Re: [Xen-devel] [PATCH] acpi: Make sure valid CPU is passed to do_pm_op()

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 14.08.12 at 18:37, Boris Ostrovsky <boris.ostrovsky@xxxxxxx> wrote:
> acpi: Make sure valid CPU is passed to do_pm_op()
> 
> Passing invalid CPU value to do_pm_op() will cause assertion
> in cpu_online().
> 
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxx>

I'd like to propose the below extension to you change instead.

Jan

Subject: acpi: Make sure valid CPU is passed to do_pm_op()

Passing invalid CPU value to do_pm_op() will cause assertion
in cpu_online().

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxx>

Such checks would, at a first glance, then also be missing at the top
of various helper functions, but these check really were already
redundant with the check in do_pm_op(). Remove the redundant checks
for clarity and brevity.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/drivers/acpi/pmstat.c
+++ b/xen/drivers/acpi/pmstat.c
@@ -201,8 +201,6 @@ static int get_cpufreq_para(struct xen_s
     struct list_head *pos;
     uint32_t cpu, i, j = 0;
 
-    if ( !op || !cpu_online(op->cpuid) )
-        return -EINVAL;
     pmpt = processor_pminfo[op->cpuid];
     policy = per_cpu(cpufreq_cpu_policy, op->cpuid);
 
@@ -305,9 +303,6 @@ static int set_cpufreq_gov(struct xen_sy
 {
     struct cpufreq_policy new_policy, *old_policy;
 
-    if ( !op || !cpu_online(op->cpuid) )
-        return -EINVAL;
-
     old_policy = per_cpu(cpufreq_cpu_policy, op->cpuid);
     if ( !old_policy )
         return -EINVAL;
@@ -326,8 +321,6 @@ static int set_cpufreq_para(struct xen_s
     int ret = 0;
     struct cpufreq_policy *policy;
 
-    if ( !op || !cpu_online(op->cpuid) )
-        return -EINVAL;
     policy = per_cpu(cpufreq_cpu_policy, op->cpuid);
 
     if ( !policy || !policy->governor )
@@ -404,22 +397,12 @@ static int set_cpufreq_para(struct xen_s
     return ret;
 }
 
-static int get_cpufreq_avgfreq(struct xen_sysctl_pm_op *op)
-{
-    if ( !op || !cpu_online(op->cpuid) )
-        return -EINVAL;
-
-    op->u.get_avgfreq = cpufreq_driver_getavg(op->cpuid, USR_GETAVG);
-
-    return 0;
-}
-
 int do_pm_op(struct xen_sysctl_pm_op *op)
 {
     int ret = 0;
     const struct processor_pminfo *pmpt;
 
-    if ( !op || !cpu_online(op->cpuid) )
+    if ( !op || op->cpuid >= nr_cpu_ids || !cpu_online(op->cpuid) )
         return -EINVAL;
     pmpt = processor_pminfo[op->cpuid];
 
@@ -455,7 +438,7 @@ int do_pm_op(struct xen_sysctl_pm_op *op
 
     case GET_CPUFREQ_AVGFREQ:
     {
-        ret = get_cpufreq_avgfreq(op);
+        op->u.get_avgfreq = cpufreq_driver_getavg(op->cpuid, USR_GETAVG);
         break;
     }

Attachment: x86-acpi-pm-op-cpu-check.patch
Description: Text document

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