Pull acpi-debug into release branch

[powerpc.git] / drivers / char / random.c

diff --git a/drivers/char/random.c b/drivers/char/random.c
index 46c1b97..397c714 100644 (file)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -693,9 +693,14 @@ static void xfer_secondary_pool(struct entropy_store *r, size_t nbytes)
 
        if (r->pull && r->entropy_count < nbytes * 8 &&
            r->entropy_count < r->poolinfo->POOLBITS) {
-               int bytes = max_t(int, random_read_wakeup_thresh / 8,
-                               min_t(int, nbytes, sizeof(tmp)));
+               /* If we're limited, always leave two wakeup worth's BITS */
                int rsvd = r->limit ? 0 : random_read_wakeup_thresh/4;
+               int bytes = nbytes;
+
+               /* pull at least as many as BYTES as wakeup BITS */
+               bytes = max_t(int, bytes, random_read_wakeup_thresh / 8);
+               /* but never more than the buffer size */
+               bytes = min_t(int, bytes, sizeof(tmp));
 
                DEBUG_ENT("going to reseed %s with %d bits "
                          "(%d of %d requested)\n",
@@ -760,7 +765,7 @@ static size_t account(struct entropy_store *r, size_t nbytes, int min,
 
 static void extract_buf(struct entropy_store *r, __u8 *out)
 {
-       int i, x;
+       int i;
        __u32 data[16], buf[5 + SHA_WORKSPACE_WORDS];
 
        sha_init(buf);
@@ -772,9 +777,11 @@ static void extract_buf(struct entropy_store *r, __u8 *out)
         * attempts to find previous ouputs), unless the hash
         * function can be inverted.
         */
-       for (i = 0, x = 0; i < r->poolinfo->poolwords; i += 16, x+=2) {
-               sha_transform(buf, (__u8 *)r->pool+i, buf + 5);
-               add_entropy_words(r, &buf[x % 5], 1);
+       for (i = 0; i < r->poolinfo->poolwords; i += 16) {
+               /* hash blocks of 16 words = 512 bits */
+               sha_transform(buf, (__u8 *)(r->pool + i), buf + 5);
+               /* feed back portion of the resulting hash */
+               add_entropy_words(r, &buf[i % 5], 1);
        }
 
        /*
@@ -782,7 +789,7 @@ static void extract_buf(struct entropy_store *r, __u8 *out)
         * portion of the pool while mixing, and hash one
         * final time.
         */
-       __add_entropy_words(r, &buf[x % 5], 1, data);
+       __add_entropy_words(r, &buf[i % 5], 1, data);
        sha_transform(buf, (__u8 *)data, buf + 5);
 
        /*
@@ -792,7 +799,7 @@ static void extract_buf(struct entropy_store *r, __u8 *out)
 
        buf[0] ^= buf[3];
        buf[1] ^= buf[4];
-       buf[0] ^= rol32(buf[3], 16);
+       buf[2] ^= rol32(buf[2], 16);
        memcpy(out, buf, EXTRACT_SIZE);
        memset(buf, 0, sizeof(buf));
 }
@@ -1018,37 +1025,44 @@ random_poll(struct file *file, poll_table * wait)
        return mask;
 }
 
-static ssize_t
-random_write(struct file * file, const char __user * buffer,
-            size_t count, loff_t *ppos)
+static int
+write_pool(struct entropy_store *r, const char __user *buffer, size_t count)
 {
-       int ret = 0;
        size_t bytes;
        __u32 buf[16];
        const char __user *p = buffer;
-       size_t c = count;
 
-       while (c > 0) {
-               bytes = min(c, sizeof(buf));
+       while (count > 0) {
+               bytes = min(count, sizeof(buf));
+               if (copy_from_user(&buf, p, bytes))
+                       return -EFAULT;
 
-               bytes -= copy_from_user(&buf, p, bytes);
-               if (!bytes) {
-                       ret = -EFAULT;
-                       break;
-               }
-               c -= bytes;
+               count -= bytes;
                p += bytes;
 
-               add_entropy_words(&input_pool, buf, (bytes + 3) / 4);
-       }
-       if (p == buffer) {
-               return (ssize_t)ret;
-       } else {
-               struct inode *inode = file->f_path.dentry->d_inode;
-               inode->i_mtime = current_fs_time(inode->i_sb);
-               mark_inode_dirty(inode);
-               return (ssize_t)(p - buffer);
+               add_entropy_words(r, buf, (bytes + 3) / 4);
        }
+
+       return 0;
+}
+
+static ssize_t
+random_write(struct file * file, const char __user * buffer,
+            size_t count, loff_t *ppos)
+{
+       size_t ret;
+       struct inode *inode = file->f_path.dentry->d_inode;
+
+       ret = write_pool(&blocking_pool, buffer, count);
+       if (ret)
+               return ret;
+       ret = write_pool(&nonblocking_pool, buffer, count);
+       if (ret)
+               return ret;
+
+       inode->i_mtime = current_fs_time(inode->i_sb);
+       mark_inode_dirty(inode);
+       return (ssize_t)count;
 }
 
 static int
@@ -1087,8 +1101,8 @@ random_ioctl(struct inode * inode, struct file * file,
                        return -EINVAL;
                if (get_user(size, p++))
                        return -EFAULT;
-               retval = random_write(file, (const char __user *) p,
-                                     size, &file->f_pos);
+               retval = write_pool(&input_pool, (const char __user *)p,
+                                   size);
                if (retval < 0)
                        return retval;
                credit_entropy_store(&input_pool, ent_count);