15 files changed, 40 insertions, 69 deletions

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index c2ae3cd331fe..219e4efee1a6 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -533,8 +533,7 @@ int vectors_user_mapping(void)
         struct mm_struct *mm = current->mm;
         return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
                                        VM_READ | VM_EXEC |
-                                       VM_MAYREAD | VM_MAYEXEC |
-                                       VM_ALWAYSDUMP | VM_RESERVED,
+                                       VM_MAYREAD | VM_MAYEXEC | VM_RESERVED,
                                        NULL);
 }
 
diff --git a/arch/hexagon/kernel/vdso.c b/arch/hexagon/kernel/vdso.c
index 16277c33308a..f212a453b527 100644
--- a/arch/hexagon/kernel/vdso.c
+++ b/arch/hexagon/kernel/vdso.c
@@ -78,8 +78,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
         /* MAYWRITE to allow gdb to COW and set breakpoints. */
         ret = install_special_mapping(mm, vdso_base, PAGE_SIZE,
                                       VM_READ|VM_EXEC|
-                                      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
-                                      VM_ALWAYSDUMP,
+                                      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
                                       &vdso_page);
 
         if (ret)
diff --git a/arch/mips/kernel/vdso.c b/arch/mips/kernel/vdso.c
index e5cdfd603f8f..0f1af58b036a 100644
--- a/arch/mips/kernel/vdso.c
+++ b/arch/mips/kernel/vdso.c
@@ -88,8 +88,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 
         ret = install_special_mapping(mm, addr, PAGE_SIZE,
                                       VM_READ|VM_EXEC|
-                                      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
-                                      VM_ALWAYSDUMP,
+                                      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
                                       &vdso_page);
 
         if (ret)
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index 7d14bb697d40..d36ee1055f88 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -263,17 +263,11 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
          * the "data" page of the vDSO or you'll stop getting kernel updates
          * and your nice userland gettimeofday will be totally dead.
          * It's fine to use that for setting breakpoints in the vDSO code
-         * pages though
-         *
-         * Make sure the vDSO gets into every core dump.
-         * Dumping its contents makes post-mortem fully interpretable later
-         * without matching up the same kernel and hardware config to see
-         * what PC values meant.
+         * pages though.
          */
         rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
                                      VM_READ|VM_EXEC|
-                                     VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
-                                     VM_ALWAYSDUMP,
+                                     VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
                                      vdso_pagelist);
         if (rc) {
                 current->mm->context.vdso_base = 0;
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index e704a9965f90..9c80138206b0 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -241,17 +241,11 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
          * on the "data" page of the vDSO or you'll stop getting kernel
          * updates and your nice userland gettimeofday will be totally dead.
          * It's fine to use that for setting breakpoints in the vDSO code
-         * pages though
-         *
-         * Make sure the vDSO gets into every core dump.
-         * Dumping its contents makes post-mortem fully interpretable later
-         * without matching up the same kernel and hardware config to see
-         * what PC values meant.
+         * pages though.
          */
         rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
                                      VM_READ|VM_EXEC|
-                                     VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
-                                     VM_ALWAYSDUMP,
+                                     VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
                                      vdso_pagelist);
         if (rc)
                 current->mm->context.vdso_base = 0;
diff --git a/arch/sh/kernel/vsyscall/vsyscall.c b/arch/sh/kernel/vsyscall/vsyscall.c
index 1d6d51a1ce79..5ca579720a09 100644
--- a/arch/sh/kernel/vsyscall/vsyscall.c
+++ b/arch/sh/kernel/vsyscall/vsyscall.c
@@ -73,8 +73,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 
         ret = install_special_mapping(mm, addr, PAGE_SIZE,
                                       VM_READ | VM_EXEC |
-                                      VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC |
-                                      VM_ALWAYSDUMP,
+                                      VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
                                       syscall_pages);
         if (unlikely(ret))
                 goto up_fail;
diff --git a/arch/tile/mm/elf.c b/arch/tile/mm/elf.c
index 55e58e93bfc5..1a00fb64fc88 100644
--- a/arch/tile/mm/elf.c
+++ b/arch/tile/mm/elf.c
@@ -117,17 +117,11 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
 
         /*
          * MAYWRITE to allow gdb to COW and set breakpoints
-         *
-         * Make sure the vDSO gets into every core dump.  Dumping its
-         * contents makes post-mortem fully interpretable later
-         * without matching up the same kernel and hardware config to
-         * see what PC values meant.
          */
         vdso_base = VDSO_BASE;
         retval = install_special_mapping(mm, vdso_base, PAGE_SIZE,
                                          VM_READ|VM_EXEC|
-                                         VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
-                                         VM_ALWAYSDUMP,
+                                         VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
                                          vdso_pages);
 
 #ifndef __tilegx__
diff --git a/arch/unicore32/kernel/process.c b/arch/unicore32/kernel/process.c
index 52edc2b62873..432b4291f37b 100644
--- a/arch/unicore32/kernel/process.c
+++ b/arch/unicore32/kernel/process.c
@@ -381,7 +381,7 @@ int vectors_user_mapping(void)
         return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
                                        VM_READ | VM_EXEC |
                                        VM_MAYREAD | VM_MAYEXEC |
-                                       VM_ALWAYSDUMP | VM_RESERVED,
+                                       VM_RESERVED,
                                        NULL);
 }
 
diff --git a/arch/x86/um/mem_32.c b/arch/x86/um/mem_32.c
index 639900a6fde9..f40281e5d6a2 100644
--- a/arch/x86/um/mem_32.c
+++ b/arch/x86/um/mem_32.c
@@ -23,14 +23,6 @@ static int __init gate_vma_init(void)
         gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
         gate_vma.vm_page_prot = __P101;
 
-        /*
-         * Make sure the vDSO gets into every core dump.
-         * Dumping its contents makes post-mortem fully interpretable later
-         * without matching up the same kernel and hardware config to see
-         * what PC values meant.
-         */
-        gate_vma.vm_flags |= VM_ALWAYSDUMP;
-
         return 0;
 }
 __initcall(gate_vma_init);
diff --git a/arch/x86/um/vdso/vma.c b/arch/x86/um/vdso/vma.c
index 91f4ec9a0a56..af91901babb8 100644
--- a/arch/x86/um/vdso/vma.c
+++ b/arch/x86/um/vdso/vma.c
@@ -64,8 +64,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 
         err = install_special_mapping(mm, um_vdso_addr, PAGE_SIZE,
                 VM_READ|VM_EXEC|
-                VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
-                VM_ALWAYSDUMP,
+                VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
                 vdsop);
 
         up_write(&mm->mmap_sem);
diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index 468d591dde31..a944020fa859 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -250,13 +250,7 @@ static int __init gate_vma_init(void)
         gate_vma.vm_end = FIXADDR_USER_END;
         gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
         gate_vma.vm_page_prot = __P101;
-        /*
-         * Make sure the vDSO gets into every core dump.
-         * Dumping its contents makes post-mortem fully interpretable later
-         * without matching up the same kernel and hardware config to see
-         * what PC values meant.
-         */
-        gate_vma.vm_flags |= VM_ALWAYSDUMP;
+
         return 0;
 }
 
@@ -343,17 +337,10 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
         if (compat_uses_vma || !compat) {
                 /*
                  * MAYWRITE to allow gdb to COW and set breakpoints
-                 *
-                 * Make sure the vDSO gets into every core dump.
-                 * Dumping its contents makes post-mortem fully
-                 * interpretable later without matching up the same
-                 * kernel and hardware config to see what PC values
-                 * meant.
                  */
                 ret = install_special_mapping(mm, addr, PAGE_SIZE,
                                               VM_READ|VM_EXEC|
-                                              VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
-                                              VM_ALWAYSDUMP,
+                                              VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
                                               vdso32_pages);
 
                 if (ret)
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index 153407c35b75..17e18279649f 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -124,8 +124,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 
         ret = install_special_mapping(mm, addr, vdso_size,
                                       VM_READ|VM_EXEC|
-                                      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
-                                      VM_ALWAYSDUMP,
+                                      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
                                       vdso_pages);
         if (ret) {
                 current->mm->context.vdso = NULL;
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 81878b78c9d4..b64be5b5ac21 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1093,6 +1093,29 @@ out:
  */
 
 /*
+ * 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.
  */
 static unsigned long vma_dump_size(struct vm_area_struct *vma,
@@ -1100,8 +1123,8 @@ 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;
 
         /* Hugetlb memory check */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 7330742e7973..2de2ddba51d4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -111,7 +111,6 @@ extern unsigned int kobjsize(const void *objp);
 #define VM_HUGEPAGE     0x01000000      /* MADV_HUGEPAGE marked this vma */
 #endif
 #define VM_INSERTPAGE   0x02000000      /* The vma has had "vm_insert_page()" done on it */
-#define VM_ALWAYSDUMP   0x04000000      /* Always include in core dumps */
 
 #define VM_CAN_NONLINEAR 0x08000000     /* Has ->fault & does nonlinear pages */
 #define VM_MIXEDMAP     0x10000000      /* Can contain "struct page" and pure PFN pages */
diff --git a/mm/memory.c b/mm/memory.c
index 3416b6e018d6..6105f475fa86 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3623,13 +3623,7 @@ static int __init gate_vma_init(void)
         gate_vma.vm_end = FIXADDR_USER_END;
         gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
         gate_vma.vm_page_prot = __P101;
-        /*
-         * Make sure the vDSO gets into every core dump.
-         * Dumping its contents makes post-mortem fully interpretable later
-         * without matching up the same kernel and hardware config to see
-         * what PC values meant.
-         */
-        gate_vma.vm_flags |= VM_ALWAYSDUMP;
+
         return 0;
 }
 __initcall(gate_vma_init);