From: Florian Weimer <fweimer@redhat.com>
To: Jim Wilson <jimw@sifive.com>
Cc: GNU C Library <libc-alpha@sourceware.org>
Subject: Re: [PATCH 00/30] RFC: elf: glibc-hwcaps support
Date: Sat, 11 Jul 2020 11:02:40 +0200 [thread overview]
Message-ID: <87eepiwhjj.fsf@oldenburg2.str.redhat.com> (raw)
In-Reply-To: <CAFyWVaZpB2byhWp=d5nVBeG0rbc7oK+AexcjwXwKq1+wmdUVhg@mail.gmail.com> (Jim Wilson's message of "Fri, 10 Jul 2020 14:47:44 -0700")
* Jim Wilson:
> On Mon, Jun 22, 2020 at 8:13 AM Florian Weimer via Libc-alpha
> <libc-alpha@sourceware.org> wrote:
>> With these changes, on a current x86-64 machine (with AVX2-level CPU
>> features), you can drop a shared object into the directory
>> /usr/lib64/glibc-hwcaps/x86-102
>
> This appears to violate the Filesystem Hierarchy Standard (FHS)
> https://refspecs.linuxfoundation.org/FHS_3.0/fhs/index.html
> which states that libraries can only be in /usr/lib or /usr/lib<qual>.
> And it is implied but not clearly stated that <qual> is not allowed to
> contain a slash. There is an exception for applications that can have
> a dir under /usr/lib or /usr/lib<qual>, but glibc isn't an
> application. Unless maybe you want to claim that ld.so is an
> application and these are ld.so specific files? But then all
> libraries used by ld.so must be in there which is not true.
I thought about this. For use with the library path, it has to be a
subdirectory not a sibling directory, otherwise the behavior would be
really surprising.
In the end, it's no different from the "tls" directory we already search
(along with a bunch of others). I posted a list of the subdirectories
searched on s390x:
<https://sourceware.org/pipermail/libc-alpha/2020-May/113757.html>
At least the "glibc-hwcaps" name is architecture-independent, and we can
add it to FHS if we wanted.
Thanks,
Florian
prev parent reply other threads:[~2020-07-11 9:02 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-22 15:12 Florian Weimer
2020-06-22 15:13 ` [PATCH 01/30] elf: Include <stdbool.h> in <dl-tunables.h> because bool is used Florian Weimer
2020-06-23 21:06 ` Tulio Magno Quites Machado Filho
2020-06-24 9:03 ` Florian Weimer
2020-06-22 15:13 ` [PATCH 02/30] elf: Include <stddef.h> (for size_t), <sys/stat.h> in <ldconfig.h> Florian Weimer
2020-06-25 13:16 ` Carlos O'Donell
2020-06-22 15:13 ` [PATCH 03/30] elf: Do not search HWCAP subdirectories in statically linked binaries Florian Weimer
2020-06-22 15:13 ` [PATCH 04/30] elf: Implement __rtld_malloc_is_full Florian Weimer
2020-06-22 15:13 ` [PATCH 05/30] elf: Implement _dl_write Florian Weimer
2020-06-22 15:13 ` [PATCH 06/30] elf: Extract command-line/environment variables state from rtld.c Florian Weimer
2020-06-22 15:13 ` [PATCH 07/30] elf: Move ld.so error/help output to _dl_usage Florian Weimer
2020-06-22 15:13 ` [PATCH 08/30] elf: Record whether paths come from LD_LIBRARY_PATH or --library-path Florian Weimer
2020-06-22 15:13 ` [PATCH 09/30] elf: Implement ld.so --help Florian Weimer
2020-06-22 15:13 ` [PATCH 10/30] elf: Implement ld.so --version Florian Weimer
2020-06-22 15:13 ` [PATCH 11/30] scripts/update-copyrights: Update csu/version.c, elf/dl-usage.c Florian Weimer
2020-06-22 15:14 ` [PATCH 12/30] elf: Use the term "program interpreter" in the ld.so help message Florian Weimer
2020-06-22 15:14 ` [PATCH 13/30] elf: Print the full name of the dynamic loader " Florian Weimer
2020-06-22 15:14 ` [PATCH 14/30] elf: Make __rtld_env_path_list and __rtld_search_dirs global variables Florian Weimer
2020-06-22 15:14 ` [PATCH 15/30] elf: Add library search path information to ld.so --help Florian Weimer
2020-06-22 15:14 ` [PATCH 16/30] elf: Enhance ld.so --help to print HWCAP subdirectories Florian Weimer
2020-06-22 15:14 ` [PATCH 17/30] elf: Do not pass GLRO(dl_platform), GLRO(dl_platformlen) to _dl_important_hwcaps Florian Weimer
2020-06-22 15:14 ` [PATCH 18/30] elf: Add glibc-hwcaps support for LD_LIBRARY_PATH Florian Weimer
2020-06-22 15:14 ` [PATCH 19/30] x86_64: Add glibc-hwcaps support Florian Weimer
2020-06-25 10:13 ` Florian Weimer
2020-06-25 13:50 ` H.J. Lu
2020-06-22 15:14 ` [PATCH 20/30] powerpc64le: " Florian Weimer
2020-06-22 15:14 ` [PATCH 21/30] s390x: Add " Florian Weimer
2020-06-22 15:14 ` [PATCH 22/30] aarch64: " Florian Weimer
2020-06-22 15:14 ` [PATCH 23/30] elf: Add endianness markup to ld.so.cache Florian Weimer
2020-06-22 15:15 ` [PATCH 24/30] elf: Add extension mechanism " Florian Weimer
2020-06-22 15:15 ` [PATCH 25/30] elf: Unify old and new format cache handling code in ld.so Florian Weimer
2020-06-22 15:15 ` [PATCH 26/30] elf: Implement a string table for ldconfig, with tail merging Florian Weimer
2020-06-22 15:15 ` [PATCH 27/30] elf: Implement tail merging of strings in ldconfig Florian Weimer
2020-06-22 15:15 ` [PATCH 28/30] elf: In ldconfig, extract the new_sub_entry function from search_dir Florian Weimer
2020-06-22 15:15 ` [PATCH 29/30] elf: Process glibc-hwcaps subdirectories in ldconfig Florian Weimer
2020-06-22 15:15 ` [PATCH 30/30] elf: Add glibc-hwcaps subdirectory support to ld.so cache processing Florian Weimer
2020-07-10 21:47 ` [PATCH 00/30] RFC: elf: glibc-hwcaps support Jim Wilson
2020-07-11 9:02 ` Florian Weimer [this message]
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