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Linux: Remove rseq support

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The kernel ABI is not finalized, and there are now various proposals
to change the size of struct rseq, which would make the glibc ABI
dependent on the version of the kernels used for building glibc.
This is of course not acceptable.

This reverts commit 48699da1c4 ("elf:
Support at least 32-byte alignment in static dlopen"), commit
8f4632deb3 ("Linux: rseq registration
tests"), commit 6e29cb3f61 ("Linux: Use
rseq in sched_getcpu if available"), and commit
0c76fc3c2b ("Linux: Perform rseq
registration at C startup and thread creation"), resolving the conflicts
introduced by the ARC port and the TLS static surplus changes.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This commit is contained in:
Florian Weimer
2020-07-16 17:55:35 +02:00
parent da7d62b503
commit efedd1ed3d
54 changed files with 6 additions and 1197 deletions
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62
sysdeps/unix/sysv/linux/mips/bits/rseq.h
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@ -1,62 +0,0 @@
/* Restartable Sequences Linux mips architecture header.
Copyright (C) 2020 Free Software Foundation, Inc.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _SYS_RSEQ_H
# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
#endif
/* RSEQ_SIG is a signature required before each abort handler code.
It is a 32-bit value that maps to actual architecture code compiled
into applications and libraries. It needs to be defined for each
architecture. When choosing this value, it needs to be taken into
account that generating invalid instructions may have ill effects on
tools like objdump, and may also have impact on the CPU speculative
execution efficiency in some cases.
RSEQ_SIG uses the break instruction. The instruction pattern is:
On MIPS:
0350000d break 0x350
On nanoMIPS:
00100350 break 0x350
On microMIPS:
0000d407 break 0x350
For nanoMIPS32 and microMIPS, the instruction stream is encoded as
16-bit halfwords, so the signature halfwords need to be swapped
accordingly for little-endian. */
#if defined (__nanomips__)
# ifdef __MIPSEL__
# define RSEQ_SIG 0x03500010
# else
# define RSEQ_SIG 0x00100350
# endif
#elif defined (__mips_micromips)
# ifdef __MIPSEL__
# define RSEQ_SIG 0xd4070000
# else
# define RSEQ_SIG 0x0000d407
# endif
#elif defined (__mips__)
# define RSEQ_SIG 0x0350000d
#else
/* Unknown MIPS architecture. */
#endif