1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* kexec_handover_debugfs.c - kexec handover debugfs interfaces
* Copyright (C) 2023 Alexander Graf <graf@amazon.com>
* Copyright (C) 2025 Microsoft Corporation, Mike Rapoport <rppt@kernel.org>
* Copyright (C) 2025 Google LLC, Changyuan Lyu <changyuanl@google.com>
* Copyright (C) 2025 Google LLC, Pasha Tatashin <pasha.tatashin@soleen.com>
*/
#define pr_fmt(fmt) "KHO: " fmt
#include <linux/init.h>
#include <linux/io.h>
#include <linux/libfdt.h>
#include <linux/mm.h>
#include "kexec_handover_internal.h"
static struct dentry *debugfs_root;
struct fdt_debugfs {
struct list_head list;
struct debugfs_blob_wrapper wrapper;
struct dentry *file;
};
static int __kho_debugfs_fdt_add(struct list_head *list, struct dentry *dir,
const char *name, const void *fdt)
{
struct fdt_debugfs *f;
struct dentry *file;
f = kmalloc(sizeof(*f), GFP_KERNEL);
if (!f)
return -ENOMEM;
f->wrapper.data = (void *)fdt;
f->wrapper.size = fdt_totalsize(fdt);
file = debugfs_create_blob(name, 0400, dir, &f->wrapper);
if (IS_ERR(file)) {
kfree(f);
return PTR_ERR(file);
}
f->file = file;
list_add(&f->list, list);
return 0;
}
int kho_debugfs_fdt_add(struct kho_debugfs *dbg, const char *name,
const void *fdt, bool root)
{
struct dentry *dir;
if (root)
dir = dbg->dir;
else
dir = dbg->sub_fdt_dir;
return __kho_debugfs_fdt_add(&dbg->fdt_list, dir, name, fdt);
}
void kho_debugfs_fdt_remove(struct kho_debugfs *dbg, void *fdt)
{
struct fdt_debugfs *ff;
list_for_each_entry(ff, &dbg->fdt_list, list) {
if (ff->wrapper.data == fdt) {
debugfs_remove(ff->file);
list_del(&ff->list);
kfree(ff);
break;
}
}
}
static int kho_out_finalize_get(void *data, u64 *val)
{
*val = kho_finalized();
return 0;
}
static int kho_out_finalize_set(void *data, u64 val)
{
if (val)
return kho_finalize();
else
return -EINVAL;
}
DEFINE_DEBUGFS_ATTRIBUTE(kho_out_finalize_fops, kho_out_finalize_get,
kho_out_finalize_set, "%llu\n");
static int scratch_phys_show(struct seq_file *m, void *v)
{
for (int i = 0; i < kho_scratch_cnt; i++)
seq_printf(m, "0x%llx\n", kho_scratch[i].addr);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(scratch_phys);
static int scratch_len_show(struct seq_file *m, void *v)
{
for (int i = 0; i < kho_scratch_cnt; i++)
seq_printf(m, "0x%llx\n", kho_scratch[i].size);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(scratch_len);
__init void kho_in_debugfs_init(struct kho_debugfs *dbg, const void *fdt)
{
struct dentry *dir, *sub_fdt_dir;
int err, child;
INIT_LIST_HEAD(&dbg->fdt_list);
dir = debugfs_create_dir("in", debugfs_root);
if (IS_ERR(dir)) {
err = PTR_ERR(dir);
goto err_out;
}
sub_fdt_dir = debugfs_create_dir("sub_fdts", dir);
if (IS_ERR(sub_fdt_dir)) {
err = PTR_ERR(sub_fdt_dir);
goto err_rmdir;
}
err = __kho_debugfs_fdt_add(&dbg->fdt_list, dir, "fdt", fdt);
if (err)
goto err_rmdir;
fdt_for_each_subnode(child, fdt, 0) {
int len = 0;
const char *name = fdt_get_name(fdt, child, NULL);
const u64 *fdt_phys;
fdt_phys = fdt_getprop(fdt, child, "fdt", &len);
if (!fdt_phys)
continue;
if (len != sizeof(*fdt_phys)) {
pr_warn("node %s prop fdt has invalid length: %d\n",
name, len);
continue;
}
err = __kho_debugfs_fdt_add(&dbg->fdt_list, sub_fdt_dir, name,
phys_to_virt(*fdt_phys));
if (err) {
pr_warn("failed to add fdt %s to debugfs: %pe\n", name,
ERR_PTR(err));
continue;
}
}
dbg->dir = dir;
dbg->sub_fdt_dir = sub_fdt_dir;
return;
err_rmdir:
debugfs_remove_recursive(dir);
err_out:
/*
* Failure to create /sys/kernel/debug/kho/in does not prevent
* reviving state from KHO and setting up KHO for the next
* kexec.
*/
if (err) {
pr_err("failed exposing handover FDT in debugfs: %pe\n",
ERR_PTR(err));
}
}
__init int kho_out_debugfs_init(struct kho_debugfs *dbg)
{
struct dentry *dir, *f, *sub_fdt_dir;
INIT_LIST_HEAD(&dbg->fdt_list);
dir = debugfs_create_dir("out", debugfs_root);
if (IS_ERR(dir))
return -ENOMEM;
sub_fdt_dir = debugfs_create_dir("sub_fdts", dir);
if (IS_ERR(sub_fdt_dir))
goto err_rmdir;
f = debugfs_create_file("scratch_phys", 0400, dir, NULL,
&scratch_phys_fops);
if (IS_ERR(f))
goto err_rmdir;
f = debugfs_create_file("scratch_len", 0400, dir, NULL,
&scratch_len_fops);
if (IS_ERR(f))
goto err_rmdir;
f = debugfs_create_file("finalize", 0600, dir, NULL,
&kho_out_finalize_fops);
if (IS_ERR(f))
goto err_rmdir;
dbg->dir = dir;
dbg->sub_fdt_dir = sub_fdt_dir;
return 0;
err_rmdir:
debugfs_remove_recursive(dir);
return -ENOENT;
}
__init int kho_debugfs_init(void)
{
debugfs_root = debugfs_create_dir("kho", NULL);
if (IS_ERR(debugfs_root))
return -ENOENT;
return 0;
}
|
