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
|
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Will McVicker <willmcvicker@google.com>
Date: Thu, 19 Nov 2020 13:46:37 -0800
Subject: ANDROID: modules: re-introduce the MODULE_SCMVERSION config
Config MODULE_SCMVERSION introduces a new module attribute --
`scmversion` -- which can be used to identify a given module's SCM
version. This is very useful for developers that update their kernel
independently from their kernel modules or vice-versa since the SCM
version provided by UTS_RELEASE (`uname -r`) will now differ from the
module's vermagic attribute.
For example, we have a CI setup that tests new kernel changes on the
hikey960 and db845c devices without updating their kernel modules. When
these tests fail, we need to be able to identify the exact device
configuration the test was using. By including MODULE_SCMVERSION, we can
identify the exact kernel and modules' SCM versions for debugging the
failures.
Additionally, by exposing the SCM version via the sysfs node
/sys/module/MODULENAME/scmversion, one can also verify the SCM versions
of the modules loaded from the initramfs. Currently, modinfo can only
retrieve module attributes from the module's ko on disk and not from the
actual module that is loaded in RAM.
You can retrieve the SCM version in two ways,
1) By using modinfo:
> modinfo -F scmversion MODULENAME
2) By module sysfs node:
> cat /sys/module/MODULENAME/scmversion
Bug: 180027765
Bug: 236871190
Link: https://lore.kernel.org/all/20210121213641.3477522-1-willmcvicker@google.com/
Signed-off-by: Will McVicker <willmcvicker@google.com>
Signed-off-by: Yifan Hong <elsk@google.com>
Change-Id: Iad77caff63c4ddef3a3c92182cdacb0b90b124c7
---
Documentation/ABI/stable/sysfs-module | 18 ++++++++++++++++++
include/linux/module.h | 1 +
kernel/module/Kconfig | 14 ++++++++++++++
kernel/module/main.c | 2 ++
scripts/Makefile.modpost | 27 +++++++++++++++++++++++++++
scripts/mod/modpost.c | 10 +++++++++-
6 files changed, 71 insertions(+), 1 deletion(-)
diff --git a/Documentation/ABI/stable/sysfs-module b/Documentation/ABI/stable/sysfs-module
--- a/Documentation/ABI/stable/sysfs-module
+++ b/Documentation/ABI/stable/sysfs-module
@@ -45,3 +45,21 @@ Date: Jun 2005
Description:
If the module source has MODULE_VERSION, this file will contain
the version of the source code.
+
+What: /sys/module/MODULENAME/scmversion
+Date: November 2020
+KernelVersion: 5.12
+Contact: Will McVicker <willmcvicker@google.com>
+Description: This read-only file will appear if modpost was supplied with an
+ SCM version for the module. It can be enabled with the config
+ MODULE_SCMVERSION. The SCM version is retrieved by
+ scripts/setlocalversion, which means that the presence of this
+ file depends on CONFIG_LOCALVERSION_AUTO=y. When read, the SCM
+ version that the module was compiled with is returned. The SCM
+ version is returned in the following format::
+
+ ===
+ Git: g[a-f0-9]\+(-dirty)\?
+ Mercurial: hg[a-f0-9]\+(-dirty)\?
+ Subversion: svn[0-9]\+
+ ===
diff --git a/include/linux/module.h b/include/linux/module.h
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -418,6 +418,7 @@ struct module {
struct module_attribute *modinfo_attrs;
const char *version;
const char *srcversion;
+ const char *scmversion;
struct kobject *holders_dir;
/* Exported symbols */
diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
--- a/kernel/module/Kconfig
+++ b/kernel/module/Kconfig
@@ -186,6 +186,20 @@ config MODULE_SRCVERSION_ALL
the version). With this option, such a "srcversion" field
will be created for all modules. If unsure, say N.
+config MODULE_SCMVERSION
+ bool "SCM version for modules"
+ depends on LOCALVERSION_AUTO
+ help
+ This enables the module attribute "scmversion" which can be used
+ by developers to identify the SCM version of a given module, e.g.
+ git sha1 or hg sha1. The SCM version can be queried by modinfo or
+ via the sysfs node: /sys/modules/MODULENAME/scmversion. This is
+ useful when the kernel or kernel modules are updated separately
+ since that causes the vermagic of the kernel and the module to
+ differ.
+
+ If unsure, say N.
+
config MODULE_SIG
bool "Module signature verification"
select MODULE_SIG_FORMAT
diff --git a/kernel/module/main.c b/kernel/module/main.c
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -528,6 +528,7 @@ static struct module_attribute modinfo_##field = { \
MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);
+MODINFO_ATTR(scmversion);
static struct {
char name[MODULE_NAME_LEN + 1];
@@ -980,6 +981,7 @@ struct module_attribute *modinfo_attrs[] = {
&module_uevent,
&modinfo_version,
&modinfo_srcversion,
+ &modinfo_scmversion,
&modinfo_initstate,
&modinfo_coresize,
#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -65,6 +65,33 @@ modpost-args += -T $(MODORDER)
modpost-deps += $(MODORDER)
endif
+ifeq ($(CONFIG_MODULE_SCMVERSION),y)
+ifeq ($(KBUILD_EXTMOD),)
+module_srcpath := $(srctree)
+else
+# Get the external module's source path. KBUILD_EXTMOD could either be an
+# absolute path or relative path from $(srctree). This makes sure that we
+# aren't using a relative path from a separate working directory (O= or
+# KBUILD_OUTPUT) since that may not be the actual module's SCM project path. So
+# check the path relative to $(srctree) first.
+ifneq ($(realpath $(srctree)/$(KBUILD_EXTMOD) 2>/dev/null),)
+ module_srcpath := $(srctree)/$(KBUILD_EXTMOD)
+else
+ module_srcpath := $(KBUILD_EXTMOD)
+endif
+endif
+
+# Get the SCM version of the module. Sed verifies setlocalversion returns
+# a proper revision based on the SCM type, e.g. git, mercurial, or svn.
+# Note: relative M= paths are not supported when building the kernel out of the
+# srctree since setlocalversion won't be able to find the module srctree.
+module_scmversion := $(shell $(srctree)/scripts/setlocalversion $(module_srcpath) | \
+ sed -n 's/.*-\(\(g\|hg\)[a-fA-F0-9]\+\(-dirty\)\?\|svn[0-9]\+\).*/\1/p')
+ifneq ($(module_scmversion),)
+modpost-args += -v $(module_scmversion)
+endif
+endif
+
ifeq ($(KBUILD_EXTMOD),)
# Generate the list of in-tree objects in vmlinux
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -30,6 +30,8 @@ static bool modversions;
static bool all_versions;
/* If we are modposting external module set to 1 */
static bool external_module;
+#define MODULE_SCMVERSION_SIZE 64
+static char module_scmversion[MODULE_SCMVERSION_SIZE];
/* Only warn about unresolved symbols */
static bool warn_unresolved;
@@ -1841,6 +1843,9 @@ static void add_header(struct buffer *b, struct module *mod)
if (!external_module)
buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
+ if (module_scmversion[0] != '\0')
+ buf_printf(b, "\nMODULE_INFO(scmversion, \"%s\");\n", module_scmversion);
+
buf_printf(b,
"\n"
"#ifdef CONFIG_RETPOLINE\n"
@@ -2183,7 +2188,7 @@ int main(int argc, char **argv)
LIST_HEAD(dump_lists);
struct dump_list *dl, *dl2;
- while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) {
+ while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:v:")) != -1) {
switch (opt) {
case 'e':
external_module = true;
@@ -2232,6 +2237,9 @@ int main(int argc, char **argv)
case 'd':
missing_namespace_deps = optarg;
break;
+ case 'v':
+ strncpy(module_scmversion, optarg, sizeof(module_scmversion) - 1);
+ break;
default:
exit(1);
}
|
