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authorAndi Kleen <ak@suse.de>2007-04-16 10:30:27 +0200
committerAndi Kleen <andi@basil.nowhere.org>2007-04-16 10:30:27 +0200
commit1714f9bfc92d6ee67e84127332a1fae27772acfe (patch)
treea89256be07359cbb0586a52c00ae985e1de12561 /arch/x86_64
parent08269c6d38e003adb12f55c6d795daa89bdc1bae (diff)
[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>
Diffstat (limited to 'arch/x86_64')
-rw-r--r--arch/x86_64/kernel/nmi.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c
index a90996c27dc8..dfab9f167366 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