Trouble with dynamic executables

[Jayachandran C.]

On Fri, Apr 15, 2011 at 12:47 AM, Andrew Duane <aduane at juniper.net> wrote:
> I've figured out what the problem is. The elf header of a sample dynamic executable shows:
>
> Elf file type is EXEC (Executable file)
> Entry point 0x1200028f0
> There are 7 program headers, starting at offset 64
>
> Program Headers:
>  Type           Offset             VirtAddr           PhysAddr           FileSiz            MemSiz              Flags  Align
>  PHDR           0x0000000000000040 0x0000000120000040 0x0000000120000040 0x0000000000000188 0x0000000000000188  R E    8
>  INTERP         0x0000000000012788 0x0000000120012788 0x0000000120012788 0x0000000000000015 0x0000000000000015  R      1
>      [Requesting program interpreter: /libexec/ld-elf.so.1]
>  LOAD           0x0000000000000000 0x0000000120000000 0x0000000120000000 0x00000000000127bc 0x00000000000127bc  R E    10000
>  LOAD           0x0000000000013000 0x0000000120023000 0x0000000120023000 0x00000000000017d8 0x0000000000003c28  RW     10000
>  DYNAMIC        0x0000000000000808 0x0000000120000808 0x0000000120000808 0x00000000000001e0 0x00000000000001e0  RWE    8
>  NOTE           0x00000000000127a4 0x00000001200127a4 0x00000001200127a4 0x0000000000000018 0x0000000000000018  R      4
>  NULL           0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000000         8
>
> Note section 1 the INTERP header: the offset is 0x12788. There's a check in the ELF64 image activator to see if the offset is outside the first page and returns ENOEXEC. The exec path reads in the first page first, and tries to figure out what to do with the rest. So if the interpreter name isn't in the first page, it can't decode it.
>
> This is a toolchain issue, or some setup issue.

This may be a mip64r2 issue.

I use the  mips64 config and 32 and 64 bit dynamic executables have
been working for a long time.

For reference, here is my setup:

Environment for buildworld:
export TARGET=mips
export TARGET_ARCH=mips64eb
export TARGET_CPUTYPE=mips64

Makeoptions in conf  file (from XLP64)

makeoptions     KERNLOADADDR=0xffffffff80100000
makeoptions     ARCH_FLAGS="-march=mips64 -mabi=64"
options         ISA_MIPS64

And on the XLR engineering board:

xlrboard# uname -a
FreeBSD xlrboard.netlogicmicro.com 9.0-CURRENT FreeBSD 9.0-CURRENT #2
r220649M: Fri Apr 15 11:27:57 IST 2011
jc at daemon.razamicroelectronics.com:/var/obj/jc/freebsd-obj-64/mips.mips64eb/work/jayachandranc/freebsd-devel-clean/sys/XLRJC64
 mips
xlrboard# ldd /bin/ls
/bin/ls:
        libutil.so.9 => /lib/libutil.so.9 (0x16024d000)
        libncurses.so.8 => /lib/libncurses.so.8 (0x16035f000)
        libc.so.7 => /lib/libc.so.7 (0x1604b3000)
xlrboard# readelf -a /bin/ls
ELF Header:
  Magic:   7f 45 4c 46 02 02 01 09 00 00 00 00 00 00 00 00
  Class:                             ELF64
  Data:                              2's complement, big endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - FreeBSD
  ABI Version:                       0
  Type:                              EXEC (Executable file)
  Machine:                           MIPS R3000
  Version:                           0x1
  Entry point address:               0x120001dd0
  Start of program headers:          64 (bytes into file)
  Start of section headers:          34808 (bytes into file)
  Flags:                             0x60000007, noreorder, pic, cpic, mips64
  Size of this header:               64 (bytes)
  Size of program headers:           56 (bytes)
  Number of program headers:         6
  Size of section headers:           64 (bytes)
  Number of section headers:         29
  Section header string table index: 28

Section Headers:
  [Nr] Name              Type             Address           Offset
       Size              EntSize          Flags  Link  Info  Align
  [ 0]                   NULL             0000000000000000  00000000
       0000000000000000  0000000000000000           0     0     0
  [ 1] .interp           PROGBITS         0000000120000190  00000190
       0000000000000015  0000000000000000   A       0     0     1
  [ 2] .note.ABI-tag     NOTE             00000001200001a8  000001a8
       0000000000000018  0000000000000000   A       0     0     4
  [ 3] .MIPS.options     MIPS_OPTIONS     00000001200001c0  000001c0
       0000000000000168  0000000000000001  Ao       0     0     8
  [ 4] .dynamic          DYNAMIC          0000000120000328  00000328
       0000000000000200  0000000000000010   A       7     0     8
  [ 5] .hash             HASH             0000000120000528  00000528
       0000000000000450  0000000000000004   A       6     0     8
  [ 6] .dynsym           DYNSYM           0000000120000978  00000978
....

The .interp offset is reasonable here...

JC.