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binutils/objdump: Fix disassemble for huge elf sections

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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.
This commit is contained in:
Ravi Bangoria 2017-07-14 13:26:27 +05:30 committed by Alan Modra
parent 86038de0d8
commit 0f6329bd7f
4 changed files with 14 additions and 4 deletions
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5
include/ChangeLog
View File

@ -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.

2
include/dis-asm.h
View File

@ -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

5
opcodes/ChangeLog
View File

@ -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/.

6
opcodes/dis-buf.c
View File

@ -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