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From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: Manuel Lauss <manuel.lauss@gmail.com>, libc-alpha@sourceware.org
Subject: Re: segfaults in _dl_fixup since 4af6982
Date: Wed, 13 Oct 2021 07:58:34 -0300	[thread overview]
Message-ID: <F61DF32C-DE90-46F5-9DEA-0CC0AD24BB18@linaro.org> (raw)
In-Reply-To: <20211013091845.GP2700@arm.com>



> On 13 Oct 2021, at 06:19, Szabolcs Nagy <szabolcs.nagy@arm.com> wrote:
> 
> The 10/13/2021 08:42, Manuel Lauss via Libc-alpha wrote:
>> [resend with libc-alpha]
>> Hi Adhemerval,
>> 
>> Your recent commit 4af6982e4c9fc465ffb7a54b794aaaa134241f05 ("elf: Fix
>> elf_get_dynamic_info definition")  causes a lot (but not all) of my
>> applications
>> to segfault:
>> 
>> Program received signal SIGSEGV, Segmentation fault.
>> _dl_fixup (l=<optimized out>, reloc_arg=<optimized out>) at dl-runtime.c:146
>> 146       return elf_machine_fixup_plt (l, result, refsym, sym, reloc,
>> rel_addr, value);
>> (gdb) bt
>> #0  _dl_fixup (l=<optimized out>, reloc_arg=<optimized out>) at dl-runtime.c:146
>> #1  0x00007ffff7fe251a in _dl_runtime_resolve_xsavec () at
>> ../sysdeps/x86_64/dl-trampoline.h:126
>> #2  0x000055555555634e in main (argc=1, argv=0x7fffffffd568) at
>> iconvconfig.c:288
>> 
>> Reverting the commit fixes the problem. Gcc, python, etc seem to be
>> not affected, while for example iconvconfig and openssh are.
> 
> on aarch64 buildbot i see
> 
> FAIL: nptl/test-cond-printers
> FAIL: nptl/test-condattr-printers
> FAIL: nptl/test-mutex-printers
> FAIL: nptl/test-mutexattr-printers
> FAIL: nptl/test-rwlock-printers
> FAIL: nptl/test-rwlockattr-printers
> 
> and
> 
> $ cat nptl/test-cond-printers.out
> Error: Response does not match the expected pattern.
> Command: start
> Expected pattern: main
> Response:  Temporary breakpoint 1 at 0xac4: file test-cond-printers.c, line 36.
> Starting program: /work/glibc-aarch64-linux/build/build/nptl/test-cond-printers
> 
> Program received signal SIGSEGV, Segmentation fault.
> _dl_fixup (l=<optimized out>, reloc_arg=<optimized out>) at dl-runtime.c:146
> 146       return elf_machine_fixup_plt (l, result, refsym, sym, reloc, rel_addr, value);
> (gdb)
> 
> 
> it seems to be a bind-now pie where PLT relocs are not yet
> processed when __libc_start_main is called but PLTGOT is
> already marked readonly so _dl_fixup crashes.

I will check this out.

  reply	other threads:[~2021-10-13 10:58 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CAOLZvyH+V0TokSzHumaxJF9JA=Kxoxh2NVr+ZZbdBD5qZ-urZg@mail.gmail.com>
2021-10-13  6:42 ` Fwd: " Manuel Lauss
2021-10-13  9:18   ` Szabolcs Nagy
2021-10-13 10:58     ` Adhemerval Zanella [this message]
2021-10-13 11:44       ` Adhemerval Zanella
2021-10-13 11:56         ` Adhemerval Zanella
2021-10-13 13:46           ` Adhemerval Zanella
2021-10-13 13:55             ` Manuel Lauss
2021-10-13 14:41               ` Adhemerval Zanella
2021-10-13 14:51                 ` Manuel Lauss
2021-10-13 15:12                   ` Adhemerval Zanella
2021-10-13 17:28                 ` Szabolcs Nagy
2021-10-13 18:15                   ` Adhemerval Zanella

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