freebsd-dev/lib/libc/arm/aeabi/aeabi_int_div.S
Michal Meloun cd9bdb7362 Publish __aeabi_uidiv and __aeabi_idiv as compatible symbols from libc.
Due to bug[1] in libcompiler_rt, all symbols declared by
DEFINE_AEABI_FUNCTION_ALIAS() are not hidden. All these but two
are explicitly exported from libc and don't causes problems.

Remaining two, __aeabi_uidiv and __aeabi_idiv, infecting all
non-versioned shared libraries. And these symbols are consumed
by many (if not all) packages[2].

As workaround, export these from libc as compatible symbols,
in global namespace. With this, these are still visible for
rtld, but static linker doesn't use then.

[1]
DEFINE_AEABI_FUNCTION_ALIAS() macro uses '.set' directive for
declaration of aliased symbol. Unfortunately, '.set' doesn't
inherit visibility of base symbol, and macro don't explicitly
sets visibility for aliased one.

[2]
Given symbols are exported from non-versioned libraries only if
library itself uses them. So, if world is built for CPU with
HW divide, these function are not used and given symbols are
not exported. By this, contents of these libraries is not stable,
and all packages fails to run.

Note: Due to r313823 I'm forced to commit this too early, without
leave enough time for proper review.

MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D9632
2017-02-17 11:16:19 +00:00

52 lines
2.0 KiB
ArmAsm

/*
* Copyright (C) 2017 Michal Meloun
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <machine/asm.h>
__FBSDID("$FreeBSD$");
/*
* Due to bug in libcompiler_rt, all symbols declared by
* DEFINE_AEABI_FUNCTION_ALIAS() are not hidden. All these but
* __aeabi_uidiv_compat and/or __aeabi_idiv_compat are explicitly
* exported from libc and don't causes problems.
*
* As workaround, export these from libc as compatible symbols,
* in global namespace
*/
ENTRY(__aeabi_uidiv_compat)
.symver __aeabi_uidiv_compat, __aeabi_uidiv@
b __udivsi3
END(__aeabi_uidiv_compat)
ENTRY(__aeabi_idiv_compat)
.symver __aeabi_idiv_compat, __aeabi_idiv@
b __divsi3
END(__aeabi_idiv_compat)
.section .note.GNU-stack,"",%progbits