From a2246aaad96e062eb3bab55af9526aaa70adcfd0 Mon Sep 17 00:00:00 2001

From: Dima Kogan <dkogan@debian.org>

Date: Fri, 8 Dec 2017 01:45:10 -0800

Subject: [PATCH 1/2] libdw: dwarf_aggregate_size() works with

 multi-dimensional arrays

If we have a multidimensional array of dimensions (a,b,c) the number of elements

should be a*b*c, but prior to this patch dwarf_aggregate_size() would report

a+b+c instead.

This patch fixes the bug and adds a test that demonstrates the bug (the test

fails without the functional part of this patch).

Fixes: https://sourceware.org/bugzilla/show_bug.cgi?id=22546

Signed-off-by: Dima Kogan <dima@secretsauce.net>

---

 libdw/ChangeLog              |   5 +++++

 libdw/dwarf_aggregate_size.c |  43 ++++++++++++++++++++++---------------------

 tests/ChangeLog              |   6 ++++++

 tests/run-aggregate-size.sh  |   2 ++

 tests/run-peel-type.sh       |   1 +

 tests/testfile-sizes3.o.bz2  | Bin 1147 -> 1208 bytes

 6 files changed, 36 insertions(+), 21 deletions(-)

diff --git a/libdw/dwarf_aggregate_size.c b/libdw/dwarf_aggregate_size.c

index 838468d..3010c0a 100644

--- a/libdw/dwarf_aggregate_size.c

+++ b/libdw/dwarf_aggregate_size.c

@@ -63,7 +63,7 @@ array_size (Dwarf_Die *die, Dwarf_Word *size,

     return -1;

   bool any = false;

-  Dwarf_Word total = 0;

+  Dwarf_Word count_total = 1;

   do

     {

       Dwarf_Word count;

@@ -134,34 +134,35 @@ array_size (Dwarf_Die *die, Dwarf_Word *size,

 	  continue;

 	}

-      /* This is a subrange_type or enumeration_type and we've set COUNT.

-	 Now determine the stride for this array dimension.  */

-      Dwarf_Word stride = eltsize;

-      if (INTUSE(dwarf_attr_integrate) (&child, DW_AT_byte_stride,

-					attr_mem) != NULL)

-	{

-	  if (INTUSE(dwarf_formudata) (attr_mem, &stride) != 0)

-	    return -1;

-	}

-      else if (INTUSE(dwarf_attr_integrate) (&child, DW_AT_bit_stride,

-					     attr_mem) != NULL)

-	{

-	  if (INTUSE(dwarf_formudata) (attr_mem, &stride) != 0)

-	    return -1;

-	  if (stride % 8) 	/* XXX maybe compute in bits? */

-	    return -1;

-	  stride /= 8;

-	}

+      count_total *= count;

       any = true;

-      total += stride * count;

     }

   while (INTUSE(dwarf_siblingof) (&child, &child) == 0);

   if (!any)

     return -1;

-  *size = total;

+  /* This is a subrange_type or enumeration_type and we've set COUNT.

+     Now determine the stride for this array.  */

+  Dwarf_Word stride = eltsize;

+  if (INTUSE(dwarf_attr_integrate) (die, DW_AT_byte_stride,

+                                    attr_mem) != NULL)

+    {

+      if (INTUSE(dwarf_formudata) (attr_mem, &stride) != 0)

+        return -1;

+    }

+  else if (INTUSE(dwarf_attr_integrate) (die, DW_AT_bit_stride,

+                                         attr_mem) != NULL)

+    {

+      if (INTUSE(dwarf_formudata) (attr_mem, &stride) != 0)

+        return -1;

+      if (stride % 8) 	/* XXX maybe compute in bits? */

+        return -1;

+      stride /= 8;

+    }

+

+  *size = count_total * stride;

   return 0;

 }

diff --git a/tests/run-aggregate-size.sh b/tests/run-aggregate-size.sh

index 42b0742..6d8aa24 100755

--- a/tests/run-aggregate-size.sh

+++ b/tests/run-aggregate-size.sh

@@ -54,6 +54,7 @@

 # volatile int ia[32];

 # const volatile void * const volatile restrict va[64];

 # struct s sa[8];

+# double d3d[3][4][5];

 #

 # typedef const int foo;

 # typedef volatile foo bar;

@@ -98,6 +99,7 @@ ca size 16

 ia size 128

 va size 512

 sa size 128

+d3d size 480

 f size 4

 b size 4

 EOF

diff --git a/tests/run-peel-type.sh b/tests/run-peel-type.sh

index 7fd96e8..668e316 100755

--- a/tests/run-peel-type.sh

+++ b/tests/run-peel-type.sh

@@ -55,6 +55,7 @@ ca raw type array_type

 ia raw type array_type

 va raw type array_type

 sa raw type array_type

+d3d raw type array_type

 f raw type base_type

 b raw type base_type

 EOF

-- 

1.8.3.1

From c25dc62e59dc42378370602b0d05415a42b051d6 Mon Sep 17 00:00:00 2001

From: Mark Wielaard <mark@klomp.org>

Date: Mon, 11 Dec 2017 23:58:34 +0100

Subject: [PATCH 2/2] libdw: dwarf_aggregate_size should not peel the given

 DIE.

Reserve memory for a new DIE first. The caller might not care, but it

isn't really nice to change the DIE the caller gave us.

See also https://sourceware.org/bugzilla/show_bug.cgi?id=22546#c5

Signed-off-by: Mark Wielaard <mark@klomp.org>

---

 libdw/ChangeLog              | 5 +++++

 libdw/dwarf_aggregate_size.c | 6 +++---

 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/libdw/dwarf_aggregate_size.c b/libdw/dwarf_aggregate_size.c

index 3010c0a..6e50185 100644

--- a/libdw/dwarf_aggregate_size.c

+++ b/libdw/dwarf_aggregate_size.c

@@ -199,12 +199,12 @@ aggregate_size (Dwarf_Die *die, Dwarf_Word *size, Dwarf_Die *type_mem)

 int

 dwarf_aggregate_size (Dwarf_Die *die, Dwarf_Word *size)

 {

-  Dwarf_Die type_mem;

+  Dwarf_Die die_mem, type_mem;

-  if (INTUSE (dwarf_peel_type) (die, die) != 0)

+  if (INTUSE (dwarf_peel_type) (die, &die_mem) != 0)

     return -1;

-  return aggregate_size (die, size, &type_mem);

+  return aggregate_size (&die_mem, size, &type_mem);

 }

 INTDEF (dwarf_aggregate_size)

 OLD_VERSION (dwarf_aggregate_size, ELFUTILS_0.144)

-- 

1.8.3.1