Merge tag 'kvmarm-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm...

[linux-2.6-microblaze.git] / fs / proc / page.c

diff --git a/fs/proc/page.c b/fs/proc/page.c
index 7c952ee..f909243 100644 (file)
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -21,6 +21,21 @@
 #define KPMMASK (KPMSIZE - 1)
 #define KPMBITS (KPMSIZE * BITS_PER_BYTE)
 
+static inline unsigned long get_max_dump_pfn(void)
+{
+#ifdef CONFIG_SPARSEMEM
+       /*
+        * The memmap of early sections is completely populated and marked
+        * online even if max_pfn does not fall on a section boundary -
+        * pfn_to_online_page() will succeed on all pages. Allow inspecting
+        * these memmaps.
+        */
+       return round_up(max_pfn, PAGES_PER_SECTION);
+#else
+       return max_pfn;
+#endif
+}
+
 /* /proc/kpagecount - an array exposing page counts
  *
  * Each entry is a u64 representing the corresponding
@@ -29,6 +44,7 @@
 static ssize_t kpagecount_read(struct file *file, char __user *buf,
                             size_t count, loff_t *ppos)
 {
+       const unsigned long max_dump_pfn = get_max_dump_pfn();
        u64 __user *out = (u64 __user *)buf;
        struct page *ppage;
        unsigned long src = *ppos;
@@ -37,9 +53,11 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf,
        u64 pcount;
 
        pfn = src / KPMSIZE;
-       count = min_t(size_t, count, (max_pfn * KPMSIZE) - src);
        if (src & KPMMASK || count & KPMMASK)
                return -EINVAL;
+       if (src >= max_dump_pfn * KPMSIZE)
+               return 0;
+       count = min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src);
 
        while (count > 0) {
                /*
@@ -71,9 +89,9 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf,
        return ret;
 }
 
-static const struct file_operations proc_kpagecount_operations = {
-       .llseek = mem_lseek,
-       .read = kpagecount_read,
+static const struct proc_ops kpagecount_proc_ops = {
+       .proc_lseek     = mem_lseek,
+       .proc_read      = kpagecount_read,
 };
 
 /* /proc/kpageflags - an array exposing page flags
@@ -206,6 +224,7 @@ u64 stable_page_flags(struct page *page)
 static ssize_t kpageflags_read(struct file *file, char __user *buf,
                             size_t count, loff_t *ppos)
 {
+       const unsigned long max_dump_pfn = get_max_dump_pfn();
        u64 __user *out = (u64 __user *)buf;
        struct page *ppage;
        unsigned long src = *ppos;
@@ -213,9 +232,11 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf,
        ssize_t ret = 0;
 
        pfn = src / KPMSIZE;
-       count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
        if (src & KPMMASK || count & KPMMASK)
                return -EINVAL;
+       if (src >= max_dump_pfn * KPMSIZE)
+               return 0;
+       count = min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src);
 
        while (count > 0) {
                /*
@@ -242,15 +263,16 @@ static ssize_t kpageflags_read(struct file *file, char __user *buf,
        return ret;
 }
 
-static const struct file_operations proc_kpageflags_operations = {
-       .llseek = mem_lseek,
-       .read = kpageflags_read,
+static const struct proc_ops kpageflags_proc_ops = {
+       .proc_lseek     = mem_lseek,
+       .proc_read      = kpageflags_read,
 };
 
 #ifdef CONFIG_MEMCG
 static ssize_t kpagecgroup_read(struct file *file, char __user *buf,
                                size_t count, loff_t *ppos)
 {
+       const unsigned long max_dump_pfn = get_max_dump_pfn();
        u64 __user *out = (u64 __user *)buf;
        struct page *ppage;
        unsigned long src = *ppos;
@@ -259,9 +281,11 @@ static ssize_t kpagecgroup_read(struct file *file, char __user *buf,
        u64 ino;
 
        pfn = src / KPMSIZE;
-       count = min_t(unsigned long, count, (max_pfn * KPMSIZE) - src);
        if (src & KPMMASK || count & KPMMASK)
                return -EINVAL;
+       if (src >= max_dump_pfn * KPMSIZE)
+               return 0;
+       count = min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src);
 
        while (count > 0) {
                /*
@@ -293,18 +317,18 @@ static ssize_t kpagecgroup_read(struct file *file, char __user *buf,
        return ret;
 }
 
-static const struct file_operations proc_kpagecgroup_operations = {
-       .llseek = mem_lseek,
-       .read = kpagecgroup_read,
+static const struct proc_ops kpagecgroup_proc_ops = {
+       .proc_lseek     = mem_lseek,
+       .proc_read      = kpagecgroup_read,
 };
 #endif /* CONFIG_MEMCG */
 
 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);
+       proc_create("kpagecount", S_IRUSR, NULL, &kpagecount_proc_ops);
+       proc_create("kpageflags", S_IRUSR, NULL, &kpageflags_proc_ops);
 #ifdef CONFIG_MEMCG
-       proc_create("kpagecgroup", S_IRUSR, NULL, &proc_kpagecgroup_operations);
+       proc_create("kpagecgroup", S_IRUSR, NULL, &kpagecgroup_proc_ops);
 #endif
        return 0;
 }