kcore: register module area in generic way

Some archs define MODULED_VADDR/MODULES_END which is not in VMALLOC area.
This is handled only in x86-64.  This patch make it more generic.  And we
can use vread/vwrite to access the area.  Fix it.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 28 insertions, 5 deletions

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index d5d23cc24076..5a4398a6006b 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -647,7 +647,7 @@ EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
 
 #endif /* CONFIG_MEMORY_HOTPLUG */
 
-static struct kcore_list kcore_modules, kcore_vsyscall;
+static struct kcore_list kcore_vsyscall;
 
 void __init mem_init(void)
 {
@@ -676,8 +676,6 @@ void __init mem_init(void)
         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 
         /* Register memory areas for /proc/kcore */
-        kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN,
-                        KCORE_OTHER);
         kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
                          VSYSCALL_END - VSYSCALL_START, KCORE_OTHER);
 
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index 78970e6f715c..c6a5ec731972 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -490,7 +490,7 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
                 if (m == NULL) {
                         if (clear_user(buffer, tsz))
                                 return -EFAULT;
-                } else if (is_vmalloc_addr((void *)start)) {
+                } else if (is_vmalloc_or_module_addr((void *)start)) {
                         char * elf_buf;
 
                         elf_buf = kzalloc(tsz, GFP_KERNEL);
@@ -586,6 +586,22 @@ static void __init proc_kcore_text_init(void)
 }
 #endif
 
+#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
+/*
+ * MODULES_VADDR has no intersection with VMALLOC_ADDR.
+ */
+struct kcore_list kcore_modules;
+static void __init add_modules_range(void)
+{
+        kclist_add(&kcore_modules, (void *)MODULES_VADDR,
+                        MODULES_END - MODULES_VADDR, KCORE_VMALLOC);
+}
+#else
+static void __init add_modules_range(void)
+{
+}
+#endif
+
 static int __init proc_kcore_init(void)
 {
         proc_root_kcore = proc_create("kcore", S_IRUSR, NULL,
@@ -595,6 +611,7 @@ static int __init proc_kcore_init(void)
         /* Store vmalloc area */
         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
                 VMALLOC_END - VMALLOC_START, KCORE_VMALLOC);
+        add_modules_range();
         /* Store direct-map area from physical memory map */
         kcore_update_ram();
         hotplug_memory_notifier(kcore_callback, 0);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5946e2ff9fe8..b6eae5e3144b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -285,6 +285,14 @@ static inline int is_vmalloc_addr(const void *x)
         return 0;
 #endif
 }
+#ifdef CONFIG_MMU
+extern int is_vmalloc_or_module_addr(const void *x);
+#else
+static int is_vmalloc_or_module_addr(const void *x)
+{
+        return 0;
+}
+#endif
 
 static inline struct page *compound_head(struct page *page)
 {
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 5535da1d6961..69511e663234 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -184,7 +184,7 @@ static int vmap_page_range(unsigned long start, unsigned long end,
         return ret;
 }
 
-static inline int is_vmalloc_or_module_addr(const void *x)
+int is_vmalloc_or_module_addr(const void *x)
 {
         /*
          * ARM, x86-64 and sparc64 put modules in a special place,