Hi Alok, On Thu, 2012-03-08 at 13:33 -0800, Alok Kataria wrote: > Hi Toshi, > > > > > The change looks good. I suggest you also add the following line to > > prevent such bug in future. > > > > kfree(buffer.pointer); > > buffer.length = ACPI_ALLOCATE_BUFFER; > > buffer.pointer = NULL; > > + lapic = NULL; > > That's a good suggestion, below is the updated patch. Thanks !! Looks good. Thanks for the update. -Toshi > -- > > From: Petr Vandrovec <petr@xxxxxxxxxx> > > When processor is being hot-added to the system, acpi_map_lsapic invokes > ACPI _MAT method to find APIC ID and flags, verifies that returned structure > is indeed ACPI's local APIC structure, and that flags contain MADT_ENABLED > bit. Then saves APIC ID, frees structure - and accesses structure when > computing arguments for acpi_register_lapic call. Which sometime leads > to acpi_register_lapic call being made with second argument zero, failing > to bring processor online with error 'Unable to map lapic to logical cpu > number'. > > As lapic->lapic_flags & ACPI_MADT_ENABLED was already confirmed to be non-zero > few lines above, we can just pass unconditional ACPI_MADT_ENABLED to the > acpi_register_lapic. > > Signed-off-by: Petr Vandrovec <petr@xxxxxxxxxx> > Signed-off-by: Alok N Kataria <akataria@xxxxxxxxxx> > Cc : Toshi Kani <toshi.kani@xxxxxx> > > > Index: linux-2.6/arch/x86/kernel/acpi/boot.c > =================================================================== > --- linux-2.6.orig/arch/x86/kernel/acpi/boot.c 2012-01-24 14:48:56.000000000 -0800 > +++ linux-2.6/arch/x86/kernel/acpi/boot.c 2012-03-08 13:25:39.000000000 -0800 > @@ -642,6 +642,7 @@ static int __cpuinit _acpi_map_lsapic(ac > kfree(buffer.pointer); > buffer.length = ACPI_ALLOCATE_BUFFER; > buffer.pointer = NULL; > + lapic = NULL; > > if (!alloc_cpumask_var(&tmp_map, GFP_KERNEL)) > goto out; > @@ -650,7 +651,7 @@ static int __cpuinit _acpi_map_lsapic(ac > goto free_tmp_map; > > cpumask_copy(tmp_map, cpu_present_mask); > - acpi_register_lapic(physid, lapic->lapic_flags & ACPI_MADT_ENABLED); > + acpi_register_lapic(physid, ACPI_MADT_ENABLED); > > /* > * If mp_register_lapic successfully generates a new logical cpu > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
