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Re: [PATCH] Fix output of LD_SHOW_AUXV=1.
On 3/12/19 11:06 AM, Stefan Liebler wrote:
> commit 988376a08d6d36ea321203b9c039db4b266609ae
> Author: Stefan Liebler <stli@linux.ibm.com>
> Date: Fri Mar 8 11:18:53 2019 +0100
>
> Fix output of LD_SHOW_AUXV=1.
>
> Starting with commit 1616d034b61622836d3a36af53dcfca7624c844e
> the output was corrupted on some platforms as _dl_procinfo
> was called for every auxv entry and on some architectures like s390
> all entries were represented as "AT_HWCAP".
>
> This patch is removing the condition and let _dl_procinfo decide if
> an entry is printed in a platform specific or generic way.
> This patch also adjusts all _dl_procinfo implementations which assumed
> that they are only called for AT_HWCAP or AT_HWCAP2. They are now just
> returning a non-zero-value for entries which are not handled platform
> specifc.
>
> ChangeLog:
>
> * elf/dl-sysdep.c (_dl_show_auxv): Remove condition and always
> call _dl_procinfo.
> * sysdeps/unix/sysv/linux/s390/dl-procinfo.h (_dl_procinfo):
> Ignore types other than AT_HWCAP.
> * sysdeps/sparc/dl-procinfo.h (_dl_procinfo): Likewise.
> * sysdeps/unix/sysv/linux/i386/dl-procinfo.h (_dl_procinfo):
> Likewise.
Thanks for the cleanup, this makes it really clear how this is intended to work.
OK for master if you...
- Fix ARM and POWERPC backend _dl_procinfo to remove "/* This should not happen. */"
comment in dl-procinfo.c. It *does* happen now because we pass all options to
the machine version first.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
> diff --git a/elf/dl-sysdep.c b/elf/dl-sysdep.c
> index 5f6c679a3f..5d19b100b2 100644
> --- a/elf/dl-sysdep.c
> +++ b/elf/dl-sysdep.c
> @@ -328,14 +328,9 @@ _dl_show_auxv (void)
> assert (AT_NULL == 0);
> assert (AT_IGNORE == 1);
>
> - if (av->a_type == AT_HWCAP || av->a_type == AT_HWCAP2
> - || AT_L1I_CACHEGEOMETRY || AT_L1D_CACHEGEOMETRY
> - || AT_L2_CACHEGEOMETRY || AT_L3_CACHEGEOMETRY)
> - {
> - /* These are handled in a special way per platform. */
> - if (_dl_procinfo (av->a_type, av->a_un.a_val) == 0)
> - continue;
> - }
> + /* Some entries are handled in a special way per platform. */
> + if (_dl_procinfo (av->a_type, av->a_un.a_val) == 0)
> + continue;
OK.
OK. ARM backend returns -1 with default handling.
OK. POWERPC backend return -1 with default handling.
>
> if (idx < sizeof (auxvars) / sizeof (auxvars[0])
> && auxvars[idx].form != unknown)
> diff --git a/sysdeps/sparc/dl-procinfo.h b/sysdeps/sparc/dl-procinfo.h
> index 282b8c5117..cc2687e99b 100644
> --- a/sysdeps/sparc/dl-procinfo.h
> +++ b/sysdeps/sparc/dl-procinfo.h
> @@ -32,7 +32,7 @@ _dl_procinfo (unsigned int type, unsigned long int word)
> int i;
>
> /* Fallback to unknown output mechanism. */
> - if (type == AT_HWCAP2)
> + if (type != AT_HWCAP)
OK.
> return -1;
>
> _dl_printf ("AT_HWCAP: ");
> diff --git a/sysdeps/unix/sysv/linux/i386/dl-procinfo.h b/sysdeps/unix/sysv/linux/i386/dl-procinfo.h
> index 22b43431bc..3aef14c6c1 100644
> --- a/sysdeps/unix/sysv/linux/i386/dl-procinfo.h
> +++ b/sysdeps/unix/sysv/linux/i386/dl-procinfo.h
> @@ -31,7 +31,7 @@ _dl_procinfo (unsigned int type, unsigned long int word)
> int i;
>
> /* Fallback to unknown output mechanism. */
> - if (type == AT_HWCAP2)
> + if (type != AT_HWCAP)
OK.
> return -1;
>
> _dl_printf ("AT_HWCAP: ");
> diff --git a/sysdeps/unix/sysv/linux/s390/dl-procinfo.h b/sysdeps/unix/sysv/linux/s390/dl-procinfo.h
> index 19329a335b..16739fd6cd 100644
> --- a/sysdeps/unix/sysv/linux/s390/dl-procinfo.h
> +++ b/sysdeps/unix/sysv/linux/s390/dl-procinfo.h
> @@ -33,7 +33,7 @@ _dl_procinfo (unsigned int type, unsigned long int word)
> int i;
>
> /* Fallback to unknown output mechanism. */
> - if (type == AT_HWCAP2)
> + if (type != AT_HWCAP)
OK.
> return -1;
>
> _dl_printf ("AT_HWCAP: ");
--
Cheers,
Carlos.