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
37 struct buffer_stage_data {
38 size_t total_buffer_size;
39 size_t current_size;
40 char buffer[];
41 };
42
43 static void
buffer_stage_reset(struct kdp_output_stage * stage)44 buffer_stage_reset(struct kdp_output_stage *stage)
45 {
46 struct buffer_stage_data *data = (struct buffer_stage_data *) stage->kos_data;
47
48 data->current_size = 0;
49 stage->kos_bypass = false;
50 stage->kos_bytes_written = 0;
51 }
52
53 static kern_return_t
buffer_stage_flush(struct kdp_output_stage * stage)54 buffer_stage_flush(struct kdp_output_stage *stage)
55 {
56 kern_return_t err = KERN_SUCCESS;
57 struct buffer_stage_data *data = (struct buffer_stage_data *) stage->kos_data;
58 struct kdp_output_stage *next_stage = STAILQ_NEXT(stage, kos_next);
59
60 err = next_stage->kos_funcs.kosf_outproc(next_stage, KDP_DATA, NULL, data->current_size, data->buffer);
61
62 if (KERN_SUCCESS != err) {
63 return err;
64 } else {
65 stage->kos_bytes_written += data->current_size;
66 data->current_size = 0;
67 }
68
69 return err;
70 }
71
72 static kern_return_t
buffer_stage_outproc(struct kdp_output_stage * stage,unsigned int request,char * corename,uint64_t length,void * panic_data)73 buffer_stage_outproc(struct kdp_output_stage *stage, unsigned int request,
74 char *corename, uint64_t length, void * panic_data)
75 {
76 kern_return_t err = KERN_SUCCESS;
77 struct buffer_stage_data *data = (struct buffer_stage_data *) stage->kos_data;
78 struct kdp_output_stage *next_stage = STAILQ_NEXT(stage, kos_next);
79
80 boolean_t should_flush = FALSE;
81
82 assert(next_stage != NULL);
83
84 if ((data->current_size && (request == KDP_SEEK || request == KDP_FLUSH || request == KDP_EOF))
85 || (request == KDP_DATA && length == 0 && !panic_data)) {
86 should_flush = TRUE;
87 }
88
89 if (should_flush) {
90 err = buffer_stage_flush(stage);
91 if (KERN_SUCCESS != err) {
92 kern_coredump_log(NULL, "buffer_stage_outproc (during flush) returned 0x%x\n", err);
93 return err;
94 }
95 }
96
97 if (request == KDP_WRQ || request == KDP_SEEK || request == KDP_EOF) {
98 err = next_stage->kos_funcs.kosf_outproc(next_stage, request, corename, length, panic_data);
99
100 if (KERN_SUCCESS != err) {
101 kern_coredump_log(NULL, "buffer_stage_outproc (during forwarding) returned 0x%x\n", err);
102 return err;
103 }
104 } else if (request == KDP_DATA) {
105 while (length != 0) {
106 size_t bytes_to_copy = data->total_buffer_size - data->current_size;
107
108 if (length < bytes_to_copy) {
109 /* Safe to cast to size_t here since we just checked that 'length' is less
110 * than a size_t value. */
111 bytes_to_copy = (size_t) length;
112 }
113
114 bcopy(panic_data, (void *)((uintptr_t)data->buffer + data->current_size), bytes_to_copy);
115
116 data->current_size += bytes_to_copy;
117 length -= bytes_to_copy;
118 panic_data = (void *) ((uintptr_t) panic_data + bytes_to_copy);
119
120 if (data->current_size == data->total_buffer_size) {
121 err = buffer_stage_flush(stage);
122 if (KERN_SUCCESS != err) {
123 kern_coredump_log(NULL, "buffer_stage_outproc (during flush) returned 0x%x\n", err);
124 return err;
125 }
126 }
127 }
128 }
129
130 return err;
131 }
132
133 static void
buffer_stage_free(struct kdp_output_stage * stage)134 buffer_stage_free(struct kdp_output_stage *stage)
135 {
136 kmem_free(kernel_map, (vm_offset_t) stage->kos_data, stage->kos_data_size);
137
138 stage->kos_data = NULL;
139 stage->kos_data_size = 0;
140 stage->kos_initialized = false;
141 }
142
143 kern_return_t
buffer_stage_initialize(struct kdp_output_stage * stage,size_t buffer_size)144 buffer_stage_initialize(struct kdp_output_stage *stage, size_t buffer_size)
145 {
146 kern_return_t ret = KERN_SUCCESS;
147 struct buffer_stage_data *data = NULL;
148
149 assert(stage != NULL);
150 assert(stage->kos_initialized == false);
151 assert(stage->kos_data == NULL);
152 assert(buffer_size != 0);
153
154 stage->kos_data_size = sizeof(struct buffer_stage_data) + buffer_size;
155 ret = kmem_alloc(kernel_map, (vm_offset_t*) &stage->kos_data, stage->kos_data_size,
156 KMA_DATA, VM_KERN_MEMORY_DIAG);
157 if (KERN_SUCCESS != ret) {
158 printf("buffer_stage_initialize failed to allocate memory. Error 0x%x\n", ret);
159 return ret;
160 }
161
162 data = (struct buffer_stage_data *) stage->kos_data;
163 data->total_buffer_size = buffer_size;
164 data->current_size = 0;
165
166 stage->kos_funcs.kosf_reset = buffer_stage_reset;
167 stage->kos_funcs.kosf_outproc = buffer_stage_outproc;
168 stage->kos_funcs.kosf_free = buffer_stage_free;
169
170 stage->kos_initialized = true;
171
172 return KERN_SUCCESS;
173 }
174
175 #endif /* CONFIG_KDP_INTERACTIVE_DEBUGGING */
176