Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm...

[pandora-kernel.git] / fs / binfmt_elf.c

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 1827653..7d7ff20 100644 (file)
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1093,6 +1093,29 @@ out:
  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
  */
 
+/*
+ * The purpose of always_dump_vma() is to make sure that special kernel mappings
+ * that are useful for post-mortem analysis are included in every core dump.
+ * In that way we ensure that the core dump is fully interpretable later
+ * without matching up the same kernel and hardware config to see what PC values
+ * meant. These special mappings include - vDSO, vsyscall, and other
+ * architecture specific mappings
+ */
+static bool always_dump_vma(struct vm_area_struct *vma)
+{
+       /* Any vsyscall mappings? */
+       if (vma == get_gate_vma(vma->vm_mm))
+               return true;
+       /*
+        * arch_vma_name() returns non-NULL for special architecture mappings,
+        * such as vDSO sections.
+        */
+       if (arch_vma_name(vma))
+               return true;
+
+       return false;
+}
+
 /*
  * Decide what to dump of a segment, part, all or none.
  */
@@ -1101,10 +1124,13 @@ static unsigned long vma_dump_size(struct vm_area_struct *vma,
 {
 #define FILTER(type)   (mm_flags & (1UL << MMF_DUMP_##type))
 
-       /* The vma can be set up to tell us the answer directly.  */
-       if (vma->vm_flags & VM_ALWAYSDUMP)
+       /* always dump the vdso and vsyscall sections */
+       if (always_dump_vma(vma))
                goto whole;
 
+       if (vma->vm_flags & VM_NODUMP)
+               return 0;
+
        /* Hugetlb memory check */
        if (vma->vm_flags & VM_HUGETLB) {
                if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))