From 505422517d3f126bb939439e9d15dece94e11d2c Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Fri, 11 Dec 2009 18:14:40 +0100 Subject: x86, msr: Add support for non-contiguous cpumasks The current rd/wrmsr_on_cpus helpers assume that the supplied cpumasks are contiguous. However, there are machines out there like some K8 multinode Opterons which have a non-contiguous core enumeration on each node (e.g. cores 0,2 on node 0 instead of 0,1), see http://www.gossamer-threads.com/lists/linux/kernel/1160268. This patch fixes out-of-bounds writes (see URL above) by adding per-CPU msr structs which are used on the respective cores. Additionally, two helpers, msrs_{alloc,free}, are provided for use by the callers of the MSR accessors. Cc: H. Peter Anvin Cc: Mauro Carvalho Chehab Cc: Aristeu Rozanski Cc: Randy Dunlap Cc: Doug Thompson Signed-off-by: Borislav Petkov LKML-Reference: <20091211171440.GD31998@aftab> Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/msr.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/x86/include/asm/msr.h') diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h index 5bef931f8b14..2d228fc9b4b7 100644 --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -244,6 +244,9 @@ do { \ #define write_rdtscp_aux(val) wrmsr(0xc0000103, (val), 0) +struct msr *msrs_alloc(void); +void msrs_free(struct msr *msrs); + #ifdef CONFIG_SMP int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h); int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h); -- cgit