linux-kernel - [PATCH 5/20] Introduce struct upid

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <46BC506F.mailGJ711PNHE@openvz.org>
Date:	Fri, 10 Aug 2007 15:47:59 +0400
From:	xemul@...nvz.org
To:	akpm@...l.org
Cc:	xemul@...nvz.org, devel@...nvz.org, linux-kernel@...r.kernel.org,
	containers@...ts.osdl.org, oleg@...sign.ru, sukadev@...ibm.com
Subject: [PATCH 5/20] Introduce struct upid

From: Sukadev Bhattiprolu <sukadev@...ibm.com>

Since task will be visible from different pid namespaces each of them have to
be addressed by multiple pids. struct upid is to store the information about
which id refers to which namespace.

The constuciton looks like this. Each struct pid carried the reference counter
and the list of tasks attached to this pid. At its end it has a variable length
array of struct upid-s. Each struct upid has a numerical id (pid itself),
pointer to the namespace, this ID is valid in and is hashed into a pid_hash
for searching the pids.

The nr and pid_chain fields are kept in struct pid for a while to make kernel
still work (no patch initialize the upids yet), but it will be removed at the
end of this series when we switch to upids completely.

Signed-off-by: Sukadev Bhattiprolu <sukadev@...ibm.com>
Signed-off-by: Pavel Emelyanov <xemul@...nvz.org>
Cc: Oleg Nesterov <oleg@...sign.ru>

---

 init_task.h |    6 ++++++
 pid.h       |   16 ++++++++++++++++
 2 files changed, 22 insertions(+)

diff -upr linux-2.6.23-rc1-mm1.orig/include/linux/init_task.h linux-2.6.23-rc1-mm1-7/include/linux/init_task.h
--- linux-2.6.23-rc1-mm1.orig/include/linux/init_task.h	2007-07-26 16:34:45.000000000 +0400
+++ linux-2.6.23-rc1-mm1-7/include/linux/init_task.h	2007-07-26 16:36:36.000000000 +0400
@@ -93,6 +93,12 @@ extern struct group_info init_groups;
 		{ .first = &init_task.pids[PIDTYPE_SID].node },		\
 	},								\
 	.rcu		= RCU_HEAD_INIT,				\
+	.level		= 0,						\
+	.numbers	= { {						\
+		.nr		= 0,					\
+		.ns		= &init_pid_ns,				\
+		.pid_chain	= { .next = NULL, .pprev = NULL },	\
+	}, }								\
 }
 
 #define INIT_PID_LINK(type) 					\
diff -upr linux-2.6.23-rc1-mm1.orig/include/linux/pid.h linux-2.6.23-rc1-mm1-7/include/linux/pid.h
--- linux-2.6.23-rc1-mm1.orig/include/linux/pid.h	2007-07-26 16:34:45.000000000 +0400
+++ linux-2.6.23-rc1-mm1-7/include/linux/pid.h	2007-07-26 16:36:37.000000000 +0400
@@ -40,6 +40,20 @@ enum pid_type
  * processes.
  */
 
+
+/*
+ * struct upid is used to get the id of the struct pid, as it is
+ * seen in particular namespace. Later the struct pid is found with
+ * find_pid_ns() using the int nr and struct pid_namespace *ns.
+ */
+
+struct upid {
+	/* Try to keep pid_chain in the same cacheline as nr for find_pid */
+	int nr;
+	struct pid_namespace *ns;
+	struct hlist_node pid_chain;
+};
+
 struct pid
 {
 	atomic_t count;
@@ -50,6 +50,8 @@ struct pid
 	/* lists of tasks that use this pid */
 	struct hlist_head tasks[PIDTYPE_MAX];
 	struct rcu_head rcu;
+	int level;
+	struct upid numbers[1];
 };
 
 extern struct pid init_struct_pid;

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/