Commit 1fbbd684 authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds

[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: default avatarJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 98c18238
...@@ -143,8 +143,10 @@ static int not_dead_yet(char *dir) ...@@ -143,8 +143,10 @@ static int not_dead_yet(char *dir)
goto out_close; 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; return 1;
}
err = actually_do_remove(dir); err = actually_do_remove(dir);
if(err) if(err)
...@@ -234,33 +236,44 @@ int __init make_umid(void) ...@@ -234,33 +236,44 @@ int __init make_umid(void)
err = mkdir(tmp, 0777); err = mkdir(tmp, 0777);
if(err < 0){ if(err < 0){
err = -errno; err = -errno;
if(errno != EEXIST) if(err != -EEXIST)
goto err; 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; goto err;
err = mkdir(tmp, 0777); err = mkdir(tmp, 0777);
} }
if(err < 0){ if(err){
printk("Failed to create '%s' - err = %d\n", umid, err); err = -errno;
goto err_rmdir; printk("Failed to create '%s' - err = %d\n", umid, -errno);
goto err;
} }
umid_setup = 1; umid_setup = 1;
create_pid_file(); create_pid_file();
return 0; err = 0;
err_rmdir:
rmdir(tmp);
err: err:
return err; return err;
} }
static int __init make_umid_init(void) 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(); make_umid();
return 0; return 0;
......
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