From: Sergey Bugaev <bugaevc@gmail.com>
To: Samuel Thibault <samuel.thibault@gnu.org>
Cc: libc-alpha@sourceware.org, bug-hurd@gnu.org
Subject: Re: [RFC PATCH glibc 24/34] hurd: Only check for TLS initialization inside rtld or in static builds
Date: Tue, 11 Apr 2023 23:27:35 +0300 [thread overview]
Message-ID: <CAN9u=Hc0A6uB+GWctXbn5_y7Fe4NV76_nps=vm9mLvBgT5Dezw@mail.gmail.com> (raw)
In-Reply-To: <20230411185705.22jygrepjq4mhbvk@begin>
On Tue, Apr 11, 2023 at 9:57 PM Samuel Thibault <samuel.thibault@gnu.org> wrote:
>
> Hello,
>
> Had you actually tested it on i386? It seems to be breaking the
> testsuite completely. I would expect that a submitted patch series has
> gone through the testsuite.
Ouch!
I have tested that it works on i386, as in I was able to run bash and
apt with it. I'll re-check whether it (still) works, maybe I'm
misremembering and my testing wasn't with the latest iteration of the
change (although I'm fairly sure that it was, hm).
I have not run the testsuite, because:
* I'm cross-compiling
* I never managed to run it to completion on the Hurd in the first
place... but maybe you have already fixed this.
I'll try to run the full testsuite once I get to my other machine.
But also, I think I've made it clear enough that this is an RFC and
while I have done some testing, it wasn't comprehensive. I was happy
to see it pushed, but that's because I assumed that you have verified
that my assumptions & reasoning are sound and that this change doesn't
break anything. Please don't just blindly trust me with this patchset!
> Sergey Bugaev, le dim. 19 mars 2023 18:10:07 +0300, a ecrit:
> > When glibc is built as a shared library, TLS is always initialized by
> > the call of TLS_INIT_TP () macro made inside the dynamic loader, prior
> > to running the main program (see dl-call_tls_init_tp.h).
>
> Yes, but apparently we load libc.so before calling TLS_INIT_TP? (and
> thus start using its functions)
If that was the case, wouldn't we also explode on e.g. errno accesses?
Note that the Hurd port doesn't use RTLD_PRIVATE_ERRNO.
As I understand it, rtld starts using libc functions after the call to
_dl_relocate_object (&GL(dl_rtld_map), main_map->l_scope, 0, 0) at
elf/rtld.c:2372. TLS has already been initialized by that point, and
in fact there's a comment there saying, "We must do this after TLS
initialization in case after this re-relocation, we might call a
user-supplied function (e.g. calloc from _dl_relocate_object) that
uses TLS data."
Here's some evidence to support that theory: I've uploaded a log with
LD_DEBUG + gdb here: [0]. As you can see, i386_set_gdt gets hit *way*
before ld.so gets reallocated / bound to libc.so symbols. The same can
be seen in a file that explicitly links against libdl (this doesn't
seem to make any difference).
[0]: https://paste.gg/p/anonymous/ae39453264334d3e92670a3cd964806d
But of course it's hard to argue with test failures :(
> I'm thinking that we should as well just assume that the hardware is old
> enough to support rdfsbase, that'll be *way* simpler to test for TLS.
Maybe that, yes.
> I have reverted that change for now, so we get back to a working glibc.
Good.
Sergey
next prev parent reply other threads:[~2023-04-11 20:27 UTC|newest]
Thread overview: 140+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-19 15:09 [RFC PATCH 00/34] The rest of the x86_64-gnu port Sergey Bugaev
2023-03-19 15:09 ` [RFC PATCH gnumach 01/34] Add i386_fsgs_base_state Sergey Bugaev
2023-04-02 22:43 ` Samuel Thibault
2023-03-19 15:09 ` [RFC PATCH gnumach 02/34] Remove bootstrap.defs Sergey Bugaev
2023-04-02 22:43 ` Samuel Thibault
2023-04-03 9:39 ` Sergey Bugaev
2023-03-19 15:09 ` [RFC PATCH gnumach 03/34] Make exception subcode a long Sergey Bugaev
2023-04-02 22:45 ` Samuel Thibault
2023-04-03 9:32 ` Sergey Bugaev
2023-04-06 2:11 ` Flávio Cruz
2023-04-10 23:52 ` Samuel Thibault
2023-03-19 15:09 ` [RFC PATCH glibc 04/34] hurd: " Sergey Bugaev
2023-04-02 22:52 ` Samuel Thibault
2023-03-19 15:09 ` [RFC PATCH glibc 05/34] hurd: Remove __hurd_threadvar_stack_{offset,mask} Sergey Bugaev
2023-04-02 22:53 ` Samuel Thibault
2023-03-19 15:09 ` [RFC PATCH glibc 06/34] hurd: Swap around two function calls Sergey Bugaev
2023-04-02 22:54 ` Samuel Thibault
2023-03-19 15:09 ` [RFC PATCH glibc 07/34] hurd: Fix file name in #error Sergey Bugaev
2023-04-02 22:55 ` Samuel Thibault
2023-03-19 15:09 ` [RFC PATCH glibc 08/34] hurd: Disable O_TRUNC and FS_RETRY_MAGICAL in rtld Sergey Bugaev
2023-04-02 22:57 ` Samuel Thibault
2023-03-19 15:09 ` [RFC PATCH glibc 09/34] hurd: Fix _hurd_setup_sighandler () signature Sergey Bugaev
2023-04-02 22:58 ` Samuel Thibault
2023-03-19 15:09 ` [RFC PATCH glibc 10/34] stdio-common: Fix building when !IS_IN (libc) Sergey Bugaev
2023-04-02 23:01 ` Samuel Thibault
2023-03-19 15:09 ` [RFC PATCH glibc 11/34] mach, hurd: Drop __libc_lock_self0 Sergey Bugaev
2023-04-02 23:02 ` Samuel Thibault
2023-03-19 15:09 ` [RFC PATCH glibc 12/34] hurd: More 64-bit integer casting fixes Sergey Bugaev
2023-04-02 23:03 ` Samuel Thibault
2023-03-19 15:09 ` [RFC PATCH glibc 13/34] x86-64: Disable prefer_map_32bit_exec tunable on non-Linux Sergey Bugaev
2023-04-02 23:09 ` Samuel Thibault
2023-04-03 10:10 ` Sergey Bugaev
2023-04-03 19:02 ` H.J. Lu
2023-04-03 20:11 ` Sergey Bugaev
2023-03-19 15:09 ` [RFC PATCH glibc 14/34] hurd: Move rtld-strncpy-c.c out of mach/hurd/ Sergey Bugaev
2023-04-02 23:10 ` Samuel Thibault
2023-03-19 15:09 ` [RFC PATCH glibc 15/34] hurd: Use uintptr_t for register values in trampoline.c Sergey Bugaev
2023-04-02 23:13 ` Samuel Thibault
2023-03-19 15:09 ` [RFC PATCH glibc 16/34] hurd: Add sys/ucontext.h and sigcontext.h for x86_64 Sergey Bugaev
2023-04-10 18:39 ` Samuel Thibault
2023-04-10 19:07 ` Sergey Bugaev
2023-04-10 19:21 ` Samuel Thibault
2023-04-10 18:58 ` Samuel Thibault
2023-04-10 19:13 ` Sergey Bugaev
2023-04-10 19:21 ` Samuel Thibault
2023-04-10 21:50 ` Sergey Bugaev
2023-04-10 22:23 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 17/34] hurd: Implement x86_64/intr-msg.h Sergey Bugaev
2023-04-10 18:41 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 18/34] hurd: Port trampoline.c to x86_64 Sergey Bugaev
2023-04-03 11:56 ` [PATCH v2 18.0/34] Alignment-respecting x86_64 trampoline.c Sergey Bugaev
2023-04-03 11:56 ` [PATCH v2 18.1/34] hurd: Do not declare local variables volatile Sergey Bugaev
2023-04-10 18:42 ` Samuel Thibault
2023-04-03 11:56 ` [PATCH v2 18.2/34] hurd: Port trampoline.c to x86_64 Sergey Bugaev
2023-04-10 19:04 ` Samuel Thibault
2023-04-10 21:33 ` Sergey Bugaev
2023-03-19 15:10 ` [RFC PATCH glibc 19/34] hurd: Move a couple of singal-related files to x86 Sergey Bugaev
2023-04-02 23:15 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 20/34] htl: Add tcb-offsets.sym for x86_64 Sergey Bugaev
2023-04-02 23:16 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 21/34] x86_64: Add rtld-stpncpy & rtld-strncpy Sergey Bugaev
2023-04-02 23:18 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 22/34] htl: Implement thread_set_pcsptp for x86_64 Sergey Bugaev
2023-04-02 23:19 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 23/34] elf: Stop including tls.h in ldsodefs.h Sergey Bugaev
2023-04-02 23:20 ` Samuel Thibault
2023-04-03 9:26 ` Sergey Bugaev
2023-04-10 21:26 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 24/34] hurd: Only check for TLS initialization inside rtld or in static builds Sergey Bugaev
2023-04-10 21:33 ` Samuel Thibault
2023-04-11 18:57 ` Samuel Thibault
2023-04-11 19:18 ` Samuel Thibault
2023-04-11 20:03 ` Samuel Thibault
2023-04-11 20:27 ` Sergey Bugaev [this message]
2023-04-11 21:23 ` Samuel Thibault
2023-04-12 8:36 ` Sergey Bugaev
2023-04-12 9:00 ` Samuel Thibault
2023-04-12 10:42 ` Sergey Bugaev
2023-04-12 10:45 ` Samuel Thibault
2023-04-12 17:18 ` Sergey Bugaev
2023-04-12 23:46 ` Samuel Thibault
2023-04-13 10:02 ` Sergey Bugaev
2023-04-13 10:10 ` Samuel Thibault
2023-04-13 12:17 ` Sergey Bugaev
2023-04-13 21:47 ` Samuel Thibault
2023-04-13 22:21 ` Samuel Thibault
2023-04-14 8:29 ` Sergey Bugaev
2023-04-14 8:36 ` Samuel Thibault
2023-04-14 8:53 ` Sergey Bugaev
2023-04-14 9:09 ` Samuel Thibault
2023-04-14 9:23 ` Sergey Bugaev
2023-04-14 9:31 ` Samuel Thibault
2023-04-17 7:16 ` Samuel Thibault
2023-04-14 17:34 ` Samuel Thibault
2023-04-14 19:52 ` Sergey Bugaev
2023-03-19 15:10 ` [RFC PATCH glibc 25/34] hurd: Improve reply port handling when exiting signal handlers Sergey Bugaev
2023-04-10 22:03 ` Samuel Thibault
2023-04-11 7:44 ` Sergey Bugaev
2023-04-11 20:15 ` Samuel Thibault
2023-04-11 20:35 ` Sergey Bugaev
2023-04-12 22:54 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 26/34] hurd: Remove __hurd_local_reply_port Sergey Bugaev
2023-04-10 22:07 ` Samuel Thibault
2023-04-10 22:35 ` Samuel Thibault
2023-04-11 8:00 ` Sergey Bugaev
2023-04-11 20:18 ` Samuel Thibault
2023-04-13 11:58 ` [RFC PATCH glibc v2 " Sergey Bugaev
2023-04-13 13:12 ` Samuel Thibault
2023-04-13 13:20 ` Sergey Bugaev
2023-04-13 21:28 ` Samuel Thibault
2023-04-14 17:33 ` Samuel Thibault
2023-04-14 20:29 ` Sergey Bugaev
2023-04-15 6:45 ` Samuel Thibault
2023-04-15 7:34 ` Sergey Bugaev
2023-04-15 7:42 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 27/34] hurd: Don't leak __hurd_reply_port0 Sergey Bugaev
2023-04-10 22:25 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 28/34] hurd: Implement _hurd_longjmp_thread_state for x86_64 Sergey Bugaev
2023-04-02 23:23 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 29/34] hurd: Add vm_param.h " Sergey Bugaev
2023-04-02 23:24 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 30/34] hurd: Implement longjmp " Sergey Bugaev
2023-03-19 15:10 ` [RFC PATCH glibc 31/34] hurd: Microoptimize _hurd_self_sigstate () Sergey Bugaev
2023-04-02 23:26 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 32/34] hurd: Implement sigreturn for x86_64 Sergey Bugaev
2023-04-03 11:47 ` [PATCH v2] " Sergey Bugaev
2023-03-19 15:10 ` [RFC PATCH glibc 33/34] hurd: Create abilist files for lib{mach,hurd}user Sergey Bugaev
2023-03-19 15:19 ` Samuel Thibault
2023-03-19 15:39 ` Sergey Bugaev
2023-03-19 15:43 ` Samuel Thibault
2023-03-19 15:10 ` [RFC PATCH glibc 34/34] hurd: Add expected abilist files for x86_64 Sergey Bugaev
2023-03-19 18:04 ` Florian Weimer
2023-03-19 20:14 ` [PATCH v2] " Sergey Bugaev
2023-03-20 6:30 ` Florian Weimer
2023-03-19 16:44 ` [RFC PATCH 00/34] The rest of the x86_64-gnu port Luca
2023-03-20 5:03 ` Flávio Cruz
2023-04-02 23:30 ` Samuel Thibault
2023-04-10 19:20 ` Samuel Thibault
2023-04-10 21:24 ` Sergey Bugaev
2023-04-10 21:27 ` Samuel Thibault
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