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 kern_return_t
buffer_stage_reset(struct kdp_output_stage * stage,__unused const char * corename,__unused kern_coredump_type_t coretype)45 buffer_stage_reset(struct kdp_output_stage *stage, __unused const char *corename, __unused kern_coredump_type_t coretype)
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 return KERN_SUCCESS;
54 }
55
56 static kern_return_t
buffer_stage_flush(struct kdp_output_stage * stage)57 buffer_stage_flush(struct kdp_output_stage *stage)
58 {
59 kern_return_t err = KERN_SUCCESS;
60 struct buffer_stage_data *data = (struct buffer_stage_data *) stage->kos_data;
61 struct kdp_output_stage *next_stage = STAILQ_NEXT(stage, kos_next);
62
63 err = next_stage->kos_funcs.kosf_outproc(next_stage, KDP_DATA, NULL, data->current_size, data->buffer);
64
65 if (KERN_SUCCESS != err) {
66 return err;
67 } else {
68 stage->kos_bytes_written += data->current_size;
69 data->current_size = 0;
70 }
71
72 return err;
73 }
74
75 static kern_return_t
buffer_stage_outproc(struct kdp_output_stage * stage,unsigned int request,char * corename,uint64_t length,void * panic_data)76 buffer_stage_outproc(struct kdp_output_stage *stage, unsigned int request,
77 char *corename, uint64_t length, void * panic_data)
78 {
79 kern_return_t err = KERN_SUCCESS;
80 struct buffer_stage_data *data = (struct buffer_stage_data *) stage->kos_data;
81 struct kdp_output_stage *next_stage = STAILQ_NEXT(stage, kos_next);
82
83 boolean_t should_flush = FALSE;
84
85 assert(next_stage != NULL);
86
87 if ((data->current_size && (request == KDP_SEEK || request == KDP_FLUSH || request == KDP_EOF))
88 || (request == KDP_DATA && length == 0 && !panic_data)) {
89 should_flush = TRUE;
90 }
91
92 if (should_flush) {
93 err = buffer_stage_flush(stage);
94 if (KERN_SUCCESS != err) {
95 kern_coredump_log(NULL, "buffer_stage_outproc (during flush) returned 0x%x\n", err);
96 return err;
97 }
98 }
99
100 if (request == KDP_WRQ || request == KDP_SEEK || request == KDP_EOF) {
101 err = next_stage->kos_funcs.kosf_outproc(next_stage, request, corename, length, panic_data);
102
103 if (KERN_SUCCESS != err) {
104 kern_coredump_log(NULL, "buffer_stage_outproc (during forwarding) returned 0x%x\n", err);
105 return err;
106 }
107 } else if (request == KDP_DATA) {
108 while (length != 0) {
109 size_t bytes_to_copy = data->total_buffer_size - data->current_size;
110
111 if (length < bytes_to_copy) {
112 /* Safe to cast to size_t here since we just checked that 'length' is less
113 * than a size_t value. */
114 bytes_to_copy = (size_t) length;
115 }
116
117 bcopy(panic_data, (void *)((uintptr_t)data->buffer + data->current_size), bytes_to_copy);
118
119 data->current_size += bytes_to_copy;
120 length -= bytes_to_copy;
121 panic_data = (void *) ((uintptr_t) panic_data + bytes_to_copy);
122
123 if (data->current_size == data->total_buffer_size) {
124 err = buffer_stage_flush(stage);
125 if (KERN_SUCCESS != err) {
126 kern_coredump_log(NULL, "buffer_stage_outproc (during flush) returned 0x%x\n", err);
127 return err;
128 }
129 }
130 }
131 }
132
133 return err;
134 }
135
136 static void
buffer_stage_free(struct kdp_output_stage * stage)137 buffer_stage_free(struct kdp_output_stage *stage)
138 {
139 kmem_free(kernel_map, (vm_offset_t) stage->kos_data, stage->kos_data_size);
140
141 stage->kos_data = NULL;
142 stage->kos_data_size = 0;
143 stage->kos_initialized = false;
144 }
145
146 kern_return_t
buffer_stage_initialize(struct kdp_output_stage * stage,size_t buffer_size)147 buffer_stage_initialize(struct kdp_output_stage *stage, size_t buffer_size)
148 {
149 kern_return_t ret = KERN_SUCCESS;
150 struct buffer_stage_data *data = NULL;
151
152 assert(stage != NULL);
153 assert(stage->kos_initialized == false);
154 assert(stage->kos_data == NULL);
155 assert(buffer_size != 0);
156
157 stage->kos_data_size = sizeof(struct buffer_stage_data) + buffer_size;
158 ret = kmem_alloc(kernel_map, (vm_offset_t*) &stage->kos_data, stage->kos_data_size,
159 KMA_DATA_SHARED, VM_KERN_MEMORY_DIAG);
160 if (KERN_SUCCESS != ret) {
161 printf("buffer_stage_initialize failed to allocate memory. Error 0x%x\n", ret);
162 return ret;
163 }
164
165 data = (struct buffer_stage_data *) stage->kos_data;
166 data->total_buffer_size = buffer_size;
167 data->current_size = 0;
168
169 stage->kos_funcs.kosf_reset = buffer_stage_reset;
170 stage->kos_funcs.kosf_outproc = buffer_stage_outproc;
171 stage->kos_funcs.kosf_free = buffer_stage_free;
172
173 stage->kos_initialized = true;
174
175 return KERN_SUCCESS;
176 }
177
178 #endif /* CONFIG_KDP_INTERACTIVE_DEBUGGING */
179