[Xen-changelog] [xen-unstable] [LINUX] Eliminate microcode driver's dependency on sys_m{, un}lock as

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Node ID 9943e06e966e24773459c654975310f36ba5daa2
# Parent  7f861cd3d0c3508612c9e5cf92ec8ff362645cb7
[LINUX] Eliminate microcode driver's dependency on sys_m{,un}lock as
well as the needless use of static variables.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
---
 linux-2.6-xen-sparse/arch/i386/kernel/microcode-xen.c |   38 +++++++-----------
 1 files changed, 16 insertions(+), 22 deletions(-)

diff -r 7f861cd3d0c3 -r 9943e06e966e 
linux-2.6-xen-sparse/arch/i386/kernel/microcode-xen.c
--- a/linux-2.6-xen-sparse/arch/i386/kernel/microcode-xen.c     Wed Oct 18 
17:39:52 2006 +0100
+++ b/linux-2.6-xen-sparse/arch/i386/kernel/microcode-xen.c     Wed Oct 18 
17:41:36 2006 +0100
@@ -50,9 +50,6 @@ MODULE_LICENSE("GPL");
 
 /* no concurrent ->write()s are allowed on /dev/cpu/microcode */
 static DECLARE_MUTEX(microcode_sem);
-
-static void __user *user_buffer;       /* user area microcode data buffer */
-static unsigned int user_buffer_size;  /* it's size */
                                
 static int microcode_open (struct inode *unused1, struct file *unused2)
 {
@@ -60,21 +57,26 @@ static int microcode_open (struct inode 
 }
 
 
-static int do_microcode_update (void)
+static int do_microcode_update (const void __user *ubuf, size_t len)
 {
        int err;
-       dom0_op_t op;
+       void *kbuf;
 
-       err = sys_mlock((unsigned long)user_buffer, user_buffer_size);
-       if (err != 0)
-               return err;
+       kbuf = vmalloc(len);
+       if (!kbuf)
+               return -ENOMEM;
 
-       op.cmd = DOM0_MICROCODE;
-       set_xen_guest_handle(op.u.microcode.data, user_buffer);
-       op.u.microcode.length = user_buffer_size;
-       err = HYPERVISOR_dom0_op(&op);
+       if (copy_from_user(kbuf, ubuf, len) == 0) {
+               dom0_op_t op;
 
-       (void)sys_munlock((unsigned long)user_buffer, user_buffer_size);
+               op.cmd = DOM0_MICROCODE;
+               set_xen_guest_handle(op.u.microcode.data, kbuf);
+               op.u.microcode.length = len;
+               err = HYPERVISOR_dom0_op(&op);
+       } else
+               err = -EFAULT;
+
+       vfree(kbuf);
 
        return err;
 }
@@ -88,17 +90,9 @@ static ssize_t microcode_write (struct f
                return -EINVAL;
        }
 
-       if ((len >> PAGE_SHIFT) > num_physpages) {
-               printk(KERN_ERR "microcode: too much data (max %ld pages)\n", 
num_physpages);
-               return -EINVAL;
-       }
-
        down(&microcode_sem);
 
-       user_buffer = (void __user *) buf;
-       user_buffer_size = (int) len;
-
-       ret = do_microcode_update();
+       ret = do_microcode_update(buf, len);
        if (!ret)
                ret = (ssize_t)len;
 

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