* [PATCH v4 1/5] mm, doc: Add doc for MPOL_F_NUMA_BALANCING
2023-12-08 9:06 [PATCH v4 0/5] mm, security, bpf: Fine-grained control over memory policy adjustments with lsm bpf Yafang Shao
@ 2023-12-08 9:06 ` Yafang Shao
2023-12-08 9:06 ` [PATCH v4 2/5] mm: mempolicy: Revise comment regarding mempolicy mode flags Yafang Shao
` (3 subsequent siblings)
4 siblings, 0 replies; 10+ messages in thread
From: Yafang Shao @ 2023-12-08 9:06 UTC (permalink / raw)
To: akpm, paul, jmorris, serge, omosnace, mhocko, ying.huang
Cc: linux-mm, linux-security-module, bpf, ligang.bdlg, Yafang Shao
The document on MPOL_F_NUMA_BALANCING was missed in the initial commit
The MPOL_F_NUMA_BALANCING document was inadvertently omitted from the
initial commit bda420b98505 ("numa balancing: migrate on fault among
multiple bound nodes")
Let's ensure its inclusion.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
---
.../admin-guide/mm/numa_memory_policy.rst | 27 ++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/Documentation/admin-guide/mm/numa_memory_policy.rst b/Documentation/admin-guide/mm/numa_memory_policy.rst
index eca38fa..19071b71 100644
--- a/Documentation/admin-guide/mm/numa_memory_policy.rst
+++ b/Documentation/admin-guide/mm/numa_memory_policy.rst
@@ -332,6 +332,33 @@ MPOL_F_RELATIVE_NODES
MPOL_PREFERRED policies that were created with an empty nodemask
(local allocation).
+MPOL_F_NUMA_BALANCING (since Linux 5.12)
+ When operating in MPOL_BIND mode, enables NUMA balancing for tasks,
+ contingent upon kernel support. This feature optimizes page
+ placement within the confines of the specified memory binding
+ policy. The addition of the MPOL_F_NUMA_BALANCING flag augments the
+ control mechanism for NUMA balancing:
+
+ - The sysctl knob numa_balancing governs global activation or
+ deactivation of NUMA balancing.
+
+ - Even if sysctl numa_balancing is enabled, NUMA balancing remains
+ disabled by default for memory areas or applications utilizing
+ explicit memory policies.
+
+ - The MPOL_F_NUMA_BALANCING flag facilitates NUMA balancing
+ activation for applications employing explicit memory policies
+ (MPOL_BIND).
+
+ This flags enables various optimizations for page placement through
+ NUMA balancing. For instance, when an application's memory is bound
+ to multiple nodes (MPOL_BIND), the hint page fault handler attempts
+ to migrate accessed pages to reduce cross-node access if the
+ accessing node aligns with the policy nodemask.
+
+ If the flag isn't supported by the kernel, or is used with mode
+ other than MPOL_BIND, -1 is returned and errno is set to EINVAL.
+
Memory Policy Reference Counting
================================
--
1.8.3.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH v4 2/5] mm: mempolicy: Revise comment regarding mempolicy mode flags
2023-12-08 9:06 [PATCH v4 0/5] mm, security, bpf: Fine-grained control over memory policy adjustments with lsm bpf Yafang Shao
2023-12-08 9:06 ` [PATCH v4 1/5] mm, doc: Add doc for MPOL_F_NUMA_BALANCING Yafang Shao
@ 2023-12-08 9:06 ` Yafang Shao
2023-12-08 9:06 ` [PATCH v4 3/5] mm, security: Add lsm hook for memory policy adjustment Yafang Shao
` (2 subsequent siblings)
4 siblings, 0 replies; 10+ messages in thread
From: Yafang Shao @ 2023-12-08 9:06 UTC (permalink / raw)
To: akpm, paul, jmorris, serge, omosnace, mhocko, ying.huang
Cc: linux-mm, linux-security-module, bpf, ligang.bdlg, Yafang Shao,
Eric Dumazet
MPOL_F_STATIC_NODES, MPOL_F_RELATIVE_NODES, and MPOL_F_NUMA_BALANCING are
mode flags applicable to both set_mempolicy(2) and mbind(2) system calls.
It's worth noting that MPOL_F_NUMA_BALANCING was initially introduced in
commit bda420b98505 ("numa balancing: migrate on fault among multiple bound
nodes") exclusively for set_mempolicy(2). However, it was later made a
shared flag for both set_mempolicy(2) and mbind(2) following
commit 6d2aec9e123b ("mm/mempolicy: do not allow illegal
MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind()").
This revised version aims to clarify the details regarding the mode flags.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Eric Dumazet <edumazet@google.com>
---
include/uapi/linux/mempolicy.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h
index a8963f7..afed4a4 100644
--- a/include/uapi/linux/mempolicy.h
+++ b/include/uapi/linux/mempolicy.h
@@ -26,7 +26,7 @@ enum {
MPOL_MAX, /* always last member of enum */
};
-/* Flags for set_mempolicy */
+/* Flags for set_mempolicy() or mbind() */
#define MPOL_F_STATIC_NODES (1 << 15)
#define MPOL_F_RELATIVE_NODES (1 << 14)
#define MPOL_F_NUMA_BALANCING (1 << 13) /* Optimize with NUMA balancing if possible */
--
1.8.3.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH v4 3/5] mm, security: Add lsm hook for memory policy adjustment
2023-12-08 9:06 [PATCH v4 0/5] mm, security, bpf: Fine-grained control over memory policy adjustments with lsm bpf Yafang Shao
2023-12-08 9:06 ` [PATCH v4 1/5] mm, doc: Add doc for MPOL_F_NUMA_BALANCING Yafang Shao
2023-12-08 9:06 ` [PATCH v4 2/5] mm: mempolicy: Revise comment regarding mempolicy mode flags Yafang Shao
@ 2023-12-08 9:06 ` Yafang Shao
2023-12-08 17:30 ` Casey Schaufler
2023-12-08 9:06 ` [PATCH v4 4/5] security: selinux: Implement set_mempolicy hook Yafang Shao
2023-12-08 9:06 ` [PATCH v4 5/5] selftests/bpf: Add selftests for set_mempolicy with a lsm prog Yafang Shao
4 siblings, 1 reply; 10+ messages in thread
From: Yafang Shao @ 2023-12-08 9:06 UTC (permalink / raw)
To: akpm, paul, jmorris, serge, omosnace, mhocko, ying.huang
Cc: linux-mm, linux-security-module, bpf, ligang.bdlg, Yafang Shao
In a containerized environment, independent memory binding by a user can
lead to unexpected system issues or disrupt tasks being run by other users
on the same server. If a user genuinely requires memory binding, we will
allocate dedicated servers to them by leveraging kubelet deployment.
At present, users have the capability to bind their memory to a specific
node without explicit agreement or authorization from us. Consequently, a
new LSM hook is introduced to mitigate this. This implementation allows us
to exercise fine-grained control over memory policy adjustments within our
container environment
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
include/linux/lsm_hook_defs.h | 3 +++
include/linux/security.h | 9 +++++++++
mm/mempolicy.c | 8 ++++++++
security/security.c | 13 +++++++++++++
4 files changed, 33 insertions(+)
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index ff217a5..5580127 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -419,3 +419,6 @@
LSM_HOOK(int, 0, uring_sqpoll, void)
LSM_HOOK(int, 0, uring_cmd, struct io_uring_cmd *ioucmd)
#endif /* CONFIG_IO_URING */
+
+LSM_HOOK(int, 0, set_mempolicy, unsigned long mode, unsigned short mode_flags,
+ nodemask_t *nmask, unsigned int flags)
diff --git a/include/linux/security.h b/include/linux/security.h
index 1d1df326..cc4a19a 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -484,6 +484,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
int security_locked_down(enum lockdown_reason what);
+int security_set_mempolicy(unsigned long mode, unsigned short mode_flags,
+ nodemask_t *nmask, unsigned int flags);
#else /* CONFIG_SECURITY */
static inline int call_blocking_lsm_notifier(enum lsm_event event, void *data)
@@ -1395,6 +1397,13 @@ static inline int security_locked_down(enum lockdown_reason what)
{
return 0;
}
+
+static inline int
+security_set_mempolicy(unsigned long mode, unsigned short mode_flags,
+ nodemask_t *nmask, unsigned int flags)
+{
+ return 0;
+}
#endif /* CONFIG_SECURITY */
#if defined(CONFIG_SECURITY) && defined(CONFIG_WATCH_QUEUE)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 10a590e..9535d9e 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1483,6 +1483,10 @@ static long kernel_mbind(unsigned long start, unsigned long len,
if (err)
return err;
+ err = security_set_mempolicy(lmode, mode_flags, &nodes, flags);
+ if (err)
+ return err;
+
return do_mbind(start, len, lmode, mode_flags, &nodes, flags);
}
@@ -1577,6 +1581,10 @@ static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
if (err)
return err;
+ err = security_set_mempolicy(lmode, mode_flags, &nodes, 0);
+ if (err)
+ return err;
+
return do_set_mempolicy(lmode, mode_flags, &nodes);
}
diff --git a/security/security.c b/security/security.c
index dcb3e70..685ad79 100644
--- a/security/security.c
+++ b/security/security.c
@@ -5337,3 +5337,16 @@ int security_uring_cmd(struct io_uring_cmd *ioucmd)
return call_int_hook(uring_cmd, 0, ioucmd);
}
#endif /* CONFIG_IO_URING */
+
+/**
+ * security_set_mempolicy() - Check if memory policy can be adjusted
+ * @mode: The memory policy mode to be set
+ * @mode_flags: optional mode flags
+ * @nmask: modemask to which the mode applies
+ * @flags: mode flags for mbind(2) only
+ */
+int security_set_mempolicy(unsigned long mode, unsigned short mode_flags,
+ nodemask_t *nmask, unsigned int flags)
+{
+ return call_int_hook(set_mempolicy, 0, mode, mode_flags, nmask, flags);
+}
--
1.8.3.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* Re: [PATCH v4 3/5] mm, security: Add lsm hook for memory policy adjustment
2023-12-08 9:06 ` [PATCH v4 3/5] mm, security: Add lsm hook for memory policy adjustment Yafang Shao
@ 2023-12-08 17:30 ` Casey Schaufler
2023-12-10 2:54 ` Yafang Shao
0 siblings, 1 reply; 10+ messages in thread
From: Casey Schaufler @ 2023-12-08 17:30 UTC (permalink / raw)
To: Yafang Shao, akpm, paul, jmorris, serge, omosnace, mhocko,
ying.huang
Cc: linux-mm, linux-security-module, bpf, ligang.bdlg,
Casey Schaufler
On 12/8/2023 1:06 AM, Yafang Shao wrote:
> In a containerized environment, independent memory binding by a user can
> lead to unexpected system issues or disrupt tasks being run by other users
> on the same server. If a user genuinely requires memory binding, we will
> allocate dedicated servers to them by leveraging kubelet deployment.
>
> At present, users have the capability to bind their memory to a specific
> node without explicit agreement or authorization from us. Consequently, a
> new LSM hook is introduced to mitigate this. This implementation allows us
> to exercise fine-grained control over memory policy adjustments within our
> container environment
I wonder if security_vm_enough_memory() ought to be reimplemented as
an option to security_set_mempolicy(). I'm not convinced either way,
but I can argue both.
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> ---
> include/linux/lsm_hook_defs.h | 3 +++
> include/linux/security.h | 9 +++++++++
> mm/mempolicy.c | 8 ++++++++
> security/security.c | 13 +++++++++++++
> 4 files changed, 33 insertions(+)
>
> diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
> index ff217a5..5580127 100644
> --- a/include/linux/lsm_hook_defs.h
> +++ b/include/linux/lsm_hook_defs.h
> @@ -419,3 +419,6 @@
> LSM_HOOK(int, 0, uring_sqpoll, void)
> LSM_HOOK(int, 0, uring_cmd, struct io_uring_cmd *ioucmd)
> #endif /* CONFIG_IO_URING */
> +
> +LSM_HOOK(int, 0, set_mempolicy, unsigned long mode, unsigned short mode_flags,
> + nodemask_t *nmask, unsigned int flags)
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 1d1df326..cc4a19a 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -484,6 +484,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
> int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
> int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
> int security_locked_down(enum lockdown_reason what);
> +int security_set_mempolicy(unsigned long mode, unsigned short mode_flags,
> + nodemask_t *nmask, unsigned int flags);
> #else /* CONFIG_SECURITY */
>
> static inline int call_blocking_lsm_notifier(enum lsm_event event, void *data)
> @@ -1395,6 +1397,13 @@ static inline int security_locked_down(enum lockdown_reason what)
> {
> return 0;
> }
> +
> +static inline int
> +security_set_mempolicy(unsigned long mode, unsigned short mode_flags,
> + nodemask_t *nmask, unsigned int flags)
> +{
> + return 0;
> +}
> #endif /* CONFIG_SECURITY */
>
> #if defined(CONFIG_SECURITY) && defined(CONFIG_WATCH_QUEUE)
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 10a590e..9535d9e 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -1483,6 +1483,10 @@ static long kernel_mbind(unsigned long start, unsigned long len,
> if (err)
> return err;
>
> + err = security_set_mempolicy(lmode, mode_flags, &nodes, flags);
> + if (err)
> + return err;
> +
> return do_mbind(start, len, lmode, mode_flags, &nodes, flags);
> }
>
> @@ -1577,6 +1581,10 @@ static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
> if (err)
> return err;
>
> + err = security_set_mempolicy(lmode, mode_flags, &nodes, 0);
> + if (err)
> + return err;
> +
> return do_set_mempolicy(lmode, mode_flags, &nodes);
> }
>
> diff --git a/security/security.c b/security/security.c
> index dcb3e70..685ad79 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -5337,3 +5337,16 @@ int security_uring_cmd(struct io_uring_cmd *ioucmd)
> return call_int_hook(uring_cmd, 0, ioucmd);
> }
> #endif /* CONFIG_IO_URING */
> +
> +/**
> + * security_set_mempolicy() - Check if memory policy can be adjusted
> + * @mode: The memory policy mode to be set
> + * @mode_flags: optional mode flags
> + * @nmask: modemask to which the mode applies
> + * @flags: mode flags for mbind(2) only
> + */
> +int security_set_mempolicy(unsigned long mode, unsigned short mode_flags,
> + nodemask_t *nmask, unsigned int flags)
> +{
> + return call_int_hook(set_mempolicy, 0, mode, mode_flags, nmask, flags);
> +}
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH v4 3/5] mm, security: Add lsm hook for memory policy adjustment
2023-12-08 17:30 ` Casey Schaufler
@ 2023-12-10 2:54 ` Yafang Shao
0 siblings, 0 replies; 10+ messages in thread
From: Yafang Shao @ 2023-12-10 2:54 UTC (permalink / raw)
To: Casey Schaufler
Cc: akpm, paul, jmorris, serge, omosnace, mhocko, ying.huang,
linux-mm, linux-security-module, bpf, ligang.bdlg
On Sat, Dec 9, 2023 at 1:30 AM Casey Schaufler <casey@schaufler-ca.com> wrote:
>
> On 12/8/2023 1:06 AM, Yafang Shao wrote:
> > In a containerized environment, independent memory binding by a user can
> > lead to unexpected system issues or disrupt tasks being run by other users
> > on the same server. If a user genuinely requires memory binding, we will
> > allocate dedicated servers to them by leveraging kubelet deployment.
> >
> > At present, users have the capability to bind their memory to a specific
> > node without explicit agreement or authorization from us. Consequently, a
> > new LSM hook is introduced to mitigate this. This implementation allows us
> > to exercise fine-grained control over memory policy adjustments within our
> > container environment
>
> I wonder if security_vm_enough_memory() ought to be reimplemented as
> an option to security_set_mempolicy(). I'm not convinced either way,
> but I can argue both.
The function security_vm_enough_memory() serves to verify the
permissibility of a new memory map, while security_set_mempolicy()
comes into play post-memory map allocation. Expanding
security_vm_enough_memory() to include memory policy checks might
potentially lead to regressions. Therefore, I would prefer to
introduce a new function, security_set_mempolicy(), to handle these
checks separately.
--
Regards
Yafang
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v4 4/5] security: selinux: Implement set_mempolicy hook
2023-12-08 9:06 [PATCH v4 0/5] mm, security, bpf: Fine-grained control over memory policy adjustments with lsm bpf Yafang Shao
` (2 preceding siblings ...)
2023-12-08 9:06 ` [PATCH v4 3/5] mm, security: Add lsm hook for memory policy adjustment Yafang Shao
@ 2023-12-08 9:06 ` Yafang Shao
2023-12-08 9:06 ` [PATCH v4 5/5] selftests/bpf: Add selftests for set_mempolicy with a lsm prog Yafang Shao
4 siblings, 0 replies; 10+ messages in thread
From: Yafang Shao @ 2023-12-08 9:06 UTC (permalink / raw)
To: akpm, paul, jmorris, serge, omosnace, mhocko, ying.huang
Cc: linux-mm, linux-security-module, bpf, ligang.bdlg, Yafang Shao
Add a SELinux access control for the newly introduced set_mempolicy lsm
hook. A new permission "setmempolicy" is defined under the "process" class
for it.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
security/selinux/hooks.c | 8 ++++++++
security/selinux/include/classmap.h | 2 +-
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index feda711..1528d4d 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4238,6 +4238,13 @@ static int selinux_userns_create(const struct cred *cred)
USER_NAMESPACE__CREATE, NULL);
}
+static int selinux_set_mempolicy(unsigned long mode, unsigned short mode_flags,
+ nodemask_t *nmask, unsigned int flags)
+{
+ return avc_has_perm(current_sid(), task_sid_obj(current), SECCLASS_PROCESS,
+ PROCESS__SETMEMPOLICY, NULL);
+}
+
/* Returns error only if unable to parse addresses */
static int selinux_parse_skb_ipv4(struct sk_buff *skb,
struct common_audit_data *ad, u8 *proto)
@@ -7072,6 +7079,7 @@ static int selinux_uring_cmd(struct io_uring_cmd *ioucmd)
LSM_HOOK_INIT(task_kill, selinux_task_kill),
LSM_HOOK_INIT(task_to_inode, selinux_task_to_inode),
LSM_HOOK_INIT(userns_create, selinux_userns_create),
+ LSM_HOOK_INIT(set_mempolicy, selinux_set_mempolicy),
LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission),
LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid),
diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
index a3c3807..c280d92 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -51,7 +51,7 @@
"getattr", "setexec", "setfscreate", "noatsecure", "siginh",
"setrlimit", "rlimitinh", "dyntransition", "setcurrent",
"execmem", "execstack", "execheap", "setkeycreate",
- "setsockcreate", "getrlimit", NULL } },
+ "setsockcreate", "getrlimit", "setmempolicy", NULL } },
{ "process2",
{ "nnp_transition", "nosuid_transition", NULL } },
{ "system",
--
1.8.3.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH v4 5/5] selftests/bpf: Add selftests for set_mempolicy with a lsm prog
2023-12-08 9:06 [PATCH v4 0/5] mm, security, bpf: Fine-grained control over memory policy adjustments with lsm bpf Yafang Shao
` (3 preceding siblings ...)
2023-12-08 9:06 ` [PATCH v4 4/5] security: selinux: Implement set_mempolicy hook Yafang Shao
@ 2023-12-08 9:06 ` Yafang Shao
2023-12-12 19:22 ` KP Singh
4 siblings, 1 reply; 10+ messages in thread
From: Yafang Shao @ 2023-12-08 9:06 UTC (permalink / raw)
To: akpm, paul, jmorris, serge, omosnace, mhocko, ying.huang
Cc: linux-mm, linux-security-module, bpf, ligang.bdlg, Yafang Shao
The result as follows,
#263/1 set_mempolicy/MPOL_BIND_without_lsm:OK
#263/2 set_mempolicy/MPOL_DEFAULT_without_lsm:OK
#263/3 set_mempolicy/MPOL_BIND_with_lsm:OK
#263/4 set_mempolicy/MPOL_DEFAULT_with_lsm:OK
#263 set_mempolicy:OK
Summary: 1/4 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
.../selftests/bpf/prog_tests/set_mempolicy.c | 81 ++++++++++++++++++++++
.../selftests/bpf/progs/test_set_mempolicy.c | 28 ++++++++
2 files changed, 109 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/set_mempolicy.c
create mode 100644 tools/testing/selftests/bpf/progs/test_set_mempolicy.c
diff --git a/tools/testing/selftests/bpf/prog_tests/set_mempolicy.c b/tools/testing/selftests/bpf/prog_tests/set_mempolicy.c
new file mode 100644
index 0000000..736b5e3
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/set_mempolicy.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2023 Yafang Shao <laoar.shao@gmail.com> */
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <linux/mempolicy.h>
+#include <test_progs.h>
+#include "test_set_mempolicy.skel.h"
+
+#define SIZE 4096
+
+static void mempolicy_bind(bool success)
+{
+ unsigned long mask = 1;
+ char *addr;
+ int err;
+
+ addr = mmap(NULL, SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+ if (!ASSERT_OK_PTR(addr, "mmap"))
+ return;
+
+ /* -lnuma is required by mbind(2), so use __NR_mbind to avoid the dependency. */
+ err = syscall(__NR_mbind, addr, SIZE, MPOL_BIND, &mask, sizeof(mask), 0);
+ if (success)
+ ASSERT_OK(err, "mbind_success");
+ else
+ ASSERT_ERR(err, "mbind_fail");
+
+ munmap(addr, SIZE);
+}
+
+static void mempolicy_default(void)
+{
+ char *addr;
+ int err;
+
+ addr = mmap(NULL, SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+ if (!ASSERT_OK_PTR(addr, "mmap"))
+ return;
+
+ err = syscall(__NR_mbind, addr, SIZE, MPOL_DEFAULT, NULL, 0, 0);
+ ASSERT_OK(err, "mbind_success");
+
+ munmap(addr, SIZE);
+}
+
+void test_set_mempolicy(void)
+{
+ struct test_set_mempolicy *skel;
+ int err;
+
+ skel = test_set_mempolicy__open();
+ if (!ASSERT_OK_PTR(skel, "open"))
+ return;
+
+ skel->bss->target_pid = getpid();
+
+ err = test_set_mempolicy__load(skel);
+ if (!ASSERT_OK(err, "load"))
+ goto destroy;
+
+ if (test__start_subtest("MPOL_BIND_without_lsm"))
+ mempolicy_bind(true);
+ if (test__start_subtest("MPOL_DEFAULT_without_lsm"))
+ mempolicy_default();
+
+ /* Attach LSM prog first */
+ err = test_set_mempolicy__attach(skel);
+ if (!ASSERT_OK(err, "attach"))
+ goto destroy;
+
+ /* syscall to adjust memory policy */
+ if (test__start_subtest("MPOL_BIND_with_lsm"))
+ mempolicy_bind(false);
+ if (test__start_subtest("MPOL_DEFAULT_with_lsm"))
+ mempolicy_default();
+
+destroy:
+ test_set_mempolicy__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_set_mempolicy.c b/tools/testing/selftests/bpf/progs/test_set_mempolicy.c
new file mode 100644
index 0000000..b5356d5
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_set_mempolicy.c
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2023 Yafang Shao <laoar.shao@gmail.com> */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+int target_pid;
+
+static int mem_policy_adjustment(u64 mode)
+{
+ struct task_struct *task = bpf_get_current_task_btf();
+
+ if (task->pid != target_pid)
+ return 0;
+
+ if (mode != MPOL_BIND)
+ return 0;
+ return -1;
+}
+
+SEC("lsm/set_mempolicy")
+int BPF_PROG(setmempolicy, u64 mode, u16 mode_flags, nodemask_t *nmask, u32 flags)
+{
+ return mem_policy_adjustment(mode);
+}
+
+char _license[] SEC("license") = "GPL";
--
1.8.3.1
^ permalink raw reply related [flat|nested] 10+ messages in thread* Re: [PATCH v4 5/5] selftests/bpf: Add selftests for set_mempolicy with a lsm prog
2023-12-08 9:06 ` [PATCH v4 5/5] selftests/bpf: Add selftests for set_mempolicy with a lsm prog Yafang Shao
@ 2023-12-12 19:22 ` KP Singh
2023-12-13 3:08 ` Yafang Shao
0 siblings, 1 reply; 10+ messages in thread
From: KP Singh @ 2023-12-12 19:22 UTC (permalink / raw)
To: Yafang Shao
Cc: akpm, paul, jmorris, serge, omosnace, mhocko, ying.huang,
linux-mm, linux-security-module, bpf, ligang.bdlg
On Fri, Dec 8, 2023 at 10:06 AM Yafang Shao <laoar.shao@gmail.com> wrote:
>
> The result as follows,
> #263/1 set_mempolicy/MPOL_BIND_without_lsm:OK
> #263/2 set_mempolicy/MPOL_DEFAULT_without_lsm:OK
> #263/3 set_mempolicy/MPOL_BIND_with_lsm:OK
> #263/4 set_mempolicy/MPOL_DEFAULT_with_lsm:OK
> #263 set_mempolicy:OK
> Summary: 1/4 PASSED, 0 SKIPPED, 0 FAILED
Please write a commit description on what the test actually does. I
even think of something simple that mentions a BPF LSM program that
denies all mbind with the mode MPOL_BIND and checks whether the
corresponding syscall is denied when the program is loaded.
>
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> ---
> .../selftests/bpf/prog_tests/set_mempolicy.c | 81 ++++++++++++++++++++++
> .../selftests/bpf/progs/test_set_mempolicy.c | 28 ++++++++
> 2 files changed, 109 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/set_mempolicy.c
> create mode 100644 tools/testing/selftests/bpf/progs/test_set_mempolicy.c
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/set_mempolicy.c b/tools/testing/selftests/bpf/prog_tests/set_mempolicy.c
> new file mode 100644
> index 0000000..736b5e3
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/set_mempolicy.c
> @@ -0,0 +1,81 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (C) 2023 Yafang Shao <laoar.shao@gmail.com> */
> +
> +#include <unistd.h>
> +#include <sys/types.h>
> +#include <sys/mman.h>
> +#include <linux/mempolicy.h>
> +#include <test_progs.h>
> +#include "test_set_mempolicy.skel.h"
> +
> +#define SIZE 4096
> +
> +static void mempolicy_bind(bool success)
> +{
> + unsigned long mask = 1;
> + char *addr;
> + int err;
> +
> + addr = mmap(NULL, SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
> + if (!ASSERT_OK_PTR(addr, "mmap"))
> + return;
> +
> + /* -lnuma is required by mbind(2), so use __NR_mbind to avoid the dependency. */
> + err = syscall(__NR_mbind, addr, SIZE, MPOL_BIND, &mask, sizeof(mask), 0);
> + if (success)
> + ASSERT_OK(err, "mbind_success");
> + else
> + ASSERT_ERR(err, "mbind_fail");
> +
> + munmap(addr, SIZE);
> +}
> +
> +static void mempolicy_default(void)
> +{
> + char *addr;
> + int err;
> +
> + addr = mmap(NULL, SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
> + if (!ASSERT_OK_PTR(addr, "mmap"))
> + return;
> +
> + err = syscall(__NR_mbind, addr, SIZE, MPOL_DEFAULT, NULL, 0, 0);
> + ASSERT_OK(err, "mbind_success");
> +
> + munmap(addr, SIZE);
> +}
> +
> +void test_set_mempolicy(void)
> +{
> + struct test_set_mempolicy *skel;
> + int err;
> +
> + skel = test_set_mempolicy__open();
> + if (!ASSERT_OK_PTR(skel, "open"))
> + return;
> +
> + skel->bss->target_pid = getpid();
> +
> + err = test_set_mempolicy__load(skel);
> + if (!ASSERT_OK(err, "load"))
> + goto destroy;
> +
> + if (test__start_subtest("MPOL_BIND_without_lsm"))
> + mempolicy_bind(true);
> + if (test__start_subtest("MPOL_DEFAULT_without_lsm"))
> + mempolicy_default();
> +
> + /* Attach LSM prog first */
> + err = test_set_mempolicy__attach(skel);
> + if (!ASSERT_OK(err, "attach"))
> + goto destroy;
> +
> + /* syscall to adjust memory policy */
> + if (test__start_subtest("MPOL_BIND_with_lsm"))
> + mempolicy_bind(false);
> + if (test__start_subtest("MPOL_DEFAULT_with_lsm"))
> + mempolicy_default();
> +
> +destroy:
> + test_set_mempolicy__destroy(skel);
> +}
> diff --git a/tools/testing/selftests/bpf/progs/test_set_mempolicy.c b/tools/testing/selftests/bpf/progs/test_set_mempolicy.c
> new file mode 100644
> index 0000000..b5356d5
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/test_set_mempolicy.c
> @@ -0,0 +1,28 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (C) 2023 Yafang Shao <laoar.shao@gmail.com> */
> +
> +#include "vmlinux.h"
> +#include <bpf/bpf_helpers.h>
> +#include <bpf/bpf_tracing.h>
> +
> +int target_pid;
> +
> +static int mem_policy_adjustment(u64 mode)
> +{
> + struct task_struct *task = bpf_get_current_task_btf();
> +
> + if (task->pid != target_pid)
> + return 0;
> +
> + if (mode != MPOL_BIND)
> + return 0;
> + return -1;
> +}
> +
> +SEC("lsm/set_mempolicy")
> +int BPF_PROG(setmempolicy, u64 mode, u16 mode_flags, nodemask_t *nmask, u32 flags)
> +{
> + return mem_policy_adjustment(mode);
> +}
> +
> +char _license[] SEC("license") = "GPL";
> --
> 1.8.3.1
>
>
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH v4 5/5] selftests/bpf: Add selftests for set_mempolicy with a lsm prog
2023-12-12 19:22 ` KP Singh
@ 2023-12-13 3:08 ` Yafang Shao
0 siblings, 0 replies; 10+ messages in thread
From: Yafang Shao @ 2023-12-13 3:08 UTC (permalink / raw)
To: KP Singh
Cc: akpm, paul, jmorris, serge, omosnace, mhocko, ying.huang,
linux-mm, linux-security-module, bpf, ligang.bdlg
On Wed, Dec 13, 2023 at 3:22 AM KP Singh <kpsingh@kernel.org> wrote:
>
> On Fri, Dec 8, 2023 at 10:06 AM Yafang Shao <laoar.shao@gmail.com> wrote:
> >
> > The result as follows,
> > #263/1 set_mempolicy/MPOL_BIND_without_lsm:OK
> > #263/2 set_mempolicy/MPOL_DEFAULT_without_lsm:OK
> > #263/3 set_mempolicy/MPOL_BIND_with_lsm:OK
> > #263/4 set_mempolicy/MPOL_DEFAULT_with_lsm:OK
> > #263 set_mempolicy:OK
> > Summary: 1/4 PASSED, 0 SKIPPED, 0 FAILED
>
> Please write a commit description on what the test actually does. I
will do it.
> even think of something simple that mentions a BPF LSM program that
> denies all mbind with the mode MPOL_BIND and checks whether the
> corresponding syscall is denied when the program is loaded.
It does. Additionally, it verifies whether the mbind syscall is denied
with different modes, such as MPOL_DEFAULT."
--
Regards
Yafang
^ permalink raw reply [flat|nested] 10+ messages in thread