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
|
From: Michael Chang <mchang@suse.com>
Date: Thu, 18 Mar 2021 19:30:26 +0800
Subject: i386-pc: build verifiers API as module
Given no core functions on i386-pc would require verifiers to work and
the only consumer of the verifier API is the pgp module, it looks good
to me that we can move the verifiers out of the kernel image and let
moddep.lst to auto-load it when pgp is loaded on i386-pc platform.
This helps to reduce the size of core image and thus can relax the
tension of exploding on some i386-pc system with very short MBR gap
size. See also a very comprehensive summary from Colin [1] about the
details.
[1] https://lists.gnu.org/archive/html/grub-devel/2021-03/msg00240.html
V2:
Drop COND_NOT_i386_pc and use !COND_i386_pc.
Add comment in kern/verifiers.c to help understanding what's going on
without digging into the commit history.
Reported-by: Colin Watson <cjwatson@debian.org>
Reviewed-by: Colin Watson <cjwatson@debian.org>
Signed-off-by: Michael Chang <mchang@suse.com>
Origin: other, https://lists.gnu.org/archive/html/grub-devel/2021-03/msg00251.html
Bug-Debian: https://bugs.debian.org/984488
Bug-Debian: https://bugs.debian.org/985374
Last-Update: 2021-09-24
Patch-Name: pc-verifiers-module.patch
---
grub-core/Makefile.am | 2 ++
grub-core/Makefile.core.def | 8 +++++++-
grub-core/kern/main.c | 4 ++++
grub-core/kern/verifiers.c | 17 +++++++++++++++++
include/grub/verify.h | 9 +++++++++
5 files changed, 39 insertions(+), 1 deletion(-)
diff --git a/grub-core/Makefile.am b/grub-core/Makefile.am
index f18550c..f9d4aa2 100644
--- a/grub-core/Makefile.am
+++ b/grub-core/Makefile.am
@@ -93,7 +93,9 @@ KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/partition.h
KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/stack_protector.h
KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/term.h
KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/time.h
+if !COND_i386_pc
KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/verify.h
+endif
KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/mm_private.h
KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/net.h
KERNEL_HEADER_FILES += $(top_srcdir)/include/grub/memory.h
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 044e53c..333d3fe 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -152,7 +152,7 @@ kernel = {
common = kern/rescue_parser.c;
common = kern/rescue_reader.c;
common = kern/term.c;
- common = kern/verifiers.c;
+ nopc = kern/verifiers.c;
noemu = kern/compiler-rt.c;
noemu = kern/mm.c;
@@ -975,6 +975,12 @@ module = {
cppflags = '-I$(srcdir)/lib/posix_wrap';
};
+module = {
+ name = verifiers;
+ common = kern/verifiers.c;
+ enable = i386_pc;
+};
+
module = {
name = hdparm;
common = commands/hdparm.c;
diff --git a/grub-core/kern/main.c b/grub-core/kern/main.c
index 8401bc3..1258514 100644
--- a/grub-core/kern/main.c
+++ b/grub-core/kern/main.c
@@ -29,7 +29,9 @@
#include <grub/command.h>
#include <grub/reader.h>
#include <grub/parser.h>
+#ifndef GRUB_MACHINE_PCBIOS
#include <grub/verify.h>
+#endif
#ifdef GRUB_MACHINE_PCBIOS
#include <grub/machine/memory.h>
@@ -296,8 +298,10 @@ grub_main (void)
#endif
#endif
+#ifndef GRUB_MACHINE_PCBIOS
/* Init verifiers API. */
grub_verifiers_init ();
+#endif
grub_load_config ();
diff --git a/grub-core/kern/verifiers.c b/grub-core/kern/verifiers.c
index 75d7994..1245d0d 100644
--- a/grub-core/kern/verifiers.c
+++ b/grub-core/kern/verifiers.c
@@ -221,8 +221,25 @@ grub_verify_string (char *str, enum grub_verify_string_type type)
return GRUB_ERR_NONE;
}
+/*
+ * It is intended to build verifiers as module on i386-pc platform to minimize
+ * the impact of growing core image size could blow up the 63 sectors limit of
+ * some MBR gap one day. It is also adequate to do so, given no core function
+ * on i386-pc would require the verifiers API to work.
+ */
+#ifdef GRUB_MACHINE_PCBIOS
+GRUB_MOD_INIT(verifiers)
+#else
void
grub_verifiers_init (void)
+#endif
{
grub_file_filter_register (GRUB_FILE_FILTER_VERIFY, grub_verifiers_open);
}
+
+#ifdef GRUB_MACHINE_PCBIOS
+GRUB_MOD_FINI(verifiers)
+{
+ grub_file_filter_unregister (GRUB_FILE_FILTER_VERIFY);
+}
+#endif
diff --git a/include/grub/verify.h b/include/grub/verify.h
index 672ae16..6744816 100644
--- a/include/grub/verify.h
+++ b/include/grub/verify.h
@@ -65,10 +65,14 @@ struct grub_file_verifier
grub_err_t (*verify_string) (char *str, enum grub_verify_string_type type);
};
+#ifdef GRUB_MACHINE_PCBIOS
+extern struct grub_file_verifier *grub_file_verifiers;
+#else
extern struct grub_file_verifier *EXPORT_VAR (grub_file_verifiers);
extern void
grub_verifiers_init (void);
+#endif
static inline void
grub_verifier_register (struct grub_file_verifier *ver)
@@ -82,7 +86,12 @@ grub_verifier_unregister (struct grub_file_verifier *ver)
grub_list_remove (GRUB_AS_LIST (ver));
}
+#ifdef GRUB_MACHINE_PCBIOS
+grub_err_t
+grub_verify_string (char *str, enum grub_verify_string_type type);
+#else
extern grub_err_t
EXPORT_FUNC (grub_verify_string) (char *str, enum grub_verify_string_type type);
+#endif
#endif /* ! GRUB_VERIFY_HEADER */
|
