On Wed 30-10-19 17:34:28, Yunsheng Lin wrote: > When passing the return value of dev_to_node() to cpumask_of_node() > without checking if the device's node id is NUMA_NO_NODE, there is > global-out-of-bounds detected by KASAN. > > >From the discussion [1], NUMA_NO_NODE really means no node affinity, > which also means all cpus should be usable. So the cpumask_of_node() > should always return all cpus online when user passes the node id as > NUMA_NO_NODE, just like similar semantic that page allocator handles > NUMA_NO_NODE. > > But we cannot really copy the page allocator logic. Simply because the > page allocator doesn't enforce the near node affinity. It just picks it > up as a preferred node but then it is free to fallback to any other numa > node. This is not the case here and node_to_cpumask_map will only restrict > to the particular node's cpus which would have really non deterministic > behavior depending on where the code is executed. So in fact we really > want to return cpu_online_mask for NUMA_NO_NODE. > > Also there is a debugging version of node_to_cpumask_map() for x86 and > arm64, which is only used when CONFIG_DEBUG_PER_CPU_MAPS is defined, this > patch changes it to handle NUMA_NO_NODE as normal node_to_cpumask_map(). > > [1] https://lkml.org/lkml/2019/9/11/66 Please do not use lkml.org links. They tend to break quite often. Use http://lkml.kernel.org/r/$msg_id or lore.kernel.org > Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx> > Suggested-by: Michal Hocko <mhocko@xxxxxxxxxx> > Acked-by: Michal Hocko <mhocko@xxxxxxxx> > Acked-by: Paul Burton <paul.burton@xxxxxxxx> # MIPS bits > --- > V7: replace -1 with NUMA_NO_NODE for mips ip27 as suggested by Paul. > V6: Drop the cpu_all_mask -> cpu_online_mask change for it seems a > little controversial, may need deeper investigation, and rebased > on the latest linux-next. > V5: Drop unsigned "fix" change for x86/arm64, and change comment log > according to Michal's comment. > V4: Have all these changes in a single patch. > V3: Change to only handle NUMA_NO_NODE, and return cpu_online_mask > for NUMA_NO_NODE case, and change the commit log to better justify > the change. > V2: make the node id checking change to other arches too. > --- > arch/arm64/include/asm/numa.h | 3 +++ > arch/arm64/mm/numa.c | 3 +++ > arch/mips/include/asm/mach-ip27/topology.h | 2 +- > arch/mips/include/asm/mach-loongson64/topology.h | 4 +++- > arch/s390/include/asm/topology.h | 3 +++ > arch/x86/include/asm/topology.h | 3 +++ > arch/x86/mm/numa.c | 3 +++ > 7 files changed, 19 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/numa.h b/arch/arm64/include/asm/numa.h > index 626ad01..c8a4b31 100644 > --- a/arch/arm64/include/asm/numa.h > +++ b/arch/arm64/include/asm/numa.h > @@ -25,6 +25,9 @@ const struct cpumask *cpumask_of_node(int node); > /* Returns a pointer to the cpumask of CPUs on Node 'node'. */ > static inline const struct cpumask *cpumask_of_node(int node) > { > + if (node == NUMA_NO_NODE) > + return cpu_online_mask; > + > return node_to_cpumask_map[node]; > } > #endif > diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c > index 4decf16..5ae7eea 100644 > --- a/arch/arm64/mm/numa.c > +++ b/arch/arm64/mm/numa.c > @@ -46,6 +46,9 @@ EXPORT_SYMBOL(node_to_cpumask_map); > */ > const struct cpumask *cpumask_of_node(int node) > { > + if (node == NUMA_NO_NODE) > + return cpu_online_mask; > + > if (WARN_ON(node >= nr_node_ids)) > return cpu_none_mask; > > diff --git a/arch/mips/include/asm/mach-ip27/topology.h b/arch/mips/include/asm/mach-ip27/topology.h > index 965f079..db293cf 100644 > --- a/arch/mips/include/asm/mach-ip27/topology.h > +++ b/arch/mips/include/asm/mach-ip27/topology.h > @@ -15,7 +15,7 @@ struct cpuinfo_ip27 { > extern struct cpuinfo_ip27 sn_cpu_info[NR_CPUS]; > > #define cpu_to_node(cpu) (sn_cpu_info[(cpu)].p_nodeid) > -#define cpumask_of_node(node) ((node) == -1 ? \ > +#define cpumask_of_node(node) ((node) == NUMA_NO_NODE ? \ > cpu_all_mask : \ > &hub_data(node)->h_cpus) > struct pci_bus; > diff --git a/arch/mips/include/asm/mach-loongson64/topology.h b/arch/mips/include/asm/mach-loongson64/topology.h > index 7ff819a..e78daa6 100644 > --- a/arch/mips/include/asm/mach-loongson64/topology.h > +++ b/arch/mips/include/asm/mach-loongson64/topology.h > @@ -5,7 +5,9 @@ > #ifdef CONFIG_NUMA > > #define cpu_to_node(cpu) (cpu_logical_map(cpu) >> 2) > -#define cpumask_of_node(node) (&__node_data[(node)]->cpumask) > +#define cpumask_of_node(node) ((node) == NUMA_NO_NODE ? \ > + cpu_online_mask : \ > + &__node_data[(node)]->cpumask) > > struct pci_bus; > extern int pcibus_to_node(struct pci_bus *); > diff --git a/arch/s390/include/asm/topology.h b/arch/s390/include/asm/topology.h > index cca406f..1bd2e73 100644 > --- a/arch/s390/include/asm/topology.h > +++ b/arch/s390/include/asm/topology.h > @@ -78,6 +78,9 @@ static inline int cpu_to_node(int cpu) > #define cpumask_of_node cpumask_of_node > static inline const struct cpumask *cpumask_of_node(int node) > { > + if (node == NUMA_NO_NODE) > + return cpu_online_mask; > + > return &node_to_cpumask_map[node]; > } > > diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h > index 4b14d23..7fa82e1 100644 > --- a/arch/x86/include/asm/topology.h > +++ b/arch/x86/include/asm/topology.h > @@ -69,6 +69,9 @@ extern const struct cpumask *cpumask_of_node(int node); > /* Returns a pointer to the cpumask of CPUs on Node 'node'. */ > static inline const struct cpumask *cpumask_of_node(int node) > { > + if (node == NUMA_NO_NODE) > + return cpu_online_mask; > + > return node_to_cpumask_map[node]; > } > #endif > diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c > index 4123100e..9859acb 100644 > --- a/arch/x86/mm/numa.c > +++ b/arch/x86/mm/numa.c > @@ -861,6 +861,9 @@ void numa_remove_cpu(int cpu) > */ > const struct cpumask *cpumask_of_node(int node) > { > + if (node == NUMA_NO_NODE) > + return cpu_online_mask; > + > if ((unsigned)node >= nr_node_ids) { > printk(KERN_WARNING > "cpumask_of_node(%d): (unsigned)node >= nr_node_ids(%u)\n", > -- > 2.8.1 -- Michal Hocko SUSE Labs
