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 b75dbf4..5903057 100644 (file)
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -13,6 +13,7 @@
 #include <linux/file.h>
 #include <linux/ctype.h>
 #include <linux/netdevice.h>
+#include <linux/slab.h>
 
 #ifdef CONFIG_SYSCTL_SYSCALL
 
@@ -1331,7 +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);
@@ -1342,15 +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;
@@ -1361,7 +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;
 
@@ -1399,6 +1397,13 @@ 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 (name[0] == CTL_KERN && name[1] == KERN_VERSION)
+               return;
+
        if (printk_ratelimit()) {
                printk(KERN_INFO
                        "warning: process `%s' used the deprecated sysctl "
@@ -1410,6 +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)
 {
@@ -1424,7 +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);
 }