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path: root/src/runtime/stubs_arm64.go
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2021-02-19runtime: convert windows/arm64 assemblyRuss Cox
The assembly is mostly a straightforward conversion of the equivalent arm assembly. This CL is part of a stack adding windows/arm64 support (#36439), intended to land in the Go 1.17 cycle. Change-Id: I61b15d712ade4d3a7285c7680de8e0987aacba10 Reviewed-on: https://go-review.googlesource.com/c/go/+/288828 Trust: Russ Cox <rsc@golang.org> Trust: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-02-19runtime: clean up system calls during cgo callback initRuss Cox
During a cgocallback, the runtime calls needm to get an m. The calls made during needm cannot themselves assume that there is an m or a g (which is attached to the m). In the old days of making direct system calls, the only thing you had to do for such functions was mark them //go:nosplit, to avoid the use of g in the stack split prologue. But now, on operating systems that make system calls through shared libraries and use code that saves state in the g or m before doing so, it's not safe to assume g exists. In fact, it is not even safe to call getg(), because it might fault deferencing the TLS storage to find the g pointer (that storage may not be initialized yet, at least on Windows, and perhaps on other systems in the future). The specific routines that are problematic are usleep and osyield, which are called during lock contention in lockextra, called from needm. All this is rather subtle and hidden, so in addition to fixing the problem on Windows, this CL makes the fact of not running on a g much clearer by introducing variants usleep_no_g and osyield_no_g whose names should make clear that there is no g. And then we can remove the various sketchy getg() == nil checks in the existing routines. As part of this cleanup, this CL also deletes onosstack on Windows. onosstack is from back when the runtime was implemented in C. It predates systemstack but does essentially the same thing. Instead of having two different copies of this code, we can use systemstack consistently. This way we need not port onosstack to each architecture. This CL is part of a stack adding windows/arm64 support (#36439), intended to land in the Go 1.17 cycle. This CL is, however, not windows/arm64-specific. It is cleanup meant to make the port (and future ports) easier. Change-Id: I3352de1fd0a3c26267c6e209063e6e86abd26187 Reviewed-on: https://go-review.googlesource.com/c/go/+/288793 Trust: Russ Cox <rsc@golang.org> Trust: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
2019-10-25runtime: define emptyfunc as static function in assembly for freebsd/arm64Tobias Klauser
CL 198544 broke the linux/arm64 build because it declares emptyfunc for GOARCH=arm64, but only freebsd/arm64 defines it. Make it a static assembly function specific for freebsd/arm64 and remove the stub. Fixes #35160 Change-Id: I5fd94249b60c6fd259c251407b6eccc8fa512934 Reviewed-on: https://go-review.googlesource.com/c/go/+/203418 Reviewed-by: Bryan C. Mills <bcmills@google.com>
2019-10-25runtime: add support for freebsd/arm64Tobias Klauser
Based on work by Mikaël Urankar (@MikaelUrankar), Shigeru YAMAMOTO (@bsd-hacker) and @myfreeweb. Updates #24715 Change-Id: If3189a693ca0aa627029e22b0f91534bcf322bc0 Reviewed-on: https://go-review.googlesource.com/c/go/+/198544 Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-05-09runtime: fix vet complaints for linux/arm64, linux/mips*, linux/ppc64*, ↵Russ Cox
linux/s390x Working toward making the tree vet-safe instead of having so many exceptions in cmd/vet/all/whitelist. This CL makes "go vet -unsafeptr=false runtime" happy for these GOOS/GOARCHes, except for an unresolved complaint on mips/mipsle that is a bug in vet, while keeping "GO_BUILDER_NAME=misc-vetall go tool dist test" happy too. For #31916. Change-Id: I6ef7e982a2fdbbfbc22cee876ca37ac54d8109e5 Reviewed-on: https://go-review.googlesource.com/c/go/+/176102 Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Austin Clements <austin@google.com>