alpha toolchain broken for static builds in bookworm?

[Alex Bennée]

Hi,

While updating QEMU's debian-all-test-cross docker image to bookworm I
found "check-tcg" broke for alpha. The docker image is essentially a
slim debian image with minimal qemu build deps and all the cross
compilers Debian packages that support a QEMU guest.

Digging into the failure it was pretty early on in start-up code:

(gdb) x/5i $pc
=> 0x12003e370 <__ctype_init+48>: ldq t0,0(t0)
0x12003e374 <__ctype_init+52>: ldq t4,56(t0)
0x12003e378 <__ctype_init+56>: ldq t2,64(t0)
0x12003e37c <__ctype_init+60>: ldq t0,80(t0)
0x12003e380 <__ctype_init+64>: lda t4,256(t4)
(gdb) p/x $t0
$1 = 0x0

which looks like TLS is very broken on static builds. Chatting with
Peter and Adhemerval pointed me to:

https://lists.debian.org/debian-alpha/2023/01/msg00020.html

which has been merged into glibc. However I can't work out if its in the
bookwork packages. I suspect not because I ran a test where I bumped
debian-all-test-cross to trixie (which ships 2.37-3cross1) and alpha
passes check-tcg. However I'm not sure how to navigate the
cross-toolchain-base-ports-62 to work out if the fix is in. The upstream
doesn't have any stable release tags beyond glibc-2.36.

In the release/2.36/master branch the fix is:

d5aaece8a3 elf: Fix GL(dl_phdr) and GL(dl_phnum) for static builds [BZ #29864]

So to summarise:

- what does Debian's 2.36-8cross1 map to on the release branch?
- if it doesn't include the above commit can we get a newer release
with a fix?

Thanks,

--
Alex Bennée
Virtualisation Tech Lead @ Linaro

[Alex Bennée]

Ahh I was looking in the wrong place - glibc-sources shows the fix in 2.36-9+deb12u1:

glibc (2.36-9+deb12u1) bookworm; urgency=medium

  [ Aurelien Jarno ]
  * debian/patches/git-updates.diff: update from upstream stable branch:
    - Affecting bookworm release architectures:
      - Improve mcount overflow handling in gmon.
      - Fix a buffer overflow in gmon (CVE-2023-0687).
      - Fix a memory corruption when incorrectly calling gmon functions
        repeatedly on in wrong order.
      - Fix a deadlock in getaddrinfo (__check_pf) with deferred cancellation.
      - Fix y2038 support in strftime on 32-bit architectures.
      - Fix corner case parsing of /etc/gshadow which can return bad pointers
        causing segfaults in applications.
      - Fix a deadlock in system() when called concurrently from multiple
        threads.
      - cdefs: limit definition of fortification macros to __FORTIFY_LEVEL > 0
        to support old C90 compilers.
    - Not affecting bookworm release architectures:
      - Fix LFS POSIX lock constants for powerpc64.
      - Fix GL(dl_phdr) and GL(dl_phnum) for static builds.  Closes: #1028200.
    - Not affecting debian architectures:
      - Fix LFS POSIX lock constants on 32 bit arch with 64 bit default
        time_t.
    - No change in the generated code:
      - Fix asm constraints in amd64 version of feraiseexcept (bug not visible
        with GCC 12).

So I guess we just need a rebuild of the later glibc for the alpha cross compiler?

--

Alex Bennée
Emulation and Virtualisation Tech Lead @ Linaro