From 7ea07a1500f05e06ebf0136763c781244f77a2a1 Mon Sep 17 00:00:00 2001
From: Glauber de Oliveira Costa <gcosta@redhat.com>
Date: Mon, 7 Jan 2008 11:05:26 -0200
Subject: [PATCH] lguest: make write() operation smp aware
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>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
drivers/lguest/lguest_user.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c
index 9f0a44329947..2562082a3ea3 100644
--- a/drivers/lguest/lguest_user.c
+++ b/drivers/lguest/lguest_user.c
@@ -227,14 +227,21 @@ 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_cpu *cpu;
+ unsigned int cpu_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 || (cpu_id >= lg->nr_cpus))
+ return -EINVAL;
+ cpu = &lg->cpus[cpu_id];
+ if (!cpu)
+ return -EINVAL;
+ }
/* Once the Guest is dead, all you can do is read() why it died. */
if (lg && lg->dead)
--
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