[PATCH 05/16] make write() operation smp aware

Glauber de Oliveira Costa
2008-01-07T13:07:52Z

This patch makes the write() file operation smp aware. Which means, receiving
the vcpu_id value through the offset parameter, and being well aware to which
vcpu we're talking to.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
---
drivers/lguest/lguest_user.c | 11 +++++++++--
1 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c
index 216514b..d176004 100644
--- a/drivers/lguest/lguest_user.c
+++ b/drivers/lguest/lguest_user.c
@@ -230,14 +230,21 @@ static ssize_t write(struct file *file, const char __user *in,
struct lguest *lg = file->private_data;
const unsigned long __user *input = (const unsigned long __user *)in;
unsigned long req;
+ struct lg_vcpu *vcpu = NULL;
+ int vcpu_id = *off;

if (get_user(req, input) != 0)
return -EFAULT;
input++;

/* If you haven't initialized, you must do that first. */
- if (req != LHREQ_INITIALIZE && !lg)
- return -EINVAL;
+ if (req != LHREQ_INITIALIZE) {
+ if (!lg || (vcpu_id > lg->nr_vcpus))
+ return -EINVAL;
+ vcpu = &lg->vcpus[vcpu_id];
+ if (!vcpu)
+ return -EINVAL;
+ }

/* Once the Guest is dead, all you can do is read() why it died. */
if (lg && lg->dead)
--
1.5.0.6