diff options
| author | Mike Travis <travis@sgi.com> | 2008-01-30 13:30:55 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:30:55 +0100 |
| commit | 7bf0c23ed24b0d95a2a717f86dce1f210e16f8a5 (patch) | |
| tree | 64f1d21cfcc7746d430c4ad70c864e176536ac8d | |
| parent | 0fa376e027f0bd71368e1485f863f0dff8f7c897 (diff) | |
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>
| -rw-r--r-- | arch/x86/kernel/smp_32.c | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/smpboot_32.c | 4 | ||||
| -rw-r--r-- | arch/x86/xen/smp.c | 4 |
3 files changed, 6 insertions, 6 deletions
diff --git a/arch/x86/kernel/smp_32.c b/arch/x86/kernel/smp_32.c index fcaa026eb80..d4c01a4aca6 100644 --- a/arch/x86/kernel/smp_32.c +++ b/arch/x86/kernel/smp_32.c @@ -223,7 +223,7 @@ void send_IPI_mask_sequence(cpumask_t mask, int vector) */ 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 @@ static int convert_apicid_to_cpu(int apic_id) { 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; } diff --git a/arch/x86/kernel/smpboot_32.c b/arch/x86/kernel/smpboot_32.c index 239ada1c499..0bf7f20baba 100644 --- a/arch/x86/kernel/smpboot_32.c +++ b/arch/x86/kernel/smpboot_32.c @@ -1090,7 +1090,7 @@ static void __init smp_boot_cpus(unsigned int max_cpus) * Allow the user to impress friends. */ Dprintk("Before bogomips.\n"); - for (cpu = 0; cpu < NR_CPUS; cpu++) + for_each_possible_cpu(cpu) if (cpu_isset(cpu, cpu_callout_map)) bogosum += cpu_data(cpu).loops_per_jiffy; printk(KERN_INFO @@ -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 * 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_core_map, cpu)); } diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index c1b131bcdcb..8e1234e1455 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -146,7 +146,7 @@ void __init xen_smp_prepare_boot_cpu(void) old memory can be recycled */ 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)); /* * 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) { unsigned cpu; - for (cpu = 0; cpu < NR_CPUS; cpu++) { + for_each_possible_cpu(cpu) { cpus_clear(per_cpu(cpu_sibling_map, cpu)); /* * cpu_core_ map will be zeroed when the per |