Since the commit 61a47c1ad3a4dc ("sysctl: Remove the sysctl system call"),
sys_sysctl has lost its actual role: any input can only return an error.
Delete the code and return -ENOSYS directly at the function entry
Signed-off-by: Xiaoming Ni <nixiaom...@huawei.com>
---
kernel/sysctl_binary.c | 146 +------------------------------------------------
1 file changed, 2 insertions(+), 144 deletions(-)
diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index 7d550cc..41a88f8 100644
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -1,126 +1,11 @@
// SPDX-License-Identifier: GPL-2.0
-#include <linux/stat.h>
#include <linux/sysctl.h>
-#include "../fs/xfs/xfs_sysctl.h"
-#include <linux/sunrpc/debug.h>
-#include <linux/string.h>
#include <linux/syscalls.h>
-#include <linux/namei.h>
-#include <linux/mount.h>
-#include <linux/fs.h>
-#include <linux/nsproxy.h>
-#include <linux/pid_namespace.h>
-#include <linux/file.h>
-#include <linux/ctype.h>
-#include <linux/netdevice.h>
-#include <linux/kernel.h>
-#include <linux/uuid.h>
-#include <linux/slab.h>
#include <linux/compat.h>
-static ssize_t binary_sysctl(const int *name, int nlen,
- void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
-{
- return -ENOSYS;
-}
-
-static void deprecated_sysctl_warning(const int *name, int nlen)
-{
- int i;
-
- /*
- * CTL_KERN/KERN_VERSION is used by older glibc and cannot
- * ever go away.
- */
- if (nlen >= 2 && name[0] == CTL_KERN && name[1] == KERN_VERSION)
- return;
-
- if (printk_ratelimit()) {
- printk(KERN_INFO
- "warning: process `%s' used the deprecated sysctl "
- "system call with ", current->comm);
- for (i = 0; i < nlen; i++)
- printk(KERN_CONT "%d.", name[i]);
- printk(KERN_CONT "\n");
- }
- return;
-}
-
-#define WARN_ONCE_HASH_BITS 8
-#define WARN_ONCE_HASH_SIZE (1<<WARN_ONCE_HASH_BITS)
-
-static DECLARE_BITMAP(warn_once_bitmap, WARN_ONCE_HASH_SIZE);
-
-#define FNV32_OFFSET 2166136261U
-#define FNV32_PRIME 0x01000193
-
-/*
- * Print each legacy sysctl (approximately) only once.
- * To avoid making the tables non-const use a external
- * hash-table instead.
- * Worst case hash collision: 6, but very rarely.
- * NOTE! We don't use the SMP-safe bit tests. We simply
- * don't care enough.
- */
-static void warn_on_bintable(const int *name, int nlen)
-{
- int i;
- u32 hash = FNV32_OFFSET;
-
- for (i = 0; i < nlen; i++)
- hash = (hash ^ name[i]) * FNV32_PRIME;
- hash %= WARN_ONCE_HASH_SIZE;
- if (__test_and_set_bit(hash, warn_once_bitmap))
- return;
- deprecated_sysctl_warning(name, nlen);
-}
-
-static ssize_t do_sysctl(int __user *args_name, int nlen,
- void __user *oldval, size_t oldlen, void __user *newval, size_t newlen)
-{
- int name[CTL_MAXNAME];
- int i;
-
- /* Check args->nlen. */
- if (nlen < 0 || nlen > CTL_MAXNAME)
- return -ENOTDIR;
- /* Read in the sysctl name for simplicity */
- for (i = 0; i < nlen; i++)
- if (get_user(name[i], args_name + i))
- return -EFAULT;
-
- warn_on_bintable(name, nlen);
-
- return binary_sysctl(name, nlen, oldval, oldlen, newval, newlen);
-}
-
SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
{
- struct __sysctl_args tmp;
- size_t oldlen = 0;
- ssize_t result;
-
- if (copy_from_user(&tmp, args, sizeof(tmp)))
- return -EFAULT;
-
- if (tmp.oldval && !tmp.oldlenp)
- return -EFAULT;
-
- if (tmp.oldlenp && get_user(oldlen, tmp.oldlenp))
- return -EFAULT;
-
- result = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, oldlen,
- tmp.newval, tmp.newlen);
-
- if (result >= 0) {
- oldlen = result;
- result = 0;
- }
-
- if (tmp.oldlenp && put_user(oldlen, tmp.oldlenp))
- return -EFAULT;
-
- return result;
+ return -ENOSYS;
}
@@ -138,34 +23,7 @@ struct compat_sysctl_args {
COMPAT_SYSCALL_DEFINE1(sysctl, struct compat_sysctl_args __user *, args)
{
- struct compat_sysctl_args tmp;
- compat_size_t __user *compat_oldlenp;
- size_t oldlen = 0;
- ssize_t result;
-
- if (copy_from_user(&tmp, args, sizeof(tmp)))
- return -EFAULT;
-
- if (tmp.oldval && !tmp.oldlenp)
- return -EFAULT;
-
- compat_oldlenp = compat_ptr(tmp.oldlenp);
- if (compat_oldlenp && get_user(oldlen, compat_oldlenp))
- return -EFAULT;
-
- result = do_sysctl(compat_ptr(tmp.name), tmp.nlen,
- compat_ptr(tmp.oldval), oldlen,
- compat_ptr(tmp.newval), tmp.newlen);
-
- if (result >= 0) {
- oldlen = result;
- result = 0;
- }
-
- if (compat_oldlenp && put_user(oldlen, compat_oldlenp))
- return -EFAULT;
-
- return result;
+ return -ENOSYS;
}
#endif /* CONFIG_COMPAT */
--
1.8.5.6
