From: Elena Reshetova <elena.reshetova@intel.com>
To: linux-kernel@vger.kernel.org
Cc: cgroups@vger.kernel.org, linux-audit@redhat.com,
linux-fsdevel@vger.kernel.org, peterz@infradead.org,
gregkh@linuxfoundation.org, viro@zeniv.linux.org.uk,
tj@kernel.org, mingo@redhat.com, hannes@cmpxchg.org,
lizefan@huawei.com, acme@kernel.org,
alexander.shishkin@linux.intel.com, paul@paul-moore.com,
eparis@redhat.com, akpm@linux-foundation.org, arnd@arndb.de,
luto@kernel.org, Elena Reshetova <elena.reshetova@intel.com>,
Hans Liljestrand <ishkamiel@gmail.com>,
Kees Cook <keescook@chromium.org>,
David Windsor <dwindsor@gmail.com>
Subject: [PATCH 04/19] kernel: convert task_struct.usage from atomic_t to refcount_t
Date: Mon, 20 Feb 2017 12:18:53 +0200 [thread overview]
Message-ID: <1487585948-6401-5-git-send-email-elena.reshetova@intel.com> (raw)
In-Reply-To: <1487585948-6401-1-git-send-email-elena.reshetova@intel.com>
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
---
include/linux/init_task.h | 2 +-
include/linux/sched.h | 6 +++---
kernel/fork.c | 4 ++--
3 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 1f160b2..1c6df0b 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -219,7 +219,7 @@ extern struct task_group root_task_group;
INIT_TASK_TI(tsk) \
.state = 0, \
.stack = init_stack, \
- .usage = ATOMIC_INIT(2), \
+ .usage = REFCOUNT_INIT(2), \
.flags = PF_KTHREAD, \
.prio = MAX_PRIO-20, \
.static_prio = MAX_PRIO-20, \
diff --git a/include/linux/sched.h b/include/linux/sched.h
index e90396f..d760ad6 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1489,7 +1489,7 @@ struct task_struct {
#endif
volatile long state; /* -1 unrunnable, 0 runnable, >0 stopped */
void *stack;
- atomic_t usage;
+ refcount_t usage;
unsigned int flags; /* per process flags, defined below */
unsigned int ptrace;
@@ -2220,13 +2220,13 @@ static inline int is_global_init(struct task_struct *tsk)
extern struct pid *cad_pid;
extern void free_task(struct task_struct *tsk);
-#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
+#define get_task_struct(tsk) do { refcount_inc(&(tsk)->usage); } while(0)
extern void __put_task_struct(struct task_struct *t);
static inline void put_task_struct(struct task_struct *t)
{
- if (atomic_dec_and_test(&t->usage))
+ if (refcount_dec_and_test(&t->usage))
__put_task_struct(t);
}
diff --git a/kernel/fork.c b/kernel/fork.c
index b432d1c..b9b3296 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -383,7 +383,7 @@ static inline void put_signal_struct(struct signal_struct *sig)
void __put_task_struct(struct task_struct *tsk)
{
WARN_ON(!tsk->exit_state);
- WARN_ON(atomic_read(&tsk->usage));
+ WARN_ON(refcount_read(&tsk->usage));
WARN_ON(tsk == current);
cgroup_free(tsk);
@@ -533,7 +533,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
* One for us, one for whoever does the "release_task()" (usually
* parent)
*/
- atomic_set(&tsk->usage, 2);
+ refcount_set(&tsk->usage, 2);
#ifdef CONFIG_BLK_DEV_IO_TRACE
tsk->btrace_seq = 0;
#endif
--
2.7.4
next prev parent reply other threads:[~2017-02-20 10:29 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-20 10:18 [PATCH 00/19] Kernel subsystem refcounter conversions Elena Reshetova
2017-02-20 10:18 ` [PATCH 01/19] kernel: convert sighand_struct.count from atomic_t to refcount_t Elena Reshetova
2017-02-20 12:30 ` kbuild test robot
2017-02-20 12:42 ` kbuild test robot
2017-02-20 10:18 ` [PATCH 02/19] kernel: convert signal_struct.sigcnt " Elena Reshetova
2017-02-20 10:18 ` [PATCH 03/19] kernel: convert user_struct.__count " Elena Reshetova
2017-02-20 10:18 ` Elena Reshetova [this message]
2017-02-20 10:18 ` [PATCH 05/19] kernel: convert task_struct.stack_refcount " Elena Reshetova
2017-02-20 10:18 ` [PATCH 06/19] kernel: convert perf_event_context.refcount " Elena Reshetova
2017-02-20 10:28 ` Peter Zijlstra
2017-02-20 12:14 ` Reshetova, Elena
2017-02-20 10:18 ` [PATCH 07/19] kernel: convert ring_buffer.refcount " Elena Reshetova
2017-02-20 10:18 ` [PATCH 08/19] kernel: convert ring_buffer.aux_refcount " Elena Reshetova
2017-02-20 10:18 ` [PATCH 09/19] kernel: convert uprobe.ref " Elena Reshetova
2017-02-20 10:18 ` [PATCH 10/19] kernel: convert nsproxy.count " Elena Reshetova
2017-02-20 10:19 ` [PATCH 11/19] kernel: convert cgroup_namespace.count " Elena Reshetova
2017-03-06 19:55 ` Tejun Heo
2017-02-20 10:19 ` [PATCH 12/19] kernel: convert css_set.refcount " Elena Reshetova
2017-03-06 19:54 ` Tejun Heo
2017-03-07 19:12 ` Reshetova, Elena
2017-03-07 19:21 ` Tejun Heo
2017-02-20 10:19 ` [PATCH 13/19] kernel: convert group_info.usage " Elena Reshetova
2017-02-20 10:19 ` [PATCH 14/19] kernel: convert cred.usage " Elena Reshetova
2017-02-20 10:19 ` [PATCH 15/19] kernel: convert audit_tree.count " Elena Reshetova
2017-02-20 22:07 ` Paul Moore
2017-02-21 7:15 ` Reshetova, Elena
2017-02-28 22:11 ` Paul Moore
2017-03-01 0:16 ` Kees Cook
2017-03-01 19:35 ` Paul Moore
2017-03-01 23:04 ` Kees Cook
2017-04-11 19:01 ` Paul Moore
2017-04-18 6:33 ` Reshetova, Elena
2017-02-20 10:19 ` [PATCH 16/19] kernel: convert audit_watch.count " Elena Reshetova
2017-02-20 10:19 ` [PATCH 17/19] kernel: convert numa_group.refcount " Elena Reshetova
2017-02-20 10:19 ` [PATCH 18/19] kernel: convert futex_pi_state.refcount " Elena Reshetova
2017-02-20 10:19 ` [PATCH 19/19] kernel: convert kcov.refcount " Elena Reshetova
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1487585948-6401-5-git-send-email-elena.reshetova@intel.com \
--to=elena.reshetova@intel.com \
--cc=acme@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=alexander.shishkin@linux.intel.com \
--cc=arnd@arndb.de \
--cc=cgroups@vger.kernel.org \
--cc=dwindsor@gmail.com \
--cc=eparis@redhat.com \
--cc=gregkh@linuxfoundation.org \
--cc=hannes@cmpxchg.org \
--cc=ishkamiel@gmail.com \
--cc=keescook@chromium.org \
--cc=linux-audit@redhat.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lizefan@huawei.com \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=paul@paul-moore.com \
--cc=peterz@infradead.org \
--cc=tj@kernel.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).