2023-03-01 10:06:41

by zhangpeng (AS)

Subject: [PATCH] userfaultfd: move unprivileged_userfaultfd sysctl to its own file

From: ZhangPeng <[email protected]>

The sysctl_unprivileged_userfaultfd is part of userfaultfd, move it to
its own file.

Signed-off-by: ZhangPeng <[email protected]>
---
fs/userfaultfd.c | 20 +++++++++++++++++++-
include/linux/userfaultfd_k.h | 2 --
kernel/sysctl.c | 11 -----------
3 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 44d1ee429eb0..d01f803a6b11 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -32,7 +32,22 @@
#include <linux/swapops.h>
#include <linux/miscdevice.h>

-int sysctl_unprivileged_userfaultfd __read_mostly;
+static int sysctl_unprivileged_userfaultfd __read_mostly;
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table vm_userfaultfd_table[] = {
+ {
+ .procname = "unprivileged_userfaultfd",
+ .data = &sysctl_unprivileged_userfaultfd,
+ .maxlen = sizeof(sysctl_unprivileged_userfaultfd),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ },
+ { }
+};
+#endif

static struct kmem_cache *userfaultfd_ctx_cachep __read_mostly;

@@ -2178,6 +2193,9 @@ static int __init userfaultfd_init(void)
0,
SLAB_HWCACHE_ALIGN|SLAB_PANIC,
init_once_userfaultfd_ctx);
+#ifdef CONFIG_SYSCTL
+ register_sysctl_init("vm", vm_userfaultfd_table);
+#endif
return 0;
}
__initcall(userfaultfd_init);
diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index 3767f18114ef..fff49fec0258 100644
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -36,8 +36,6 @@
#define UFFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
#define UFFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS)

-extern int sysctl_unprivileged_userfaultfd;
-
extern vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason);

/*
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 1c240d2c99bc..c14552a662ae 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2438,17 +2438,6 @@ static struct ctl_table vm_table[] = {
.extra1 = (void *)&mmap_rnd_compat_bits_min,
.extra2 = (void *)&mmap_rnd_compat_bits_max,
},
-#endif
-#ifdef CONFIG_USERFAULTFD
- {
- .procname = "unprivileged_userfaultfd",
- .data = &sysctl_unprivileged_userfaultfd,
- .maxlen = sizeof(sysctl_unprivileged_userfaultfd),
- .mode = 0644,
- .proc_handler = proc_dointvec_minmax,
- .extra1 = SYSCTL_ZERO,
- .extra2 = SYSCTL_ONE,
- },
#endif
{ }
};
--
2.25.1

2023-03-02 22:52:16

by Luis Chamberlain

Subject: Re: [PATCH] userfaultfd: move unprivileged_userfaultfd sysctl to its own file

On Wed, Mar 01, 2023 at 10:06:27AM +0000, Peng Zhang wrote:
> From: ZhangPeng <[email protected]>
>
> The sysctl_unprivileged_userfaultfd is part of userfaultfd, move it to
> its own file.
>
> Signed-off-by: ZhangPeng <[email protected]>

Looks good, I've queued this up for sysctl-testing, before all the
patches I just posted. Keep it up, hopefully soon the vm array
on kernel/sysctl.c will be gone.

Luis