Change all Unix systems to use stackt for the alternate signal
stack (some were using sigaltstackt). Add OS-specific setSignalstackSP
function to handle different types for ss_sp field, and unify all
OS-specific signalstack functions into one. Unify handling of alternate
signal stack in OS-specific minit and sigtrampgo functions via new
functions minitSignalstack and setGsignalStack.
Change-Id: Idc316dc69b1dd725717acdf61a1cd8b9f33ed174
Reviewed-on: https://go-review.googlesource.com/29757
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
We return memory to the kernel with madvise(..., DONTNEED).
Also mark returned memory with NOHUGEPAGE to keep the kernel from
merging this memory into a huge page, effectively reallocating it.
Only known to be a problem on linux/{386,amd64,amd64p32} at the moment.
It may come up on other os/arch combinations in the future.
Fixes#8832
Change-Id: Ifffc6627a0296926e3f189a8a9b6e4bdb54c79eb
Reviewed-on: https://go-review.googlesource.com/5660
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
