binutils/objdump: Fix disassemble for huge elf sections

When elf section size is beyond unsigned int max value, objdump fails
to disassemble from that section. Ex on PowerPC,

  $ objdump -h /proc/kcore
    Idx  Name   Size       VMA
      4  load2  100000000  c000000000000000

Here, size of load2 section is 0x100000000. Also note that, 0xc00....
address range is kernel space for PowerPC. Now let's try to disassemble
do_sys_open() using /proc/kcore.

  $ cat /proc/kallsyms | grep -A1 -w do_sys_open
    c00000000036c000 T do_sys_open
    c00000000036c2d0 T SyS_open

Before patch:

  $ objdump -d --start-address=0xc00000000036c000 --stop-address=0xc00000000036c2d0 /proc/kcore
    /proc/kcore:    file format elf64-powerpcle

    Disassembly of section load2:

    c00000000036c000 <load2+0x36c000>:
    c00000000036c000:    Address 0xc00000000036c000 is out of bounds.

Fix this by changing type of 'buffer_length' from unsigned int to
size_t. After patch:

  $ objdump -d --start-address=0xc00000000036c000 --stop-address=0xc00000000036c2d0 /proc/kcore
    /proc/kcore:    file format elf64-powerpcle

    Disassembly of section load2:

    c00000000036c000 <load2+0x36c000>:
    c00000000036c000: fc 00 4c 3c     addis   r2,r12,252
    c00000000036c004: 00 53 42 38     addi    r2,r2,21248
    c00000000036c008: a6 02 08 7c     mflr    r0

include/
	* dis-asm.h (struct disassemble_info): Change type of buffer_length
	field to size_t.
opcodes/
	* dis-buf.c (buffer_read_memory): Change type of end_addr_offset,
	max_addr_offset and octets variables to size_t.

diff --git a/include/ChangeLog b/include/ChangeLog
index a726f0d9a048cf951922fa5fcb97a5085da18945..3203836ce812564d174d06f4f00fd4b8ba79c2e3 100644 (file)
--- a/include/ChangeLog
+++ b/include/ChangeLog
@@ -1,3 +1,8 @@
+2017-07-14  Ravi Bangoria  <ravi.bangoria@linux.vnet.ibm.com>
+
+       * dis-asm.h (struct disassemble_info): Change type of buffer_length
+       field to size_t.
+
 2017-07-07  John Baldwin  <jhb@FreeBSD.org>
 
        * elf/common.h (NT_FREEBSD_PTLWPINFO): Define.

diff --git a/include/dis-asm.h b/include/dis-asm.h
index 9b4251405e3b01269f7fbef80d0835993c7b1210..4ff8bc95ab36e99296b6eb6ec8f7666e00f74d44 100644 (file)
--- a/include/dis-asm.h
+++ b/include/dis-asm.h
@@ -158,7 +158,7 @@ typedef struct disassemble_info
   /* These are for buffer_read_memory.  */
   bfd_byte *buffer;
   bfd_vma buffer_vma;
-  unsigned int buffer_length;
+  size_t buffer_length;
 
   /* This variable may be set by the instruction decoder.  It suggests
       the number of bytes objdump should display on a single line.  If

diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 855ac35efa82c358095acada2484523a15a25e7d..caeeee7fb9f256871ad2add9524d1047f68dad81 100644 (file)
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,8 @@
+2017-07-14  Ravi Bangoria  <ravi.bangoria@linux.vnet.ibm.com>
+
+       * dis-buf.c (buffer_read_memory): Change type of end_addr_offset,
+       max_addr_offset and octets variables to size_t.
+
 2017-07-12  Alan Modra  <amodra@gmail.com>
 
        * po/da.po: Update from translationproject.org/latest/opcodes/.

diff --git a/opcodes/dis-buf.c b/opcodes/dis-buf.c
index 061bc441a3c652a7f28581d2a803108e98c681f7..fd495bb014c3809f1ef6bf5cfce841393fe64cb5 100644 (file)
--- a/opcodes/dis-buf.c
+++ b/opcodes/dis-buf.c
@@ -32,9 +32,9 @@ buffer_read_memory (bfd_vma memaddr,
                    struct disassemble_info *info)
 {
   unsigned int opb = info->octets_per_byte;
-  unsigned int end_addr_offset = length / opb;
-  unsigned int max_addr_offset = info->buffer_length / opb;
-  unsigned int octets = (memaddr - info->buffer_vma) * opb;
+  size_t end_addr_offset = length / opb;
+  size_t max_addr_offset = info->buffer_length / opb;
+  size_t octets = (memaddr - info->buffer_vma) * opb;
 
   if (memaddr < info->buffer_vma
       || memaddr - info->buffer_vma > max_addr_offset