musl - an implementation of the standard library for Linux-based systems
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Rich Felker a01ff71f7c in membarrier fallback, allow for possibility that sigaction fails
this is a workaround to avoid a crashing regression on qemu-user when
dynamic TLS is installed at dlopen time. the sigaction syscall should
not be able to fail, but it does fail for implementation-internal
signals under qemu user-level emulation if the host libc qemu is
running under reserves the same signals for implementation-internal
use, since qemu makes no provision to redirect/emulate them. after
sigaction fails, the subsequent tkill would terminate the process
abnormally as the default action.

no provision to account for membarrier failing is made in the dynamic
linker code that installs new TLS. at the formal level, the missing
barrier in this case is incorrect, and perhaps we should fail the
dlopen operation, but in practice all the archs we support (and
probably all real-world archs except alpha, which isn't yet supported)
should give the right behavior with no barrier at all as a consequence
of consume-order properties.

in the long term, this workaround should be supplemented or replaced
by something better -- a different fallback approach to ensuring
memory consistency, or dynamic allocation of implementation-internal
signals. the latter is appealing in that it would allow cancellation
to work under qemu-user too, and would even allow many levels of
nested emulation.
2019-04-09 17:51:54 -04:00
arch aarch64: add HWCAP_ definitions from linux v5.0 2019-03-13 12:35:02 -04:00
crt define and use internal macros for hidden visibility, weak refs 2018-09-05 14:05:14 -04:00
dist add another example option to dist/config.mak 2012-04-24 16:49:11 -04:00
include fix signature of function accepted by makecontext 2019-04-05 17:29:00 -04:00
ldso fix the use of syscall result in dl_mmap 2019-04-06 09:38:49 -04:00
src in membarrier fallback, allow for possibility that sigaction fails 2019-04-09 17:51:54 -04:00
tools fix musl-gcc wrapper to be compatible with default-pie gcc toolchains 2018-08-02 19:15:48 -04:00
.gitignore remove obsolete gitignore rules 2016-07-06 00:21:25 -04:00
configure configure: accept ppc[64] as alias for powerpc[64] in gcc tuples 2019-01-19 18:39:54 -05:00
COPYRIGHT new tsearch implementation 2018-09-20 17:57:47 -04:00
dynamic.list fix regression in access to optopt object 2018-11-19 13:20:41 -05:00
INSTALL add powerpc64 and s390x to list of supported archs in INSTALL file 2017-08-29 20:48:02 -04:00
Makefile overhaul internally-public declarations using wrapper headers 2018-09-12 14:34:33 -04:00
README update version reference in the README file 2014-06-25 14:16:53 -04:00
VERSION release 1.1.21 2019-01-21 12:30:47 -05:00
WHATSNEW release 1.1.21 2019-01-21 12:30:47 -05:00

    musl libc

musl, pronounced like the word "mussel", is an MIT-licensed
implementation of the standard C library targetting the Linux syscall
API, suitable for use in a wide range of deployment environments. musl
offers efficient static and dynamic linking support, lightweight code
and low runtime overhead, strong fail-safe guarantees under correct
usage, and correctness in the sense of standards conformance and
safety. musl is built on the principle that these goals are best
achieved through simple code that is easy to understand and maintain.

The 1.1 release series for musl features coverage for all interfaces
defined in ISO C99 and POSIX 2008 base, along with a number of
non-standardized interfaces for compatibility with Linux, BSD, and
glibc functionality.

For basic installation instructions, see the included INSTALL file.
Information on full musl-targeted compiler toolchains, system
bootstrapping, and Linux distributions built on musl can be found on
the project website:

    http://www.musl-libc.org/