1 /*
2 * Copyright (c) 2021 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
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.
14 *
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
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29 #ifdef CONFIG_KDP_INTERACTIVE_DEBUGGING
30
31 #include <mach/mach_types.h>
32 #include <IOKit/IOTypes.h>
33 #include <kdp/output_stages/output_stages.h>
34 #include <kdp/kdp_core.h>
35 #include <kdp/processor_core.h>
36 #include <vm/vm_kern_xnu.h>
37
38 struct buffer_stage_data {
39 size_t total_buffer_size;
40 size_t current_size;
41 char buffer[];
42 };
43
44 static void
buffer_stage_reset(struct kdp_output_stage * stage)45 buffer_stage_reset(struct kdp_output_stage *stage)
46 {
47 struct buffer_stage_data *data = (struct buffer_stage_data *) stage->kos_data;
48
49 data->current_size = 0;
50 stage->kos_bypass = false;
51 stage->kos_bytes_written = 0;
52 }
53
54 static kern_return_t
buffer_stage_flush(struct kdp_output_stage * stage)55 buffer_stage_flush(struct kdp_output_stage *stage)
56 {
57 kern_return_t err = KERN_SUCCESS;
58 struct buffer_stage_data *data = (struct buffer_stage_data *) stage->kos_data;
59 struct kdp_output_stage *next_stage = STAILQ_NEXT(stage, kos_next);
60
61 err = next_stage->kos_funcs.kosf_outproc(next_stage, KDP_DATA, NULL, data->current_size, data->buffer);
62
63 if (KERN_SUCCESS != err) {
64 return err;
65 } else {
66 stage->kos_bytes_written += data->current_size;
67 data->current_size = 0;
68 }
69
70 return err;
71 }
72
73 static kern_return_t
buffer_stage_outproc(struct kdp_output_stage * stage,unsigned int request,char * corename,uint64_t length,void * panic_data)74 buffer_stage_outproc(struct kdp_output_stage *stage, unsigned int request,
75 char *corename, uint64_t length, void * panic_data)
76 {
77 kern_return_t err = KERN_SUCCESS;
78 struct buffer_stage_data *data = (struct buffer_stage_data *) stage->kos_data;
79 struct kdp_output_stage *next_stage = STAILQ_NEXT(stage, kos_next);
80
81 boolean_t should_flush = FALSE;
82
83 assert(next_stage != NULL);
84
85 if ((data->current_size && (request == KDP_SEEK || request == KDP_FLUSH || request == KDP_EOF))
86 || (request == KDP_DATA && length == 0 && !panic_data)) {
87 should_flush = TRUE;
88 }
89
90 if (should_flush) {
91 err = buffer_stage_flush(stage);
92 if (KERN_SUCCESS != err) {
93 kern_coredump_log(NULL, "buffer_stage_outproc (during flush) returned 0x%x\n", err);
94 return err;
95 }
96 }
97
98 if (request == KDP_WRQ || request == KDP_SEEK || request == KDP_EOF) {
99 err = next_stage->kos_funcs.kosf_outproc(next_stage, request, corename, length, panic_data);
100
101 if (KERN_SUCCESS != err) {
102 kern_coredump_log(NULL, "buffer_stage_outproc (during forwarding) returned 0x%x\n", err);
103 return err;
104 }
105 } else if (request == KDP_DATA) {
106 while (length != 0) {
107 size_t bytes_to_copy = data->total_buffer_size - data->current_size;
108
109 if (length < bytes_to_copy) {
110 /* Safe to cast to size_t here since we just checked that 'length' is less
111 * than a size_t value. */
112 bytes_to_copy = (size_t) length;
113 }
114
115 bcopy(panic_data, (void *)((uintptr_t)data->buffer + data->current_size), bytes_to_copy);
116
117 data->current_size += bytes_to_copy;
118 length -= bytes_to_copy;
119 panic_data = (void *) ((uintptr_t) panic_data + bytes_to_copy);
120
121 if (data->current_size == data->total_buffer_size) {
122 err = buffer_stage_flush(stage);
123 if (KERN_SUCCESS != err) {
124 kern_coredump_log(NULL, "buffer_stage_outproc (during flush) returned 0x%x\n", err);
125 return err;
126 }
127 }
128 }
129 }
130
131 return err;
132 }
133
134 static void
buffer_stage_free(struct kdp_output_stage * stage)135 buffer_stage_free(struct kdp_output_stage *stage)
136 {
137 kmem_free(kernel_map, (vm_offset_t) stage->kos_data, stage->kos_data_size);
138
139 stage->kos_data = NULL;
140 stage->kos_data_size = 0;
141 stage->kos_initialized = false;
142 }
143
144 kern_return_t
buffer_stage_initialize(struct kdp_output_stage * stage,size_t buffer_size)145 buffer_stage_initialize(struct kdp_output_stage *stage, size_t buffer_size)
146 {
147 kern_return_t ret = KERN_SUCCESS;
148 struct buffer_stage_data *data = NULL;
149
150 assert(stage != NULL);
151 assert(stage->kos_initialized == false);
152 assert(stage->kos_data == NULL);
153 assert(buffer_size != 0);
154
155 stage->kos_data_size = sizeof(struct buffer_stage_data) + buffer_size;
156 ret = kmem_alloc(kernel_map, (vm_offset_t*) &stage->kos_data, stage->kos_data_size,
157 KMA_DATA, VM_KERN_MEMORY_DIAG);
158 if (KERN_SUCCESS != ret) {
159 printf("buffer_stage_initialize failed to allocate memory. Error 0x%x\n", ret);
160 return ret;
161 }
162
163 data = (struct buffer_stage_data *) stage->kos_data;
164 data->total_buffer_size = buffer_size;
165 data->current_size = 0;
166
167 stage->kos_funcs.kosf_reset = buffer_stage_reset;
168 stage->kos_funcs.kosf_outproc = buffer_stage_outproc;
169 stage->kos_funcs.kosf_free = buffer_stage_free;
170
171 stage->kos_initialized = true;
172
173 return KERN_SUCCESS;
174 }
175
176 #endif /* CONFIG_KDP_INTERACTIVE_DEBUGGING */
177