From 33ead538f642a33b1d658782a5d14a40b5014d1f Mon Sep 17 00:00:00 2001 From: Yasuaki Ishimatsu Date: Fri, 3 Oct 2014 19:06:03 +0900 Subject: driver/base/node: remove unnecessary kfree of node struct from unregister_one_node Commit 92d585ef067d ("numa: fix NULL pointer access and memory leak in unregister_one_node()") added kfree() of node struct in unregister_one_node(). But node struct is freed by node_device_release() which is called in unregister_node(). So by adding the kfree(), node struct is freed two times. While hot removing memory, the commit leads the following BUG_ON(): kernel BUG at mm/slub.c:3346! invalid opcode: 0000 [#1] SMP [...] Call Trace: [...] unregister_one_node [...] try_offline_node [...] remove_memory [...] acpi_memory_device_remove [...] acpi_bus_trim [...] acpi_bus_trim [...] acpi_device_hotplug [...] acpi_hotplug_work_fn [...] process_one_work [...] worker_thread [...] ? rescuer_thread [...] kthread [...] ? kthread_create_on_node [...] ret_from_fork [...] ? kthread_create_on_node This patch removes unnecessary kfree() from unregister_one_node(). Signed-off-by: Yasuaki Ishimatsu Cc: Xishi Qiu Cc: stable@vger.kernel.org # v3.16+ Fixes: 92d585ef067d "numa: fix NULL pointer access and memory leak in unregister_one_node()" Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/base/node.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/base/node.c') diff --git a/drivers/base/node.c b/drivers/base/node.c index c6d3ae05f1ca..d51c49c9bafa 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -603,7 +603,6 @@ void unregister_one_node(int nid) return; unregister_node(node_devices[nid]); - kfree(node_devices[nid]); node_devices[nid] = NULL; } -- cgit v1.2.3 From 1f13ae399c58af5a05b5cee61da864e1f4071de4 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 9 Oct 2014 15:27:39 -0700 Subject: mm: remove noisy remainder of the scan_unevictable interface The deprecation warnings for the scan_unevictable interface triggers by scripts doing `sysctl -a | grep something else'. This is annoying and not helpful. The interface has been defunct since 264e56d8247e ("mm: disable user interface to manually rescue unevictable pages"), which was in 2011, and there haven't been any reports of usecases for it, only reports that the deprecation warnings are annying. It's unlikely that anybody is using this interface specifically at this point, so remove it. Signed-off-by: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/ABI/stable/sysfs-devices-node | 8 ---- drivers/base/node.c | 3 -- include/linux/swap.h | 16 -------- kernel/sysctl.c | 7 ---- mm/vmscan.c | 63 ----------------------------- 5 files changed, 97 deletions(-) (limited to 'drivers/base/node.c') diff --git a/Documentation/ABI/stable/sysfs-devices-node b/Documentation/ABI/stable/sysfs-devices-node index ce259c13c36a..5b2d0f08867c 100644 --- a/Documentation/ABI/stable/sysfs-devices-node +++ b/Documentation/ABI/stable/sysfs-devices-node @@ -85,14 +85,6 @@ Description: will be compacted. When it completes, memory will be freed into blocks which have as many contiguous pages as possible -What: /sys/devices/system/node/nodeX/scan_unevictable_pages -Date: October 2008 -Contact: Lee Schermerhorn -Description: - When set, it triggers scanning the node's unevictable lists - and move any pages that have become evictable onto the respective - zone's inactive list. See mm/vmscan.c - What: /sys/devices/system/node/nodeX/hugepages/hugepages-/ Date: December 2009 Contact: Lee Schermerhorn diff --git a/drivers/base/node.c b/drivers/base/node.c index d51c49c9bafa..472168cd0c97 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -289,8 +289,6 @@ static int register_node(struct node *node, int num, struct node *parent) device_create_file(&node->dev, &dev_attr_distance); device_create_file(&node->dev, &dev_attr_vmstat); - scan_unevictable_register_node(node); - hugetlb_register_node(node); compaction_register_node(node); @@ -314,7 +312,6 @@ void unregister_node(struct node *node) device_remove_file(&node->dev, &dev_attr_distance); device_remove_file(&node->dev, &dev_attr_vmstat); - scan_unevictable_unregister_node(node); hugetlb_unregister_node(node); /* no-op, if memoryless node */ device_unregister(&node->dev); diff --git a/include/linux/swap.h b/include/linux/swap.h index 1b72060f093a..ea4f926e6b9b 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -354,22 +354,6 @@ static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order) extern int page_evictable(struct page *page); extern void check_move_unevictable_pages(struct page **, int nr_pages); -extern unsigned long scan_unevictable_pages; -extern int scan_unevictable_handler(struct ctl_table *, int, - void __user *, size_t *, loff_t *); -#ifdef CONFIG_NUMA -extern int scan_unevictable_register_node(struct node *node); -extern void scan_unevictable_unregister_node(struct node *node); -#else -static inline int scan_unevictable_register_node(struct node *node) -{ - return 0; -} -static inline void scan_unevictable_unregister_node(struct node *node) -{ -} -#endif - extern int kswapd_run(int nid); extern void kswapd_stop(int nid); #ifdef CONFIG_MEMCG diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 75875a741b5e..91180987e40e 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1460,13 +1460,6 @@ static struct ctl_table vm_table[] = { .extra2 = &one, }, #endif - { - .procname = "scan_unevictable_pages", - .data = &scan_unevictable_pages, - .maxlen = sizeof(scan_unevictable_pages), - .mode = 0644, - .proc_handler = scan_unevictable_handler, - }, #ifdef CONFIG_MEMORY_FAILURE { .procname = "memory_failure_early_kill", diff --git a/mm/vmscan.c b/mm/vmscan.c index 1a71b8b1ea34..af72fe8e8d74 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3797,66 +3797,3 @@ void check_move_unevictable_pages(struct page **pages, int nr_pages) } } #endif /* CONFIG_SHMEM */ - -static void warn_scan_unevictable_pages(void) -{ - printk_once(KERN_WARNING - "%s: The scan_unevictable_pages sysctl/node-interface has been " - "disabled for lack of a legitimate use case. If you have " - "one, please send an email to linux-mm@kvack.org.\n", - current->comm); -} - -/* - * scan_unevictable_pages [vm] sysctl handler. On demand re-scan of - * all nodes' unevictable lists for evictable pages - */ -unsigned long scan_unevictable_pages; - -int scan_unevictable_handler(struct ctl_table *table, int write, - void __user *buffer, - size_t *length, loff_t *ppos) -{ - warn_scan_unevictable_pages(); - proc_doulongvec_minmax(table, write, buffer, length, ppos); - scan_unevictable_pages = 0; - return 0; -} - -#ifdef CONFIG_NUMA -/* - * per node 'scan_unevictable_pages' attribute. On demand re-scan of - * a specified node's per zone unevictable lists for evictable pages. - */ - -static ssize_t read_scan_unevictable_node(struct device *dev, - struct device_attribute *attr, - char *buf) -{ - warn_scan_unevictable_pages(); - return sprintf(buf, "0\n"); /* always zero; should fit... */ -} - -static ssize_t write_scan_unevictable_node(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) -{ - warn_scan_unevictable_pages(); - return 1; -} - - -static DEVICE_ATTR(scan_unevictable_pages, S_IRUGO | S_IWUSR, - read_scan_unevictable_node, - write_scan_unevictable_node); - -int scan_unevictable_register_node(struct node *node) -{ - return device_create_file(&node->dev, &dev_attr_scan_unevictable_pages); -} - -void scan_unevictable_unregister_node(struct node *node) -{ - device_remove_file(&node->dev, &dev_attr_scan_unevictable_pages); -} -#endif -- cgit v1.2.3 From 5aaba36318e5995e8c95d077a46d9a4d00fcc1cd Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Tue, 30 Sep 2014 14:48:22 +0100 Subject: cpumask: factor out show_cpumap into separate helper function Many sysfs *_show function use cpu{list,mask}_scnprintf to copy cpumap to the buffer aligned to PAGE_SIZE, append '\n' and '\0' to return null terminated buffer with newline. This patch creates a new helper function cpumap_print_to_pagebuf in cpumask.h using newly added bitmap_print_to_pagebuf and consolidates most of those sysfs functions using the new helper function. Signed-off-by: Sudeep Holla Suggested-by: Stephen Boyd Tested-by: Stephen Boyd Acked-by: "Rafael J. Wysocki" Acked-by: Bjorn Helgaas Acked-by: Peter Zijlstra (Intel) Cc: Greg Kroah-Hartman Cc: x86@kernel.org Cc: linux-acpi@vger.kernel.org Cc: linux-pci@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/perf_event_amd_iommu.c | 5 +--- arch/x86/kernel/cpu/perf_event_amd_uncore.c | 6 +---- arch/x86/kernel/cpu/perf_event_intel_rapl.c | 6 +---- arch/x86/kernel/cpu/perf_event_intel_uncore.c | 6 +---- drivers/acpi/acpi_pad.c | 8 +++--- drivers/base/cpu.c | 5 +--- drivers/base/node.c | 14 +++------- drivers/base/topology.c | 22 ++------------- drivers/pci/pci-sysfs.c | 39 +++++++-------------------- include/linux/bitmap.h | 3 +++ include/linux/cpumask.h | 17 ++++++++++++ lib/bitmap.c | 29 ++++++++++++++++++++ 12 files changed, 73 insertions(+), 87 deletions(-) (limited to 'drivers/base/node.c') diff --git a/arch/x86/kernel/cpu/perf_event_amd_iommu.c b/arch/x86/kernel/cpu/perf_event_amd_iommu.c index 639d1289b1ba..97242a9242bd 100644 --- a/arch/x86/kernel/cpu/perf_event_amd_iommu.c +++ b/arch/x86/kernel/cpu/perf_event_amd_iommu.c @@ -130,10 +130,7 @@ static ssize_t _iommu_cpumask_show(struct device *dev, struct device_attribute *attr, char *buf) { - int n = cpulist_scnprintf(buf, PAGE_SIZE - 2, &iommu_cpumask); - buf[n++] = '\n'; - buf[n] = '\0'; - return n; + return cpumap_print_to_pagebuf(true, buf, &iommu_cpumask); } static DEVICE_ATTR(cpumask, S_IRUGO, _iommu_cpumask_show, NULL); diff --git a/arch/x86/kernel/cpu/perf_event_amd_uncore.c b/arch/x86/kernel/cpu/perf_event_amd_uncore.c index 30790d798e6b..cc6cedb8f25d 100644 --- a/arch/x86/kernel/cpu/perf_event_amd_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_amd_uncore.c @@ -219,7 +219,6 @@ static ssize_t amd_uncore_attr_show_cpumask(struct device *dev, struct device_attribute *attr, char *buf) { - int n; cpumask_t *active_mask; struct pmu *pmu = dev_get_drvdata(dev); @@ -230,10 +229,7 @@ static ssize_t amd_uncore_attr_show_cpumask(struct device *dev, else return 0; - n = cpulist_scnprintf(buf, PAGE_SIZE - 2, active_mask); - buf[n++] = '\n'; - buf[n] = '\0'; - return n; + return cpumap_print_to_pagebuf(true, buf, active_mask); } static DEVICE_ATTR(cpumask, S_IRUGO, amd_uncore_attr_show_cpumask, NULL); diff --git a/arch/x86/kernel/cpu/perf_event_intel_rapl.c b/arch/x86/kernel/cpu/perf_event_intel_rapl.c index d64f275fe274..673f930c700f 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_rapl.c +++ b/arch/x86/kernel/cpu/perf_event_intel_rapl.c @@ -365,11 +365,7 @@ static void rapl_pmu_event_read(struct perf_event *event) static ssize_t rapl_get_attr_cpumask(struct device *dev, struct device_attribute *attr, char *buf) { - int n = cpulist_scnprintf(buf, PAGE_SIZE - 2, &rapl_cpu_mask); - - buf[n++] = '\n'; - buf[n] = '\0'; - return n; + return cpumap_print_to_pagebuf(true, buf, &rapl_cpu_mask); } static DEVICE_ATTR(cpumask, S_IRUGO, rapl_get_attr_cpumask, NULL); diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c index 9762dbd9f3f7..08f3fed2b0f2 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c @@ -647,11 +647,7 @@ static int uncore_pmu_event_init(struct perf_event *event) static ssize_t uncore_get_attr_cpumask(struct device *dev, struct device_attribute *attr, char *buf) { - int n = cpulist_scnprintf(buf, PAGE_SIZE - 2, &uncore_cpu_mask); - - buf[n++] = '\n'; - buf[n] = '\0'; - return n; + return cpumap_print_to_pagebuf(true, buf, &uncore_cpu_mask); } static DEVICE_ATTR(cpumask, S_IRUGO, uncore_get_attr_cpumask, NULL); diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c index f148a0580e04..c7b105c0e1d3 100644 --- a/drivers/acpi/acpi_pad.c +++ b/drivers/acpi/acpi_pad.c @@ -350,12 +350,10 @@ static ssize_t acpi_pad_idlecpus_store(struct device *dev, static ssize_t acpi_pad_idlecpus_show(struct device *dev, struct device_attribute *attr, char *buf) { - int n = 0; - n = cpumask_scnprintf(buf, PAGE_SIZE-2, to_cpumask(pad_busy_cpus_bits)); - buf[n++] = '\n'; - buf[n] = '\0'; - return n; + return cpumap_print_to_pagebuf(false, buf, + to_cpumask(pad_busy_cpus_bits)); } + static DEVICE_ATTR(idlecpus, S_IRUGO|S_IWUSR, acpi_pad_idlecpus_show, acpi_pad_idlecpus_store); diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 006b1bc5297d..4d8a56406fbb 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -207,11 +207,8 @@ static ssize_t show_cpus_attr(struct device *dev, char *buf) { struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr); - int n = cpulist_scnprintf(buf, PAGE_SIZE-2, *(ca->map)); - buf[n++] = '\n'; - buf[n] = '\0'; - return n; + return cpumap_print_to_pagebuf(true, buf, *ca->map); } #define _CPU_ATTR(name, map) \ diff --git a/drivers/base/node.c b/drivers/base/node.c index 472168cd0c97..a3b82e9c7f20 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -25,32 +25,26 @@ static struct bus_type node_subsys = { }; -static ssize_t node_read_cpumap(struct device *dev, int type, char *buf) +static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf) { struct node *node_dev = to_node(dev); const struct cpumask *mask = cpumask_of_node(node_dev->dev.id); - int len; /* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */ BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1)); - len = type? - cpulist_scnprintf(buf, PAGE_SIZE-2, mask) : - cpumask_scnprintf(buf, PAGE_SIZE-2, mask); - buf[len++] = '\n'; - buf[len] = '\0'; - return len; + return cpumap_print_to_pagebuf(list, buf, mask); } static inline ssize_t node_read_cpumask(struct device *dev, struct device_attribute *attr, char *buf) { - return node_read_cpumap(dev, 0, buf); + return node_read_cpumap(dev, false, buf); } static inline ssize_t node_read_cpulist(struct device *dev, struct device_attribute *attr, char *buf) { - return node_read_cpumap(dev, 1, buf); + return node_read_cpumap(dev, true, buf); } static DEVICE_ATTR(cpumap, S_IRUGO, node_read_cpumask, NULL); diff --git a/drivers/base/topology.c b/drivers/base/topology.c index be7c1fb7c0c9..f7c353843ddf 100644 --- a/drivers/base/topology.c +++ b/drivers/base/topology.c @@ -42,29 +42,11 @@ static ssize_t show_##name(struct device *dev, \ return sprintf(buf, "%d\n", topology_##name(dev->id)); \ } -#if defined(topology_thread_cpumask) || defined(topology_core_cpumask) || \ - defined(topology_book_cpumask) -static ssize_t show_cpumap(int type, const struct cpumask *mask, char *buf) -{ - ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf; - int n = 0; - - if (len > 1) { - n = type? - cpulist_scnprintf(buf, len-2, mask) : - cpumask_scnprintf(buf, len-2, mask); - buf[n++] = '\n'; - buf[n] = '\0'; - } - return n; -} -#endif - #define define_siblings_show_map(name) \ static ssize_t show_##name(struct device *dev, \ struct device_attribute *attr, char *buf) \ { \ - return show_cpumap(0, topology_##name(dev->id), buf); \ + return cpumap_print_to_pagebuf(false, buf, topology_##name(dev->id));\ } #define define_siblings_show_list(name) \ @@ -72,7 +54,7 @@ static ssize_t show_##name##_list(struct device *dev, \ struct device_attribute *attr, \ char *buf) \ { \ - return show_cpumap(1, topology_##name(dev->id), buf); \ + return cpumap_print_to_pagebuf(true, buf, topology_##name(dev->id));\ } #define define_siblings_show_func(name) \ diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 2c6643fdc0cf..368bdac42603 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -77,11 +77,10 @@ static ssize_t broken_parity_status_store(struct device *dev, } static DEVICE_ATTR_RW(broken_parity_status); -static ssize_t pci_dev_show_local_cpu(struct device *dev, int type, +static ssize_t pci_dev_show_local_cpu(struct device *dev, bool list, struct device_attribute *attr, char *buf) { const struct cpumask *mask; - int len; #ifdef CONFIG_NUMA mask = (dev_to_node(dev) == -1) ? cpu_online_mask : @@ -89,59 +88,41 @@ static ssize_t pci_dev_show_local_cpu(struct device *dev, int type, #else mask = cpumask_of_pcibus(to_pci_dev(dev)->bus); #endif - len = type ? - cpumask_scnprintf(buf, PAGE_SIZE-2, mask) : - cpulist_scnprintf(buf, PAGE_SIZE-2, mask); - - buf[len++] = '\n'; - buf[len] = '\0'; - return len; + return cpumap_print_to_pagebuf(list, buf, mask); } static ssize_t local_cpus_show(struct device *dev, struct device_attribute *attr, char *buf) { - return pci_dev_show_local_cpu(dev, 1, attr, buf); + return pci_dev_show_local_cpu(dev, false, attr, buf); } static DEVICE_ATTR_RO(local_cpus); static ssize_t local_cpulist_show(struct device *dev, struct device_attribute *attr, char *buf) { - return pci_dev_show_local_cpu(dev, 0, attr, buf); + return pci_dev_show_local_cpu(dev, true, attr, buf); } static DEVICE_ATTR_RO(local_cpulist); /* * PCI Bus Class Devices */ -static ssize_t pci_bus_show_cpuaffinity(struct device *dev, int type, - struct device_attribute *attr, - char *buf) -{ - int ret; - const struct cpumask *cpumask; - - cpumask = cpumask_of_pcibus(to_pci_bus(dev)); - ret = type ? - cpulist_scnprintf(buf, PAGE_SIZE-2, cpumask) : - cpumask_scnprintf(buf, PAGE_SIZE-2, cpumask); - buf[ret++] = '\n'; - buf[ret] = '\0'; - return ret; -} - static ssize_t cpuaffinity_show(struct device *dev, struct device_attribute *attr, char *buf) { - return pci_bus_show_cpuaffinity(dev, 0, attr, buf); + const struct cpumask *cpumask = cpumask_of_pcibus(to_pci_bus(dev)); + + return cpumap_print_to_pagebuf(false, buf, cpumask); } static DEVICE_ATTR_RO(cpuaffinity); static ssize_t cpulistaffinity_show(struct device *dev, struct device_attribute *attr, char *buf) { - return pci_bus_show_cpuaffinity(dev, 1, attr, buf); + const struct cpumask *cpumask = cpumask_of_pcibus(to_pci_bus(dev)); + + return cpumap_print_to_pagebuf(true, buf, cpumask); } static DEVICE_ATTR_RO(cpulistaffinity); diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index e1c8d080c427..9d5c3224a1e2 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -60,6 +60,7 @@ * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region * bitmap_release_region(bitmap, pos, order) Free specified bit region * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region + * bitmap_print_to_pagebuf(list, buf, mask, nbits) Print bitmap src as list/hex */ /* @@ -145,6 +146,8 @@ extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int o extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order); extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits); extern int bitmap_ord_to_pos(const unsigned long *bitmap, int n, int bits); +extern int bitmap_print_to_pagebuf(bool list, char *buf, + const unsigned long *maskp, int nmaskbits); #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG)) #define BITMAP_LAST_WORD_MASK(nbits) \ diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index 0a9a6da21e74..b950e9d6008b 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -803,6 +803,23 @@ static inline const struct cpumask *get_cpu_mask(unsigned int cpu) } #endif /* NR_CPUS > BITS_PER_LONG */ +/** + * cpumap_print_to_pagebuf - copies the cpumask into the buffer either + * as comma-separated list of cpus or hex values of cpumask + * @list: indicates whether the cpumap must be list + * @mask: the cpumask to copy + * @buf: the buffer to copy into + * + * Returns the length of the (null-terminated) @buf string, zero if + * nothing is copied. + */ +static inline ssize_t +cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask) +{ + return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask), + nr_cpumask_bits); +} + /* * * From here down, all obsolete. Use cpumask_ variants! diff --git a/lib/bitmap.c b/lib/bitmap.c index b499ab6ada29..5bc7a1128fe8 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -12,6 +12,8 @@ #include #include #include + +#include #include /* @@ -583,6 +585,33 @@ int bitmap_scnlistprintf(char *buf, unsigned int buflen, } EXPORT_SYMBOL(bitmap_scnlistprintf); +/** + * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string + * @list: indicates whether the bitmap must be list + * @buf: page aligned buffer into which string is placed + * @maskp: pointer to bitmap to convert + * @nmaskbits: size of bitmap, in bits + * + * Output format is a comma-separated list of decimal numbers and + * ranges if list is specified or hex digits grouped into comma-separated + * sets of 8 digits/set. Returns the number of characters written to buf. + */ +int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, + int nmaskbits) +{ + ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf - 2; + int n = 0; + + if (len > 1) { + n = list ? bitmap_scnlistprintf(buf, len, maskp, nmaskbits) : + bitmap_scnprintf(buf, len, maskp, nmaskbits); + buf[n++] = '\n'; + buf[n] = '\0'; + } + return n; +} +EXPORT_SYMBOL(bitmap_print_to_pagebuf); + /** * __bitmap_parselist - convert list format ASCII string to bitmap * @buf: read nul-terminated user string from this buffer -- cgit v1.2.3