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.
include * dis-asm.h (struct disassemble_info): Add stop_vma field.
binuti * objdump.c (disassemble_bytes): Set the stop_vma field in the
disassemble_info structure when disassembling code sections with
-d.
* doc/binutils.texi (objdump): Document the discrepancy between -d
and -D.
opcodes * dis-buf.c (buffer_read_memory): Fail is stop_vma is set and the
requested region lies beyond it.
* bfin-dis.c (print_insn_bfin): Ignore sysop instructions when
looking for 32-bit insns.
* mcore-dis.c (print_insn_mcore): Disable stop_vma when reading
data.
* sh-dis.c (print_insn_sh): Likewise.
* tic6x-dis.c (print_insn_tic6x): Disable stop_vma when reading
blocks of instructions.
* vax-dis.c (print_insn_vax): Check that the requested address
does not clash with the stop_vma.
tests * gas/arm/backslash-at.s: Add extra .byte directives so that the
foo symbol does not appear to point half way through an
instruction.
* gas/arm/backslash-at.d: Update expected disassembly.
* gas/i386/ilp32/x86-64-opcode-inval-intel.d: Likewise.
* gas/i386/ilp32/x86-64-opcode-inval.d: Likewise.
* gas/i386/x86-64-opcode-inval-intel.d: Likewise.
* gas/i386/x86-64-opcode-inval.d: Likewise.
(generic_strcat_address): Add cast to avoid warning.
* i386-dis.c: Initialize all structure fields to avoid warnings.
Add ATTRIBUTE_UNUSED as appropriate.
