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[PATCH] uml: prevent umid theft 

Behavior when booting two UMLs with the same umid was broken.  The second one
would steal the umid.  This fixes that, making the second UML take a random
umid instead.

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>
This commit is contained in:
Jeff Dike 2006-03-27 01:14:39 -08:00 committed by Linus Torvalds
parent 98c18238f1
commit 1fbbd6844e
1 changed files with 23 additions and 10 deletions
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33
arch/um/os-Linux/umid.c
View File

@ -143,8 +143,10 @@ static int not_dead_yet(char *dir)
goto out_close;
}
if((kill(p, 0) == 0) || (errno != ESRCH))
if((kill(p, 0) == 0) || (errno != ESRCH)){
printk("umid \"%s\" is already in use by pid %d\n", umid, p);
return 1;
}
err = actually_do_remove(dir);
if(err)
@ -234,33 +236,44 @@ int __init make_umid(void)
err = mkdir(tmp, 0777);
if(err < 0){
err = -errno;
if(errno != EEXIST)
if(err != -EEXIST)
goto err;
if(not_dead_yet(tmp) < 0)
/* 1 -> this umid is already in use
* < 0 -> we couldn't remove the umid directory
* In either case, we can't use this umid, so return -EEXIST.
*/
if(not_dead_yet(tmp) != 0)
goto err;
err = mkdir(tmp, 0777);
}
if(err < 0){
printk("Failed to create '%s' - err = %d\n", umid, err);
goto err_rmdir;
if(err){
err = -errno;
printk("Failed to create '%s' - err = %d\n", umid, -errno);
goto err;
}
umid_setup = 1;
create_pid_file();
return 0;
err_rmdir:
rmdir(tmp);
err = 0;
err:
return err;
}
static int __init make_umid_init(void)
{
if(!make_umid())
return 0;
/* If initializing with the given umid failed, then try again with
* a random one.
*/
printk("Failed to initialize umid \"%s\", trying with a random umid\n",
umid);
*umid = '\0';
make_umid();
return 0;