[PATCH v7] numa: make node_to_cpumask_map() NUMA_NO_NODE aware
Michal Hocko
mhocko at kernel.org
Wed Oct 30 21:20:54 AEDT 2019
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 at huawei.com>
> Suggested-by: Michal Hocko <mhocko at kernel.org>
> Acked-by: Michal Hocko <mhocko at suse.com>
> Acked-by: Paul Burton <paul.burton at mips.com> # 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
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