Commit 7bf0c23e authored by Mike Travis's avatar Mike Travis Committed by Ingo Molnar

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: default avatarMike Travis <travis@sgi.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: <pageexec@freemail.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 0fa376e0
...@@ -223,7 +223,7 @@ void send_IPI_mask_sequence(cpumask_t mask, int vector) ...@@ -223,7 +223,7 @@ void send_IPI_mask_sequence(cpumask_t mask, int vector)
*/ */
local_irq_save(flags); 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)) { if (cpu_isset(query_cpu, mask)) {
__send_IPI_dest_field(cpu_to_logical_apicid(query_cpu), __send_IPI_dest_field(cpu_to_logical_apicid(query_cpu),
vector); vector);
...@@ -675,7 +675,7 @@ static int convert_apicid_to_cpu(int apic_id) ...@@ -675,7 +675,7 @@ static int convert_apicid_to_cpu(int apic_id)
{ {
int i; int i;
for (i = 0; i < NR_CPUS; i++) { for_each_possible_cpu(i) {
if (per_cpu(x86_cpu_to_apicid, i) == apic_id) if (per_cpu(x86_cpu_to_apicid, i) == apic_id)
return i; return i;
} }
......
...@@ -1090,7 +1090,7 @@ static void __init smp_boot_cpus(unsigned int max_cpus) ...@@ -1090,7 +1090,7 @@ static void __init smp_boot_cpus(unsigned int max_cpus)
* Allow the user to impress friends. * Allow the user to impress friends.
*/ */
Dprintk("Before bogomips.\n"); Dprintk("Before bogomips.\n");
for (cpu = 0; cpu < NR_CPUS; cpu++) for_each_possible_cpu(cpu)
if (cpu_isset(cpu, cpu_callout_map)) if (cpu_isset(cpu, cpu_callout_map))
bogosum += cpu_data(cpu).loops_per_jiffy; bogosum += cpu_data(cpu).loops_per_jiffy;
printk(KERN_INFO printk(KERN_INFO
...@@ -1121,7 +1121,7 @@ static void __init smp_boot_cpus(unsigned int max_cpus) ...@@ -1121,7 +1121,7 @@ static void __init smp_boot_cpus(unsigned int max_cpus)
* construct cpu_sibling_map, so that we can tell sibling CPUs * construct cpu_sibling_map, so that we can tell sibling CPUs
* efficiently. * efficiently.
*/ */
for (cpu = 0; cpu < NR_CPUS; cpu++) { for_each_possible_cpu(cpu) {
cpus_clear(per_cpu(cpu_sibling_map, cpu)); cpus_clear(per_cpu(cpu_sibling_map, cpu));
cpus_clear(per_cpu(cpu_core_map, cpu)); cpus_clear(per_cpu(cpu_core_map, cpu));
} }
......
...@@ -146,7 +146,7 @@ void __init xen_smp_prepare_boot_cpu(void) ...@@ -146,7 +146,7 @@ void __init xen_smp_prepare_boot_cpu(void)
old memory can be recycled */ old memory can be recycled */
make_lowmem_page_readwrite(&per_cpu__gdt_page); make_lowmem_page_readwrite(&per_cpu__gdt_page);
for (cpu = 0; cpu < NR_CPUS; cpu++) { for_each_possible_cpu(cpu) {
cpus_clear(per_cpu(cpu_sibling_map, cpu)); cpus_clear(per_cpu(cpu_sibling_map, cpu));
/* /*
* cpu_core_map lives in a per cpu area that is cleared * cpu_core_map lives in a per cpu area that is cleared
...@@ -163,7 +163,7 @@ void __init xen_smp_prepare_cpus(unsigned int max_cpus) ...@@ -163,7 +163,7 @@ void __init xen_smp_prepare_cpus(unsigned int max_cpus)
{ {
unsigned cpu; unsigned cpu;
for (cpu = 0; cpu < NR_CPUS; cpu++) { for_each_possible_cpu(cpu) {
cpus_clear(per_cpu(cpu_sibling_map, cpu)); cpus_clear(per_cpu(cpu_sibling_map, cpu));
/* /*
* cpu_core_ map will be zeroed when the per * cpu_core_ map will be zeroed when the per
......
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