src-test/lib/libc/powerpc64/gen, branch main

[POWERPC] Fix ppc64 makecontext() parameter overflow handling.

2020-08-06T17:49:19Z

On ELFv2, the overflow parameters in the stack frame are at a different offset from sp than ELFv1. Adjust code to use the correct offset in all cases. This had resulted in argv[8] and up being copied to the incorrect address in the new context's initial stack frame. This is not necessarily the only bug in this function, I need to do a full review still and ensure the rest of the math is sane for ELFv2 stack frames. Reported by: pherde (Probably. My notes are a bit unclear.) Reviewed by: jhibbits (in irc) Sponsored by: Tag1 Consulting, Inc.

[PowerPC] Fix *context on ELFv2

2019-11-16T20:33:46Z

Due to ELFv1 specific code in _ctx_start.S and makecontext.c, userspace context switching was completely broken on ELFv2. With this change, we now pass the libthr test suite. Approved by: jhibbits (mentor) Differential Revision: https://reviews.freebsd.org/D22421

Remove bogus checks against NCARGS.

2018-01-31T17:57:59Z

NCARGS isn't a limit on the number of arguments to pass to a function, but the number of bytes that can be consumed by arguments to exec. As such, it is not suitable for a limit on the count of arguments passed to makecontext(). Sponsored by: DARPA / AFRL

libc: further adoption of SPDX licensing ID tags.

2017-11-25T17:12:48Z

Mainly focus on files that use BSD 2-Clause license, however the tool I was using mis-identified many licenses so this was mostly a manual - error prone - task. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts.

libc: make some more use of the nitems() macro.

2016-04-16T17:52:00Z

We have an nitems() macro in the header that is convenient to re-use as it makes things easier to read. Given that it is available already without adding additional headers and other parts of libc already use it, extend a bit more its use.

Make unions in PowerPC libc endian-safe.

2016-02-26T20:38:23Z

Add include for declaration of _set_tp(). Eliminates -Wmissing-prototypes warnings.

2015-09-20T04:59:01Z

Save and restore non-volatile floating-point registers during longjmp().

2015-03-08T19:37:08Z

This should also save and restore non-volatile Altivec registers, but that needs to wait on solving two problems: 1. Adding the nonvolatile vector registers means we need 5 more than _JBLEN entries in jmp_buf on 32-bit targets (64-bit is OK). 2. Need to figure out how to determine if saving/restoring vector regs is supported on the current CPU from userland. MFC after: 1 month

Remove duplicate copies of trivial getcontextx.c

2015-01-12T18:13:38Z

Only i386 and amd64 provide a non-trivial __getcontextx(). Use a common trivial implementation in gen/ for other architectures, rather than copying the file to each MD subdirectory. Reviewed by: kib Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D1472

Avoid use of register variables. Clang 3.5 treats this as undefined behavior,

2015-01-06T03:50:43Z

and bad things happen. MFC after: 1 week