1 files changed, 167 insertions, 12 deletions

diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index fdde1cc78392..802de33d6341 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -17,10 +17,14 @@
 #include <linux/elfcore.h>
 #include <linux/vmalloc.h>
 #include <linux/highmem.h>
+#include <linux/bootmem.h>
 #include <linux/init.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
 #include <linux/list.h>
+#include <linux/ioport.h>
+#include <linux/mm.h>
+#include <linux/memory.h>
 #include <asm/sections.h>
 
 #define CORE_STR "CORE"
@@ -31,17 +35,6 @@
 
 static struct proc_dir_entry *proc_root_kcore;
 
-static int open_kcore(struct inode * inode, struct file * filp)
-{
-        return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
-}
-
-static ssize_t read_kcore(struct file *, char __user *, size_t, loff_t *);
-
-static const struct file_operations proc_kcore_operations = {
-        .read           = read_kcore,
-        .open           = open_kcore,
-};
 
 #ifndef kc_vaddr_to_offset
 #define kc_vaddr_to_offset(v) ((v) - PAGE_OFFSET)
@@ -61,6 +54,7 @@ struct memelfnote
 
 static LIST_HEAD(kclist_head);
 static DEFINE_RWLOCK(kclist_lock);
+static int kcore_need_update = 1;
 
 void
 kclist_add(struct kcore_list *new, void *addr, size_t size, int type)
@@ -99,6 +93,126 @@ static size_t get_kcore_size(int *nphdr, size_t *elf_buflen)
         return size + *elf_buflen;
 }
 
+static void free_kclist_ents(struct list_head *head)
+{
+        struct kcore_list *tmp, *pos;
+
+        list_for_each_entry_safe(pos, tmp, head, list) {
+                list_del(&pos->list);
+                kfree(pos);
+        }
+}
+/*
+ * Replace all KCORE_RAM information with passed list.
+ */
+static void __kcore_update_ram(struct list_head *list)
+{
+        struct kcore_list *tmp, *pos;
+        LIST_HEAD(garbage);
+
+        write_lock(&kclist_lock);
+        if (kcore_need_update) {
+                list_for_each_entry_safe(pos, tmp, &kclist_head, list) {
+                        if (pos->type == KCORE_RAM)
+                                list_move(&pos->list, &garbage);
+                }
+                list_splice_tail(list, &kclist_head);
+        } else
+                list_splice(list, &garbage);
+        kcore_need_update = 0;
+        write_unlock(&kclist_lock);
+
+        free_kclist_ents(&garbage);
+}
+
+
+#ifdef CONFIG_HIGHMEM
+/*
+ * If no highmem, we can assume [0...max_low_pfn) continuous range of memory
+ * because memory hole is not as big as !HIGHMEM case.
+ * (HIGHMEM is special because part of memory is _invisible_ from the kernel.)
+ */
+static int kcore_update_ram(void)
+{
+        LIST_HEAD(head);
+        struct kcore_list *ent;
+        int ret = 0;
+
+        ent = kmalloc(sizeof(*ent), GFP_KERNEL);
+        if (!ent)
+                return -ENOMEM;
+        ent->addr = (unsigned long)__va(0);
+        ent->size = max_low_pfn << PAGE_SHIFT;
+        ent->type = KCORE_RAM;
+        list_add(&ent->list, &head);
+        __kcore_update_ram(&head);
+        return ret;
+}
+
+#else /* !CONFIG_HIGHMEM */
+
+static int
+kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg)
+{
+        struct list_head *head = (struct list_head *)arg;
+        struct kcore_list *ent;
+
+        ent = kmalloc(sizeof(*ent), GFP_KERNEL);
+        if (!ent)
+                return -ENOMEM;
+        ent->addr = (unsigned long)__va((pfn << PAGE_SHIFT));
+        ent->size = nr_pages << PAGE_SHIFT;
+
+        /* Sanity check: Can happen in 32bit arch...maybe */
+        if (ent->addr < (unsigned long) __va(0))
+                goto free_out;
+
+        /* cut not-mapped area. ....from ppc-32 code. */
+        if (ULONG_MAX - ent->addr < ent->size)
+                ent->size = ULONG_MAX - ent->addr;
+
+        /* cut when vmalloc() area is higher than direct-map area */
+        if (VMALLOC_START > (unsigned long)__va(0)) {
+                if (ent->addr > VMALLOC_START)
+                        goto free_out;
+                if (VMALLOC_START - ent->addr < ent->size)
+                        ent->size = VMALLOC_START - ent->addr;
+        }
+
+        ent->type = KCORE_RAM;
+        list_add_tail(&ent->list, head);
+        return 0;
+free_out:
+        kfree(ent);
+        return 1;
+}
+
+static int kcore_update_ram(void)
+{
+        int nid, ret;
+        unsigned long end_pfn;
+        LIST_HEAD(head);
+
+        /* Not inialized....update now */
+        /* find out "max pfn" */
+        end_pfn = 0;
+        for_each_node_state(nid, N_HIGH_MEMORY) {
+                unsigned long node_end;
+                node_end  = NODE_DATA(nid)->node_start_pfn +
+                        NODE_DATA(nid)->node_spanned_pages;
+                if (end_pfn < node_end)
+                        end_pfn = node_end;
+        }
+        /* scan 0 to max_pfn */
+        ret = walk_system_ram_range(0, end_pfn, &head, kclist_add_private);
+        if (ret) {
+                free_kclist_ents(&head);
+                return -ENOMEM;
+        }
+        __kcore_update_ram(&head);
+        return ret;
+}
+#endif /* CONFIG_HIGHMEM */
 
 /*****************************************************************************/
 /*
@@ -373,6 +487,39 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
         return acc;
 }
 
+
+static int open_kcore(struct inode *inode, struct file *filp)
+{
+        if (!capable(CAP_SYS_RAWIO))
+                return -EPERM;
+        if (kcore_need_update)
+                kcore_update_ram();
+        return 0;
+}
+
+
+static const struct file_operations proc_kcore_operations = {
+        .read           = read_kcore,
+        .open           = open_kcore,
+};
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+/* just remember that we have to update kcore */
+static int __meminit kcore_callback(struct notifier_block *self,
+                                    unsigned long action, void *arg)
+{
+        switch (action) {
+        case MEM_ONLINE:
+        case MEM_OFFLINE:
+                write_lock(&kclist_lock);
+                kcore_need_update = 1;
+                write_unlock(&kclist_lock);
+        }
+        return NOTIFY_OK;
+}
+#endif
+
+
 static struct kcore_list kcore_vmalloc;
 
 #ifdef CONFIG_ARCH_PROC_KCORE_TEXT
@@ -393,10 +540,18 @@ static void __init proc_kcore_text_init(void)
 
 static int __init proc_kcore_init(void)
 {
-        proc_root_kcore = proc_create("kcore", S_IRUSR, NULL, &proc_kcore_operations);
+        proc_root_kcore = proc_create("kcore", S_IRUSR, NULL,
+                                      &proc_kcore_operations);
+        /* Store text area if it's special */
         proc_kcore_text_init();
+        /* Store vmalloc area */
         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
                 VMALLOC_END - VMALLOC_START, KCORE_VMALLOC);
+        /* Store direct-map area from physical memory map */
+        kcore_update_ram();
+        hotplug_memory_notifier(kcore_callback, 0);
+        /* Other special area, area-for-module etc is arch specific. */
+
         return 0;
 }
 module_init(proc_kcore_init);