Re: [2.16] [PATCH] Skip audit if l_reloc_result is NULL

["Carlos O'Donell" <carlos at systemhalted dot org>]

On Mon, Nov 26, 2012 at 8:04 PM, H.J. Lu <hongjiu.lu@intel.com> wrote:
> Hi,
>
> This patch backports the fix for BZ #14831, which is a 2.16 regression
> from 2.15. Tested on x32 and ia32.  OK for 2.16 branch?  This patch also
> needs backporting:
>
> http://sourceware.org/git/?p=glibc.git;a=commit;h=e510ab5efff3450b723dbe71734e8b22be14d1c6
> http://sourceware.org/git/?p=glibc.git;a=commit;h=d072f3f7724d85ceaf230806660235f0cf2f9c3b
>
> for glibc-ports 2.16 branch.

This looks good to me for 2.16. Please notify the m68k and sh
maintainers directly to get them to assist with the backport to 2.16.

One nit...

> H.J.
> ---
> Cherry-pick commit 2e64d2659d3edaebc792ac596a9863f1626e5c25
>
> Conflicts:
>         ChangeLog
>         NEWS
> ---
>  ChangeLog        | 13 +++++++++++++
>  NEWS             |  2 +-
>  elf/Makefile     |  6 +++++-
>  elf/dl-runtime.c | 22 +++++++++++++++++++++-
>  elf/tst-audit8.c |  1 +
>  5 files changed, 41 insertions(+), 3 deletions(-)
>  create mode 100644 elf/tst-audit8.c
>
> diff --git a/ChangeLog b/ChangeLog
> index 66817c9..368ede1 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,16 @@
> +2012-11-14  H.J. Lu  <hongjiu.lu@intel.com>
> +
> +       [BZ #14831]
> +       * elf/Makefile (tests): Add tst-audit8.
> +       ($(objpfx)tst-audit8): Also depend on $(common-objpfx)math/libm.so.
> +       ($(objpfx)tst-audit8.out): New target.
> +       (tst-audit8-ENV): New variable.
> +       * elf/dl-runtime.c (_dl_profile_fixup): Call _dl_fixup to skip
> +       audit if l_reloc_result is NULL.
> +       (ELF_MACHINE_RUNTIME_FIXUP_PARAMS): Issue an error if it isn't
> +       defined and ELF_MACHINE_RUNTIME_FIXUP_ARGS is defined.
> +       * elf/tst-audit8.c: New file.
> +
>  2012-11-07  Andreas Jaeger  <aj@suse.de>
>
>         [BZ #14809]
> diff --git a/NEWS b/NEWS
> index 459553b..81af41d 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -9,7 +9,7 @@ Version 2.16.1
>
>  * The following bugs are resolved with this release:
>
> -  6530, 14195, 14459, 14476, 14562, 14621, 14648, 14756, 14809
> +  6530, 14195, 14459, 14476, 14562, 14621, 14648, 14756, 14809, 14865

This is the wrong BZ#.

>
>  Version 2.16
>
> diff --git a/elf/Makefile b/elf/Makefile
> index 0c26ce5..a621a1c 100644
> --- a/elf/Makefile
> +++ b/elf/Makefile
> @@ -138,7 +138,7 @@ tests += loadtest restest1 preloadtest loadfail multiload origtest resolvfail \
>          tst-dlmodcount tst-dlopenrpath tst-deep1 \
>          tst-dlmopen1 tst-dlmopen2 tst-dlmopen3 \
>          unload3 unload4 unload5 unload6 unload7 unload8 tst-global1 order2 \
> -        tst-audit1 tst-audit2 \
> +        tst-audit1 tst-audit2 tst-audit8 \
>          tst-stackguard1 tst-addr1 tst-thrlock \
>          tst-unique1 tst-unique2 tst-unique3 tst-unique4 \
>          tst-initorder tst-initorder2 tst-relsort1
> @@ -1024,6 +1024,10 @@ $(objpfx)tst-audit7: $(objpfx)tst-auditmod7a.so
>  $(objpfx)tst-audit7.out: $(objpfx)tst-auditmod7b.so
>  tst-audit7-ENV = LD_AUDIT=$(objpfx)tst-auditmod7b.so
>
> +$(objpfx)tst-audit8: $(common-objpfx)math/libm.so
> +$(objpfx)tst-audit8.out: $(objpfx)tst-auditmod1.so
> +tst-audit8-ENV = LD_AUDIT=$(objpfx)tst-auditmod1.so
> +
>  $(objpfx)tst-global1: $(libdl)
>  $(objpfx)tst-global1.out: $(objpfx)testobj6.so $(objpfx)testobj2.so
>
> diff --git a/elf/dl-runtime.c b/elf/dl-runtime.c
> index fdaa364..009d366 100644
> --- a/elf/dl-runtime.c
> +++ b/elf/dl-runtime.c
> @@ -1,5 +1,5 @@
>  /* On-demand PLT fixup for shared objects.
> -   Copyright (C) 1995-2009, 2010, 2011 Free Software Foundation, Inc.
> +   Copyright (C) 1995-2012 Free Software Foundation, Inc.
>     This file is part of the GNU C Library.
>
>     The GNU C Library is free software; you can redistribute it and/or
> @@ -168,6 +168,26 @@ _dl_profile_fixup (
>  {
>    void (*mcount_fct) (ElfW(Addr), ElfW(Addr)) = INTUSE(_dl_mcount);
>
> +  if (l->l_reloc_result == NULL)
> +    {
> +      /* BZ #14843: ELF_DYNAMIC_RELOCATE is called before l_reloc_result
> +        is allocated.  We will get here if ELF_DYNAMIC_RELOCATE calls a
> +        resolver function to resolve an IRELATIVE relocation and that
> +        resolver calls a function that is not yet resolved (lazy).  For
> +        example, the resolver in x86-64 libm.so calls __get_cpu_features
> +        defined in libc.so.  Skip audit and resolve the external function
> +        in this case.  */
> +      *framesizep = -1;
> +      return _dl_fixup (
> +# ifdef ELF_MACHINE_RUNTIME_FIXUP_ARGS
> +#  ifndef ELF_MACHINE_RUNTIME_FIXUP_PARAMS
> +#   error Please define ELF_MACHINE_RUNTIME_FIXUP_PARAMS.
> +#  endif
> +                       ELF_MACHINE_RUNTIME_FIXUP_PARAMS,
> +# endif
> +                       l, reloc_arg);
> +    }
> +
>    /* This is the address in the array where we store the result of previous
>       relocations.  */
>    struct reloc_result *reloc_result = &l->l_reloc_result[reloc_index];
> diff --git a/elf/tst-audit8.c b/elf/tst-audit8.c
> new file mode 100644
> index 0000000..63656b4
> --- /dev/null
> +++ b/elf/tst-audit8.c
> @@ -0,0 +1 @@
> +#include "../io/pwd.c"
> --
> 1.7.11.7
>

Cheers,
Carlos.