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2025-08-21runtime: remove remaining windows/arm files and commentsqmuntal
CL 648795 deleted most of windows/arm code, but some files escaped from the purge. This CL finishes the job. For #71671 Change-Id: Id454c40a673a1a2a9f190d79248e6d56104cdd61 Reviewed-on: https://go-review.googlesource.com/c/go/+/698036 Reviewed-by: qiu laidongfeng <2645477756@qq.com> Reviewed-by: Carlos Amedee <carlos@golang.org> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
2025-07-28internal/runtime/syscall/windows: factor out code from runtimeqmuntal
Factor out the code related to doing calls using the Windows stdcall calling convention into a separate package. This will allow us to reuse it in other low-level packages that can't depend on syscall. Updates #51087. Cq-Include-Trybots: luci.golang.try:gotip-windows-arm64,gotip-windows-amd64-longtest,gotip-solaris-amd64 Change-Id: I68640b07091183b50da6bef17406c10a397896e9 Reviewed-on: https://go-review.googlesource.com/c/go/+/689156 Reviewed-by: Michael Pratt <mpratt@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2024-08-22runtime: fix nanotime1 on windows/armqmuntal
nanotime1 is broken on windows/arm since CL 526358, which unintentionally removed a necessary instruction. It hasn't been noticed till now because the there is no windows/arm builder. This CL restores the instruction. Fixes #68996. Change-Id: I52ef6891a3bd8e608b8538f456d181e08f93efaa Reviewed-on: https://go-review.googlesource.com/c/go/+/607776 Reviewed-by: Cherry Mui <cherryyz@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Ian Lance Taylor <iant@google.com>
2023-09-21runtime: implement usleep in Go instead of assembly on Windowsqmuntal
Windows APIs are normally not arch-specific, so it's better to implement them in Go instead of assembly. It was previously implemented in assembly because it was the only way to support calls without a valid g. This CL defines a new function, stdcall_no_g, that can be used in such cases. While here, I've also replaced the use of the deprecated syscall NtWaitForSingleObject with WaitForSingleObject. The former may give the illusion of being more accurate, as it takes a higher resolution timeout, but it's not. Windows time resolution is 15.6ms, and can be as high as 1ms when using a high resolution timer, which WaitForSingleObject supports. Change-Id: I903400220ade4d4ccc15685c8da47182430f8686 Reviewed-on: https://go-review.googlesource.com/c/go/+/526477 Reviewed-by: Bryan Mills <bcmills@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Alex Brainman <alex.brainman@gmail.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
2023-09-20runtime: implement osyield in Go instead of assembly on Windowsqmuntal
Windows APIs are normally not arch-specific, so it's better to implement them in Go instead of assembly. It was previously implemented in assembly because it was the only way to support calls without a valid g. This CL defines a new function, stdcall_no_g, that can be used in such cases. Change-Id: I26a223b918c6c462b06ac256bdacf9ddb78752bc Reviewed-on: https://go-review.googlesource.com/c/go/+/526476 TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Alex Brainman <alex.brainman@gmail.com> Run-TryBot: Quim Muntal <quimmuntal@gmail.com> Reviewed-by: Bryan Mills <bcmills@google.com>
2023-09-07runtime: remove slow time compatibility hacks for wineqmuntal
This reapplies CL 191759, which was reverted in CL 192622. Wine fixed the compatibility issue more than 3 years ago, in version 5.10 (see [1]). We no longer have to keep the compatibility hack on our side. Updates #34021 [1]: https://github.com/wine-mirror/wine/commit/1ae10889647c1c84c36660749508a42e99e64a5e Change-Id: I3b77701d01fdf58fbf350321fc0a957c0f247d32 Reviewed-on: https://go-review.googlesource.com/c/go/+/526358 Reviewed-by: Daniel Martí <mvdan@mvdan.cc> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Bryan Mills <bcmills@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Quim Muntal <quimmuntal@gmail.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2023-03-13runtime: implement high resolution timer on windows arm/arm64qmuntal
This CL moves the usleep2HighRes from assembly to good old Go. This is safe because since CL 288793 usleep is always called with a g, else one wold have to call usleep_no_g. This condition was not enforced when high resolution timers were first implemented on Windows (CL 248699), so the implementation was done in assembly. Other than removing a bunch of obscure assembly code, this CL makes high resolution timers work on windows arm/arm64 by free, as the system calls are the same in all windows platforms. Change-Id: I41ecf78026fd7e11e85258a411ae074a77e8c7fc Reviewed-on: https://go-review.googlesource.com/c/go/+/471142 TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Alex Brainman <alex.brainman@gmail.com> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Bryan Mills <bcmills@google.com> Auto-Submit: Michael Pratt <mpratt@google.com> Run-TryBot: Quim Muntal <quimmuntal@gmail.com>
2023-03-01runtime: remove unnecessary NOFRAME flags on windowsqmuntal
This CL removes some NOFRAME flags on Windows assembly files for several reasons: - windows/386 does not use a frame pointer - Leaf frameless functions already skip the frame pointer - Some non-leaf functions do not contain enough dragons to justify not using the frame pointer Updates #58378 Change-Id: I31e71bf7f769e1957a4adba91778da5af66ce1e4 Reviewed-on: https://go-review.googlesource.com/c/go/+/466835 Reviewed-by: Keith Randall <khr@golang.org> Reviewed-by: Keith Randall <khr@google.com> Run-TryBot: Quim Muntal <quimmuntal@gmail.com> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-01-25runtime: delete unused cbctxts variable on windows assemblyqmuntal
runtime·cbctxts has been unused since CL 258938, but it was left over. Change-Id: I374ad26e668a36994e41f5d17593b33090bdc644 Reviewed-on: https://go-review.googlesource.com/c/go/+/463119 TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Bryan Mills <bcmills@google.com> Run-TryBot: Quim Muntal <quimmuntal@gmail.com> Reviewed-by: Cherry Mui <cherryyz@google.com>
2023-01-24runtime: remove unused badsignal2 on windowsqmuntal
This CL removes badsignal2 function, as it is unused on Windows. badsignal2 was originally intended to abort the process when an exception was raised on a non-Go thread, following the same approach as Linux and others. Since it was added, back on https://golang.org/cl/5797068, it has caused several issues on Windows, see #8224 and #50877. That's because we can't know wether the signal is bad or not, as our trap might not be at the end of the exception handler chain. To fix those issues, https://golang.org/cl/104200046 and CL 442896 stopped calling badsignal2, and CL 458135 removed one last incorrect call on amd64 and 386. Change-Id: I5bd31ee2672118ae0f1a2c8b46a1bb0f4893a011 Reviewed-on: https://go-review.googlesource.com/c/go/+/463116 Reviewed-by: Bryan Mills <bcmills@google.com> Run-TryBot: Quim Muntal <quimmuntal@gmail.com> Reviewed-by: Alex Brainman <alex.brainman@gmail.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-01-24runtime: factor out windows sigtrampqmuntal
This CL factors out part of the Windows sigtramp implementation, which was duplicated in all four architectures. The new common code is implemented in Go rather than in assembly, which will make Windows error handling easier to reason and maintain. While here, implement the control flow guard workaround on windows/386, which almost comes for free. Change-Id: I0bf38c28c54793225126e161bd95527a62de05e0 Reviewed-on: https://go-review.googlesource.com/c/go/+/458135 Run-TryBot: Quim Muntal <quimmuntal@gmail.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Alex Brainman <alex.brainman@gmail.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Bryan Mills <bcmills@google.com> Reviewed-by: Michael Pratt <mpratt@google.com>
2022-10-19runtime: ignore exceptions from non-Go threads on windows arm/arm64qmuntal
If there is no current G while handling an exception it means the exception was originated in a non-Go thread. The best we can do is ignore the exception and let it flow through other vectored and structured error handlers. I've removed badsignal2 from sigtramp because we can't really know if the signal is bad or not, it might be handled later in the chain. Fixes #50877 Updates #56082 Change-Id: Ica159eb843629986d1fb5482f0b59a9c1ed91698 Reviewed-on: https://go-review.googlesource.com/c/go/+/442896 Reviewed-by: Alex Brainman <alex.brainman@gmail.com> Auto-Submit: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com> Run-TryBot: Quim Muntal <quimmuntal@gmail.com> Reviewed-by: David Chase <drchase@google.com>
2022-05-18all: fix spellingJohn Bampton
Change-Id: I63eb42f3ce5ca452279120a5b33518f4ce16be45 GitHub-Last-Rev: a88f2f72bef402344582ae997a4907457002b5df GitHub-Pull-Request: golang/go#52951 Reviewed-on: https://go-review.googlesource.com/c/go/+/406843 Run-TryBot: Robert Griesemer <gri@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Ian Lance Taylor <iant@google.com> Reviewed-by: Ian Lance Taylor <iant@google.com> Reviewed-by: Robert Griesemer <gri@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com>
2021-11-03runtime: on windows, read nanotime with one instruction or issue barrierJason A. Donenfeld
On 64-bit, this is more efficient, and on ARM64, this prevents the time from moving backwards due to the weaker memory model. On ARM32 due to the weaker memory model, we issue a memory barrier. Updates #48072. Change-Id: If4695716c3039d8af14e14808af217f5c99fc93a Reviewed-on: https://go-review.googlesource.com/c/go/+/361057 Trust: Jason A. Donenfeld <Jason@zx2c4.com> Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2021-05-21[dev.typeparams] runtime: use internal/abi.FuncPCABI0 to take address of ↵Cherry Mui
assembly functions There are a few assembly functions in the runtime that are marked as ABIInternal, solely because funcPC can get the right address. The functions themselves do not actually follow ABIInternal (or irrelevant). Now we have internal/abi.FuncPCABI0, use that, and un-mark the functions. Also un-mark assembly functions that are only called in assembly. For them, it only matters if the caller and callee are consistent. Change-Id: I240e126ac13cb362f61ff8482057ee9f53c24097 Reviewed-on: https://go-review.googlesource.com/c/go/+/321950 Trust: Cherry Mui <cherryyz@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-05-04runtime: abort when receiving a signal on a non-Go thread on WindowsMichael Anthony Knyszek
Currently if a signal lands on a non-Go thread that's handled by the Go handler, Go will emit a message. However, unlike everywhere else in the runtime, Go will not abort the process after, and the signal handler will try to continue executing. This leads to cascading failures and possibly even memory corruption. For #45638. Change-Id: I546f4e82f339d555bed295528d819ac883b92bc6 Reviewed-on: https://go-review.googlesource.com/c/go/+/316809 Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Michael Knyszek <mknyszek@google.com> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-04-28runtime: move Windows time.now implementations into separate filesIan Lance Taylor
This is a step toward separating whether time.now is implemented in assembly from whether we are using faketime. Change-Id: I8bf059b44a103b034835e3d3b799319cc05e9552 Reviewed-on: https://go-review.googlesource.com/c/go/+/314273 Trust: Ian Lance Taylor <iant@golang.org> Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-04-28runtime: consolidate Windows time constants into single copyIan Lance Taylor
Change-Id: I1a583d3da9cca4ac51f3fec9b508b7638b452d60 Reviewed-on: https://go-review.googlesource.com/c/go/+/314270 Trust: Ian Lance Taylor <iant@golang.org> Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-04-23runtime: add windows/arm64 cgo-linking codeRuss Cox
This code is needed for use with cgo proper (as opposed to hand-written DLL calls, which we always use but only exercise cgo execution, not cgo linking). Change-Id: Iddc31d9c1c924d83d032b80dca65ddfda6624046 Reviewed-on: https://go-review.googlesource.com/c/go/+/312041 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-04-13runtime: eliminate externalthreadhandlerAustin Clements
This function is no longer used. Eliminating this actually fixes several problems: - It made assumptions about what registers memclrNoHeapPointers would preserve. Besides being an abstraction violation and lurking maintenance issue, this actively became a problem for regabi because the call to memclrNoHeapPointers now happens through an ABI wrapper, which is generated by the compiler and hence we can't easily control what registers it clobbers. - The amd64 implementation (at least), does not interact with the host ABI correctly. Notably, it doesn't save many of the registers that are callee-save in the host ABI but caller-save in the Go ABI. - It interacts strangely with the NOSPLIT checker because it allocates an entire M and G on its stack. It worked around this on arm64, and happened to do things the NOSPLIT checker couldn't track on 386 and amd64, and happened to be *4 bytes* below the limit on arm (so any addition to the m or g structs would cause a NOSPLIT failure). See CL 309031 for a more complete explanation. Fixes #45530. Updates #40724. Change-Id: Ic70d4d7e1c17f1d796575b3377b8529449e93576 Reviewed-on: https://go-review.googlesource.com/c/go/+/309634 Trust: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-04-13runtime: use newm for profileloopAustin Clements
This replaces the externalthreadhandler-based implementation of profileloop with one that uses newm to start a new thread. This is a step toward eliminating externalthreadhandler. For #45530. Change-Id: Id8e5540423fe2d2004024b649afec6998f77b092 Reviewed-on: https://go-review.googlesource.com/c/go/+/309633 Trust: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-04-13runtime: use compileCallback for ctrlhandlerAustin Clements
This replaces the externalthreadhandler-based implementation of ctrlhandler with one based on compileCallback. This is a step toward eliminating externalthreadhandler. For #45530. Change-Id: I2de2f2f37777af292db67ccf8057b7566aab81f8 Reviewed-on: https://go-review.googlesource.com/c/go/+/309632 Trust: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-04-12runtime: replace outdated documentation link in Windows' nanotimePaschalis Tsilias
Fixes #45498 Change-Id: I89365f3517bc84376f0f580c64a57f38aaba0cbb Reviewed-on: https://go-review.googlesource.com/c/go/+/308997 Reviewed-by: Ian Lance Taylor <iant@golang.org> Trust: Alex Brainman <alex.brainman@gmail.com>
2021-03-29runtime: fix some typos徐志伟
Change-Id: I31f2081eb7c30a9583f479f9194e636fe721b9b3 GitHub-Last-Rev: d09f5fbdc5785dc3963b22ad75309740e0de258e GitHub-Pull-Request: golang/go#45278 Reviewed-on: https://go-review.googlesource.com/c/go/+/305231 Reviewed-by: Emmanuel Odeke <emmanuel@orijtech.com> Reviewed-by: Ian Lance Taylor <iant@golang.org> Run-TryBot: Emmanuel Odeke <emmanuel@orijtech.com> TryBot-Result: Go Bot <gobot@golang.org>
2021-03-19runtime: mark Windows' address-taken asm routines as ABIInternalMichael Anthony Knyszek
In the runtime there are Windows-specific assembly routines that are address-taken via funcPC and are not intended to be called through a wrapper. Mark them as ABIInternal so that we don't grab the wrapper, because that will break in all sorts of contexts. For #40724. For #44065. Change-Id: I12a728786786f423e5b229f8622e4a80ec27a31c Reviewed-on: https://go-review.googlesource.com/c/go/+/302109 Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Michael Knyszek <mknyszek@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-02-23runtime: fix usleep on windows/armRuss Cox
Changed calling convention to pre-multiply the argument by -100, and then deleted the * 100 but not the negation in the windows/arm assembly. Delete the negation. Fixes the current all.bash breakage on windows/arm builder. (Maybe that will uncover more.) Change-Id: I13006a44866ecc007586deb180a49c038d70aa99 Reviewed-on: https://go-review.googlesource.com/c/go/+/295529 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-02-23runtime: fix windows/arm signal handling assemblyRuss Cox
Bug introduced in CL 288799: R12 is used but not set. Fixes windows/arm builder. Change-Id: I015a5a83cfa3bdd23da1ffb73713623764f2f817 Reviewed-on: https://go-review.googlesource.com/c/go/+/295109 Trust: Russ Cox <rsc@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
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: fix windows/arm externalthreadhandlerRuss Cox
Externalthreadhandler was not handling its own stack correctly. It incorrectly referred to the saved LR slot (uninitialized, it turned out) as holding the return value from the called function. Externalthreadhandler is used to call two different functions: profileloop1 and ctrlhandler1. Profileloop1 does not return, so no harm done. Ctrlhandler1 returns a boolean indicating whether the handler took care of the control event (if true, no other handlers run). It's hard to say exactly what uninitialized values are likely to have been returned instead of ctrlhandler1's result, but it probably wasn't helping matters. Change-Id: Ia02f1c033df618cb82c2193b3a8241ed048a8b18 Reviewed-on: https://go-review.googlesource.com/c/go/+/288812 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>
2021-02-19runtime: fix time on windows/arm under WINERuss Cox
This code has clearly never run successfully, since one of the “tail calls" calls the wrong function, and both of them appear in functions with stack frames that are never going to be properly unwound. Probably there is no windows/arm under WINE at all. But might as well fix the code. Change-Id: I5fa62274b3661bc6bce098657b5bcf11d59655eb Reviewed-on: https://go-review.googlesource.com/c/go/+/288811 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>
2021-02-19runtime: find g in Windows profiler using SPRuss Cox
The architecture-specific interpretation of m->tls[0] is unnecessary and fragile. Delete it. 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: I927345e52fa2f1741d4914478a29d1fb8acb0dc3 Reviewed-on: https://go-review.googlesource.com/c/go/+/288806 Trust: Russ Cox <rsc@golang.org> Trust: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-02-19runtime: use TOPFRAME to identify top-of-frame functionsRuss Cox
No change to actual runtime, but helps reduce the laundry list of functions. mcall, morestack, and asmcgocall are not actually top-of-frame, so those need more attention in follow-up CLs. mstart moved to assembly so that it can be marked TOPFRAME. Since TOPFRAME also tells DWARF consumers not to unwind this way, this change should also improve debuggers a marginal amount. 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: If1e0d46ca973de5e46b62948d076f675f285b5d9 Reviewed-on: https://go-review.googlesource.com/c/go/+/288802 Trust: Russ Cox <rsc@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-02-19runtime: unify asmcgocall and systemstack traceback setupRuss Cox
Both asmcgocall and systemstack need to save the calling Go code's context for use by traceback, but they do it differently. Systemstack's appraoch is better, because it doesn't require a special case in traceback. So make them both use that. While we are here, the fake mstart caller in systemstack is no longer needed and can be removed. (traceback knows to stop in systemstack because of the writes to SP.) Also remove the fake mstarts in sys_windows_*.s. And while we are there, fix the control flow guard code in sys_windows_arm.s. The current code is using pointers to a stack frame that technically is gone once we hit the RET instruction. Clearly it's working OK, but better not to depend on data below SP being preserved, even for just a few instructions. Store the value we need in other registers instead. (This code is only used for pushing a sigpanic call, which does not actually return to the site of the fault and therefore doesn't need to preserve any of the registers.) 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: Id1e3ef5e54f7ad786e4b87043f2626eba7c3bbd9 Reviewed-on: https://go-review.googlesource.com/c/go/+/288799 Trust: Russ Cox <rsc@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2021-02-19runtime: delete windows setlasterror (unused)Russ Cox
This is dead code and need not be ported 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: I2d0072b377f73e49d7158ea304670c26f5486c59 Reviewed-on: https://go-review.googlesource.com/c/go/+/288794 Trust: Russ Cox <rsc@golang.org> Trust: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Alex Brainman <alex.brainman@gmail.com> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.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>
2020-11-19runtime: support new callbackasm1 calling convention on windows/armJason A. Donenfeld
This updates the callbacks implementation on windows/arm for the changes made in CL 258938. At the time, that was left as a TODO. At the same time, it also extends the previous support for only 4 arguments to also support additional arguments on the stack. This is required for functions like SetWinEventHook, which take 7 arguments. It does this by pushing r0-r3 onto the stack before the normal prologue, and then pointing the args struct to that location. This is derived from CL 270077 and CL 270078. Updates #40724. Fixes #42591. Change-Id: Icc199e7f2c24205e41be4e00015283c7e2a9b797 Reviewed-on: https://go-review.googlesource.com/c/go/+/271178 Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com> Trust: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Austin Clements <austin@google.com>
2020-10-26runtime,cmd/cgo: simplify C -> Go call pathAustin Clements
This redesigns the way calls work from C to exported Go functions. It removes several steps from the call path, makes cmd/cgo no longer sensitive to the Go calling convention, and eliminates the use of reflectcall from cgo. In order to avoid generating a large amount of FFI glue between the C and Go ABIs, the cgo tool has long depended on generating a C function that marshals the arguments into a struct, and then the actual ABI switch happens in functions with fixed signatures that simply take a pointer to this struct. In a way, this CL simply pushes this idea further. Currently, the cgo tool generates this argument struct in the exact layout of the Go stack frame and depends on reflectcall to unpack it into the appropriate Go call (even though it's actually reflectcall'ing a function generated by cgo). In this CL, we decouple this struct from the Go stack layout. Instead, cgo generates a Go function that takes the struct, unpacks it, and calls the exported function. Since this generated function has a generic signature (like the rest of the call path), we don't need reflectcall and can instead depend on the Go compiler itself to implement the call to the exported Go function. One complication is that syscall.NewCallback on Windows, which converts a Go function into a C function pointer, depends on cgocallback's current dynamic calling approach since the signatures of the callbacks aren't known statically. For this specific case, we continue to depend on reflectcall. Really, the current approach makes some overly simplistic assumptions about translating the C ABI to the Go ABI. Now we're at least in a much better position to do a proper ABI translation. For comparison, the current cgo call path looks like: GoF (generated C function) -> crosscall2 (in cgo/asm_*.s) -> _cgoexp_GoF (generated Go function) -> cgocallback (in asm_*.s) -> cgocallback_gofunc (in asm_*.s) -> cgocallbackg (in cgocall.go) -> cgocallbackg1 (in cgocall.go) -> reflectcall (in asm_*.s) -> _cgoexpwrap_GoF (generated Go function) -> p.GoF Now the call path looks like: GoF (generated C function) -> crosscall2 (in cgo/asm_*.s) -> cgocallback (in asm_*.s) -> cgocallbackg (in cgocall.go) -> cgocallbackg1 (in cgocall.go) -> _cgoexp_GoF (generated Go function) -> p.GoF Notably: 1. We combine _cgoexp_GoF and _cgoexpwrap_GoF and move the combined operation to the end of the sequence. This combined function also handles reflectcall's previous role. 2. We combined cgocallback and cgocallback_gofunc since the only purpose of having both was to convert a raw PC into a Go function value. We instead construct the Go function value in cgocallbackg1. 3. cgocallbackg1 no longer reaches backwards through the stack to get the arguments to cgocallback_gofunc. Instead, we just pass the arguments down. 4. Currently, we need an explicit msanwrite to mark the results struct as written because reflectcall doesn't do this. Now, the results are written by regular Go assignments, so the Go compiler generates the necessary MSAN annotations. This also means we no longer need to track the size of the arguments frame. Updates #40724, since now we don't need to teach cgo about the register ABI or change how it uses reflectcall. Change-Id: I7840489a2597962aeb670e0c1798a16a7359c94f Reviewed-on: https://go-review.googlesource.com/c/go/+/258938 Trust: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-10-18runtime: use CreateWaitableTimerEx to implement usleepAlex Brainman
@jstarks suggested that recent versions of Windows provide access to high resolution timers. See https://github.com/golang/go/issues/8687#issuecomment-656259353 for details. I tried to run this C program on my Windows 10 computer ``` #include <stdio.h> #include <Windows.h> #pragma comment(lib, "Winmm.lib") // Apparently this is already defined when I use msvc cl. //#define CREATE_WAITABLE_TIMER_HIGH_RESOLUTION = 0x00000002; int usleep(HANDLE timer, LONGLONG d) { LARGE_INTEGER liDueTime; DWORD ret; LARGE_INTEGER StartingTime, EndingTime, ElapsedMicroseconds; LARGE_INTEGER Frequency; QueryPerformanceFrequency(&Frequency); QueryPerformanceCounter(&StartingTime); liDueTime.QuadPart = d; liDueTime.QuadPart = liDueTime.QuadPart * 10; // us into 100 of ns units liDueTime.QuadPart = -liDueTime.QuadPart; // negative for relative dure time if (!SetWaitableTimer(timer, &liDueTime, 0, NULL, NULL, 0)) { printf("SetWaitableTimer failed: errno=%d\n", GetLastError()); return 1; } ret = WaitForSingleObject(timer, INFINITE); if (ret != WAIT_OBJECT_0) { printf("WaitForSingleObject failed: ret=%d errno=%d\n", ret, GetLastError()); return 1; } QueryPerformanceCounter(&EndingTime); ElapsedMicroseconds.QuadPart = EndingTime.QuadPart - StartingTime.QuadPart; ElapsedMicroseconds.QuadPart *= 1000000; ElapsedMicroseconds.QuadPart /= Frequency.QuadPart; printf("delay is %lld us - slept for %lld us\n", d, ElapsedMicroseconds.QuadPart); return 0; } int testTimer(DWORD createFlag) { HANDLE timer; timer = CreateWaitableTimerEx(NULL, NULL, createFlag, TIMER_ALL_ACCESS); if (timer == NULL) { printf("CreateWaitableTimerEx failed: errno=%d\n", GetLastError()); return 1; } usleep(timer, 1000LL); usleep(timer, 100LL); usleep(timer, 10LL); usleep(timer, 1LL); CloseHandle(timer); return 0; } int main() { printf("\n1. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is off - timeBeginPeriod is off\n"); testTimer(0); printf("\n2. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is on - timeBeginPeriod is off\n"); testTimer(CREATE_WAITABLE_TIMER_HIGH_RESOLUTION); timeBeginPeriod(1); printf("\n3. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is off - timeBeginPeriod is on\n"); testTimer(0); printf("\n4. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is on - timeBeginPeriod is on\n"); testTimer(CREATE_WAITABLE_TIMER_HIGH_RESOLUTION); } ``` and I see this output ``` 1. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is off - timeBeginPeriod is off delay is 1000 us - slept for 4045 us delay is 100 us - slept for 3915 us delay is 10 us - slept for 3291 us delay is 1 us - slept for 2234 us 2. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is on - timeBeginPeriod is off delay is 1000 us - slept for 1076 us delay is 100 us - slept for 569 us delay is 10 us - slept for 585 us delay is 1 us - slept for 17 us 3. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is off - timeBeginPeriod is on delay is 1000 us - slept for 742 us delay is 100 us - slept for 893 us delay is 10 us - slept for 414 us delay is 1 us - slept for 920 us 4. CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is on - timeBeginPeriod is on delay is 1000 us - slept for 1466 us delay is 100 us - slept for 559 us delay is 10 us - slept for 535 us delay is 1 us - slept for 5 us ``` That shows, that indeed using CREATE_WAITABLE_TIMER_HIGH_RESOLUTION will provide sleeps as low as about 500 microseconds, while our current approach provides about 1 millisecond sleep. New approach also does not require for timeBeginPeriod to be on, so this change solves long standing problem with go programs draining laptop battery, because it calls timeBeginPeriod. This change will only run on systems where CREATE_WAITABLE_TIMER_HIGH_RESOLUTION flag is available. If not available, the runtime will fallback to original code that uses timeBeginPeriod. This is how this change affects benchmark reported in issue #14790 name               old time/op  new time/op  delta ChanToSyscallPing  1.05ms ± 2%  0.68ms ±11%  -35.43%  (p=0.000 n=10+10) The benchmark was run with GOMAXPROCS set to 1. Fixes #8687 Updates #14790 Change-Id: I5b97ba58289c088c17c05292e12e45285c467eae Reviewed-on: https://go-review.googlesource.com/c/go/+/248699 Run-TryBot: Alex Brainman <alex.brainman@gmail.com> TryBot-Result: Go Bot <gobot@golang.org> Trust: Alex Brainman <alex.brainman@gmail.com> Reviewed-by: Austin Clements <austin@google.com>
2019-09-04runtime: wrap nanotime, walltime, and writeAustin Clements
In preparation for general faketime support, this renames the existing nanotime, walltime, and write functions to nanotime1, walltime1, and write1 and wraps them with trivial Go functions. This will let us inject different implementations on all platforms when faketime is enabled. Updates #30439. Change-Id: Ice5ccc513a32a6d89ea051638676d3ee05b00418 Reviewed-on: https://go-review.googlesource.com/c/go/+/192738 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2019-09-02Revert "runtime: remove slow time compatibility hacks for wine"Daniel Martí
This reverts CL 191759. Reason for revert: broke most Go programs using the time package on Wine, including on 4.15, the latest stable version. Only wine-staging (with experimental patches) contains an upstream fix we could rely on. Change-Id: Ic8ba126022e54f412174042fbb9abed82d5eb318 Reviewed-on: https://go-review.googlesource.com/c/go/+/192622 Run-TryBot: Daniel Martí <mvdan@mvdan.cc> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
2019-08-29runtime: remove slow time compatibility hacks for wineJason A. Donenfeld
A few years ago, Wine-specific detection was added as an ugly hack to work around shortcomings in the emulation layer. Probably it's best to not special case this emulator versus that emulator versus the real deal, but there were two arguments presented in the hack's favor: 1. Wine is useful and developers will appreciate being able to debug stuff with it. 2. The existing KUSER_SHARED_DATA technique for gathering time is undocumented, and we shouldn't be relying on it anyway, since Microsoft might remove it without notice. As it turns out, neither one of these are, at the time of writing, true. (1) has been handled for some time by Wine with the introduction of the commit entitled "ntdll: Create thread to update user_shared_data time values when necessary". And (2) is in fact documented: https://docs.microsoft.com/en-us/windows-hardware/drivers/ddi/content/ntddk/ns-ntddk-kuser_shared_data https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/-kuser It's in use so widely by both third-party software (such as games, a massive market segment) and by Microsoft binaries that removing it from the operating system will basically never happen. So with both issues taken care of, this commit simply gets rid of the old hack. Change-Id: I80093f50e0d10d53648128d0f9dd76b1b92a119e Reviewed-on: https://go-review.googlesource.com/c/go/+/191759 Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
2019-05-09runtime, crypto/x509: fix vet complaints for all windowsRuss Cox
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 windows/*, while keeping "GO_BUILDER_NAME=misc-vetall go tool dist test" happy too. For #31916. Change-Id: If37ab2b3f6fca4696b8a6afb2ef11ba6c4fb42e0 Reviewed-on: https://go-review.googlesource.com/c/go/+/176106 Reviewed-by: Austin Clements <austin@google.com>
2018-12-19Revert "runtime: use QPC for nanotime and time.now on windows/arm"Jordan Rhee
This reverts change https://golang.org/cl/154758. Restore the previous implementations of nanotime and time.now, which are sufficiently high resolution and more efficient than QueryPerformanceCounter. The intent of the change was to improve resolution of tracing timestamps, but the change was overly broad as it was only necessary to fix cputicks(). cputicks() is fixed in a subsequent change. Updates #26148 Change-Id: Ib9883d02fe1af2cc4940e866d8f6dc7622d47781 Reviewed-on: https://go-review.googlesource.com/c/154761 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-12-18runtime: use QPC for nanotime and time.now on windows/armgo1.12beta1Jordan Rhee
The previous implementation of nanotime and time.now used a time source that was updated on the system clock tick, which has a maximum resolution of about 1ms. On 386 and amd64, this time source maps to the system performance counter, so has much higher resolution. On ARM, use QueryPerformanceCounter() to get a high resolution timestamp. Updates #26148 Change-Id: I1abc99baf927a95b472ac05020a7788626c71d08 Reviewed-on: https://go-review.googlesource.com/c/154758 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-12-12runtime: fix profiling on windows/ARMJordan Rhee
Fix profiling handler to get the correct g for the m being profiled. Store a pointer to the TLS slot holding g in the thread's m. This enables the profiling handler to get the current g for the thread, even if the thread is executing external code or system code. Updates #26148 Signed-off-by: Jordan Rhee <jordanrh@microsoft.com> Change-Id: Ie061284c12341c76c7d96cc0c2d5bac969230829 Reviewed-on: https://go-review.googlesource.com/c/153718 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-11-02runtime, time: refactor startNano handlingDmitry Vyukov
Move startNano from runtime to time package. In preparation for a subsequent change that speeds up Since and Until. This also makes code simpler as we have less assembly as the result, monotonic time handling is better localized in time package. This changes values returned from nanotime on windows (it does not account for startNano anymore), current comments state that it's important, but it's unclear how it can be important since no other OS does this. Update #25729 Change-Id: I2275d57b7b5ed8fd0d53eb0f19d55a86136cc555 Reviewed-on: https://go-review.googlesource.com/c/146340 Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-09-18runtime: support windows/armJordan Rhee
Updates #26148 Change-Id: I8f68b2c926c7b11dc86c9664ed7ff2d2f78b64b4 Reviewed-on: https://go-review.googlesource.com/128715 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>