52ee0dd6d5ccefcbf9b55748896c85801bfafd17
the previous commit addressing async-signal-safety issues around pthread_kill did not fully fix pthread_cancel, which is also required (albeit rather irrationally) to be async-cancel-safe. without blocking implementation-internal signals, it's possible that, when async cancellation is enabled, a cancel signal sent by another thread interrupts pthread_kill while the killlock for a targeted thread is held. as a result, the calling thread will terminate due to cancellation without ever unlocking the targeted thread's killlock, and thus the targeted thread will be unable to exit.
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/