x86: prevent dereferencing non-allocated per_cpu variables
'for_each_possible_cpu(i)' when there's a _remote possibility_ of
dereferencing a non-allocated per_cpu variable involved.
All files except mm/vmstat.c are x86 arch.
Thanks to pageexec@freemail.hu for pointing this out.
Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: <pageexec@freemail.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/smp_32.c b/arch/x86/kernel/smp_32.c
index fcaa026..d4c01a4 100644
--- a/arch/x86/kernel/smp_32.c
+++ b/arch/x86/kernel/smp_32.c
@@ -223,7 +223,7 @@
*/
local_irq_save(flags);
- for (query_cpu = 0; query_cpu < NR_CPUS; ++query_cpu) {
+ for_each_possible_cpu(query_cpu) {
if (cpu_isset(query_cpu, mask)) {
__send_IPI_dest_field(cpu_to_logical_apicid(query_cpu),
vector);
@@ -675,7 +675,7 @@
{
int i;
- for (i = 0; i < NR_CPUS; i++) {
+ for_each_possible_cpu(i) {
if (per_cpu(x86_cpu_to_apicid, i) == apic_id)
return i;
}