From: Jeff Dike <jdike@addtoit.com>
To: akpm@osdl.org
Cc: linux-kernel@vger.kernel.org,
user-mode-linux-devel@lists.sourceforge.net
Subject: [uml-devel] [PATCH 14/16] UML - Prevent umid theft
Date: Fri, 24 Mar 2006 13:15:03 -0500 [thread overview]
Message-ID: <200603241815.k2OIF3sG005565@ccure.user-mode-linux.org> (raw)
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>
Index: linux-2.6.15/arch/um/os-Linux/umid.c
===================================================================
--- linux-2.6.15.orig/arch/um/os-Linux/umid.c 2006-02-09 18:49:55.000000000 -0500
+++ linux-2.6.15/arch/um/os-Linux/umid.c 2006-02-10 14:11:28.000000000 -0500
@@ -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;
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WARNING: multiple messages have this Message-ID (diff)
From: Jeff Dike <jdike@addtoit.com>
To: akpm@osdl.org
Cc: linux-kernel@vger.kernel.org,
user-mode-linux-devel@lists.sourceforge.net
Subject: [PATCH 14/16] UML - Prevent umid theft
Date: Fri, 24 Mar 2006 13:15:03 -0500 [thread overview]
Message-ID: <200603241815.k2OIF3sG005565@ccure.user-mode-linux.org> (raw)
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>
Index: linux-2.6.15/arch/um/os-Linux/umid.c
===================================================================
--- linux-2.6.15.orig/arch/um/os-Linux/umid.c 2006-02-09 18:49:55.000000000 -0500
+++ linux-2.6.15/arch/um/os-Linux/umid.c 2006-02-10 14:11:28.000000000 -0500
@@ -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;
next reply other threads:[~2006-03-24 18:13 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-24 18:15 Jeff Dike [this message]
2006-03-24 18:15 ` [PATCH 14/16] UML - Prevent umid theft Jeff Dike
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