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
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
// SPDX-License-Identifier: GPL-2.0
/*
* Helper functions used by the EFI stub on multiple
* architectures. This should be #included by the EFI stub
* implementation files.
*
* Copyright 2011 Intel Corporation; author Matt Fleming
*/
#include <linux/efi.h>
#include <asm/efi.h>
#include "efistub.h"
#define MAX_FILENAME_SIZE 256
/*
* Some firmware implementations have problems reading files in one go.
* A read chunk size of 1MB seems to work for most platforms.
*
* Unfortunately, reading files in chunks triggers *other* bugs on some
* platforms, so we provide a way to disable this workaround, which can
* be done by passing "efi=nochunk" on the EFI boot stub command line.
*
* If you experience issues with initrd images being corrupt it's worth
* trying efi=nochunk, but chunking is enabled by default on x86 because
* there are far more machines that require the workaround than those that
* break with it enabled.
*/
#define EFI_READ_CHUNK_SIZE SZ_1M
struct finfo {
efi_file_info_t info;
efi_char16_t filename[MAX_FILENAME_SIZE];
};
static efi_status_t efi_open_file(efi_file_protocol_t *volume,
struct finfo *fi,
efi_file_protocol_t **handle,
unsigned long *file_size)
{
efi_guid_t info_guid = EFI_FILE_INFO_ID;
efi_file_protocol_t *fh;
unsigned long info_sz;
efi_status_t status;
status = volume->open(volume, &fh, fi->filename, EFI_FILE_MODE_READ, 0);
if (status != EFI_SUCCESS) {
efi_err("Failed to open file: %ls\n", fi->filename);
return status;
}
info_sz = sizeof(struct finfo);
status = fh->get_info(fh, &info_guid, &info_sz, fi);
if (status != EFI_SUCCESS) {
efi_err("Failed to get file info\n");
fh->close(fh);
return status;
}
*handle = fh;
*file_size = fi->info.file_size;
return EFI_SUCCESS;
}
static efi_status_t efi_open_volume(efi_loaded_image_t *image,
efi_file_protocol_t **fh)
{
efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
efi_simple_file_system_protocol_t *io;
efi_status_t status;
status = efi_bs_call(handle_protocol, image->device_handle, &fs_proto,
(void **)&io);
if (status != EFI_SUCCESS) {
efi_err("Failed to handle fs_proto\n");
return status;
}
status = io->open_volume(io, fh);
if (status != EFI_SUCCESS)
efi_err("Failed to open volume\n");
return status;
}
static int find_file_option(const efi_char16_t *cmdline, int cmdline_len,
const efi_char16_t *prefix, int prefix_size,
efi_char16_t *result, int result_len)
{
int prefix_len = prefix_size / 2;
bool found = false;
int i;
for (i = prefix_len; i < cmdline_len; i++) {
if (!memcmp(&cmdline[i - prefix_len], prefix, prefix_size)) {
found = true;
break;
}
}
if (!found)
return 0;
while (--result_len > 0 && i < cmdline_len) {
if (cmdline[i] == L'\0' ||
cmdline[i] == L'\n' ||
cmdline[i] == L' ')
break;
*result++ = cmdline[i++];
}
*result = L'\0';
return i;
}
/*
* Check the cmdline for a LILO-style file= arguments.
*
* We only support loading a file from the same filesystem as
* the kernel image.
*/
efi_status_t handle_cmdline_files(efi_loaded_image_t *image,
const efi_char16_t *optstr,
int optstr_size,
unsigned long soft_limit,
unsigned long hard_limit,
unsigned long *load_addr,
unsigned long *load_size)
{
const efi_char16_t *cmdline = image->load_options;
int cmdline_len = image->load_options_size / 2;
unsigned long efi_chunk_size = ULONG_MAX;
efi_file_protocol_t *volume = NULL;
efi_file_protocol_t *file;
unsigned long alloc_addr;
unsigned long alloc_size;
efi_status_t status;
int offset;
if (!load_addr || !load_size)
return EFI_INVALID_PARAMETER;
if (IS_ENABLED(CONFIG_X86) && !efi_nochunk)
efi_chunk_size = EFI_READ_CHUNK_SIZE;
alloc_addr = alloc_size = 0;
do {
struct finfo fi;
unsigned long size;
void *addr;
offset = find_file_option(cmdline, cmdline_len,
optstr, optstr_size,
fi.filename, ARRAY_SIZE(fi.filename));
if (!offset)
break;
cmdline += offset;
cmdline_len -= offset;
if (!volume) {
status = efi_open_volume(image, &volume);
if (status != EFI_SUCCESS)
return status;
}
status = efi_open_file(volume, &fi, &file, &size);
if (status != EFI_SUCCESS)
goto err_close_volume;
/*
* Check whether the existing allocation can contain the next
* file. This condition will also trigger naturally during the
* first (and typically only) iteration of the loop, given that
* alloc_size == 0 in that case.
*/
if (round_up(alloc_size + size, EFI_ALLOC_ALIGN) >
round_up(alloc_size, EFI_ALLOC_ALIGN)) {
unsigned long old_addr = alloc_addr;
status = EFI_OUT_OF_RESOURCES;
if (soft_limit < hard_limit)
status = efi_allocate_pages(alloc_size + size,
&alloc_addr,
soft_limit);
if (status == EFI_OUT_OF_RESOURCES)
status = efi_allocate_pages(alloc_size + size,
&alloc_addr,
hard_limit);
if (status != EFI_SUCCESS) {
efi_err("Failed to allocate memory for files\n");
goto err_close_file;
}
if (old_addr != 0) {
/*
* This is not the first time we've gone
* around this loop, and so we are loading
* multiple files that need to be concatenated
* and returned in a single buffer.
*/
memcpy((void *)alloc_addr, (void *)old_addr, alloc_size);
efi_free(alloc_size, old_addr);
}
}
addr = (void *)alloc_addr + alloc_size;
alloc_size += size;
while (size) {
unsigned long chunksize = min(size, efi_chunk_size);
status = file->read(file, &chunksize, addr);
if (status != EFI_SUCCESS) {
efi_err("Failed to read file\n");
goto err_close_file;
}
addr += chunksize;
size -= chunksize;
}
file->close(file);
} while (offset > 0);
*load_addr = alloc_addr;
*load_size = alloc_size;
if (volume)
volume->close(volume);
return EFI_SUCCESS;
err_close_file:
file->close(file);
err_close_volume:
volume->close(volume);
efi_free(alloc_size, alloc_addr);
return status;
}
|
