(vm_offset_t raddr)
{
	return ((raddr > VM_MIN_KERNEL_AND_KEXT_ADDRESS) &&
	    (raddr < VM_MAX_KERNEL_ADDRESS));
}
static unsigned int
x86_64_validate_stackptr(vm_offset_t stackptr)
{
	/* Existence and alignment check
	 */
	if (!stackptr || (stackptr & 0x7) || !x86_64_validate_raddr(stackptr))
		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)) < x86_64_RETURN_OFFSET) &&
	    !kvtophys(stackptr + x86_64_RETURN_OFFSET))
		return 0;
	return 1;
}
#endif

void
OSPrintBacktrace(void)
{
	void * btbuf[20];
	int tmp = OSBacktrace(btbuf, 20);
	int i;
	for(i=0;i<tmp;i++)
	{
		kprintf("bt[%.2d] = %p\n", i, btbuf[i]);
	}
}

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

#if   __x86_64__
#define SANE_x86_64_FRAME_SIZE (kernel_stack_size >> 1)
    vm_offset_t stackptr, stackptr_prev, raddr;
    unsigned frame_index = 0;
/* Obtain current frame pointer */

    __asm__ volatile("movq %%rbp, %0" : "=m" (stackptr)); 

    if (!x86_64_validate_stackptr(stackptr))
	    goto pad;

    raddr = *((vm_offset_t *) (stackptr + x86_64_RETURN_OFFSET));

    if (!x86_64_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 (!x86_64_validate_stackptr(stackptr))
		    break;
	/* Stack grows downwards */
	    if (stackptr < stackptr_prev)
		    break;

	    if ((stackptr - stackptr_prev) > SANE_x86_64_FRAME_SIZE)
		    break;

	    raddr = *((vm_offset_t *) (stackptr + x86_64_RETURN_OFFSET));

	    if (!x86_64_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	1	/*
39236c6e	2	* Copyright (c) 2005-2012 Apple Inc. All rights reserved.
91447636	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>
6d2010ae	31	#include <IOKit/IOLib.h>
91447636 A	32
	33	#include <sys/cdefs.h>
	34
	35	#include <stdarg.h>
	36	#include <mach/mach_types.h>
	37	#include <mach/kmod.h>
b0d623f7	38	#include <kern/locks.h>
91447636 A	39
91447636 A	40	#include <libkern/libkern.h> // From bsd's libkern directory
0c530ab8	41	#include <mach/vm_param.h>
91447636	42
2d21ac55	43	#include <sys/kdebug.h>
b0d623f7 A	44	#include <kern/thread.h>
b0d623f7 A	45
2d21ac55	46	extern int etext;
91447636 A	47	__BEGIN_DECLS
	48	// From osmfk/kern/thread.h but considered to be private
	49	extern vm_offset_t min_valid_stack_address(void);
	50	extern vm_offset_t max_valid_stack_address(void);
	51
	52	// From osfmk/kmod.c
	53	extern void kmod_dump_log(vm_offset_t *addr, unsigned int cnt);
0c530ab8 A	54
0c530ab8 A	55	extern addr64_t kvtophys(vm_offset_t va);
2d21ac55	56
91447636 A	57	__END_DECLS
91447636 A	58
b0d623f7 A	59	extern lck_grp_t *IOLockGroup;
	60
	61	static lck_mtx_t *sOSReportLock = lck_mtx_alloc_init(IOLockGroup, LCK_ATTR_NULL);
91447636	62
2d21ac55 A	63	/* Use kernel_debug() to log a backtrace */
2d21ac55 A	64	void
b0d623f7	65	trace_backtrace(uint32_t debugid, uint32_t debugid2, uintptr_t size, uintptr_t data) {
2d21ac55 A	66	void *bt[16];
	67	const unsigned cnt = sizeof(bt) / sizeof(bt[0]);
	68	unsigned i;
	69	int found = 0;
	70
	71	OSBacktrace(bt, cnt);
	72
	73	/* find first non-kernel frame */
	74	for (i = 3; i < cnt && bt[i]; i++) {
	75	if (bt[i] > (void*)&etext) {
	76	found = 1;
	77	break;
	78	}
	79	}
	80	/*
	81	* if there are non-kernel frames, only log these
	82	* otherwise, log everything but the first two
	83	*/
	84	if (!found) i=2;
	85
b0d623f7	86	#define safe_bt(a) (uintptr_t)(a<cnt ? bt[a] : 0)
2d21ac55 A	87	kernel_debug(debugid, data, size, safe_bt(i), safe_bt(i+1), 0);
	88	kernel_debug(debugid2, safe_bt(i+2), safe_bt(i+3), safe_bt(i+4), safe_bt(i+5), 0);
	89	}
	90
91447636 A	91	/* Report a message with a 4 entry backtrace - very slow */
	92	void
	93	OSReportWithBacktrace(const char *str, ...)
	94	{
	95	char buf[128];
	96	void *bt[9];
	97	const unsigned cnt = sizeof(bt) / sizeof(bt[0]);
	98	va_list listp;
	99
	100	// Ignore the our and our callers stackframes, skipping frames 0 & 1
	101	(void) OSBacktrace(bt, cnt);
	102
	103	va_start(listp, str);
	104	vsnprintf(buf, sizeof(buf), str, listp);
	105	va_end(listp);
	106
b0d623f7	107	lck_mtx_lock(sOSReportLock);
91447636	108	{
39236c6e A	109	printf("%s\nBacktrace 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n", buf,
	110	(unsigned long) VM_KERNEL_UNSLIDE(bt[2]), (unsigned long) VM_KERNEL_UNSLIDE(bt[3]),
	111	(unsigned long) VM_KERNEL_UNSLIDE(bt[4]), (unsigned long) VM_KERNEL_UNSLIDE(bt[5]),
	112	(unsigned long) VM_KERNEL_UNSLIDE(bt[6]), (unsigned long) VM_KERNEL_UNSLIDE(bt[7]),
	113	(unsigned long) VM_KERNEL_UNSLIDE(bt[8]));
b0d623f7	114	kmod_dump_log((vm_offset_t *) &bt[2], cnt - 2);
91447636	115	}
b0d623f7	116	lck_mtx_unlock(sOSReportLock);
91447636 A	117	}
	118
	119	static vm_offset_t minstackaddr = min_valid_stack_address();
	120	static vm_offset_t maxstackaddr = max_valid_stack_address();
	121
b0d623f7 A	122
	123	#if __x86_64__
	124	#define x86_64_RETURN_OFFSET 8
	125	static unsigned int
	126	x86_64_validate_raddr(vm_offset_t raddr)
	127	{
	128	return ((raddr > VM_MIN_KERNEL_AND_KEXT_ADDRESS) &&
0c530ab8 A	129	(raddr < VM_MAX_KERNEL_ADDRESS));
0c530ab8 A	130	}
b0d623f7 A	131	static unsigned int
	132	x86_64_validate_stackptr(vm_offset_t stackptr)
	133	{
	134	/* Existence and alignment check
	135	*/
	136	if (!stackptr \|\| (stackptr & 0x7) \|\| !x86_64_validate_raddr(stackptr))
	137	return 0;
	138
	139	/* Is a virtual->physical translation present?
	140	*/
	141	if (!kvtophys(stackptr))
	142	return 0;
	143
	144	/* Check if the return address lies on the same page;
	145	* If not, verify that a translation exists.
	146	*/
	147	if (((PAGE_SIZE - (stackptr & PAGE_MASK)) < x86_64_RETURN_OFFSET) &&
	148	!kvtophys(stackptr + x86_64_RETURN_OFFSET))
	149	return 0;
	150	return 1;
	151	}
0c530ab8 A	152	#endif
0c530ab8 A	153
6d2010ae A	154	void
	155	OSPrintBacktrace(void)
	156	{
	157	void * btbuf[20];
	158	int tmp = OSBacktrace(btbuf, 20);
	159	int i;
	160	for(i=0;i<tmp;i++)
	161	{
	162	kprintf("bt[%.2d] = %p\n", i, btbuf[i]);
	163	}
	164	}
b0d623f7	165
91447636 A	166	unsigned OSBacktrace(void **bt, unsigned maxAddrs)
	167	{
	168	unsigned frame;
	169
39236c6e	170	#if __x86_64__
b0d623f7 A	171	#define SANE_x86_64_FRAME_SIZE (kernel_stack_size >> 1)
	172	vm_offset_t stackptr, stackptr_prev, raddr;
	173	unsigned frame_index = 0;
	174	/* Obtain current frame pointer */
	175
	176	__asm__ volatile("movq %%rbp, %0" : "=m" (stackptr));
	177
	178	if (!x86_64_validate_stackptr(stackptr))
	179	goto pad;
	180
	181	raddr = ((vm_offset_t ) (stackptr + x86_64_RETURN_OFFSET));
	182
	183	if (!x86_64_validate_raddr(raddr))
	184	goto pad;
	185
	186	bt[frame_index++] = (void *) raddr;
	187
	188	for ( ; frame_index < maxAddrs; frame_index++) {
	189	stackptr_prev = stackptr;
	190	stackptr = ((vm_offset_t ) stackptr_prev);
	191
	192	if (!x86_64_validate_stackptr(stackptr))
	193	break;
	194	/* Stack grows downwards */
	195	if (stackptr < stackptr_prev)
	196	break;
	197
	198	if ((stackptr - stackptr_prev) > SANE_x86_64_FRAME_SIZE)
	199	break;
	200
	201	raddr = ((vm_offset_t ) (stackptr + x86_64_RETURN_OFFSET));
	202
	203	if (!x86_64_validate_raddr(raddr))
	204	break;
	205
	206	bt[frame_index] = (void *) raddr;
	207	}
	208	pad:
	209	frame = frame_index;
	210
0c530ab8 A	211	for ( ; frame_index < maxAddrs; frame_index++)
	212	bt[frame_index] = (void *) 0;
	213	#else
	214	#error arch
91447636	215	#endif
91447636 A	216	return frame;
91447636 A	217	}