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 #include <kern/clock.h>
30 #include <kern/cpu_data.h>
31 #include <kern/debug.h>
32 #include <kern/socd_client.h>
33 #include <kern/startup.h>
34 #include <os/overflow.h>
35 #include <os/atomic_private.h>
36 #include <libkern/section_keywords.h>
37
38 #define SOCD_CLIENT_HDR_VERSION 0x1
39
40 /* Configuration values mutable only at init time */
41 typedef struct {
42 vm_offset_t trace_buff_offset;
43 uint32_t trace_buff_len;
44 } socd_client_cfg_t;
45
46 static SECURITY_READ_ONLY_LATE(socd_client_cfg_t) socd_client_cfg = {0};
47 static SECURITY_READ_ONLY_LATE(bool) socd_client_trace_available = false;
48
49 /* Run-time state */
50 static struct {
51 _Atomic uint32_t trace_idx;
52 } socd_client_state = {0};
53
54 __startup_func
55 static void
socd_client_init(void)56 socd_client_init(void)
57 {
58 vm_size_t buff_size;
59 vm_size_t trace_buff_size;
60 socd_client_hdr_t hdr = {0};
61 uint64_t time_ns;
62
63 buff_size = PE_init_socd_client();
64 if (!buff_size) {
65 return;
66 }
67
68 if (os_sub_overflow(buff_size, sizeof(hdr), &trace_buff_size)) {
69 panic("socd buffer size is too small");
70 }
71
72 absolutetime_to_nanoseconds(mach_continuous_time(), &time_ns);
73 socd_client_cfg.trace_buff_offset = sizeof(hdr);
74 socd_client_cfg.trace_buff_len = (uint32_t)(trace_buff_size / sizeof(socd_client_trace_entry_t));
75 hdr.version = SOCD_CLIENT_HDR_VERSION;
76 hdr.boot_time = time_ns;
77 memcpy(&hdr.kernel_uuid, kernel_uuid, sizeof(hdr.kernel_uuid));
78 PE_write_socd_client_buffer(0, &hdr, sizeof(hdr));
79 os_atomic_store(&socd_client_trace_available, true, release);
80 }
81 STARTUP(PMAP_STEAL, 0, socd_client_init);
82
83 __startup_func
84 static void
socd_client_set_primary_kernelcache_uuid(void)85 socd_client_set_primary_kernelcache_uuid(void)
86 {
87 long available = os_atomic_load(&socd_client_trace_available, relaxed);
88 if (kernelcache_uuid_valid && available) {
89 PE_write_socd_client_buffer(offsetof(socd_client_hdr_t, primary_kernelcache_uuid), &kernelcache_uuid, sizeof(kernelcache_uuid));
90 }
91 }
92 STARTUP(EARLY_BOOT, 0, socd_client_set_primary_kernelcache_uuid);
93
94 void
socd_client_trace(uint32_t debugid,socd_client_trace_arg_t arg1,socd_client_trace_arg_t arg2,socd_client_trace_arg_t arg3,socd_client_trace_arg_t arg4)95 socd_client_trace(
96 uint32_t debugid,
97 socd_client_trace_arg_t arg1,
98 socd_client_trace_arg_t arg2,
99 socd_client_trace_arg_t arg3,
100 socd_client_trace_arg_t arg4)
101 {
102 socd_client_trace_entry_t entry;
103 uint32_t trace_idx, buff_idx, len;
104 uint64_t time_ns;
105 long available;
106 vm_offset_t offset;
107
108 available = os_atomic_load(&socd_client_trace_available, dependency);
109 if (__probable(available)) {
110 len = os_atomic_load_with_dependency_on(&socd_client_cfg.trace_buff_len, available);
111 offset = os_atomic_load_with_dependency_on(&socd_client_cfg.trace_buff_offset, available);
112 /* trace_idx is allowed to overflow */
113 trace_idx = os_atomic_inc(&socd_client_state.trace_idx, relaxed);
114 buff_idx = trace_idx % len;
115
116 absolutetime_to_nanoseconds(mach_continuous_time(), &time_ns);
117 entry.timestamp = time_ns;
118 entry.debugid = debugid;
119 entry.arg1 = arg1;
120 entry.arg2 = arg2;
121 entry.arg3 = arg3;
122 entry.arg4 = arg4;
123 PE_write_socd_client_buffer(offset + (buff_idx * sizeof(entry)), &entry, sizeof(entry));
124 }
125
126 /* Duplicate tracepoint to kdebug */
127 if (!debug_is_current_cpu_in_panic_state()) {
128 KDBG(debugid, arg1, arg2, arg3, arg4);
129 }
130 }
131