aboutsummaryrefslogtreecommitdiff
path: root/src/runtime/sys_darwin_amd64.s
AgeCommit message (Collapse)Author
2023-01-26runtime: use explicit NOFRAME on darwin/amd64qmuntal
This CL marks some darwin assembly functions as NOFRAME to avoid relying on the implicit amd64 NOFRAME heuristic, where NOSPLIT functions without stack were also marked as NOFRAME. Change-Id: I797f3909bcf7f7aad304e4ede820c884231e54f6 Reviewed-on: https://go-review.googlesource.com/c/go/+/460235 Reviewed-by: Cherry Mui <cherryyz@google.com> Run-TryBot: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2023-01-10cmd/link, runtime: Apple libc atfork workaround take 3Russ Cox
CL 451735 worked around bugs in Apple's atfork handlers by calling notify_is_valid_token and xpc_atfork_child at startup, so that init code that wouldn't be safe in the child process would be warmed up in the parent process instead, but xpc_atfork_child broke use of the xpc library in Go programs, and xpc is internally used by various macOS frameworks (#57263). CL 459175 reverted that change, and then CL 459176 tried a new approach: use __fork, which doesn't call any of the atfork handlers at all. That worked, but an Apple engineer reviewing the change in private email suggests that since __fork is not public API, it should be avoided. The same engineer (with access to the source code for the xpc library) suggests that the breakage in #57263 is caused by xpc_atfork_child marking the library as unusable, expecting an imminent call to exec, and that calling xpc_date_create_from_current instead would do the necessary initialization without marking xpc as unusable. CL 460475 reverted that change, to prepare for this one. This CL goes back to the original “call functions to warm things up” approach, replacing xpc_atfork_child with xpc_date_create_from_current. The CL also updates cmd/link to use OS and SDK version 10.13.0 for x86 macOS binaries, up from 10.9.0, also suggested by the Apple engineer. Combined with the two warmup calls, this makes the fork hangs go away. The minimum macOS version has been 10.13 High Sierra since Go 1.17, so there should be no problem with writing that in the binaries too. Fixes #33565. Fixes #56784. Fixes #57263. Fixes #57577. Change-Id: I20769d9daa1fe9ea930f8009481335f8a14dc21b Reviewed-on: https://go-review.googlesource.com/c/go/+/460476 Auto-Submit: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Bryan Mills <bcmills@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-12-22runtime: revert Apple libc atfork workaroundRuss Cox
Revert CL 451735 (1f4394a0c926), which fixed #33565 and #56784 but also introduced #57263. I have a different fix to apply instead. Since the first fix was never backported, it will be easiest to backport the new fix if the new fix is done in a separate CL from the revert. Change-Id: I6c8ea3a46e542ee4702675bbc058e29ccd2723e0 Reviewed-on: https://go-review.googlesource.com/c/go/+/459175 Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Russ Cox <rsc@golang.org>
2022-11-17runtime: work around Apple libc bugs to make exec stop hangingRuss Cox
For a while now, we've had intermittent reports about problems with os/exec on macOS, but no clear way to reproduce them. Recent changes in the os/exec package test seem to have aligned the stars just right, at least on my two x86 and ARM MacBook Pro laptops, to make the package test hang with roughly 50% probability. When it does hang, the stacks I see in the hung process match the ones reported for the Go-based hangs in #33565. (They do not match the ones reported in the so-called C reproducer in that issue, but I think that reproducer is actually reproducing a different race, between fork and exit.) The stacks obtained from the hung child processes are in libSystem_atfork_child, which is supposed to reinitialize various parts of the C library in the new process. One common stack dies in _notify_fork_child calling _notify_globals (inlined) calling _os_alloc_once, because _os_alloc_once detects that the once lock is held by the parent process and then calls _os_once_gate_corruption_abort. The allocation is setting up the globals for the notification subsystem. See the source code at [1]. To work around this, we can allocate the globals earlier in the Go program's lifetime, before any execs are involved, by calling any notify routine that is exported, calls _notify_globals, and doesn't do anything too expensive otherwise. notify_is_valid_token(0) fits the bill. The other common stack dies in xpc_atfork_child calling _objc_msgSend_uncached which ends up in WAITING_FOR_ANOTHER_THREAD_TO_FINISH_CALLING_+initialize. Of course, whatever thread the child is waiting for is in the parent process and is not going to finish anything in the child process. There is no public source code for these routines, so it is unclear exactly what the problem is. However, xpc_atfork_child turns out to be exported (for use by libSystem_atfork_child, which is in a different library, so xpc_atfork_child is unlikely to be unexported any time soon). It also stands to reason that since xpc_atfork_child is called at the start of any forked child process, it can't be too harmful to call at the start of an ordinary Go process. And whatever caches it needs for a non-deadlocking fast path during exec empirically do get initialized by calling it at startup. This CL introduces a function osinit_hack, called at osinit time, which calls notify_is_valid_token(0) and xpc_atfork_child(). Doing so makes the os/exec test pass reliably on both my laptops - I can run it successfully hundreds of times in a row when my previous record was twice in a row. Fixes #33565. Fixes #56784. [1] https://opensource.apple.com/source/Libnotify/Libnotify-241/notify_client.c.auto.html Change-Id: I16a14a800893c40244678203532a3e8d6214b6bd Reviewed-on: https://go-review.googlesource.com/c/go/+/451735 Run-TryBot: Russ Cox <rsc@golang.org> Auto-Submit: Russ Cox <rsc@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-11-01net: use libc (not cgo) for DNS on macOSRuss Cox
Change the macOS implementation to use libc calls. Using libc calls directly is what we do for all the runtime and os syscalls. Doing so here as well improves consistency and also makes it possible to cross-compile (from non-Mac systems) macOS binaries that use the native name resolver. Fixes #12524. Change-Id: I011f4fcc5c50fbb5396e494889765dcbb9342336 Reviewed-on: https://go-review.googlesource.com/c/go/+/446178 Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com>
2022-04-28runtime: mark sigtramp as TOPFRAME on the rest of unixMichael Pratt
This extends CL 402190 from Linux to the rest of the Unix OSes. Marking sigtramp as TOPFRAME allows gentraceback to stop tracebacks at the end of a signal handler, since there is not much beyond sigtramp. Change-Id: I8b7f5d55d41889f59c0a79c65351b9b0b2d77717 Reviewed-on: https://go-review.googlesource.com/c/go/+/402934 Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Austin Clements <austin@google.com> Auto-Submit: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Michael Pratt <mpratt@google.com>
2022-04-26runtime: use ABIInternal for most calls to sigtrampgoMichael Pratt
sigtramp on openbsd-arm64 is teetering on the edge of the nosplit stack limit. Add more headroom by calling sigtrampgo using ABIInternal, which eliminates a 48-byte ABI wrapper frame. openbsd-amd64 has slightly more space, but is also close to the limit, so convert it as well. Other operating systems don't have it as bad, but many have nearly identical implementations of sigtramp, so I have converted them as well. I've omitted darwin-arm64 and solaris, as those are quite different and would benefit from not needing ifdef for both cases. For #51485. Change-Id: I70512645d4208b346a59d5e5d03836a45833b1d7 Reviewed-on: https://go-review.googlesource.com/c/go/+/390814 Run-TryBot: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-02-22crypto/x509, runtime: fix occasional spurious “certificate is expired”Russ Cox
As documented in #51209, we have been seeing a low-rate failure on macOS builders caused by spurious x509 “certificate is expired” errors. The root cause is that CFDateCreate takes a float64, but it is being passed a uintptr instead. That is, we're not even putting CFDateCreate's argument in the right register during the call. Luckily, having just computed the argument by calling time.Duration.Seconds, which returns a float64, most of the time the argument we want is still in the right floating point register, somewhat accidentally. The only time the lucky accident doesn't happen is when the goroutine is rescheduled between calling time.Duration.Seconds and calling into CFDateCreate *and* the rescheduling smashes the floating point register, which can happen during various block memory moves, since the floating point registers are also the SIMD registers. Passing the float64 through explicitly eliminates the problem. It is difficult to write a test for this that is suitable for inclusion in the standard library. We will have to rely on the builders to start flaking again if somehow this problem is reintroduced. For future reference, there is a standalone test that used to fail every few seconds at https://go.dev/play/p/OWfDpxgnW9g. Fixes #51209. Change-Id: I8b334a51e41f406b13f37270e9175c64fe6f55ea Reviewed-on: https://go-review.googlesource.com/c/go/+/387255 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2021-09-27runtime: use per-thread profiler for SetCgoTraceback platformsRhys Hiltner
Updates #35057 Change-Id: I61d772a2cbfb27540fb70c14676c68593076ca94 Reviewed-on: https://go-review.googlesource.com/c/go/+/342054 Run-TryBot: Rhys Hiltner <rhys@justin.tv> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com> Trust: Michael Knyszek <mknyszek@google.com>
2021-04-26runtime: use abi.FuncPCABI0 for libc syscall wrappersCherry Zhang
In CL 288092 we made Darwin syscall wrappers as ABIInternal, so their addresses taken from Go using funcPC are the actual function entries, not the wrappers. As we introduced internal/abi.FuncPCABIxxx intrinsics, use that. And change the assembly functions back to ABI0. Change-Id: I50645af74883e2d5dfcd67a5e8c739222c6f645b Reviewed-on: https://go-review.googlesource.com/c/go/+/313250 Trust: Cherry Zhang <cherryyz@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-04-15runtime: unify C->Go ABI transitionsAustin Clements
The previous CL introduced macros for transitions from the Windows ABI to the Go ABI. This CL does the same for SysV and uses them in almost all places where we transition from the C ABI to the Go ABI. Compared to Windows, this transition is much simpler and I didn't find any places that were getting it wrong. But this does let us unify a lot of code nicely and introduces some degree of abstraction around these ABI transitions. Change-Id: Ib6bdecafce587ce18fca4c8300fcf401284a2bcd Reviewed-on: https://go-review.googlesource.com/c/go/+/309930 Trust: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-03-19cmd/compile: add clobberdeadreg modeCherry Zhang
When -clobberdeadreg flag is set, the compiler inserts code that clobbers integer registers at call sites. This may be helpful for debugging register ABI. Only implemented on AMD64 for now. Change-Id: Ia203d3f891c30fd95d0103489056fe01d63a2899 Reviewed-on: https://go-review.googlesource.com/c/go/+/302809 Trust: Cherry Zhang <cherryyz@google.com> Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com>
2021-02-03[dev.regabi] runtime, syscall, etc.: mark Darwin syscall wrappers as ABIInternalCherry Zhang
Mark the syscall wrappers as ABIInternal, as they have addresses taken from Go code, and it is important to call to them without wrappers. Previously, the wrapper is just a single JMP instruction, which makes it not matter. In the next CL we'll make the wrapper actually have a frame. The real wrappers will mess up things such as stack alignment for C ABI. This doesn't look really nice, but I don't know how we can do better... TODO: other OSes. Change-Id: Ifb3920494990a7775e3e6902fbcaf137df3cc653 Reviewed-on: https://go-review.googlesource.com/c/go/+/288092 Trust: Cherry Zhang <cherryyz@google.com> Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com>
2020-12-07internal/cpu: add darwin/arm64 CPU feature detection supportMartin Möhrmann
Fixes #42747 Change-Id: I6b1679348c77161f075f0678818bb003fc0e8c86 Reviewed-on: https://go-review.googlesource.com/c/go/+/271989 Trust: Martin Möhrmann <moehrmann@google.com> Run-TryBot: Martin Möhrmann <martisch@uos.de> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-11-30runtime: mlock signal stack on macOS/ARM64Cherry Zhang
Apparently, the macOS ARM64 kernel has a bug where when a signal arrives and the signal stack is not currently faulted in, it may kill the program with a SIGILL. Work around it by mlock the signal stacks. Fixes #42774. Change-Id: I99a4b3fdb6d8af1c945725ddc2c25568d81c510a Reviewed-on: https://go-review.googlesource.com/c/go/+/273686 Trust: Cherry Zhang <cherryyz@google.com> Reviewed-by: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Go Bot <gobot@golang.org>
2020-11-18runtime: use clock_gettime instead of gettimeofday on darwinTobias Klauser
clock_gettime has higher resolution than gettimeofday and is available since macOS 10.12. Go 1.15 already requires at least macOS 10.12 and thus clock_gettime can be used unconditionally (also see https://golang.org/doc/go1.15#darwin) Fixes #25633 Change-Id: I46305387212735e5d3a13e5f02ec90f3e6d546a4 Reviewed-on: https://go-review.googlesource.com/c/go/+/270918 Trust: Tobias Klauser <tobias.klauser@gmail.com> Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2020-05-07crypto/x509: use Security.framework without cgo for roots on macOSFilippo Valsorda
+----------------------------------------------------------------------+ | Hello, if you are reading this and run macOS, please test this code: | | | | $ GO111MODULE=on go get golang.org/dl/gotip@latest | | $ gotip download | | $ GODEBUG=x509roots=1 gotip test crypto/x509 -v -run TestSystemRoots | +----------------------------------------------------------------------+ We currently have two code paths to extract system roots on macOS: one uses cgo to invoke a maze of Security.framework APIs; the other is a horrible fallback that runs "/usr/bin/security verify-cert" on every root that has custom policies to check if it's trusted for SSL. The fallback is not only terrifying because it shells out to a binary, but also because it lets in certificates that are not trusted roots but are signed by trusted roots, and because it applies some filters (EKUs and expiration) only to roots with custom policies, as the others are not passed to verify-cert. The other code path, of course, requires cgo, so can't be used when cross-compiling and involves a large ball of C. It's all a mess, and it broke oh-so-many times (#14514, #16532, #19436, #20990, #21416, #24437, #24652, #25649, #26073, #27958, #28025, #28092, #29497, #30471, #30672, #30763, #30889, #32891, #38215, #38365, ...). Since macOS does not have a stable syscall ABI, we already dynamically link and invoke libSystem.dylib regardless of cgo availability (#17490). How that works is that functions in package syscall (like syscall.Open) take the address of assembly trampolines (like libc_open_trampoline) that jump to symbols imported with cgo_import_dynamic (like libc_open), and pass them along with arguments to syscall.syscall (which is implemented as runtime.syscall_syscall). syscall_syscall informs the scheduler and profiler, and then uses asmcgocall to switch to a system stack and invoke runtime.syscall. The latter is an assembly trampoline that unpacks the Go ABI arguments passed to syscall.syscall, finally calls the remote function, and puts the return value on the Go stack. (This last bit is the part that cgo compiles from a C wrapper.) We can do something similar to link and invoke Security.framework! The one difference is that runtime.syscall and friends check errors based on the errno convention, which Security doesn't follow, so I added runtime.syscallNoErr which just skips interpreting the return value. We only need a variant with six arguments because the calling convention is register-based, and extra arguments simply zero out some registers. That's plumbed through as crypto/x509/internal/macOS.syscall. The rest of that package is a set of wrappers for Security.framework and Core Foundation functions, like syscall is for libSystem. In theory, as long as macOS respects ABI backwards compatibility (a.k.a. as long as binaries built for a previous OS version keep running) this should be stable, as the final result is not different from what a C compiler would make. (One exception might be dictionary key strings, which we make our own copy of instead of using the dynamic symbol. If they change the value of those strings things might break. But why would they.) Finally, I rewrote the crypto/x509 cgo logic in Go using those wrappers. It works! I tried to make it match 1:1 the old logic, so that root_darwin_amd64.go can be reviewed by comparing it to root_cgo_darwin_amd64.go. The only difference is that we do proper error handling now, and assume that if there is no error the return values are there, while before we'd just check for nil pointers and move on. I kept the cgo logic to help with review and testing, but we should delete it once we are confident the new code works. The nocgo logic is gone and we shall never speak of it again. Fixes #32604 Fixes #19561 Fixes #38365 Awakens Cthulhu Change-Id: Id850962bad667f71e3af594bdfebbbb1edfbcbb4 Reviewed-on: https://go-review.googlesource.com/c/go/+/227037 Reviewed-by: Katie Hockman <katie@golang.org>
2019-10-26runtime: M-targeted signals for libc-based OSesAustin Clements
For #10958, #24543. Change-Id: I82bee63b49e15bd5a53228eb85179814c80437ef Reviewed-on: https://go-review.googlesource.com/c/go/+/201403 Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Cherry Zhang <cherryyz@google.com>
2019-10-21runtime: change read and write to return negative errno valueIan Lance Taylor
The internal read and write functions used to return -1 on error; change them to return a negative errno value instead. This will be used by later CLs in this series. For most targets this is a simplification, although for ones that call into libc it is a complication. Updates #27707 Change-Id: Id02bf9487f03e7e88e4f2b85e899e986738697ad Reviewed-on: https://go-review.googlesource.com/c/go/+/171823 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2019-06-30runtime: use a pipe to wake up signal_recv on DarwinIan Lance Taylor
The implementation of semaphores, and therefore notes, used on Darwin is not async-signal-safe. The runtime has one case where a note needs to be woken up from a signal handler: the call to notewakeup in sigsend. That notewakeup call is only called on a single note, and it doesn't need the full functionality of notes: nothing ever does a timed wait on it. So change that one note to use a different implementation on Darwin, based on a pipe. This lets the wakeup code use the write call, which is async-signal-safe. Fixes #31264 Change-Id: If705072d7a961dd908ea9d639c8d12b222c64806 Reviewed-on: https://go-review.googlesource.com/c/go/+/184169 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Russ Cox <rsc@golang.org>
2019-06-21Revert "runtime: use dispatch semaphores on Darwin"Ian Lance Taylor
This reverts https://golang.org/cl/182258. The new code caused unpredictable crashes that are not understood. The old code was occasionally flaky but still better than this approach. Fixes #32655 Updates #31264 Change-Id: I2e9d27d6052e84bf75106d8b844549ba4f571695 Reviewed-on: https://go-review.googlesource.com/c/go/+/182880 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Katie Hockman <katie@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2019-06-15runtime: use dispatch semaphores on DarwinIan Lance Taylor
Changes Darwin semaphore support from using pthread mutexes and condition variables to using dispatch semaphores. Signaling a dispatch semaphore is async-signal-safe. Fixes #31264 Change-Id: If0ce47623501db13e3804b14ace5f4d8eaef461e Reviewed-on: https://go-review.googlesource.com/c/go/+/182258 Reviewed-by: Elias Naur <mail@eliasnaur.com> Reviewed-by: Keith Randall <khr@golang.org>
2019-06-06runtime: document, fix libc error checks on macOSRuss Cox
It matters whether we are calling a function that would return a 32-bit or 64-bit -1 on error. A few sites were wrong and this key detail was omitted from syscall/syscallX docs. Change-Id: I48a421b6cc4d2d2b5e58f790cc947e3cb2f98940 Reviewed-on: https://go-review.googlesource.com/c/go/+/180841 Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2019-06-06runtime: use default system stack size, not 64 kB, on non-cgo macOSRuss Cox
At least one libc call we make (res_search, which calls _mdns_query and then mdns_item_call) pushes a 64 kB stack frame onto the stack. Then it faults on the guard page. Use the default system stack size, under the assumption that the C code being called is compatible with that stack size. For #31705. Change-Id: I1b0bfc2e54043c49f0709255988ef920ce30ee82 Reviewed-on: https://go-review.googlesource.com/c/go/+/180779 Run-TryBot: Russ Cox <rsc@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-04-03syscall: avoid _getdirentries64 on darwinKeith Randall
Getdirentries is implemented with the __getdirentries64 function in libSystem.dylib. That function works, but it's on Apple's can't-be-used-in-an-app-store-application list. Implement Getdirentries using the underlying fdopendir/readdir_r/closedir. The simulation isn't faithful, and could be slow, but it should handle common cases. Don't use Getdirentries in the stdlib, use fdopendir/readdir_r/closedir instead (via (*os.File).readdirnames). Fixes #30933 Update #28984 RELNOTE=yes Change-Id: Ia6b5d003e5bfe43ba54b1e1d9cfa792cc6511717 Reviewed-on: https://go-review.googlesource.com/c/go/+/168479 Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-12-13runtime,os,syscall,internal/poll: replace getdirentries on iOSElias Naur
The getdirentries syscall is considered private API on iOS and is rejected by the App Store submission checks. Replace it with the fdopendir/readdir_r/closedir syscalls. Fixes #28984 Change-Id: I73341b124310e9cb34834a95f946769f337ec5b7 Reviewed-on: https://go-review.googlesource.com/c/153338 Reviewed-by: Keith Randall <khr@golang.org>
2018-11-07syscall: implement syscalls on Darwin using libSystemKeith Randall
There are still some references to the bare Syscall functions in the stdlib. I will root those out in a following CL. (This CL is big enough as it is.) Most are in vendor directories: cmd/vendor/golang.org/x/sys/unix/ vendor/golang_org/x/net/route/syscall.go syscall/bpf_bsd.go syscall/exec_unix.go syscall/flock.go Update #17490 Change-Id: I69ab707811530c26b652b291cadee92f5bf5c1a4 Reviewed-on: https://go-review.googlesource.com/c/141639 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Elias Naur <elias.naur@gmail.com> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-08-16runtime: load errno as signed 32-bitKeith Randall
the function libc_errno returns a pointer to a signed-32 bit quantity, not a 64-bit quantity. Fixes #27004 Change-Id: I0623835ee34fd9655532251f096022a5accb58cd Reviewed-on: https://go-review.googlesource.com/129475 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-07-04runtime: support capturing C backtrace from signal handler on darwin/amd64Nikhil Benesch
The implementation is mostly copied from the commit that added linux/amd64 support for this feature (https://golang.org/cl/17761). Change-Id: I3f482167620a7a3daf50a48087f8849a30d713bd Reviewed-on: https://go-review.googlesource.com/102438 Reviewed-by: Ian Lance Taylor <iant@golang.org> Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-06-25runtime: respect timeout in semasleep on DarwinNikhil Benesch
semasleep on Darwin was refactored in https://golang.org/cl/118736 to use the pthread_cond_timedwait function from libc. The new code incorrectly assumed that pthread_cond_timedwait took a timeout relative to the current time, when it in fact it takes a timeout specified in absolute time. semasleep thus specified a timeout well in the past, causing it to immediately exceed the timeout and spin hot. This was the source of a large performance hit to CockroachDB (#26019). Adjust semasleep to instead call pthread_cond_timedwait_relative_np, which properly interprets its timeout parameter as relative to the current time. pthread_cond_timedwait_relative_np is non-portable, but using pthread_cond_timedwait correctly would require two calls to gettimeofday: one in the runtime package to convert the relative timeout to absolute time, then another in the pthread library to convert back to a relative offset [0], as the Darwin kernel expects a relative offset. [0]: https://opensource.apple.com/source/libpthread/libpthread-301.30.1/src/pthread_cond.c.auto.html Fix #26019. Change-Id: I1a8c2429f79513b43d2b256365cd9166d235af8b Reviewed-on: https://go-review.googlesource.com/120635 Reviewed-by: Keith Randall <khr@golang.org> Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-06-16runtime: move semaphore ops from system calls to libc calls on DarwinKeith Randall
This CL removes the last of the direct system calls in the runtime package. This is the last CL for 1.11. Use libcCall instead of asmcgocall in a few places I accidentally used the wrong one. For 1.12, we need to think about whether/how the syscall package should be moved over to libc. Update #17490 Change-Id: I4f0bd9cd6023f662f2e29588266fdfae5233898f Reviewed-on: https://go-review.googlesource.com/118736 Run-TryBot: Keith Randall <khr@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-06-13runtime: move darwin kevent calls to libcKeith Randall
kqueue, kevent, closeonexec, setitimer, with sysctl and fcntl helpers. TODO:arm,arm64 Change-Id: I9386f377186d6ac7cb99064c524a67e0c8282eba Reviewed-on: https://go-review.googlesource.com/118561 Reviewed-by: Ian Lance Taylor <iant@golang.org> Run-TryBot: Ian Lance Taylor <iant@golang.org>
2018-06-12runtime: use libc's signal functions on DarwinKeith Randall
sigaction, sigprocmask, sigaltstack, and raiseproc. Fix bug in mstart_stub where we weren't saving callee-saved registers, so if an m finished the pthread library calling mstart_stub would sometimes fail. Update #17490 Update #22805 Change-Id: Ie297ede0997910aa956834e49e85711b90cdfaa7 Reviewed-on: https://go-review.googlesource.com/116875 Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-05-29runtime: implement time.now using libcKeith Randall
Change-Id: Ibdd9202d9711ea8aab2446c9950ddb8e1f6bf4e0 Reviewed-on: https://go-review.googlesource.com/114799 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-05-21runtime: use raise instead of pthread_self and pthread_killElias Naur
pthread_self and pthread_kill are not safe to call from a signal handler. In particular, pthread_self fails in iOS when called from a signal handler context. Use raise instead; it is signal handler safe and simpler. Change-Id: I0cbfe25151aed245f55d7b76719ce06dc78c6a75 Reviewed-on: https://go-review.googlesource.com/113877 Run-TryBot: Elias Naur <elias.naur@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2018-05-20runtime: use libc for nanotime on DarwinKeith Randall
Use mach_absolute_time and mach_timebase_info to get nanosecond-level timing information from libc on Darwin. The conversion code from Apple's arbitrary time unit to nanoseconds is really annoying. It would be nice if we could replace the internal runtime "time" with arbitrary units and put the conversion to nanoseconds only in the places that really need it (so it isn't in every nanotime call). It's especially annoying because numer==denom==1 for all the machines I tried. Makes it hard to test the conversion code :( Update #17490 Change-Id: I6c5d602a802f5c24e35184e33d5e8194aa7afa86 Reviewed-on: https://go-review.googlesource.com/110655 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-05-19runtime: fix darwin 386/amd64 stack switchesKeith Randall
A few libc_ calls were missing stack switches. Unfortunately, adding the stack switches revealed a deeper problem. systemstack() is fundamentally flawed because when you do systemstack(func() { ... }) There's no way to mark the anonymous function as nosplit. At first I thought it didn't matter, as that function runs on the g0 stack. But nosplit is still required, because some syscalls are done when stack bounds are not set up correctly (e.g. in a signal handler, which runs on the g0 stack, but g is still pointing at the g stack). Instead use asmcgocall and funcPC, so we can be nosplit all the way down. Mid-stack inlining now pushes darwin over the nosplit limit also. Leaving that as a TODO. Update #23168 This might fix the cause of occasional darwin hangs. Update #25181 Update #17490 Change-Id: If9c3ef052822c7679f5a1dd192443f714483327e Reviewed-on: https://go-review.googlesource.com/111258 Reviewed-by: Ian Lance Taylor <iant@golang.org> Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-05-01runtime: move open/close/read/write from syscall to libc on DarwinKeith Randall
Update #17490 Change-Id: Ia0bb0ba10dc0bbb299290a60b8228275d55125d7 Reviewed-on: https://go-review.googlesource.com/110438 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-05-01runtime: move more syscalls to libc on DarwinKeith Randall
Moving mmap, munmap, madvise, usleep. Also introduce __error function to get at libc's errno variable. Change-Id: Ic47ac1d9eb71c64ba2668ce304644dd7e5bdfb5a Reviewed-on: https://go-review.googlesource.com/110437 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-05-01runtime: implement darwin raise with pthread_self and pthread_killElias Naur
Convert raise from raw syscalls to using the system pthread library. As a bonus, raise will now target the current thread instead of the process. Updates #17490 Change-Id: I2e44f2000bf870e99a5b4dc5ff5e0799fba91bde Reviewed-on: https://go-review.googlesource.com/110475 Run-TryBot: Elias Naur <elias.naur@gmail.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2018-05-01runtime: convert exit to use pthread library on DarwinKeith Randall
Now we no longer need to mess with TLS on Darwin 386/amd64, we always rely on the pthread library to set it up. We now just use one entry in the TLS for the G. Return from mstart to let the pthread library clean up the OS thread. Change-Id: Iccf58049d545515d9b1d090b161f420e40ffd244 Reviewed-on: https://go-review.googlesource.com/110215 Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-04-30runtime,cmd/ld: on darwin, create theads using libcKeith Randall
Replace thread creation with calls to the pthread library in libc. Update #17490 Change-Id: I1e19965c45255deb849b059231252fc6a7861d6c Reviewed-on: https://go-review.googlesource.com/108679 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-04-11runtime: use fixed TLS offsets on darwin/amd64 and darwin/386Keith Randall
Fixes #23617 Note that this CL does not affect darwin/arm and darwin/arm64, still TBD what, if anything, needs to be done for those. This is a fix of CL 105975 which was reverted in CL 106155. Needed to use movl instead of movq for 386. Change-Id: I0db7f8087173869e60cc22c6c3124fa0a0739b46 Reviewed-on: https://go-review.googlesource.com/106156 Run-TryBot: Keith Randall <khr@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-04-10Revert "runtime: use fixed TLS offsets on darwin/amd64 and darwin/386"Keith Randall
This reverts commit 76e92d1c9e2943de7093af14d58663fa2993e608. Reason for revert: Seems to have broken the darwin/386 builder, the toolchain is barfing on the new inline assembly. Change-Id: Ic83fa3c85148946529c5fd47d1e1669898031ace Reviewed-on: https://go-review.googlesource.com/106155 Reviewed-by: Keith Randall <khr@golang.org>
2018-04-10runtime: use fixed TLS offsets on darwin/amd64 and darwin/386Keith Randall
Fixes #23617 Note that this CL does not affect darwin/arm and darwin/arm64, still TBD what, if anything, needs to be done for those. Change-Id: Ie1ee02a9f4d4d1fb9cd5dc432d900f926cc157db Reviewed-on: https://go-review.googlesource.com/105975 Reviewed-by: Ian Lance Taylor <iant@golang.org>
2018-01-16runtime: fix time.Now on Sierra and olderGiovanni Bajo
CL 67332 created the fast no-syscall path for time.Now in High Sierra but managed to break Sierra and older by forcing them into the slow syscall path: the version check based on commpage version was wrong. This CL uses the Darwin version number instead. The assembly diff is noisy because many variables had to be renamed, but the only actual change is the version check. Fixes #23419. Change-Id: Ie31ef5fb88f66d1517a8693942a7fb6100c213b0 Reviewed-on: https://go-review.googlesource.com/87655 Run-TryBot: Giovanni Bajo <rasky@develer.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2017-10-18runtime: separate error result for mmapAustin Clements
Currently mmap returns an unsafe.Pointer that encodes OS errors as values less than 4096. In practice this is okay, but it borders on being really unsafe: for example, the value has to be checked immediately after return and if stack copying were ever to observe such a value, it would panic. It's also not remotely idiomatic. Fix this by making mmap return a separate pointer value and error, like a normal Go function. Updates #22218. Change-Id: Iefd965095ffc82cc91118872753a5d39d785c3a6 Reviewed-on: https://go-review.googlesource.com/71270 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-10-11runtime: make it possible to exit Go-created threadsAustin Clements
Currently, threads created by the runtime exist until the whole program exits. For #14592 and #20395, we want to be able to exit and clean up threads created by the runtime. This commit implements that mechanism. The main difficulty is how to clean up the g0 stack. In cgo mode and on Solaris and Windows where the OS manages thread stacks, we simply arrange to return from mstart and let the system clean up the thread. If the runtime allocated the g0 stack, then we use a new exitThread syscall wrapper that arranges to clear a flag in the M once the stack can safely be reaped and call the thread termination syscall. exitThread is based on the existing exit1 wrapper, which was always meant to terminate the calling thread. However, exit1 has never been used since it was introduced 9 years ago, so it was broken on several platforms. exitThread also has the additional complication of having to flag that the stack is unused, which requires some tricks on platforms that use the stack for syscalls. This still leaves the problem of how to reap the unused g0 stacks. For this, we move the M from allm to a new freem list as part of the M exiting. Later, allocm scans the freem list, finds Ms that are marked as done with their stack, removes these from the list and frees their g0 stacks. This also allows these Ms to be garbage collected. This CL does not yet use any of this functionality. Follow-up CLs will. Likewise, there are no new tests in this CL because we'll need follow-up functionality to test it. Change-Id: Ic851ee74227b6d39c6fc1219fc71b45d3004bc63 Reviewed-on: https://go-review.googlesource.com/46037 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2017-10-05runtime: fix exit1 arguments on DarwinAustin Clements
exit1 calls the bsdthread_terminate system call on Darwin. Currently it passes no arguments on 386, arm, and arm64, and an exit status on amd64. None of these are right. The signature of bsdthread_terminate is: int bsdthread_terminate(user_addr_t stackaddr, size_t freesize, uint32_t port, uint32_t sem); Fix all of the Darwin exit1 implementations to call bsdthread_terminate with 0 for all of these arguments so it doesn't try to unmap some random memory, free some random port, or signal a random semaphore. This isn't a problem in practice because exit1 is never called. However, we're about to start using exit1. Change-Id: Idc534d196e3104e5253fc399553f21eb608693d7 Reviewed-on: https://go-review.googlesource.com/46036 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-10-03runtime: fix wall time computation in macOS High SierraGiovanni Bajo
Latest macOS High Sierra changed how the wall time information is exported into the commpage. Backward compatibility was partly preserved, that is previous Go versions are basically forced to go through a syscall which is much slower and is not able to get nanosecond precision. Implement the new commpage layout and wall time computation, using a version check to fallback to the previous code on older operating systems. Fixes #22037 Change-Id: I8c2176eaca83a5d7be23443946a6b4c653ec7f68 Reviewed-on: https://go-review.googlesource.com/67332 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>