vmcore: allow user process to remap ELF note segment buffer

Now ELF note segment has been copied in the buffer on vmalloc memory.
To allow user process to remap the ELF note segment buffer with
remap_vmalloc_page, the corresponding VM area object has to have
VM_USERMAP flag set.

[akpm@linux-foundation.org: use the conventional comment layout]
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>
Cc: Lisa Mitchell <lisa.mitchell@hp.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 9b9270eb0599938303490f45eac87e26f6ff6b44..1082492e02fca4b9e006697fa64c744334c6bab1 100644 (file)
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -369,6 +369,7 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
        Elf64_Ehdr *ehdr_ptr;
        Elf64_Phdr phdr;
        u64 phdr_sz = 0, note_off;
+       struct vm_struct *vm;
 
        ehdr_ptr = (Elf64_Ehdr *)elfptr;
 
@@ -385,6 +386,14 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz,
        if (!*notes_buf)
                return -ENOMEM;
 
+       /*
+        * Allow users to remap ELF note segment buffer on vmalloc memory using
+        * remap_vmalloc_range.()
+        */
+       vm = find_vm_area(*notes_buf);
+       BUG_ON(!vm);
+       vm->flags |= VM_USERMAP;
+
        rc = copy_notes_elf64(ehdr_ptr, *notes_buf);
        if (rc < 0)
                return rc;
@@ -548,6 +557,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
        Elf32_Ehdr *ehdr_ptr;
        Elf32_Phdr phdr;
        u64 phdr_sz = 0, note_off;
+       struct vm_struct *vm;
 
        ehdr_ptr = (Elf32_Ehdr *)elfptr;
 
@@ -564,6 +574,14 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz,
        if (!*notes_buf)
                return -ENOMEM;
 
+       /*
+        * Allow users to remap ELF note segment buffer on vmalloc memory using
+        * remap_vmalloc_range()
+        */
+       vm = find_vm_area(*notes_buf);
+       BUG_ON(!vm);
+       vm->flags |= VM_USERMAP;
+
        rc = copy_notes_elf32(ehdr_ptr, *notes_buf);
        if (rc < 0)
                return rc;