ALSA: usb-audio: add support for Akai MPD16

[safe/jmp/linux-2.6] / kernel / sysctl_binary.c

diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index 471438b..5903057 100644 (file)
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -12,6 +12,8 @@
 #include <linux/pid_namespace.h>
 #include <linux/file.h>
 #include <linux/ctype.h>
+#include <linux/netdevice.h>
+#include <linux/slab.h>
 
 #ifdef CONFIG_SYSCTL_SYSCALL
 
@@ -1250,9 +1252,12 @@ out:
 static const struct bin_table *get_sysctl(const int *name, int nlen, char *path)
 {
        const struct bin_table *table = &bin_root_table[0];
-       struct net *net = current->nsproxy->net_ns;
        int ctl_name;
 
+       /* The binary sysctl tables have a small maximum depth so
+        * there is no danger of overflowing our path as it PATH_MAX
+        * bytes long.
+        */
        memcpy(path, "sys/", 4);
        path += 4;
 
@@ -1263,30 +1268,30 @@ repeat:
        name++;
        nlen--;
        for ( ; table->convert; table++) {
-               struct net_device *dev = NULL;
-               const char *procname = NULL;
-
-               /* Use the well known sysctl number to proc name mapping */
-               if (ctl_name == table->ctl_name)
-                       procname = table->procname;
+               int len = 0;
 
                /*
                 * For a wild card entry map from ifindex to network
                 * device name.
                 */
-               else if (!table->ctl_name) {
+               if (!table->ctl_name) {
+#ifdef CONFIG_NET
+                       struct net *net = current->nsproxy->net_ns;
+                       struct net_device *dev;
                        dev = dev_get_by_index(net, ctl_name);
-                       if (dev)
-                               procname = dev->name;
+                       if (dev) {
+                               len = strlen(dev->name);
+                               memcpy(path, dev->name, len);
+                               dev_put(dev);
+                       }
+#endif
+               /* Use the well known sysctl number to proc name mapping */
+               } else if (ctl_name == table->ctl_name) {
+                       len = strlen(table->procname);
+                       memcpy(path, table->procname, len);
                }
-               if (procname) {
-                       int len;
-
-                       len = strlen(procname);
-                       memcpy(path, procname, len);
+               if (len) {
                        path += len;
-                       if (dev)
-                               dev_put(dev);
                        if (table->child) {
                                *path++ = '/';
                                table = table->child;
@@ -1327,7 +1332,7 @@ static ssize_t binary_sysctl(const int *name, int nlen,
        ssize_t result;
        char *pathname;
        int flags;
-       int acc_mode, fmode;
+       int acc_mode;
 
        pathname = sysctl_getname(name, nlen, &table);
        result = PTR_ERR(pathname);
@@ -1338,15 +1343,12 @@ static ssize_t binary_sysctl(const int *name, int nlen,
        if (oldval && oldlen && newval && newlen) {
                flags = O_RDWR;
                acc_mode = MAY_READ | MAY_WRITE;
-               fmode = FMODE_READ | FMODE_WRITE;
        } else if (newval && newlen) {
                flags = O_WRONLY;
                acc_mode = MAY_WRITE;
-               fmode = FMODE_WRITE;
        } else if (oldval && oldlen) {
                flags = O_RDONLY;
                acc_mode = MAY_READ;
-               fmode = FMODE_READ;
        } else {
                result = 0;
                goto out_putname;
@@ -1357,7 +1359,7 @@ static ssize_t binary_sysctl(const int *name, int nlen,
        if (result)
                goto out_putname;
 
-       result = may_open(&nd.path, acc_mode, fmode);
+       result = may_open(&nd.path, acc_mode, flags);
        if (result)
                goto out_putpath;
 
@@ -1393,15 +1395,16 @@ static ssize_t binary_sysctl(const int *name, int nlen,
 
 static void deprecated_sysctl_warning(const int *name, int nlen)
 {
-       static int msg_count;
        int i;
 
-       /* Ignore accesses to kernel.version */
-       if ((nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
+       /*
+        * CTL_KERN/KERN_VERSION is used by older glibc and cannot
+        * ever go away.
+        */
+       if (name[0] == CTL_KERN && name[1] == KERN_VERSION)
                return;
 
-       if (msg_count < 5) {
-               msg_count++;
+       if (printk_ratelimit()) {
                printk(KERN_INFO
                        "warning: process `%s' used the deprecated sysctl "
                        "system call with ", current->comm);
@@ -1412,6 +1415,35 @@ static void deprecated_sysctl_warning(const int *name, int nlen)
        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)
 {
@@ -1426,7 +1458,7 @@ static ssize_t do_sysctl(int __user *args_name, int nlen,
                if (get_user(name[i], args_name + i))
                        return -EFAULT;
 
-       deprecated_sysctl_warning(name, nlen);
+       warn_on_bintable(name, nlen);
 
        return binary_sysctl(name, nlen, oldval, oldlen, newval, newlen);
 }