Bonjour,
J'ai un petit probl�me avec chroot :
par exemple :
$ chroot /var/cvs/ /bin/bash
chroot: cannot execute /bin/bash: No such file or directory
donc j'ai fait du google : probl�me d�j� vu mais j'ai pas trouv� de
solutions...
donc, sans me d�filer, j'ai fait un strace :
___
execve("/usr/sbin/chroot", ["chroot", "/var/cvs", "/bin/bash"], [/* 17 vars
*/]) = 0
uname({sys="Linux", node="pascalou", ...}) = 0
brk(0) = 0x804b444
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0x40015000open("/etc/ld.so.preload", O_RDONLY) = 3
fstat64(0x3, 0xbffff7b4) = -1 ENOSYS (Function not implemented)
fstat(3, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
close(3) = 0
open("/etc/ld.so.cache", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=43267, ...}) = 0
old_mmap(NULL, 43267, PROT_READ, MAP_PRIVATE, 3, 0) = 0x40016000
close(3) = 0
open("/lib/libc.so.6", O_RDONLY) = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\250\323"..., 1024) =
1024
fstat(3, {st_mode=S_IFREG|0755, st_size=1104456, ...}) = 0
old_mmap(NULL, 1120932, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0x40021000
mprotect(0x40129000, 39588, PROT_NONE) = 0
old_mmap(0x40129000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3,
0x107000) = 0x40129000
old_mmap(0x4012f000, 15012, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x4012f000
close(3) = 0
munmap(0x40016000, 43267) = 0
getpid() = 8556
brk(0) = 0x804b444
brk(0x804b46c) = 0x804b46c
brk(0x804c000) = 0x804c000
chroot("./") = 0
chdir("/") = 0
execve("/bin/bash", ["/bin/bash", "-i"], [/* 17 vars */]) = -1 ENOENT (No such
file or directory)
write(2, "chroot: ", 8chroot: ) = 8
write(2, "cannot execute /bin/bash", 24cannot execute /bin/bash) = 24
write(2, ": No such file or directory", 27: No such file or directory) = 27
write(2, "\n", 1
) = 1
_exit(1) = ?
___
(mon /bin/bash existe).
je tourne en testing avec un noyau 2.2.17.
(libc6 du paquet debian). (je pense pas que chroot soit buggu�).
Pour tout vous dire, je voudrais faire du cvs-ssh-chroot�:
et pour ce faire je lance un petit fichier C :
___
uid = getuid();
res = chdir(BASE);
if ( res ) exit(1);
printf("\nchdir ok\n");
res = chroot(BASE);
if ( res ) exit(2);
printf("\nchroot ok\n");
res = setuid(uid);
if ( res ) exit(4);
printf("\nuid ok\n");
execl("/bin/cvs", "cvs",
"server",
NULL);
___
Bien s�r, /bin/cvs existe, meme dans le nouveau chroot.
Et si je fait un strace de ce fichier compil� :
___
execve("./cvs", ["./cvs"], [/* 17 vars */]) = 0
uname({sys="Linux", node="pascalou", ...}) = 0
brk(0) = 0x804998c
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0x40015000open("/etc/ld.so.preload", O_RDONLY) = 3
fstat64(0x3, 0xbffff7c4) = -1 ENOSYS (Function not implemented)
fstat(3, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
close(3) = 0
open("/etc/ld.so.cache", O_RDONLY) = 3
fstat(3, {st_mode=S_IFREG|0644, st_size=43267, ...}) = 0
old_mmap(NULL, 43267, PROT_READ, MAP_PRIVATE, 3, 0) = 0x40016000
close(3) = 0
open("/lib/libc.so.6", O_RDONLY) = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\250\323"..., 1024) =
1024
fstat(3, {st_mode=S_IFREG|0755, st_size=1104456, ...}) = 0
old_mmap(NULL, 1120932, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0x40021000
mprotect(0x40129000, 39588, PROT_NONE) = 0
old_mmap(0x40129000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 3,
0x107000) = 0x40129000
old_mmap(0x4012f000, 15012, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x4012f000
close(3) = 0
munmap(0x40016000, 43267) = 0
getpid() = 8581
open("/run-cvs.debug", O_RDONLY) = 3
close(3) = 0
SYS_199(0x4012db4c, 0, 0x4012e860, 0x4012c2d0, 0xbffffda4) = -1 ENOSYS
(Function not implemented)
getuid() = 0
chdir("/var/cvs/yyyy/chrooted-cvs") = 0
fstat64(0x1, 0xbffff5bc) = -1 ENOSYS (Function not implemented)
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 2), ...}) = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0x40016000ioctl(1, TCGETS, {B38400 opost isig icanon echo ...}) = 0
write(1, "\n", 1
) = 1
chroot("/var/cvs/yyyy/chrooted-cvs") = 0
setuid(0) = 0
execve("/bin/strace", ["-tc", "-f", "/tmp/strace.out", "/bin/cvs", "cvs",
"server"], [/* 17 vars */]) = -1 ENOENT (No such file or directory)
munmap(0x40016000, 4096) = 0
_exit(3) = ?
___
Le chroot a l'air d'avoir march�, mail il ne me lance pas ma la derni�re
commande. Le chemin est encore bon !
Si le fstat64 qui bugue me d�range, il faut peut-etre que je recompile la
glibc, du moins la librairie io avec l'option -D_FILE_OFFSET_BITS=64 comme le
dit son auteur :
"i've written stat64, lstat64, fstat64, getdents64, mmap2 and fcntl64
syscalls. With a rebuilt glibc, these calls work fine with userspace
compiled with -D_FILE_OFFSET_BITS=64, as per the LFS standard."
[EMAIL PROTECTED] (Matthew Wilcox)
mais avant de faire ce genre de connerie, j'aimerais avoir un avis plus �clair�
sur ce bug qui m'a d�j� bouff� 3 jours.
merci.
A+
ps: j'ai le pr�sentiment que c'est juste un petit truc.
ps2: ca ne marche pas sur toutes mes stations h�t�rog�nes tournant sur testing.
--
Pascal Pucci : [EMAIL PROTECTED]
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http://www.pascalou.org, sur le mobil : [EMAIL PROTECTED]
