# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Date 1160902400 -3600
# Node ID 6ed4368b4a9e1924c983774c4b1a2b6baf8e98a6
# Parent d30ed0e261aec5ab7ce1904ae1007f3af4898b92
[XENOPROF] Add a lock around the xenoprof hypercall. It mutates global state.
Signed-off-by: Markus Armbruster <armbru@xxxxxxxxxx>
---
xen/arch/x86/oprofile/xenoprof.c | 73 ++++++++++++++++++++++++++-------------
1 files changed, 49 insertions(+), 24 deletions(-)
diff -r d30ed0e261ae -r 6ed4368b4a9e xen/arch/x86/oprofile/xenoprof.c
--- a/xen/arch/x86/oprofile/xenoprof.c Sun Oct 15 09:52:33 2006 +0100
+++ b/xen/arch/x86/oprofile/xenoprof.c Sun Oct 15 09:53:20 2006 +0100
@@ -12,6 +12,9 @@
/* Limit amount of pages used for shared buffer (per domain) */
#define MAX_OPROF_SHARED_PAGES 32
+
+/* Lock protecting the following global state */
+static spinlock_t xenoprof_lock = SPIN_LOCK_UNLOCKED;
struct domain *active_domains[MAX_OPROF_DOMAINS];
int active_ready[MAX_OPROF_DOMAINS];
@@ -514,6 +517,8 @@ int do_xenoprof_op(int op, XEN_GUEST_HAN
return -EPERM;
}
+ spin_lock(&xenoprof_lock);
+
switch ( op )
{
case XENOPROF_init:
@@ -539,23 +544,31 @@ int do_xenoprof_op(int op, XEN_GUEST_HAN
case XENOPROF_set_active:
{
domid_t domid;
- if ( xenoprof_state != XENOPROF_IDLE )
- return -EPERM;
- if ( copy_from_guest(&domid, arg, 1) )
- return -EFAULT;
+ if ( xenoprof_state != XENOPROF_IDLE ) {
+ ret = -EPERM;
+ break;
+ }
+ if ( copy_from_guest(&domid, arg, 1) ) {
+ ret = -EFAULT;
+ break;
+ }
ret = add_active_list(domid);
break;
}
case XENOPROF_set_passive:
{
- if ( xenoprof_state != XENOPROF_IDLE )
- return -EPERM;
+ if ( xenoprof_state != XENOPROF_IDLE ) {
+ ret = -EPERM;
+ break;
+ }
ret = add_passive_list(arg);
break;
}
case XENOPROF_reserve_counters:
- if ( xenoprof_state != XENOPROF_IDLE )
- return -EPERM;
+ if ( xenoprof_state != XENOPROF_IDLE ) {
+ ret = -EPERM;
+ break;
+ }
ret = nmi_reserve_counters();
if ( !ret )
xenoprof_state = XENOPROF_COUNTERS_RESERVED;
@@ -564,16 +577,20 @@ int do_xenoprof_op(int op, XEN_GUEST_HAN
case XENOPROF_counter:
{
struct xenoprof_counter counter;
- if ( xenoprof_state != XENOPROF_COUNTERS_RESERVED )
- return -EPERM;
- if ( adomains == 0 )
- return -EPERM;
-
- if ( copy_from_guest(&counter, arg, 1) )
- return -EFAULT;
-
- if ( counter.ind > OP_MAX_COUNTER )
- return -E2BIG;
+ if ( xenoprof_state != XENOPROF_COUNTERS_RESERVED || adomains == 0) {
+ ret = -EPERM;
+ break;
+ }
+
+ if ( copy_from_guest(&counter, arg, 1) ) {
+ ret = -EFAULT;
+ break;
+ }
+
+ if ( counter.ind > OP_MAX_COUNTER ) {
+ ret = -E2BIG;
+ break;
+ }
counter_config[counter.ind].count = (unsigned long) counter.count;
counter_config[counter.ind].enabled = (unsigned long)
counter.enabled;
@@ -587,8 +604,10 @@ int do_xenoprof_op(int op, XEN_GUEST_HAN
}
case XENOPROF_setup_events:
- if ( xenoprof_state != XENOPROF_COUNTERS_RESERVED )
- return -EPERM;
+ if ( xenoprof_state != XENOPROF_COUNTERS_RESERVED ) {
+ ret = -EPERM;
+ break;
+ }
ret = nmi_setup_events();
if ( !ret )
xenoprof_state = XENOPROF_READY;
@@ -621,16 +640,20 @@ int do_xenoprof_op(int op, XEN_GUEST_HAN
break;
case XENOPROF_stop:
- if ( xenoprof_state != XENOPROF_PROFILING )
- return -EPERM;
+ if ( xenoprof_state != XENOPROF_PROFILING ) {
+ ret = -EPERM;
+ break;
+ }
nmi_stop();
xenoprof_state = XENOPROF_READY;
break;
case XENOPROF_disable_virq:
if ( (xenoprof_state == XENOPROF_PROFILING) &&
- (is_active(current->domain)) )
- return -EPERM;
+ (is_active(current->domain)) ) {
+ ret = -EPERM;
+ break;
+ }
ret = reset_active(current->domain);
break;
@@ -662,6 +685,8 @@ int do_xenoprof_op(int op, XEN_GUEST_HAN
ret = -EINVAL;
}
+ spin_unlock(&xenoprof_lock);
+
if ( ret < 0 )
printk("xenoprof: operation %d failed for dom %d (status : %d)\n",
op, current->domain->domain_id, ret);
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