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
|
#
# Minimalist mconsole exec patch
#
# 3.10 version (with bit more synchronous behavior) by fingon at iki dot fi
# Adaptation to kernel 3.3.8 made by David Fernández (david at dit.upm.es) for
# Starting point: mconsole-exec-2.6.30.patch for kernel 2.6.30
# Author of original patch: Paolo Giarrusso, aka Blaisorblade
# (http://www.user-mode-linux.org/~blaisorblade)
#
# Known misfeatures:
#
# - If output is too long, blocks (and breaks horribly)
# (this misfeature from 3.10 patches, when minimalizing the patch;
# workaround: redirect to a shared filesystem if long output is expected)
#
# - Nothing useful is done with stdin
#
--- a/arch/um/drivers/mconsole.h
+++ b/arch/um/drivers/mconsole.h
@@ -85,6 +85,7 @@
extern void mconsole_stop(struct mc_request *req);
extern void mconsole_go(struct mc_request *req);
extern void mconsole_log(struct mc_request *req);
+extern void mconsole_exec(struct mc_request *req);
extern void mconsole_proc(struct mc_request *req);
extern void mconsole_stack(struct mc_request *req);
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -4,6 +4,7 @@
* Licensed under the GPL
*/
+#include "linux/kmod.h"
#include <linux/console.h>
#include <linux/ctype.h>
#include <linux/string.h>
@@ -24,6 +25,7 @@
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/file.h>
+#include <linux/completion.h>
#include <asm/uaccess.h>
#include <asm/switch_to.h>
@@ -121,6 +123,59 @@
mconsole_reply(req, "", 0, 0);
}
+void mconsole_exec(struct mc_request *req)
+{
+ struct subprocess_info *sub_info;
+ int res, len;
+ struct file *out;
+ char buf[MCONSOLE_MAX_DATA];
+
+ char *envp[] = {
+ "HOME=/", "TERM=linux",
+ "PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin",
+ NULL
+ };
+ char *argv[] = {
+ "/bin/sh", "-c",
+ req->request.data + strlen("exec "),
+ NULL
+ };
+
+ sub_info = call_usermodehelper_setup("/bin/sh", argv, envp, GFP_ATOMIC, NULL, NULL, NULL);
+ if (sub_info == NULL) {
+ mconsole_reply(req, "call_usermodehelper_setup failed", 1, 0);
+ return;
+ }
+ res = call_usermodehelper_stdoutpipe(sub_info, &out);
+ if (res < 0) {
+ kfree(sub_info);
+ mconsole_reply(req, "call_usermodehelper_stdoutpipe failed", 1, 0);
+ return;
+ }
+
+ res = call_usermodehelper_exec(sub_info, UMH_WAIT_PROC);
+ if (res < 0) {
+ kfree(sub_info);
+ mconsole_reply(req, "call_usermodehelper_exec failed", 1, 0);
+ return;
+ }
+
+ for (;;) {
+ len = out->f_op->read(out, buf, sizeof(buf), &out->f_pos);
+ if (len < 0) {
+ mconsole_reply(req, "reading output failed", 1, 0);
+ break;
+ }
+ if (len == 0)
+ break;
+ mconsole_reply_len(req, buf, len, 0, 1);
+ }
+ fput(out);
+
+ mconsole_reply_len(req, NULL, 0, 0, 0);
+}
+
+
void mconsole_proc(struct mc_request *req)
{
struct vfsmount *mnt = task_active_pid_ns(current)->proc_mnt;
@@ -187,6 +242,7 @@
stop - pause the UML; it will do nothing until it receives a 'go' \n\
go - continue the UML after a 'stop' \n\
log <string> - make UML enter <string> into the kernel log\n\
+ exec <string> - pass <string> to /bin/sh -c synchronously\n\
proc <file> - returns the contents of the UML's /proc/<file>\n\
stack <pid> - returns the stack of the specified pid\n\
"
--- a/arch/um/drivers/mconsole_user.c
+++ b/arch/um/drivers/mconsole_user.c
@@ -30,6 +30,7 @@
{ "stop", mconsole_stop, MCONSOLE_PROC },
{ "go", mconsole_go, MCONSOLE_INTR },
{ "log", mconsole_log, MCONSOLE_INTR },
+ { "exec", mconsole_exec, MCONSOLE_PROC },
{ "proc", mconsole_proc, MCONSOLE_PROC },
{ "stack", mconsole_stack, MCONSOLE_INTR },
};
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -535,6 +535,8 @@
addr.sun_family = AF_UNIX;
+ if (len > sizeof(addr.sun_path))
+ len = sizeof(addr.sun_path);
snprintf(addr.sun_path, len, "%s", file);
err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
--- a/include/linux/kmod.h
+++ b/include/linux/kmod.h
@@ -62,6 +62,7 @@
int wait;
int retval;
int (*init)(struct subprocess_info *info, struct cred *new);
+ struct file *stdout;
void (*cleanup)(struct subprocess_info *info);
void *data;
};
@@ -102,4 +103,6 @@
extern long usermodehelper_read_lock_wait(long timeout);
extern void usermodehelper_read_unlock(void);
+int call_usermodehelper_stdoutpipe(struct subprocess_info *sub_info, struct file **filp);
+
#endif /* __LINUX_KMOD_H__ */
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -39,6 +39,7 @@
#include <linux/rwsem.h>
#include <linux/ptrace.h>
#include <linux/async.h>
+#include <linux/pipe_fs_i.h>
#include <asm/uaccess.h>
#include <trace/events/module.h>
@@ -222,6 +223,28 @@
flush_signal_handlers(current, 1);
spin_unlock_irq(¤t->sighand->siglock);
+ /* Install output when needed */
+ if (sub_info->stdout) {
+ struct files_struct *f = current->files;
+ struct fdtable *fdt;
+
+ sys_close(1);
+ sys_close(2);
+ get_file(sub_info->stdout);
+ fd_install(1, sub_info->stdout);
+ fd_install(2, sub_info->stdout);
+ spin_lock(&f->file_lock);
+ fdt = files_fdtable(f);
+ __set_bit(1, fdt->open_fds);
+ __clear_bit(1, fdt->close_on_exec);
+ __set_bit(2, fdt->open_fds);
+ __clear_bit(2, fdt->close_on_exec);
+ spin_unlock(&f->file_lock);
+
+ /* disallow core files */
+ current->signal->rlim[RLIMIT_CORE] = (struct rlimit){0, 0};
+ }
+
/*
* Our parent (unbound workqueue) runs with elevated scheduling
* priority. Avoid propagating that into the userspace child.
@@ -540,6 +563,20 @@
}
EXPORT_SYMBOL(call_usermodehelper_setup);
+int call_usermodehelper_stdoutpipe(struct subprocess_info *sub_info,
+ struct file **filp)
+{
+ struct file *f[2];
+
+ if (create_pipe_files(f, 0)<0)
+ return PTR_ERR(f);
+ sub_info->stdout = f[1];
+ *filp = f[0];
+ return 0;
+}
+EXPORT_SYMBOL(call_usermodehelper_stdoutpipe);
+
+
/**
* call_usermodehelper_exec - start a usermode application
* @sub_info: information about the subprocessa
|
