There appears to be a discrepancy among the implementations
of setcontext with regards to the function called once the last
linked-to context has finished executing via setcontext.
The POSIX standard says:
~~~
If the uc_link member of the ucontext_t structure pointed to by
the ucp argument is equal to 0, then this context is the main
context, and the thread will exit when this context returns.
~~~
It says "exit" not "exit immediately" nor "exit without running
functions registered with atexit or on_exit."
Therefore the AArch64, ARM, hppa and NIOS II implementations are
wrong and no test detects it.
It is questionable if this should even be fixed or just documented
that the above 4 targets are wrong. The functions are deprecated
and nobody should be using them, but at the same time it silly to
have cross-target differences that make it hard to port old
applications from say x86_64 to AArch64.
Therefore I will ix the 4 arches, and checkin a regression
test to prevent it from changing again.
https://sourceware.org/ml/libc-alpha/2015-03/msg00720.html
I've moved the ARM port from ports to the main sysdeps hierarchy.
Beyond the README update, the move of the files was simply
git mv ports/sysdeps/arm sysdeps/arm
git mv ports/sysdeps/unix/arm sysdeps/unix/arm
git mv ports/sysdeps/unix/sysv/linux/arm sysdeps/unix/sysv/linux/arm
and in addition to the ChangeLog entries here, I put a note at the top
of ports/ChangeLog.arm similar to that at the top of
ChangeLog.powerpc. There is deliberately no NEWS change, as I think
it makes the most sense to put in a general note above all ports
having moved if we can achieve that for 2.20.
Tested that disassembly of installed shared libraries for arm is the
same before and after this patch, except for data (not instructions)
in ld.so (there are assertions in sysdeps/arm/dl-machine.h, and the
path by which that file is found, and so by which it appears in the
assertion message, changes as a result of the move).
* sysdeps/arm: Move directory from ports/sysdeps/arm.
* sysdeps/unix/arm: Move directory from ports/sysdeps/unix/arm.
* sysdeps/unix/sysv/linux/arm: Move directory from
ports/sysdeps/unix/sysv/linux/arm.
* README: Update listing for arm-*-linux-gnueabi.
ports/ChangeLog.arm:
* sysdeps/arm: Move directory to ../sysdeps/arm.
* sysdeps/unix/arm: Move directory to ../sysdeps.arm.
* sysdeps/unix/sysv/linux/arm: Move directory to
../sysdeps/unix/sysv/linux/arm.
