Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 31 insertions, 5 deletions

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 49c59bab108..48ffb3dc610 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -35,6 +35,7 @@
 #include <asm/uaccess.h>
 #include <asm/param.h>
 #include <asm/page.h>
+#include <asm/exec.h>
 
 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
 static int load_elf_library(struct file *);
@@ -712,7 +713,6 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 		goto out_free_dentry;
 
 	/* OK, This is the point of no return */
-	current->flags &= ~PF_FORKNOEXEC;
 	current->mm->def_flags = def_flags;
 
 	/* Do this immediately, since STACK_TOP as used in setup_arg_pages
@@ -934,7 +934,6 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
 
 	install_exec_creds(bprm);
-	current->flags &= ~PF_FORKNOEXEC;
 	retval = create_elf_tables(bprm, &loc->elf_ex,
 			  load_addr, interp_load_addr);
 	if (retval < 0) {
@@ -1095,6 +1094,29 @@ 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,
@@ -1102,10 +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))
@@ -2093,7 +2118,8 @@ out:
 
 static int __init init_elf_binfmt(void)
 {
-	return register_binfmt(&elf_format);
+	register_binfmt(&elf_format);
+	return 0;
 }
 
 static void __exit exit_elf_binfmt(void)