powerpc cross tools generate bogus string table

[Sergio Durigan Junior]

I'm still not entirely sure whether this problem is caused by binutils or gcc-14, but my suspicion is that it's the former.

QEMU is being affected by this problem, as can be seen in the following build log:

https://launchpadlibrarian.net/743528322/buildlog_ubuntu-oracular-amd64.qemu_1%3A9.0.2+ds-2ubuntu1~ppa6_BUILDING.txt.gz

The interesting part is this one:

...
powerpc-linux-gnu-objcopy -O srec u-boot u-boot.srec
powerpc-linux-gnu-objcopy --gap-fill=0xff -O binary u-boot u-boot.bin
powerpc-linux-gnu-objcopy: warning: u-boot has a corrupt string table index
powerpc-linux-gnu-objcopy: unable to modify 'u-boot' due to errors
make[1]: *** [Makefile:300: u-boot.srec] Error 1
...

So far I have confirmed that using the previous versions of binutils (2.42.90.20240720-2ubuntu1) and gcc-14 (14.2.0-1ubuntu1) make the QEMU build work again.

Using powerpc-linux-gnu-readelf to compare the u-boot binary generated by the "good" binutils+gcc against the "bad" ones, I see:

Good binary:

Section Headers:
  [Nr] Name Type Addr Off Size ES Flg Lk Inf Al
  [ 0] NULL 00000000 000000 000000 00 0 0 0
  [ 1] .text PROGBITS fff80000 000080 046098 00 AX 0 0 16
  [ 2] .rodata PROGBITS fffc6098 046118 00b9f9 00 A 0 0 4
  [ 3] .reloc PROGBITS fffd1b00 051b80 003678 00 WA 0 0 4
  [ 4] .data PROGBITS fffd5178 0551f8 004c94 00 WA 0 0 4
  [ 5] .u_boot_cmd PROGBITS fffd9e0c 059e8c 0003d8 00 WA 0 0 4
  [ 6] .bootpg PROGBITS fffff000 07f080 0002bc 00 AX 0 0 1
  [ 7] .resetvec PROGBITS fffffffc 08007c 000004 00 AX 0 0 1
  [ 8] .bss NOBITS 00000100 080100 012ba0 00 WA 0 0 256
  [ 9] .debug_line PROGBITS 00000000 080080 045fed 00 0 0 1
  [10] .debug_line_str PROGBITS 00000000 0c606d 000100 01 MS 0 0 1
  [11] .debug_info PROGBITS 00000000 0c616d 084c69 00 0 0 1
  [12] .debug_abbrev PROGBITS 00000000 14add6 0167bc 00 0 0 1
  [13] .debug_aranges PROGBITS 00000000 161598 003820 00 0 0 8
  [14] .debug_str PROGBITS 00000000 164db8 00fb90 01 MS 0 0 1
  [15] .debug_rnglists PROGBITS 00000000 174948 005518 00 0 0 1
  [16] .debug_loclists PROGBITS 00000000 179e60 03b8d0 00 0 0 1
  [17] .comment PROGBITS 00000000 1b5730 000025 01 MS 0 0 1
  [18] .gnu.attributes GNU_ATTRIBUTES 00000000 1b5755 000010 00 0 0 1
  [19] .symtab SYMTAB 00000000 1b5768 007b40 10 20 537 4
  [20] .strtab STRTAB 00000000 1bd2a8 006d85 00 0 0 1
  [21] .shstrtab STRTAB 00000000 1c402d 0000e2 00 0 0 1

Bad binary:

Section Headers:
  [Nr] Name Type Addr Off Size ES Flg Lk Inf Al
  [ 0] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [ 1] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [ 2] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [ 3] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [ 4] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [ 5] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [ 6] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [ 7] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [ 8] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [ 9] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [10] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [11] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [12] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [13] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [14] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [15] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [16] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [17] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [18] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [19] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [20] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [21] <no-strings> NULL 00000000 000000 000000 00 0 0 0
  [22] <no-strings> NULL 00000000 000000 000000 00 0 0 0

[Sergio Durigan Junior (sergiodj)]

Adding gcc-14 as a task just in case.

Adding qemu as a task to make sure we track the impact of this bug.

[Sergio Durigan Junior (sergiodj)]

I think I found the reason for this failure. I'm doing a test build and will post the results here soon.

[Sergio Durigan Junior (sergiodj)]

The problem was the new ELF_PACKAGE_METADATA interacting weirdly with the PPC cross linker. I don't exactly know why, and IMHO this shouldn't really happen, but I will mark this bug as Invalid for both gcc and binutils because it's fixed in QEMU.

[Launchpad Janitor (janitor)]

This bug was fixed in the package qemu - 1:9.0.2+ds-4ubuntu2

---------------
qemu (1:9.0.2+ds-4ubuntu2) oracular; urgency=medium

  * d/rules: Reinstate u-boot-sam460ex rules.
  * d/rules: Unset ELF_PACKAGE_METADATA when building ROMs.
    (LP: #2077431, #2077036)

 -- Sergio Durigan Junior <email address hidden> Tue, 20 Aug 2024 22:40:20 -0400