From: "Mickaël Salaün" <mic@digikod.net>
To: linux-kernel@vger.kernel.org
Cc: "Mickaël Salaün" <mic@digikod.net>,
"Alexei Starovoitov" <ast@kernel.org>,
"Andy Lutomirski" <luto@amacapital.net>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Daniel Mack" <daniel@zonque.org>,
"David Drysdale" <drysdale@google.com>,
"David S . Miller" <davem@davemloft.net>,
"Eric W . Biederman" <ebiederm@xmission.com>,
"James Morris" <james.l.morris@oracle.com>,
"Jann Horn" <jann@thejh.net>, "Kees Cook" <keescook@chromium.org>,
"Paul Moore" <pmoore@redhat.com>,
"Sargun Dhillon" <sargun@sargun.me>,
"Serge E . Hallyn" <serge@hallyn.com>,
"Tejun Heo" <tj@kernel.org>, "Thomas Graf" <tgraf@suug.ch>,
"Will Drewry" <wad@chromium.org>,
kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org,
linux-security-module@vger.kernel.org, netdev@vger.kernel.org,
cgroups@vger.kernel.org
Subject: [RFC v4 10/18] seccomp: Split put_seccomp_filter() with put_seccomp()
Date: Wed, 26 Oct 2016 08:56:46 +0200 [thread overview]
Message-ID: <20161026065654.19166-11-mic@digikod.net> (raw)
In-Reply-To: <20161026065654.19166-1-mic@digikod.net>
The semantic is unchanged. This will be useful for the Landlock
integration with seccomp (next commit).
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
---
include/linux/seccomp.h | 4 ++--
kernel/fork.c | 2 +-
kernel/seccomp.c | 18 +++++++++++++-----
3 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/include/linux/seccomp.h b/include/linux/seccomp.h
index ecc296c137cd..e25aee2cdfc0 100644
--- a/include/linux/seccomp.h
+++ b/include/linux/seccomp.h
@@ -77,10 +77,10 @@ static inline int seccomp_mode(struct seccomp *s)
#endif /* CONFIG_SECCOMP */
#ifdef CONFIG_SECCOMP_FILTER
-extern void put_seccomp_filter(struct task_struct *tsk);
+extern void put_seccomp(struct task_struct *tsk);
extern void get_seccomp_filter(struct task_struct *tsk);
#else /* CONFIG_SECCOMP_FILTER */
-static inline void put_seccomp_filter(struct task_struct *tsk)
+static inline void put_seccomp(struct task_struct *tsk)
{
return;
}
diff --git a/kernel/fork.c b/kernel/fork.c
index 623259fc794d..0690e43bdda5 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -349,7 +349,7 @@ void free_task(struct task_struct *tsk)
#endif
rt_mutex_debug_task_free(tsk);
ftrace_graph_exit_task(tsk);
- put_seccomp_filter(tsk);
+ put_seccomp(tsk);
arch_release_task_struct(tsk);
free_task_struct(tsk);
}
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 0db7c8a2afe2..e741a82eab4d 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -63,6 +63,8 @@ struct seccomp_filter {
/* Limit any path through the tree to 256KB worth of instructions. */
#define MAX_INSNS_PER_PATH ((1 << 18) / sizeof(struct sock_filter))
+static void put_seccomp_filter(struct seccomp_filter *filter);
+
/*
* Endianness is explicitly ignored and left for BPF program authors to manage
* as per the specific architecture.
@@ -313,7 +315,7 @@ static inline void seccomp_sync_threads(void)
* current's path will hold a reference. (This also
* allows a put before the assignment.)
*/
- put_seccomp_filter(thread);
+ put_seccomp_filter(thread->seccomp.filter);
smp_store_release(&thread->seccomp.filter,
caller->seccomp.filter);
@@ -475,10 +477,11 @@ static inline void seccomp_filter_free(struct seccomp_filter *filter)
}
}
-/* put_seccomp_filter - decrements the ref count of tsk->seccomp.filter */
-void put_seccomp_filter(struct task_struct *tsk)
+/* put_seccomp_filter - decrements the ref count of a filter */
+static void put_seccomp_filter(struct seccomp_filter *filter)
{
- struct seccomp_filter *orig = tsk->seccomp.filter;
+ struct seccomp_filter *orig = filter;
+
/* Clean up single-reference branches iteratively. */
while (orig && atomic_dec_and_test(&orig->usage)) {
struct seccomp_filter *freeme = orig;
@@ -487,6 +490,11 @@ void put_seccomp_filter(struct task_struct *tsk)
}
}
+void put_seccomp(struct task_struct *tsk)
+{
+ put_seccomp_filter(tsk->seccomp.filter);
+}
+
/**
* seccomp_send_sigsys - signals the task to allow in-process syscall emulation
* @syscall: syscall number to send to userland
@@ -898,7 +906,7 @@ long seccomp_get_filter(struct task_struct *task, unsigned long filter_off,
if (copy_to_user(data, fprog->filter, bpf_classic_proglen(fprog)))
ret = -EFAULT;
- put_seccomp_filter(task);
+ put_seccomp_filter(task->seccomp.filter);
return ret;
out:
--
2.9.3
next prev parent reply other threads:[~2016-10-26 7:06 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-26 6:56 [RFC v4 00/18] Landlock LSM: Unprivileged sandboxing Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 01/18] landlock: Add Kconfig Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 02/18] bpf: Move u64_to_ptr() to BPF headers and inline it Mickaël Salaün
2016-10-26 7:19 ` Arnd Bergmann
2016-10-26 13:52 ` [kernel-hardening] " David Sterba
2016-10-26 6:56 ` [RFC v4 03/18] bpf,landlock: Add a new arraymap type to deal with (Landlock) handles Mickaël Salaün
2016-10-26 19:01 ` [kernel-hardening] " Jann Horn
2016-10-26 20:03 ` Mickaël Salaün
2016-10-26 20:16 ` Jann Horn
2016-10-26 6:56 ` [RFC v4 04/18] bpf,landlock: Add eBPF program subtype and is_valid_subtype() verifier Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 05/18] bpf,landlock: Define an eBPF program type for Landlock Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 06/18] fs: Constify path_is_under()'s arguments Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 07/18] landlock: Add LSM hooks Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 08/18] landlock: Handle file comparisons Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 09/18] landlock: Add manager functions Mickaël Salaün
2016-10-26 6:56 ` Mickaël Salaün [this message]
2016-10-26 6:56 ` [RFC v4 11/18] seccomp,landlock: Handle Landlock hooks per process hierarchy Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 12/18] bpf: Cosmetic change for bpf_prog_attach() Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 13/18] bpf/cgroup: Replace struct bpf_prog with struct bpf_object Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 14/18] bpf/cgroup: Make cgroup_bpf_update() return an error code Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 15/18] bpf/cgroup: Move capability check Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 16/18] bpf/cgroup,landlock: Handle Landlock hooks per cgroup Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 17/18] landlock: Add update and debug access flags Mickaël Salaün
2016-10-26 6:56 ` [RFC v4 18/18] samples/landlock: Add sandbox example Mickaël Salaün
2016-10-26 14:52 ` [RFC v4 00/18] Landlock LSM: Unprivileged sandboxing Jann Horn
2016-10-26 16:56 ` Mickaël Salaün
2016-10-26 17:24 ` Mickaël Salaün
2016-11-13 14:23 ` Mickaël Salaün
2016-11-14 10:35 ` Sargun Dhillon
2016-11-14 20:51 ` Mickaël Salaün
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