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authorJeff Dike <jdike@addtoit.com>2006-01-06 03:19:01 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-06 11:33:47 -0500
commit7eebe8a9c51686927709a57b1f2725d371014abc (patch)
tree6b1543982c8656c76c25baa7e44497d5d9de307a /arch/um
parent2264c475e4bf7427e59921953c89a5693ecb506f (diff)
[PATCH] uml: umid cleanup
This patch cleans up the umid code: - The only_if_set argument to get_umid is gone. - get_umid returns an empty string rather than NULL if there is no umid. - umid_is_random is gone since its users went away. - Some printfs were turned into printks because the code runs late enough that printk is working. - Error paths were cleaned up. - Some functions now return an error and let the caller print the error message rather than printing it themselves. This eliminates the practice of passing a pointer to printf or printk in, depending on where in the boot process we are. - Major tidying of not_dead_yet - mostly error path cleanup, plus a comment explaining why it doesn't react to errors the way you might expect. - Calls to os_* interfaces that were moved under os are changed back to their native libc forms. - snprintf, strlcpy, and their bounds-checking friends are used more often, replacing by-hand bounds checking in some places. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/um')
-rw-r--r--arch/um/drivers/line.c4
-rw-r--r--arch/um/include/os.h4
-rw-r--r--arch/um/include/user_util.h1
-rw-r--r--arch/um/kernel/um_arch.c4
-rw-r--r--arch/um/kernel/umid.c12
-rw-r--r--arch/um/os-Linux/umid.c265
6 files changed, 164 insertions, 126 deletions
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index b8e3e800ee41..a3c39373adb9 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -831,8 +831,8 @@ char *add_xterm_umid(char *base)
831 char *umid, *title; 831 char *umid, *title;
832 int len; 832 int len;
833 833
834 umid = get_umid(1); 834 umid = get_umid();
835 if(umid == NULL) 835 if(*umid == '\0')
836 return base; 836 return base;
837 837
838 len = strlen(base) + strlen(" ()") + strlen(umid) + 1; 838 len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index 258444e5b9bc..c279ee6d89e4 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -216,7 +216,7 @@ extern int helper_wait(int pid);
216/* umid.c */ 216/* umid.c */
217 217
218extern int umid_file_name(char *name, char *buf, int len); 218extern int umid_file_name(char *name, char *buf, int len);
219extern int set_umid(char *name, int (*printer)(const char *fmt, ...)); 219extern int set_umid(char *name);
220extern char *get_umid(int only_if_set); 220extern char *get_umid(void);
221 221
222#endif 222#endif
diff --git a/arch/um/include/user_util.h b/arch/um/include/user_util.h
index bb505e01d994..b9984003e603 100644
--- a/arch/um/include/user_util.h
+++ b/arch/um/include/user_util.h
@@ -64,7 +64,6 @@ extern void setup_machinename(char *machine_out);
64extern void setup_hostinfo(void); 64extern void setup_hostinfo(void);
65extern void do_exec(int old_pid, int new_pid); 65extern void do_exec(int old_pid, int new_pid);
66extern void tracer_panic(char *msg, ...); 66extern void tracer_panic(char *msg, ...);
67extern char *get_umid(int only_if_set);
68extern void do_longjmp(void *p, int val); 67extern void do_longjmp(void *p, int val);
69extern int detach(int pid, int sig); 68extern int detach(int pid, int sig);
70extern int attach(int pid); 69extern int attach(int pid);
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 142a9493912b..26626b2b9172 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -146,8 +146,8 @@ void set_cmdline(char *cmd)
146 146
147 if(CHOOSE_MODE(honeypot, 0)) return; 147 if(CHOOSE_MODE(honeypot, 0)) return;
148 148
149 umid = get_umid(1); 149 umid = get_umid();
150 if(umid != NULL){ 150 if(*umid != '\0'){
151 snprintf(argv1_begin, 151 snprintf(argv1_begin,
152 (argv1_end - argv1_begin) * sizeof(*ptr), 152 (argv1_end - argv1_begin) * sizeof(*ptr),
153 "(%s) ", umid); 153 "(%s) ", umid);
diff --git a/arch/um/kernel/umid.c b/arch/um/kernel/umid.c
index 772c7cfbd8ec..4eaee823bfd2 100644
--- a/arch/um/kernel/umid.c
+++ b/arch/um/kernel/umid.c
@@ -3,15 +3,13 @@
3 * Licensed under the GPL 3 * Licensed under the GPL
4 */ 4 */
5 5
6#include "linux/stddef.h"
7#include "linux/kernel.h"
8#include "asm/errno.h" 6#include "asm/errno.h"
9#include "init.h" 7#include "init.h"
10#include "os.h" 8#include "os.h"
11#include "kern.h" 9#include "kern.h"
10#include "linux/kernel.h"
12 11
13/* Changed by set_umid_arg and umid_file_name */ 12/* Changed by set_umid_arg */
14int umid_is_random = 0;
15static int umid_inited = 0; 13static int umid_inited = 0;
16 14
17static int __init set_umid_arg(char *name, int *add) 15static int __init set_umid_arg(char *name, int *add)
@@ -22,11 +20,9 @@ static int __init set_umid_arg(char *name, int *add)
22 return 0; 20 return 0;
23 21
24 *add = 0; 22 *add = 0;
25 err = set_umid(name, printf); 23 err = set_umid(name);
26 if(err == -EEXIST){ 24 if(err == -EEXIST)
27 printf("umid '%s' already in use\n", name); 25 printf("umid '%s' already in use\n", name);
28 umid_is_random = 1;
29 }
30 else if(!err) 26 else if(!err)
31 umid_inited = 1; 27 umid_inited = 1;
32 28
diff --git a/arch/um/os-Linux/umid.c b/arch/um/os-Linux/umid.c
index 77d69a348cf4..ecf107ae5ac8 100644
--- a/arch/um/os-Linux/umid.c
+++ b/arch/um/os-Linux/umid.c
@@ -5,6 +5,7 @@
5#include <errno.h> 5#include <errno.h>
6#include <signal.h> 6#include <signal.h>
7#include <dirent.h> 7#include <dirent.h>
8#include <sys/fcntl.h>
8#include <sys/stat.h> 9#include <sys/stat.h>
9#include <sys/param.h> 10#include <sys/param.h>
10#include "init.h" 11#include "init.h"
@@ -25,15 +26,16 @@ static char *uml_dir = UML_DIR;
25static int __init make_uml_dir(void) 26static int __init make_uml_dir(void)
26{ 27{
27 char dir[512] = { '\0' }; 28 char dir[512] = { '\0' };
28 int len; 29 int len, err;
29 30
30 if(*uml_dir == '~'){ 31 if(*uml_dir == '~'){
31 char *home = getenv("HOME"); 32 char *home = getenv("HOME");
32 33
34 err = -ENOENT;
33 if(home == NULL){ 35 if(home == NULL){
34 printf("make_uml_dir : no value in environment for " 36 printk("make_uml_dir : no value in environment for "
35 "$HOME\n"); 37 "$HOME\n");
36 exit(1); 38 goto err;
37 } 39 }
38 strlcpy(dir, home, sizeof(dir)); 40 strlcpy(dir, home, sizeof(dir));
39 uml_dir++; 41 uml_dir++;
@@ -43,18 +45,26 @@ static int __init make_uml_dir(void)
43 if (len > 0 && dir[len - 1] != '/') 45 if (len > 0 && dir[len - 1] != '/')
44 strlcat(dir, "/", sizeof(dir)); 46 strlcat(dir, "/", sizeof(dir));
45 47
48 err = -ENOMEM;
46 uml_dir = malloc(strlen(dir) + 1); 49 uml_dir = malloc(strlen(dir) + 1);
47 if (uml_dir == NULL) { 50 if (uml_dir == NULL) {
48 printf("make_uml_dir : malloc failed, errno = %d\n", errno); 51 printf("make_uml_dir : malloc failed, errno = %d\n", errno);
49 exit(1); 52 goto err;
50 } 53 }
51 strcpy(uml_dir, dir); 54 strcpy(uml_dir, dir);
52 55
53 if((mkdir(uml_dir, 0777) < 0) && (errno != EEXIST)){ 56 if((mkdir(uml_dir, 0777) < 0) && (errno != EEXIST)){
54 printf("Failed to mkdir '%s': %s\n", uml_dir, strerror(errno)); 57 printf("Failed to mkdir '%s': %s\n", uml_dir, strerror(errno));
55 return(-1); 58 err = -errno;
59 goto err_free;
56 } 60 }
57 return 0; 61 return 0;
62
63err_free:
64 free(uml_dir);
65err:
66 uml_dir = NULL;
67 return err;
58} 68}
59 69
60static int actually_do_remove(char *dir) 70static int actually_do_remove(char *dir)
@@ -65,75 +75,88 @@ static int actually_do_remove(char *dir)
65 char file[256]; 75 char file[256];
66 76
67 directory = opendir(dir); 77 directory = opendir(dir);
68 if(directory == NULL){ 78 if(directory == NULL)
69 printk("actually_do_remove : couldn't open directory '%s', " 79 return -errno;
70 "errno = %d\n", dir, errno); 80
71 return(1);
72 }
73 while((ent = readdir(directory)) != NULL){ 81 while((ent = readdir(directory)) != NULL){
74 if(!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, "..")) 82 if(!strcmp(ent->d_name, ".") || !strcmp(ent->d_name, ".."))
75 continue; 83 continue;
76 len = strlen(dir) + sizeof("/") + strlen(ent->d_name) + 1; 84 len = strlen(dir) + sizeof("/") + strlen(ent->d_name) + 1;
77 if(len > sizeof(file)){ 85 if(len > sizeof(file))
78 printk("Not deleting '%s' from '%s' - name too long\n", 86 return -E2BIG;
79 ent->d_name, dir); 87
80 continue;
81 }
82 sprintf(file, "%s/%s", dir, ent->d_name); 88 sprintf(file, "%s/%s", dir, ent->d_name);
83 if(unlink(file) < 0){ 89 if(unlink(file) < 0)
84 printk("actually_do_remove : couldn't remove '%s' " 90 return -errno;
85 "from '%s', errno = %d\n", ent->d_name, dir,
86 errno);
87 return(1);
88 }
89 }
90 if(rmdir(dir) < 0){
91 printk("actually_do_remove : couldn't rmdir '%s', "
92 "errno = %d\n", dir, errno);
93 return(1);
94 } 91 }
95 return(0); 92 if(rmdir(dir) < 0)
93 return -errno;
94
95 return 0;
96} 96}
97 97
98extern int tracing_pid; 98/* This says that there isn't already a user of the specified directory even if
99 * there are errors during the checking. This is because if these errors
100 * happen, the directory is unusable by the pre-existing UML, so we might as
101 * well take it over. This could happen either by
102 * the existing UML somehow corrupting its umid directory
103 * something other than UML sticking stuff in the directory
104 * this boot racing with a shutdown of the other UML
105 * In any of these cases, the directory isn't useful for anything else.
106 */
99 107
100static int not_dead_yet(char *dir) 108static int not_dead_yet(char *dir)
101{ 109{
102 char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")]; 110 char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
103 char pid[sizeof("nnnnn\0")], *end; 111 char pid[sizeof("nnnnn\0")], *end;
104 int dead, fd, p, n; 112 int dead, fd, p, n, err;
113
114 n = snprintf(file, sizeof(file), "%s/pid", dir);
115 if(n >= sizeof(file)){
116 printk("not_dead_yet - pid filename too long\n");
117 err = -E2BIG;
118 goto out;
119 }
105 120
106 sprintf(file, "%s/pid", dir);
107 dead = 0; 121 dead = 0;
108 fd = os_open_file(file, of_read(OPENFLAGS()), 0); 122 fd = open(file, O_RDONLY);
109 if(fd < 0){ 123 if(fd < 0){
110 if(fd != -ENOENT){ 124 if(fd != -ENOENT){
111 printk("not_dead_yet : couldn't open pid file '%s', " 125 printk("not_dead_yet : couldn't open pid file '%s', "
112 "err = %d\n", file, -fd); 126 "err = %d\n", file, -fd);
113 return(1);
114 } 127 }
115 dead = 1; 128 goto out;
116 } 129 }
117 if(fd > 0){ 130
118 n = os_read_file(fd, pid, sizeof(pid)); 131 err = 0;
119 if(n < 0){ 132 n = read(fd, pid, sizeof(pid));
120 printk("not_dead_yet : couldn't read pid file '%s', " 133 if(n <= 0){
121 "err = %d\n", file, -n); 134 printk("not_dead_yet : couldn't read pid file '%s', "
122 return(1); 135 "err = %d\n", file, -n);
123 } 136 goto out_close;
124 p = strtoul(pid, &end, 0); 137 }
125 if(end == pid){ 138
126 printk("not_dead_yet : couldn't parse pid file '%s', " 139 p = strtoul(pid, &end, 0);
127 "errno = %d\n", file, errno); 140 if(end == pid){
128 dead = 1; 141 printk("not_dead_yet : couldn't parse pid file '%s', "
129 } 142 "errno = %d\n", file, errno);
130 if(((kill(p, 0) < 0) && (errno == ESRCH)) || 143 goto out_close;
131 (p == CHOOSE_MODE(tracing_pid, os_getpid())))
132 dead = 1;
133 } 144 }
134 if(!dead) 145
135 return(1); 146 if((kill(p, 0) == 0) || (errno != ESRCH))
136 return(actually_do_remove(dir)); 147 return 1;
148
149 err = actually_do_remove(dir);
150 if(err)
151 printk("not_dead_yet - actually_do_remove failed with "
152 "err = %d\n", err);
153
154 return err;
155
156 out_close:
157 close(fd);
158 out:
159 return 0;
137} 160}
138 161
139static void __init create_pid_file(void) 162static void __init create_pid_file(void)
@@ -145,26 +168,26 @@ static void __init create_pid_file(void)
145 if(umid_file_name("pid", file, sizeof(file))) 168 if(umid_file_name("pid", file, sizeof(file)))
146 return; 169 return;
147 170
148 fd = os_open_file(file, of_create(of_excl(of_rdwr(OPENFLAGS()))), 171 fd = open(file, O_RDWR | O_CREAT | O_EXCL, 0644);
149 0644);
150 if(fd < 0){ 172 if(fd < 0){
151 printf("Open of machine pid file \"%s\" failed: %s\n", 173 printk("Open of machine pid file \"%s\" failed: %s\n",
152 file, strerror(-fd)); 174 file, strerror(-fd));
153 return; 175 return;
154 } 176 }
155 177
156 sprintf(pid, "%d\n", os_getpid()); 178 snprintf(pid, sizeof(pid), "%d\n", getpid());
157 n = os_write_file(fd, pid, strlen(pid)); 179 n = write(fd, pid, strlen(pid));
158 if(n != strlen(pid)) 180 if(n != strlen(pid))
159 printf("Write of pid file failed - err = %d\n", -n); 181 printk("Write of pid file failed - err = %d\n", -n);
160 os_close_file(fd); 182
183 close(fd);
161} 184}
162 185
163int __init set_umid(char *name, int (*printer)(const char *fmt, ...)) 186int __init set_umid(char *name)
164{ 187{
165 if(strlen(name) > UMID_LEN - 1) 188 if(strlen(name) > UMID_LEN - 1)
166 (*printer)("Unique machine name is being truncated to %d " 189 return -E2BIG;
167 "characters\n", UMID_LEN); 190
168 strlcpy(umid, name, sizeof(umid)); 191 strlcpy(umid, name, sizeof(umid));
169 192
170 return 0; 193 return 0;
@@ -172,44 +195,56 @@ int __init set_umid(char *name, int (*printer)(const char *fmt, ...))
172 195
173static int umid_setup = 0; 196static int umid_setup = 0;
174 197
175int __init make_umid(int (*printer)(const char *fmt, ...)) 198int __init make_umid(void)
176{ 199{
177 int fd, err; 200 int fd, err;
178 char tmp[256]; 201 char tmp[256];
179 202
203 if(umid_setup)
204 return 0;
205
180 make_uml_dir(); 206 make_uml_dir();
181 207
182 if(*umid == '\0'){ 208 if(*umid == '\0'){
183 strlcpy(tmp, uml_dir, sizeof(tmp)); 209 strlcpy(tmp, uml_dir, sizeof(tmp));
184 strcat(tmp, "XXXXXX"); 210 strlcat(tmp, "XXXXXX", sizeof(tmp));
185 fd = mkstemp(tmp); 211 fd = mkstemp(tmp);
186 if(fd < 0){ 212 if(fd < 0){
187 (*printer)("make_umid - mkstemp(%s) failed: %s\n", 213 printk("make_umid - mkstemp(%s) failed: %s\n",
188 tmp,strerror(errno)); 214 tmp, strerror(errno));
189 return(1); 215 err = -errno;
216 goto err;
190 } 217 }
191 218
192 os_close_file(fd); 219 close(fd);
220
221 set_umid(&tmp[strlen(uml_dir)]);
222
193 /* There's a nice tiny little race between this unlink and 223 /* There's a nice tiny little race between this unlink and
194 * the mkdir below. It'd be nice if there were a mkstemp 224 * the mkdir below. It'd be nice if there were a mkstemp
195 * for directories. 225 * for directories.
196 */ 226 */
197 unlink(tmp); 227 if(unlink(tmp)){
198 set_umid(&tmp[strlen(uml_dir)], printer); 228 err = -errno;
229 goto err;
230 }
199 } 231 }
200 232
201 sprintf(tmp, "%s%s", uml_dir, umid); 233 snprintf(tmp, sizeof(tmp), "%s%s", uml_dir, umid);
202 err = mkdir(tmp, 0777); 234 err = mkdir(tmp, 0777);
203 if(err < 0){ 235 if(err < 0){
204 if(errno == EEXIST){ 236 err = -errno;
205 if(not_dead_yet(tmp)) 237 if(errno != EEXIST)
206 return -EEXIST; 238 goto err;
207 err = mkdir(tmp, 0777); 239
208 } 240 if(not_dead_yet(tmp) < 0)
241 goto err;
242
243 err = mkdir(tmp, 0777);
209 } 244 }
210 if(err < 0){ 245 if(err < 0){
211 (*printer)("Failed to create %s - errno = %d\n", umid, errno); 246 printk("Failed to create '%s' - err = %d\n", umid, err);
212 return(-1); 247 goto err_rmdir;
213 } 248 }
214 249
215 umid_setup = 1; 250 umid_setup = 1;
@@ -217,13 +252,18 @@ int __init make_umid(int (*printer)(const char *fmt, ...))
217 create_pid_file(); 252 create_pid_file();
218 253
219 return 0; 254 return 0;
255
256 err_rmdir:
257 rmdir(tmp);
258 err:
259 return err;
220} 260}
221 261
222static int __init make_umid_init(void) 262static int __init make_umid_init(void)
223{ 263{
224 make_umid(printk); 264 make_umid();
225 265
226 return(0); 266 return 0;
227} 267}
228 268
229__initcall(make_umid_init); 269__initcall(make_umid_init);
@@ -232,48 +272,48 @@ int __init umid_file_name(char *name, char *buf, int len)
232{ 272{
233 int n, err; 273 int n, err;
234 274
235 if(!umid_setup){ 275 err = make_umid();
236 err = make_umid(printk); 276 if(err)
237 if(err) 277 return err;
238 return err;
239 }
240 278
241 n = strlen(uml_dir) + strlen(umid) + strlen("/") + strlen(name) + 1; 279 n = snprintf(buf, len, "%s%s/%s", uml_dir, umid, name);
242 if(n > len){ 280 if(n >= len){
243 printk("umid_file_name : buffer too short\n"); 281 printk("umid_file_name : buffer too short\n");
244 return(-1); 282 return -E2BIG;
245 } 283 }
246 284
247 sprintf(buf, "%s%s/%s", uml_dir, umid, name); 285 return 0;
248 return(0);
249} 286}
250 287
251extern int umid_is_random; 288char *get_umid(void)
252
253char *get_umid(int only_if_set)
254{ 289{
255 if(only_if_set && umid_is_random)
256 return NULL;
257 return umid; 290 return umid;
258} 291}
259 292
260static int __init set_uml_dir(char *name, int *add) 293static int __init set_uml_dir(char *name, int *add)
261{ 294{
262 if((strlen(name) > 0) && (name[strlen(name) - 1] != '/')){ 295 if(*name == '\0'){
263 uml_dir = malloc(strlen(name) + 2); 296 printf("uml_dir can't be an empty string\n");
264 if(uml_dir == NULL){ 297 return 0;
265 printf("Failed to malloc uml_dir - error = %d\n",
266 errno);
267 uml_dir = name;
268 /* Return 0 here because do_initcalls doesn't look at
269 * the return value.
270 */
271 return(0);
272 }
273 sprintf(uml_dir, "%s/", name);
274 } 298 }
275 else uml_dir = name; 299
276 return(0); 300 if(name[strlen(name) - 1] == '/'){
301 uml_dir = name;
302 return 0;
303 }
304
305 uml_dir = malloc(strlen(name) + 2);
306 if(uml_dir == NULL){
307 printf("Failed to malloc uml_dir - error = %d\n", errno);
308
309 /* Return 0 here because do_initcalls doesn't look at
310 * the return value.
311 */
312 return 0;
313 }
314 sprintf(uml_dir, "%s/", name);
315
316 return 0;
277} 317}
278 318
279__uml_setup("uml_dir=", set_uml_dir, 319__uml_setup("uml_dir=", set_uml_dir,
@@ -283,10 +323,13 @@ __uml_setup("uml_dir=", set_uml_dir,
283 323
284static void remove_umid_dir(void) 324static void remove_umid_dir(void)
285{ 325{
286 char dir[strlen(uml_dir) + UMID_LEN + 1]; 326 char dir[strlen(uml_dir) + UMID_LEN + 1], err;
287 327
288 sprintf(dir, "%s%s", uml_dir, umid); 328 sprintf(dir, "%s%s", uml_dir, umid);
289 actually_do_remove(dir); 329 err = actually_do_remove(dir);
330 if(err)
331 printf("remove_umid_dir - actually_do_remove failed with "
332 "err = %d\n", err);
290} 333}
291 334
292__uml_exitcall(remove_umid_dir); 335__uml_exitcall(remove_umid_dir);