From 75bd50fa841db5434728d238b8b5659498ccf0ab Mon Sep 17 00:00:00 2001 From: Tian Tao Date: Fri, 6 Aug 2021 23:02:50 +1200 Subject: drivers/base/node.c: use bin_attribute to break the size limitation of cpumap ABI Reading /sys/devices/system/cpu/cpuX/nodeX/ returns cpumap and cpulist. However, the size of this file is limited to PAGE_SIZE because of the limitation for sysfs attribute. This patch moves to use bin_attribute to extend the ABI to be more than one page so that cpumap bitmask and list won't be potentially trimmed. Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Reviewed-by: Jonathan Cameron Signed-off-by: Tian Tao Signed-off-by: Barry Song Link: https://lore.kernel.org/r/20210806110251.560-5-song.bao.hua@hisilicon.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/node.c | 63 ++++++++++++++++++++++++++++++++++------------------- 1 file changed, 40 insertions(+), 23 deletions(-) (limited to 'drivers/base/node.c') diff --git a/drivers/base/node.c b/drivers/base/node.c index 2bc9089f3e78..be16bbff11cc 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -26,43 +26,47 @@ static struct bus_type node_subsys = { .dev_name = "node", }; - -static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf) +static inline ssize_t cpumap_read(struct file *file, struct kobject *kobj, + struct bin_attribute *attr, char *buf, + loff_t off, size_t count) { - ssize_t n; - cpumask_var_t mask; + struct device *dev = kobj_to_dev(kobj); struct node *node_dev = to_node(dev); - - /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */ - BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1)); + cpumask_var_t mask; + ssize_t n; if (!alloc_cpumask_var(&mask, GFP_KERNEL)) return 0; cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask); - n = cpumap_print_to_pagebuf(list, buf, mask); + n = cpumap_print_bitmask_to_buf(buf, mask, off, count); free_cpumask_var(mask); return n; } -static inline ssize_t cpumap_show(struct device *dev, - struct device_attribute *attr, - char *buf) +static BIN_ATTR_RO(cpumap, 0); + +static inline ssize_t cpulist_read(struct file *file, struct kobject *kobj, + struct bin_attribute *attr, char *buf, + loff_t off, size_t count) { - return node_read_cpumap(dev, false, buf); -} + struct device *dev = kobj_to_dev(kobj); + struct node *node_dev = to_node(dev); + cpumask_var_t mask; + ssize_t n; + + if (!alloc_cpumask_var(&mask, GFP_KERNEL)) + return 0; -static DEVICE_ATTR_RO(cpumap); + cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask); + n = cpumap_print_list_to_buf(buf, mask, off, count); + free_cpumask_var(mask); -static inline ssize_t cpulist_show(struct device *dev, - struct device_attribute *attr, - char *buf) -{ - return node_read_cpumap(dev, true, buf); + return n; } -static DEVICE_ATTR_RO(cpulist); +static BIN_ATTR_RO(cpulist, 0); /** * struct node_access_nodes - Access class device to hold user visible @@ -557,15 +561,28 @@ static ssize_t node_read_distance(struct device *dev, static DEVICE_ATTR(distance, 0444, node_read_distance, NULL); static struct attribute *node_dev_attrs[] = { - &dev_attr_cpumap.attr, - &dev_attr_cpulist.attr, &dev_attr_meminfo.attr, &dev_attr_numastat.attr, &dev_attr_distance.attr, &dev_attr_vmstat.attr, NULL }; -ATTRIBUTE_GROUPS(node_dev); + +static struct bin_attribute *node_dev_bin_attrs[] = { + &bin_attr_cpumap, + &bin_attr_cpulist, + NULL +}; + +static const struct attribute_group node_dev_group = { + .attrs = node_dev_attrs, + .bin_attrs = node_dev_bin_attrs +}; + +static const struct attribute_group *node_dev_groups[] = { + &node_dev_group, + NULL +}; #ifdef CONFIG_HUGETLBFS /* -- cgit v1.2.3-59-g8ed1b