Subject: ACPI: Add the MWAIT C-state mask to avoid overflow From: Zhao Yakui <yakui.zhao@xxxxxxxxx> Add the MWAIT C-state mask to avoid overflow Signed-off-by: Zhao Yakui <yakui.zhao@xxxxxxxxx> Acked-by:Venki Pallipadi <venkatesh.pallipadi@xxxxxxxxx> --- arch/x86/kernel/acpi/cstate.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) Index: linux-2.6/arch/x86/kernel/acpi/cstate.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/acpi/cstate.c +++ linux-2.6/arch/x86/kernel/acpi/cstate.c @@ -56,6 +56,7 @@ static struct cstate_entry *cpu_cstate_e static short mwait_supported[ACPI_PROCESSOR_MAX_POWER]; #define MWAIT_SUBSTATE_MASK (0xf) +#define MWAIT_CSTATE_MASK (0xf) #define MWAIT_SUBSTATE_SIZE (4) #define CPUID_MWAIT_LEAF (5) @@ -98,7 +99,8 @@ int acpi_processor_ffh_cstate_probe(unsi cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx); /* Check whether this particular cx_type (in CST) is supported or not */ - cstate_type = (cx->address >> MWAIT_SUBSTATE_SIZE) + 1; + cstate_type = ((cx->address >> MWAIT_SUBSTATE_SIZE) & + MWAIT_CSTATE_MASK) + 1; edx_part = edx >> (cstate_type * MWAIT_SUBSTATE_SIZE); num_cstate_subtype = edx_part & MWAIT_SUBSTATE_MASK; -- 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
