From 1714f9bfc92d6ee67e84127332a1fae27772acfe Mon Sep 17 00:00:00 2001 From: Andi Kleen <ak@suse.de> Date: Mon, 16 Apr 2007 10:30:27 +0200 Subject: [PATCH] [PATCH] x86: Fix potential overflow in perfctr reservation While reviewing this code again I found a potential overflow of the bitmap. The p4 oprofile can theoretically set bits beyond the reservation bitmap for specific configurations. Avoid that by sizing the bitmaps properly. Signed-off-by: Andi Kleen <ak@suse.de> --- arch/i386/kernel/nmi.c | 9 +++++---- arch/x86_64/kernel/nmi.c | 10 ++++++---- 2 files changed, 11 insertions(+), 8 deletions(-) diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c index a98ba88a8c0ca..9f1e8c1afab75 100644 --- a/arch/i386/kernel/nmi.c +++ b/arch/i386/kernel/nmi.c @@ -41,16 +41,17 @@ int nmi_watchdog_enabled; * different subsystems this reservation system just tries to coordinate * things a little */ -static DEFINE_PER_CPU(unsigned long, perfctr_nmi_owner); -static DEFINE_PER_CPU(unsigned long, evntsel_nmi_owner[3]); - -static cpumask_t backtrace_mask = CPU_MASK_NONE; /* this number is calculated from Intel's MSR_P4_CRU_ESCR5 register and it's * offset from MSR_P4_BSU_ESCR0. It will be the max for all platforms (for now) */ #define NMI_MAX_COUNTER_BITS 66 +#define NMI_MAX_COUNTER_LONGS BITS_TO_LONGS(NMI_MAX_COUNTER_BITS) +static DEFINE_PER_CPU(unsigned long, perfctr_nmi_owner[NMI_MAX_COUNTER_LONGS]); +static DEFINE_PER_CPU(unsigned long, evntsel_nmi_owner[NMI_MAX_COUNTER_LONGS]); + +static cpumask_t backtrace_mask = CPU_MASK_NONE; /* nmi_active: * >0: the lapic NMI watchdog is active, but can be disabled * <0: the lapic NMI watchdog has not been set up, and cannot diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c index a90996c27dc87..dfab9f1673662 100644 --- a/arch/x86_64/kernel/nmi.c +++ b/arch/x86_64/kernel/nmi.c @@ -39,15 +39,17 @@ int panic_on_unrecovered_nmi; * different subsystems this reservation system just tries to coordinate * things a little */ -static DEFINE_PER_CPU(unsigned, perfctr_nmi_owner); -static DEFINE_PER_CPU(unsigned, evntsel_nmi_owner[2]); - -static cpumask_t backtrace_mask = CPU_MASK_NONE; /* this number is calculated from Intel's MSR_P4_CRU_ESCR5 register and it's * offset from MSR_P4_BSU_ESCR0. It will be the max for all platforms (for now) */ #define NMI_MAX_COUNTER_BITS 66 +#define NMI_MAX_COUNTER_LONGS BITS_TO_LONGS(NMI_MAX_COUNTER_BITS) + +static DEFINE_PER_CPU(unsigned, perfctr_nmi_owner[NMI_MAX_COUNTER_LONGS]); +static DEFINE_PER_CPU(unsigned, evntsel_nmi_owner[NMI_MAX_COUNTER_LONGS]); + +static cpumask_t backtrace_mask = CPU_MASK_NONE; /* nmi_active: * >0: the lapic NMI watchdog is active, but can be disabled -- GitLab