[mirror_ubuntu-artful-kernel.git] / fs / proc / page.c

#include <linux/bootmem.h>
#include <linux/compiler.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/ksm.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/hugetlb.h>
#include <linux/kernel-page-flags.h>
#include <asm/uaccess.h>
#include "internal.h"

#define KPMSIZE sizeof(u64)
#define KPMMASK (KPMSIZE - 1)

/* /proc/kpagecount - an array exposing page counts
 *
 * Each entry is a u64 representing the corresponding
 * physical page count.
 */
static ssize_t kpagecount_read(struct file *file, char __user *buf,
			     size_t count, loff_t *ppos)
{
	u64 __user *out = (u64 __user *)buf;
	struct page *ppage;
	unsigned long src = *ppos;
	unsigned long pfn;
	ssize_t ret = 0;
	u64 pcount;

	pfn = src / KPMSIZE;
	count = min_t(size_t, count, (max_pfn * KPMSIZE) - src);
	if (src & KPMMASK || count & KPMMASK)
		return -EINVAL;

	while (count > 0) {
		if (pfn_valid(pfn))
			ppage = pfn_to_page(pfn);
		else
			ppage = NULL;
		if (!ppage || PageSlab(ppage))
			pcount = 0;
		else
			pcount = page_mapcount(ppage);

		if (put_user(pcount, out)) {
			ret = -EFAULT;
			break;
		}

		pfn++;
		out++;
		count -= KPMSIZE;
	}

	*ppos += (char __user *)out - buf;
	if (!ret)
		ret = (char __user *)out - buf;
	return ret;
}

static const struct file_operations proc_kpagecount_operations = {
	.llseek = mem_lseek,
	.read = kpagecount_read,
};

/* /proc/kpageflags - an array exposing page flags
 *
 * Each entry is a u64 representing the corresponding
 * physical page flags.
 */

static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
{
	return ((kflags >> kbit) & 1) << ubit;
}

u64 stable_page_flags(struct page *page)
{
	u64 k;
	u64 u;

	/*
	 * pseudo flag: KPF_NOPAGE
	 * it differentiates a memory hole from a page with no flags
	 */
	if (!page)
		return 1 << KPF_NOPAGE;

	k = page->flags;
	u = 0;

	/*
	 * pseudo flags for the well known (anonymous) memory mapped pages
	 *
	 * Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the
	 * simple test in page_mapped() is not enough.
	 */
	if (!PageSlab(page) && page_mapped(page))
		u |= 1 << KPF_MMAP;
	if (PageAnon(page))
		u |= 1 << KPF_ANON;
	if (PageKsm(page))
		u |= 1 << KPF_KSM;

	/*
	 * compound pages: export both head/tail info
	 * they together define a compound page's start/end pos and order
	 */
	if (PageHead(page))
		u |= 1 << KPF_COMPOUND_HEAD;
	if (PageTail(page))
		u |= 1 << KPF_COMPOUND_TAIL;
	if (PageHuge(page))
		u |= 1 << KPF_HUGE;

	/*
	 * Caveats on high order pages: page->_count will only be set
	 * -1 on the head page; SLUB/SLQB do the same for PG_slab;
	 * SLOB won't set PG_slab at all on compound pages.
	 */
	if (PageBuddy(page))
		u |= 1 << KPF_BUDDY;

	u |= kpf_copy_bit(k, KPF_LOCKED,	PG_locked);

	u |= kpf_copy_bit(k, KPF_SLAB,		PG_slab);

	u |= kpf_copy_bit(k, KPF_ERROR,		PG_error);
	u |= kpf_copy_bit(k, KPF_DIRTY,		PG_dirty);
	u |= kpf_copy_bit(k, KPF_UPTODATE,	PG_uptodate);
	u |= kpf_copy_bit(k, KPF_WRITEBACK,	PG_writeback);

	u |= kpf_copy_bit(k, KPF_LRU,		PG_lru);
	u |= kpf_copy_bit(k, KPF_REFERENCED,	PG_referenced);
	u |= kpf_copy_bit(k, KPF_ACTIVE,	PG_active);
	u |= kpf_copy_bit(k, KPF_RECLAIM,	PG_reclaim);

	u |= kpf_copy_bit(k, KPF_SWAPCACHE,	PG_swapcache);
	u |= kpf_copy_bit(k, KPF_SWAPBACKED,	PG_swapbacked);

	u |= kpf_copy_bit(k, KPF_UNEVICTABLE,	PG_unevictable);
	u |= kpf_copy_bit(k, KPF_MLOCKED,	PG_mlocked);

#ifdef CONFIG_MEMORY_FAILURE
	u |= kpf_copy_bit(k, KPF_HWPOISON,	PG_hwpoison);
#endif

#ifdef CONFIG_ARCH_USES_PG_UNCACHED
	u |= kpf_copy_bit(k, KPF_UNCACHED,	PG_uncached);
#endif

	u |= kpf_copy_bit(k, KPF_RESERVED,	PG_reserved);
	u |= kpf_copy_bit(k, KPF_MAPPEDTODISK,	PG_mappedtodisk);
	u |= kpf_copy_bit(k, KPF_PRIVATE,	PG_private);
	u |= kpf_copy_bit(k, KPF_PRIVATE_2,	PG_private_2);
	u |= kpf_copy_bit(k, KPF_OWNER_PRIVATE,	PG_owner_priv_1);
	u |= kpf_copy_bit(k, KPF_ARCH,		PG_arch_1);

	return u;
};

static ssize_t kpageflags_read(struct file *file, char __user *buf,
			     size_t count, loff_t *ppos)
{
	u64 __user *out = (u64 __user *)buf;
	struct page *ppage;
	unsigned long src = *ppos;
	unsigned long pfn;
	ssize_t ret = 0;

	pfn = src / KPMSIZE;
	count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
	if (src & KPMMASK || count & KPMMASK)
		return -EINVAL;

	while (count > 0) {
		if (pfn_valid(pfn))
			ppage = pfn_to_page(pfn);
		else
			ppage = NULL;

		if (put_user(stable_page_flags(ppage), out)) {
			ret = -EFAULT;
			break;
		}

		pfn++;
		out++;
		count -= KPMSIZE;
	}

	*ppos += (char __user *)out - buf;
	if (!ret)
		ret = (char __user *)out - buf;
	return ret;
}

static const struct file_operations proc_kpageflags_operations = {
	.llseek = mem_lseek,
	.read = kpageflags_read,
};

static int __init proc_page_init(void)
{
	proc_create("kpagecount", S_IRUSR, NULL, &proc_kpagecount_operations);
	proc_create("kpageflags", S_IRUSR, NULL, &proc_kpageflags_operations);
	return 0;
}
module_init(proc_page_init);
Commit	Line	Data
6d80e53f AD	1	#include <linux/bootmem.h>
	2	#include <linux/compiler.h>
	3	#include <linux/fs.h>
	4	#include <linux/init.h>
9a840895	5	#include <linux/ksm.h>
6d80e53f AD	6	#include <linux/mm.h>
	7	#include <linux/mmzone.h>
	8	#include <linux/proc_fs.h>
	9	#include <linux/seq_file.h>
20a0307c	10	#include <linux/hugetlb.h>
1a9b5b7f	11	#include <linux/kernel-page-flags.h>
6d80e53f AD	12	#include <asm/uaccess.h>
	13	#include "internal.h"
	14
	15	#define KPMSIZE sizeof(u64)
	16	#define KPMMASK (KPMSIZE - 1)
ed7ce0f1	17
6d80e53f AD	18	/* /proc/kpagecount - an array exposing page counts
	19	*
	20	* Each entry is a u64 representing the corresponding
	21	* physical page count.
	22	*/
	23	static ssize_t kpagecount_read(struct file file, char __user buf,
	24	size_t count, loff_t *ppos)
	25	{
	26	u64 __user out = (u64 __user )buf;
	27	struct page *ppage;
	28	unsigned long src = *ppos;
	29	unsigned long pfn;
	30	ssize_t ret = 0;
	31	u64 pcount;
	32
	33	pfn = src / KPMSIZE;
	34	count = min_t(size_t, count, (max_pfn * KPMSIZE) - src);
	35	if (src & KPMMASK \|\| count & KPMMASK)
	36	return -EINVAL;
	37
	38	while (count > 0) {
6d80e53f AD	39	if (pfn_valid(pfn))
6d80e53f AD	40	ppage = pfn_to_page(pfn);
ed7ce0f1 WF	41	else
ed7ce0f1 WF	42	ppage = NULL;
a6fc86d2	43	if (!ppage \|\| PageSlab(ppage))
6d80e53f AD	44	pcount = 0;
	45	else
	46	pcount = page_mapcount(ppage);
	47
ed7ce0f1	48	if (put_user(pcount, out)) {
6d80e53f AD	49	ret = -EFAULT;
	50	break;
	51	}
	52
ed7ce0f1 WF	53	pfn++;
ed7ce0f1 WF	54	out++;
6d80e53f AD	55	count -= KPMSIZE;
	56	}
	57
	58	ppos += (char __user )out - buf;
	59	if (!ret)
	60	ret = (char __user *)out - buf;
	61	return ret;
	62	}
	63
	64	static const struct file_operations proc_kpagecount_operations = {
	65	.llseek = mem_lseek,
	66	.read = kpagecount_read,
	67	};
	68
	69	/* /proc/kpageflags - an array exposing page flags
	70	*
	71	* Each entry is a u64 representing the corresponding
	72	* physical page flags.
	73	*/
	74
17797549 WF	75	static inline u64 kpf_copy_bit(u64 kflags, int ubit, int kbit)
	76	{
	77	return ((kflags >> kbit) & 1) << ubit;
	78	}
	79
1a9b5b7f	80	u64 stable_page_flags(struct page *page)
17797549 WF	81	{
	82	u64 k;
	83	u64 u;
	84
	85	/*
	86	* pseudo flag: KPF_NOPAGE
	87	* it differentiates a memory hole from a page with no flags
	88	*/
	89	if (!page)
	90	return 1 << KPF_NOPAGE;
	91
	92	k = page->flags;
	93	u = 0;
	94
	95	/*
	96	* pseudo flags for the well known (anonymous) memory mapped pages
	97	*
	98	* Note that page->_mapcount is overloaded in SLOB/SLUB/SLQB, so the
	99	* simple test in page_mapped() is not enough.
	100	*/
	101	if (!PageSlab(page) && page_mapped(page))
	102	u \|= 1 << KPF_MMAP;
	103	if (PageAnon(page))
	104	u \|= 1 << KPF_ANON;
9a840895 HD	105	if (PageKsm(page))
9a840895 HD	106	u \|= 1 << KPF_KSM;
17797549 WF	107
	108	/*
	109	* compound pages: export both head/tail info
	110	* they together define a compound page's start/end pos and order
	111	*/
	112	if (PageHead(page))
	113	u \|= 1 << KPF_COMPOUND_HEAD;
	114	if (PageTail(page))
	115	u \|= 1 << KPF_COMPOUND_TAIL;
	116	if (PageHuge(page))
	117	u \|= 1 << KPF_HUGE;
	118
17797549	119	/*
5f24ce5f AA	120	* Caveats on high order pages: page->_count will only be set
	121	* -1 on the head page; SLUB/SLQB do the same for PG_slab;
	122	* SLOB won't set PG_slab at all on compound pages.
17797549	123	*/
5f24ce5f AA	124	if (PageBuddy(page))
	125	u \|= 1 << KPF_BUDDY;
	126
	127	u \|= kpf_copy_bit(k, KPF_LOCKED, PG_locked);
	128
17797549	129	u \|= kpf_copy_bit(k, KPF_SLAB, PG_slab);
17797549 WF	130
	131	u \|= kpf_copy_bit(k, KPF_ERROR, PG_error);
	132	u \|= kpf_copy_bit(k, KPF_DIRTY, PG_dirty);
	133	u \|= kpf_copy_bit(k, KPF_UPTODATE, PG_uptodate);
	134	u \|= kpf_copy_bit(k, KPF_WRITEBACK, PG_writeback);
	135
	136	u \|= kpf_copy_bit(k, KPF_LRU, PG_lru);
	137	u \|= kpf_copy_bit(k, KPF_REFERENCED, PG_referenced);
	138	u \|= kpf_copy_bit(k, KPF_ACTIVE, PG_active);
	139	u \|= kpf_copy_bit(k, KPF_RECLAIM, PG_reclaim);
	140
	141	u \|= kpf_copy_bit(k, KPF_SWAPCACHE, PG_swapcache);
	142	u \|= kpf_copy_bit(k, KPF_SWAPBACKED, PG_swapbacked);
	143
17797549 WF	144	u \|= kpf_copy_bit(k, KPF_UNEVICTABLE, PG_unevictable);
17797549 WF	145	u \|= kpf_copy_bit(k, KPF_MLOCKED, PG_mlocked);
17797549	146
253fb02d WF	147	#ifdef CONFIG_MEMORY_FAILURE
	148	u \|= kpf_copy_bit(k, KPF_HWPOISON, PG_hwpoison);
	149	#endif
	150
ed430fec	151	#ifdef CONFIG_ARCH_USES_PG_UNCACHED
17797549 WF	152	u \|= kpf_copy_bit(k, KPF_UNCACHED, PG_uncached);
	153	#endif
	154
	155	u \|= kpf_copy_bit(k, KPF_RESERVED, PG_reserved);
	156	u \|= kpf_copy_bit(k, KPF_MAPPEDTODISK, PG_mappedtodisk);
	157	u \|= kpf_copy_bit(k, KPF_PRIVATE, PG_private);
	158	u \|= kpf_copy_bit(k, KPF_PRIVATE_2, PG_private_2);
	159	u \|= kpf_copy_bit(k, KPF_OWNER_PRIVATE, PG_owner_priv_1);
	160	u \|= kpf_copy_bit(k, KPF_ARCH, PG_arch_1);
	161
	162	return u;
	163	};
6d80e53f AD	164
	165	static ssize_t kpageflags_read(struct file file, char __user buf,
	166	size_t count, loff_t *ppos)
	167	{
	168	u64 __user out = (u64 __user )buf;
	169	struct page *ppage;
	170	unsigned long src = *ppos;
	171	unsigned long pfn;
	172	ssize_t ret = 0;
6d80e53f AD	173
	174	pfn = src / KPMSIZE;
	175	count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
	176	if (src & KPMMASK \|\| count & KPMMASK)
	177	return -EINVAL;
	178
	179	while (count > 0) {
6d80e53f AD	180	if (pfn_valid(pfn))
6d80e53f AD	181	ppage = pfn_to_page(pfn);
ed7ce0f1 WF	182	else
ed7ce0f1 WF	183	ppage = NULL;
17797549	184
1a9b5b7f	185	if (put_user(stable_page_flags(ppage), out)) {
6d80e53f AD	186	ret = -EFAULT;
	187	break;
	188	}
	189
ed7ce0f1 WF	190	pfn++;
ed7ce0f1 WF	191	out++;
6d80e53f AD	192	count -= KPMSIZE;
	193	}
	194
	195	ppos += (char __user )out - buf;
	196	if (!ret)
	197	ret = (char __user *)out - buf;
	198	return ret;
	199	}
	200
	201	static const struct file_operations proc_kpageflags_operations = {
	202	.llseek = mem_lseek,
	203	.read = kpageflags_read,
	204	};
	205
	206	static int __init proc_page_init(void)
	207	{
	208	proc_create("kpagecount", S_IRUSR, NULL, &proc_kpagecount_operations);
	209	proc_create("kpageflags", S_IRUSR, NULL, &proc_kpageflags_operations);
	210	return 0;
	211	}
	212	module_init(proc_page_init);