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path: root/src/runtime/traceback.go
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2023-03-10runtime: move cgo traceback into unwinderAustin Clements
Currently, gentraceback's loop ends with a call to tracebackCgoContext to process cgo frames. This requires spreading various parts of the printing and pcbuf logic across these two functions. Clean this up by moving cgo unwinding into unwinder and then lifting the printing and pcbuf logic from tracebackCgoContext into gentraceback along with the other printing and pcbuf logic. Updates #54466. Change-Id: Ic71afaa5ae110c0ea5be9409e267e4284e36a8c9 Reviewed-on: https://go-review.googlesource.com/c/go/+/468299 Reviewed-by: Michael Pratt <mpratt@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-03-10runtime: simplify traceback PC back-up logicAustin Clements
Updates #54466. Change-Id: If070cf3f484e3e02b8e586bff466e0018b1a1845 Reviewed-on: https://go-review.googlesource.com/c/go/+/468298 Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-03-10runtime: replace all callback uses of gentraceback with unwinderAustin Clements
This is a really nice simplification for all of these call sites. It also achieves a nice performance improvement for stack copying: goos: linux goarch: amd64 pkg: runtime cpu: Intel(R) Xeon(R) CPU E5-2690 v3 @ 2.60GHz │ before │ after │ │ sec/op │ sec/op vs base │ StackCopyPtr-48 89.25m ± 1% 79.78m ± 1% -10.62% (p=0.000 n=20) StackCopy-48 83.48m ± 2% 71.88m ± 1% -13.90% (p=0.000 n=20) StackCopyNoCache-48 2.504m ± 2% 2.195m ± 1% -12.32% (p=0.000 n=20) StackCopyWithStkobj-48 21.66m ± 1% 21.02m ± 2% -2.95% (p=0.000 n=20) geomean 25.21m 22.68m -10.04% Updates #54466. Change-Id: I31715b7b6efd65726940041d3052bb1c0a1186f3 Reviewed-on: https://go-review.googlesource.com/c/go/+/468297 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com>
2023-03-10runtime: implement traceback iteratorAustin Clements
Currently, all stack walking logic is in one venerable, large, and very, very complicated function: runtime.gentraceback. This function has three distinct operating modes: printing, populating a PC buffer, or invoking a callback. And it has three different modes of unwinding: physical Go frames, inlined Go frames, and cgo frames. It also has several flags. All of this logic is very interwoven. This CL reimplements the monolithic gentraceback function as an "unwinder" type with an iterator API. It moves all of the logic for stack walking into this new type, and gentraceback is now a much-simplified wrapper around the new unwinder type that still implements printing, populating a PC buffer, and invoking a callback. Follow-up CLs will replace uses of gentraceback with direct uses of unwinder. Exposing traceback functionality as an iterator API will enable a lot of follow-up work such as simplifying the open-coded defer implementation (which should in turn help with #26813 and #37233), printing the bottom of deep stacks (#7181), and eliminating the small limit on CPU stacks in profiles (#56029). Fixes #54466. Change-Id: I36e046dc423c9429c4f286d47162af61aff49a0d Reviewed-on: https://go-review.googlesource.com/c/go/+/458218 Reviewed-by: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Austin Clements <austin@google.com>
2023-03-10runtime: replace cgoCtxt slice with index in tracebackAustin Clements
Currently, gentraceback consumes the gp.cgoCtxt slice by copying the slice header and then sub-slicing it as it unwinds. The code for this is nice and clear, but we're about to lift this state into a structure and mutating it is going to introduce write barriers that are disallowed in gentraceback. This CL replaces the mutable slice header with an index into gp.cgoCtxt. For #54466. Change-Id: I6b701bb67d657290a784baaca34ed02d8247ede2 Reviewed-on: https://go-review.googlesource.com/c/go/+/466863 Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-03-10runtime: use inlineUnwinderAustin Clements
This converts all places in the runtime that perform inline expansion to use the new inlineUnwinder abstraction. For #54466. Change-Id: I48d996fb6263ed5225bd21d30914a27ae434528d Reviewed-on: https://go-review.googlesource.com/c/go/+/466099 Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com>
2023-03-10runtime: use srcFunc for showframeAustin Clements
Since srcFunc can represent information for either an real text function or an inlined function, this means we no longer have to synthesize a fake _func just to call showframe on an inlined frame. This is cleaner and also eliminates the one case where _func values live in the heap. This will let us mark them NotInHeap, which will in turn eliminate pesky write barriers in the traceback rewrite. For #54466. Change-Id: Ibf5e24d01ee4bf384c825e1a4e2922ef444a438e Reviewed-on: https://go-review.googlesource.com/c/go/+/466097 Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-03-10runtime: resolve caller funcInfo after processing current frameAustin Clements
Currently, gentraceback resolves the funcInfo of the caller prior to processing the current frame (calling the callback, printing it, etc). As a result, if this lookup fails in a verbose context, it will print the failure before printing the frame that it's already resolved. To fix this, move the resolution of LR to a funcInfo to after current frame processing. This also has the advantage that we can reduce the scope of "flr" (the caller's funcInfo) to only the post-frame part of the loop, which will make it easier to stack-rip gentraceback into an iterator. For #54466. Change-Id: I8be44d4eac598a686c32936ab37018b8aa97c00b Reviewed-on: https://go-review.googlesource.com/c/go/+/458217 TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Felix Geisendörfer <felix.geisendoerfer@datadoghq.com>
2023-03-10runtime: eliminate waspanic from gentracebackAustin Clements
gentraceback also tracks the funcID of the callee, which is more general. Fix this up to happen in all cases and eliminate waspanic in favor of checking the funcID of the caller. For #54466. Change-Id: Idc98365a6f05022db18ddcd5b3ed8684a6872a88 Reviewed-on: https://go-review.googlesource.com/c/go/+/458216 Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Felix Geisendörfer <felix.geisendoerfer@datadoghq.com> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-03-10runtime: don't track stack separately in gentracebackAustin Clements
Currently, gentraceback keeps a copy of the stack bounds of the stack it's walking in the "stack" variable. Now that "gp" always refers to the G whose stack it's walking, we can simply use gp.stack instead of keeping a separate copy. For #54466. Change-Id: I68256e5dff6212cfcf14eda615487e66a92d4914 Reviewed-on: https://go-review.googlesource.com/c/go/+/458215 Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Felix Geisendörfer <felix.geisendoerfer@datadoghq.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2023-02-21runtime: record parent goroutine ID, and print it in stack tracesNick Ripley
Fixes #38651 Change-Id: Id46d684ee80e208c018791a06c26f304670ed159 Reviewed-on: https://go-review.googlesource.com/c/go/+/435337 Run-TryBot: Nick Ripley <nick.ripley@datadoghq.com> Reviewed-by: Ethan Reesor <ethan.reesor@gmail.com> Auto-Submit: Michael Pratt <mpratt@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-11-07runtime: fix a few function names on commentscui fliter
Change-Id: I9ef4898d68dfd06618c0bd8e23f81a1d2c77a836 Signed-off-by: cui fliter <imcusg@gmail.com> Reviewed-on: https://go-review.googlesource.com/c/go/+/447460 Auto-Submit: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> Run-TryBot: Michael Pratt <mpratt@google.com>
2022-10-14cmd/compile,cmd/link,runtime: add start line numbers to func metadataMichael Pratt
This adds the function "start line number" to runtime._func and runtime.inlinedCall objects. The "start line number" is the line number of the func keyword or TEXT directive for assembly. Subtracting the start line number from PC line number provides the relative line offset of a PC from the the start of the function. This helps with source stability by allowing code above the function to move without invalidating samples within the function. Encoding start line rather than relative lines directly is convenient because the pprof format already contains a start line field. This CL uses a straightforward encoding of explictly including a start line field in every _func and inlinedCall. It is possible that we could compress this further in the future. e.g., functions with a prologue usually have <line of PC 0> == <start line>. In runtime.test, 95% of functions have <line of PC 0> == <start line>. According to bent, this is geomean +0.83% binary size vs master and -0.31% binary size vs 1.19. Note that //line directives can change the file and line numbers arbitrarily. The encoded start line is as adjusted by //line directives. Since this can change in the middle of a function, `line - start line` offset calculations may not be meaningful if //line directives are in use. For #55022. Change-Id: Iaabbc6dd4f85ffdda294266ef982ae838cc692f6 Reviewed-on: https://go-review.googlesource.com/c/go/+/429638 Run-TryBot: Michael Pratt <mpratt@google.com> Auto-Submit: Michael Pratt <mpratt@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-10-05runtime: don't jump stack if at entry of systemstackCherry Mui
The traceback code has special "jump stack" logic, to trace back stack switches through systemstack. If we're at the entry of systemstack, the stack switch hasn't happened, so don't jump to user stack. The jump stack logic is only used if we're on the g0 stack. It can happen that we're at the entry of a recursive systemstack call on the g0 stack. In we jump stack here, there will be two problems: 1. There are frames between entering the g0 stack and this recursive systemstack call. Those frames will be lost. 2. Worse, we switched frame.sp but frame.fp calculation will use the entry SP delta (0), which will be wrong, which in turn leads wrong frame.lr and things will go off. For now, don't jump stack if we're at entry of systemstack (SP delta is 0). Using a per-PC SPWRITE marker may be a better fix. If we haven't written the SP, we haven't switched the stack so we can just unwind like a normal function. May fix #55851. Change-Id: I2b624c8c086b235b34d9c7d3cebd4a37264f00f8 Reviewed-on: https://go-review.googlesource.com/c/go/+/437299 TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Cherry Mui <cherryyz@google.com> Reviewed-by: Michael Pratt <mpratt@google.com>
2022-09-07runtime: rename _func.nameoff and friends to nameOffMichael Pratt
Switch to the more Go-style name to match inlinedCall.nameOff. Change-Id: I2115b27af8309e1ead7d61ecc65fe4fc966030f7 Reviewed-on: https://go-review.googlesource.com/c/go/+/428657 Run-TryBot: Michael Pratt <mpratt@google.com> Auto-Submit: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-09-07runtime: rename inlinedCall.func_ to inlinedCall.nameOffMichael Pratt
The meaning of this field is unchanged, this CL simply gives it a more descriptive name, as func_ makes it sound like a reference to the _func. Change-Id: I70e54f34bede7636ce4d7b9dd0f7557308f02143 Reviewed-on: https://go-review.googlesource.com/c/go/+/427961 Reviewed-by: Cherry Mui <cherryyz@google.com> Run-TryBot: Michael Pratt <mpratt@google.com> Reviewed-by: Austin Clements <austin@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-09-06runtime: in traceback, only jump stack if M doesn't changeAustin Clements
CL 424257 modified gentraceback to switch gp when jumping from a system stack to a user stack to simplify reasoning through the rest of the function. This has the unintended side-effect of also switching all references to gp.m. The vast majority of the time, g0.m and curg.m are the same across a stack switch, making this a no-op, but there's at least one case where this isn't true: if a profiling signal happens in execute between setting mp.curg and setting gp.m. In this case, mp.curg.m is briefly nil, which can cause gentraceback to crash with a nil pointer dereference. We see this failure (surprisingly frequently!) in profiling tests in the morestack=mayMoreStackPreempt testing mode (#48297). Fix this by making only jumping stacks if doing so will not switch Ms. This restores the original property that gp.m doesn't change across the stack jump, and makes gentraceback a little more conservative about jumping stacks. Fixes #54885. Change-Id: Ib1524c41c748eeff35896e0f3abf9a7efbe5969f Reviewed-on: https://go-review.googlesource.com/c/go/+/428656 Reviewed-by: Michael Pratt <mpratt@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Austin Clements <austin@google.com>
2022-09-05runtime: refactor finalizer goroutine statusLeonard Wang
Use an atomic.Uint32 to represent the state of finalizer goroutine. fingStatus will only be changed to fingWake in non fingWait state, so it is safe to set fingRunningFinalizer status in runfinq. name old time/op new time/op delta Finalizer-8 592µs ± 4% 561µs ± 1% -5.22% (p=0.000 n=10+10) FinalizerRun-8 694ns ± 6% 675ns ± 7% ~ (p=0.059 n=9+8) Change-Id: I7e4da30cec98ce99f7d8cf4c97f933a8a2d1cae1 Reviewed-on: https://go-review.googlesource.com/c/go/+/400134 Reviewed-by: Joedian Reid <joedian@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Daniel Martí <mvdan@mvdan.cc> Reviewed-by: Michael Pratt <mpratt@google.com>
2022-09-02runtime: consolidate stkframe and its methods into stkframe.goAustin Clements
The stkframe struct and its methods are strewn across different source files. Since they actually have a pretty coherent theme at this point, migrate it all into a new file, stkframe.go. There are no code changes in this CL. For #54466, albeit rather indirectly. Change-Id: Ibe53fc4b1106d131005e1c9d491be838a8f14211 Reviewed-on: https://go-review.googlesource.com/c/go/+/424516 Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Austin Clements <austin@google.com> Auto-Submit: Austin Clements <austin@google.com>
2022-09-02runtime: replace stkframe.arglen/argmap with methodsAustin Clements
Currently, stkframe.arglen and stkframe.argmap are populated by gentraceback under a particular set of circumstances. But because they can be constructed from other fields in stkframe, they don't need to be computed eagerly at all. They're also rather misleading, as they're only part of computing the actual argument map and most callers should be using getStackMap, which does the rest of the work. This CL drops these fields from stkframe. It shifts the functions that used to compute them, getArgInfoFast and getArgInfo, into corresponding methods stkframe.argBytes and stkframe.argMapInternal. argBytes is expected to be used by callers that need to know only the argument frame size, while argMapInternal is used only by argBytes and getStackMap. We also move some of the logic from getStackMap into argMapInternal because the previous split of responsibilities didn't make much sense. This lets us return just a bitvector from argMapInternal, rather than both a bitvector, which carries a size, and an "actually use this size". The getArgInfoFast function was inlined before (and inl_test checked this). We drop that requirement from stkframe.argBytes because the uses of this have shifted and now it's only called from heap dumping (which never happens) and conservative stack frame scanning (which very, very rarely happens). There will be a few follow-up clean-up CLs. For #54466. This is a nice clean-up on its own, but it also serves to remove pointers from the traceback state that would eventually become troublesome write barriers once we stack-rip gentraceback. Change-Id: I107f98ed8e7b00185c081de425bbf24af02a4163 Reviewed-on: https://go-review.googlesource.com/c/go/+/424514 Run-TryBot: Austin Clements <austin@google.com> Auto-Submit: Austin Clements <austin@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-09-02runtime: switch gp when jumping stacks during tracebackAustin Clements
Currently, when traceback jumps from the system stack to a user stack (e.g., during profiling tracebacks), it leaves gp pointing at the g0. This is currently harmless since it's only used during profiling, so the code paths in gentraceback that care about gp aren't used, but it's really confusing and would certainly break if _TraceJumpStack were ever used in a context other than profiling. Fix this by updating gp to point to the user g when we switch stacks. For #54466. Change-Id: I1541e004667a52e37671803ce45c91d8c5308830 Reviewed-on: https://go-review.googlesource.com/c/go/+/424257 Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Auto-Submit: Austin Clements <austin@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Austin Clements <austin@google.com>
2022-09-02runtime: drop redundant argument to getArgInfoAustin Clements
The f funcInfo argument is always the same as frame.fn, so we don't need to pass it. I suspect that was there to make the signatures of getArgInfoFast and getArgInfo more similar, but it's not necessary. For #54466. Change-Id: Idc717f4df09e97cad49d52c5b7edf28090908cba Reviewed-on: https://go-review.googlesource.com/c/go/+/424255 Run-TryBot: Austin Clements <austin@google.com> Auto-Submit: Austin Clements <austin@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-09-02runtime: drop function context from tracebackAustin Clements
Currently, gentraceback tracks the closure context of the outermost frame. This used to be important for "unstarted" calls to reflect function stubs, where "unstarted" calls are either deferred functions or the entry-point of a goroutine that hasn't run. Because reflect function stubs have a dynamic argument map, we have to reach into their closure context to fetch to map, and how to do this differs depending on whether the function has started. This was discovered in issue #25897. However, as part of the register ABI, "go" and "defer" were made much simpler, and any "go" or "defer" of a function that takes arguments or returns results gets wrapped in a closure that provides those arguments (and/or discards the results). Hence, we'll see that closure instead of a direct call to a reflect stub, and can get its static argument map without any trouble. The one case where we may still see an unstarted reflect stub is if the function takes no arguments and has no results, in which case the compiler can optimize away the wrapper closure. But in this case we know the argument map is empty: the compiler can apply this optimization precisely because the target function has no argument frame. As a result, we no longer need to track the closure context during traceback, so this CL drops all of that mechanism. We still have to be careful about the unstarted case because we can't reach into the function's locals frame to pull out its context (because it has no locals frame). We double-check that in this case we're at the function entry. I would prefer to do this with some in-code PCDATA annotations of where to find the dynamic argument map, but that's a lot of mechanism to introduce for just this. It might make sense to consider this along with #53609. Finally, we beef up the test for this so it more reliably forces the runtime down this path. It's fundamentally probabilistic, but this tweak makes it better. Scheduler testing hooks (#54475) would make it possible to write a reliable test for this. For #54466, but it's a nice clean-up all on its own. Change-Id: I16e4f2364ba2ea4b1fec1e27f971b06756e7b09f Reviewed-on: https://go-review.googlesource.com/c/go/+/424254 Run-TryBot: Austin Clements <austin@google.com> Reviewed-by: Michael Pratt <mpratt@google.com> Auto-Submit: Austin Clements <austin@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-08-18runtime: convert m.cgoCallersUse to atomic typeCuong Manh Le
Updates #53821 Change-Id: I99b01f8e91b798e73275635c8a63fcdc4a8df9f1 Reviewed-on: https://go-review.googlesource.com/c/go/+/423888 Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Michael Pratt <mpratt@google.com> Reviewed-by: Keith Randall <khr@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
2022-08-12runtime: convert panicking to atomic typeMichael Pratt
For #53821. Change-Id: I93409f377881a3c029b41b0f1fbcef5e21091f2f Reviewed-on: https://go-review.googlesource.com/c/go/+/419438 Reviewed-by: Austin Clements <austin@google.com> Run-TryBot: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-08-02runtime: tricky replacements of g in traceback.goMichael Pratt
Change-Id: I80e847451b697de049a01df051a73b5976b39d4a Reviewed-on: https://go-review.googlesource.com/c/go/+/418589 Reviewed-by: Austin Clements <austin@google.com> Run-TryBot: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-08-02runtime: fix outdated g.m comment in traceback.goMichael Pratt
Change-Id: Idfd02781a9ee550da240ef53898943e8cd37dd64 Reviewed-on: https://go-review.googlesource.com/c/go/+/418574 Run-TryBot: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2022-07-11internal/trace: don't report regions on system goroutinesMichael Pratt
If a goroutine is started within a user region, internal/trace assigns the child goroutine a nameless region for its entire lifetime which is assosciated the same task as the parent's region. This is not strictly necessary: a child goroutine is not necessarily related to the task unless it performs some task operation (in which case it will be associated with the task through the standard means). However, it can be quite handy to see child goroutines within a region, which may be child worker goroutines that you simply didn't perform task operations on. If the first GC occurs during a region, the GC worker goroutines will also inherit a child region. We know for sure that these aren't related to the task, so filter them out from the region list. Note that we can't exclude system goroutines from setting activeRegions in EvGoCreate handling, because we don't know the goroutine start function name until the first EvGoStart. Fixes #53784. Change-Id: Ic83d84e23858a8400a76d1ae2f1418ef49951178 Reviewed-on: https://go-review.googlesource.com/c/go/+/416858 Run-TryBot: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2022-04-28runtime: use saved LR when unwinding through morestackCherry Mui
On LR machine, consider F calling G calling H, which grows stack. The stack looks like ... G's frame: ... locals ... saved LR = return PC in F <- SP points here at morestack H's frame (to be created) At morestack, we save gp.sched.pc = H's morestack call gp.sched.sp = H's entry SP (the arrow above) gp.sched.lr = return PC in G Currently, when unwinding through morestack (if _TraceJumpStack is set), we switch PC and SP but not LR. We then have frame.pc = H's morestack call frame.sp = H's entry SP (the arrow above) As LR is not set, we load it from stack at *sp, so frame.lr = return PC in F As the SP hasn't decremented at the morestack call, frame.fp = frame.sp = H's entry SP Unwinding a frame, we have frame.pc = old frame.lr = return PC in F frame.sp = old frame.fp = H's entry SP a.k.a. G's SP The PC and SP don't match. The unwinding will go off if F and G have different frame sizes. Fix this by preserving the LR when switching stack. Also add code to detect infinite loop in unwinding. TODO: add some test. I can reproduce the infinite loop (or throw with added check) but the frequency is low. May fix #52116. Change-Id: I6e1294f1c6e55f664c962767a1cf6c466a0c0eff Reviewed-on: https://go-review.googlesource.com/c/go/+/400575 TryBot-Result: Gopher Robot <gobot@golang.org> Run-TryBot: Cherry Mui <cherryyz@google.com> Reviewed-by: Eric Fang <eric.fang@arm.com> Reviewed-by: Benny Siegert <bsiegert@gmail.com>
2022-04-28runtime: simply user throws, expand runtime throwsMichael Pratt
This gives explicit names to the possible states of throwing (-1, 0, 1). m.throwing is now one of: throwTypeOff: not throwing, previously == 0 throwTypeUser: user throw, previously == -1 throwTypeRuntime: runtime throw, previously == 1 For runtime throws, we now always include frame metadata and system goroutines regardless of GOTRACEBACK to aid in debugging the runtime. For user throws, we no longer include frame metadata or runtime frames, unless GOTRACEBACK=system or higher. For #51485. Change-Id: If252e2377a0b6385ce7756b937929be4273a56c0 Reviewed-on: https://go-review.googlesource.com/c/go/+/390421 Run-TryBot: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Austin Clements <austin@google.com>
2022-04-23runtime: support for debugger function calls on linux/arm64eric fang
This CL adds support for debugger function calls on linux arm64 platform. The protocol is basically the same as in CL 109699, except for the following differences: 1, The abi difference which affect parameter passing and frame layout. 2, Stores communication information in R20. 3, The closure register is R26. 4, Use BRK 0 instruction to generate a breakpoint. The saved PC in sigcontext is the PC where the signal occurred, not the next PC. In addition, this CL refactors the existing code (which is dedicated to amd64) for easier multi-arch scaling. Fixes #50614 Change-Id: I06b14e345cc89aab175f4a5f2287b765da85a86b Reviewed-on: https://go-review.googlesource.com/c/go/+/395754 Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com> Run-TryBot: Eric Fang <eric.fang@arm.com> TryBot-Result: Gopher Robot <gobot@golang.org>
2022-03-07runtime: print goid when throwing in gentracebackMichael Pratt
This makes it easier to figure out where the crash is occurring. Change-Id: Ie1f78a360367090dcd61c61b2a55c34f3e2ff2eb Reviewed-on: https://go-review.googlesource.com/c/go/+/390034 Trust: David Chase <drchase@google.com> Reviewed-by: David Chase <drchase@google.com> Trust: Michael Pratt <mpratt@google.com> Run-TryBot: Michael Pratt <mpratt@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-03-04runtime: support cgo traceback on linux arm64eric fang
Code essentially mirrors AMD64 implementation. Change-Id: Ie97627a3041d1858fb1a30d2fc500302ab4011b3 Reviewed-on: https://go-review.googlesource.com/c/go/+/373363 Trust: Eric Fang <eric.fang@arm.com> Run-TryBot: Eric Fang <eric.fang@arm.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>
2021-11-12runtime: start ARM atomic kernel helper traceback in callerMichael Pratt
Like the VDSO, we cannot directly traceback from the Linux kernel ARM atomic/barrier helpers. However, unlike the VDSO, this functions are extremely simple. Neither of the functions we use, kuser_cmpxchg and kuser_memory_barrier, touch SP or LR. We can use this to our advantage to read LR and simply start tracebacks in the caller. Fixes #49182 Change-Id: I890edbeb7c128938000fe7baf6f913c02a956edd Reviewed-on: https://go-review.googlesource.com/c/go/+/362977 Trust: Michael Pratt <mpratt@google.com> Run-TryBot: Michael Pratt <mpratt@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-11-02runtime, syscall: add calls to asan functionsfanzha02
Add explicit address sanitizer instrumentation to the runtime and syscall packages. The compiler does not instrument the runtime package. It does instrument the syscall package, but we need to add a couple of cases that it can't see. Refer to the implementation of the asan malloc runtime library, this patch also allocates extra memory as the redzone, around the returned memory region, and marks the redzone as unaddressable to detect the overflows or underflows. Updates #44853. Change-Id: I2753d1cc1296935a66bf521e31ce91e35fcdf798 Reviewed-on: https://go-review.googlesource.com/c/go/+/298614 Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org> Trust: fannie zhang <Fannie.Zhang@arm.com>
2021-10-27cmd/compile, runtime: track argument stack slot livenessCherry Mui
Currently, for stack traces (e.g. at panic or when runtime.Stack is called), we print argument values from the stack. With register ABI, we may never store the argument to stack therefore the argument value on stack may be meaningless. This causes confusion. This CL makes the compiler keep trace of which argument stack slots are meaningful. If it is meaningful, it will be printed in stack traces as before. If it may not be meaningful, it will be printed as the stack value with a question mark ("?"). In general, the value could be meaningful on some code paths but not others depending on the execution, and the compiler couldn't know statically, so we still print the stack value, instead of not printing it at all. Also note that if the argument variable is updated in the function body the printed value may be stale (like before register ABI) but still considered meaningful. Arguments passed on stack are always meaningful therefore always printed without a question mark. Results are never printed, as before. (Due to a bug in the compiler we sometimes don't spill args into their dedicated spill slots (as we should), causing it having fewer meaningful values than it should be.) This increases binary sizes a bit: old new hello 1129760 1142080 +1.09% cmd/go 13932320 14088016 +1.12% cmd/link 6267696 6329168 +0.98% Fixes #45728. Change-Id: I308a0402e5c5ab94ca0953f8bd85a56acd28f58c Reviewed-on: https://go-review.googlesource.com/c/go/+/352057 Trust: Cherry Mui <cherryyz@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-10-26runtime: handle async fatal signals in VDSOMichael Pratt
If we receive an async signal while running in the VDSO, such as a SIGABRT or SIGSEGV sent from another process, we fail to print the stacktrace with "runtime: unknown pc <vdso PC>". We already have machinery to handle SIGPROF in the VDSO, but it isn't hooked up for other signals. Add it to the general signal traceback path. This case is covered by TestSegv by making the test more strict w.r.t. accepted output. Fixes #47537 Change-Id: I755585f70e0c23e207e135bc6bd2aa68298e5d24 Reviewed-on: https://go-review.googlesource.com/c/go/+/339990 Trust: Michael Pratt <mpratt@google.com> Run-TryBot: Michael Pratt <mpratt@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-09-27runtime: convert _func.entry to a methodJosh Bleecher Snyder
A subsequent change will alter the semantics of _func.entry. To make that change obvious and clear, change _func.entry to a method, and rename the field to _func.entryPC. Change-Id: I05d66b54d06c5956d4537b0729ddf4290c3e2635 Reviewed-on: https://go-review.googlesource.com/c/go/+/351460 Trust: Josh Bleecher Snyder <josharian@gmail.com> Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-08-17all: fix typosYasuhiro Matsumoto
Change-Id: I83180c472db8795803c1b9be3a33f35959e4dcc2 Reviewed-on: https://go-review.googlesource.com/c/go/+/336889 Reviewed-by: Rob Pike <r@golang.org> Reviewed-by: Austin Clements <austin@google.com>
2021-06-17[dev.typeparams] runtime/internal/sys: replace BigEndian with ↵Michael Anthony Knyszek
goarch.BigEndian [generated] [git-generate] cd src/runtime/internal/atomic gofmt -w -r "sys.BigEndian -> goarch.BigEndian" . goimports -w *.go cd ../.. gofmt -w -r "sys.BigEndian -> goarch.BigEndian" . goimports -w *.go Change-Id: Iad35d2b367d8defb081a77ca837e7a7c805c2b7b Reviewed-on: https://go-review.googlesource.com/c/go/+/329190 Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Michael Knyszek <mknyszek@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Go Bot <gobot@golang.org>
2021-06-17[dev.typeparams] runtime: fix import sort order [generated]Michael Anthony Knyszek
[git-generate] cd src/runtime goimports -w *.go Change-Id: I1387af0f2fd1a213dc2f4c122e83a8db0fcb15f0 Reviewed-on: https://go-review.googlesource.com/c/go/+/329189 Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Michael Knyszek <mknyszek@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Go Bot <gobot@golang.org>
2021-06-17[dev.typeparams] runtime: replace uses of runtime/internal/sys.PtrSize with ↵Michael Anthony Knyszek
internal/goarch.PtrSize [generated] [git-generate] cd src/runtime/internal/math gofmt -w -r "sys.PtrSize -> goarch.PtrSize" . goimports -w *.go cd ../.. gofmt -w -r "sys.PtrSize -> goarch.PtrSize" . goimports -w *.go Change-Id: I43491cdd54d2e06d4d04152b3d213851b7d6d423 Reviewed-on: https://go-review.googlesource.com/c/go/+/328337 Trust: Michael Knyszek <mknyszek@google.com> Run-TryBot: Michael Knyszek <mknyszek@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2021-06-14[dev.typeparams] all: merge master (fdab5be) into dev.typeparamsMatthew Dempsky
Two non-conflict changes included because they're needed for all.bash: 1. Bump internal/goversion.Version to 18. This will happen eventually anyway (dev.typeparams will not be merged back to Go 1.17), and is needed for cmd/api to allow new API additions. 2. Add fixedbugs/issue46725.go (new test added on master) to the list of known failures for -G=3. This test exercises a bug that was fixed in typecheck, but -G=3 mode has duplicated that code and will need to be fixed as well. That's outside of the scope of a merge. Conflicts: - src/runtime/traceback.go Nearby lines were removed on both master and dev.typeparams. Merge List: + 2021-06-14 fdab5be159 doc/go1.17: further revise OpenBSD release notes + 2021-06-14 326ea438bb cmd/compile: rewrite a, b = f() to use temporaries when type not identical + 2021-06-14 3249b645c9 cmd/compile: factor out rewrite multi-valued f() + 2021-06-13 14305bf0b9 misc/cgo: generate Windows import libraries for clang + 2021-06-13 24cff0f044 cmd/go, misc/cgo: skip test if no .edata + 2021-06-13 67b1b6a2e3 cmd/compile: allow ir.OSLICE2ARRPTR in mayCall + 2021-06-12 1ed0d129e9 runtime: testprogcgo: don't call exported Go functions directly from Go + 2021-06-12 9d46ee5ac4 reflect: handle stack-to-register translation in callMethod + 2021-06-11 e552a6d312 cmd/go: remove hint when no module is suggested + 2021-06-11 16b5d766d8 syscall: do not load native libraries on non-native powershell on arm + 2021-06-11 77aa209b38 runtime: loop on EINTR in macOS sigNoteSleep + 2021-06-11 e2dc6dd5c9 doc/go1.17: clean up formatting of gofmt section + 2021-06-11 2f1128461d cmd/go: match Windows paths in TestScript/mod_invalid_version + 2021-06-11 2721da2608 doc/go1.17: fix formatting near httptest + 2021-06-10 770f1de8c5 net/http: remove test-only private key from production binaries + 2021-06-10 8d11b1d117 cmd/go: report the imports of CompiledGoFiles in ImportMap + 2021-06-10 dc00dc6c6b crypto/tls: let HTTP/1.1 clients connect to servers with NextProtos "h2" + 2021-06-09 27f83723e9 api: promote next to go1.17 + 2021-06-09 182157c81a doc/go1.17: remove lingering TODO + 2021-06-09 a5bc060b42 doc/go1.17: document strconv changes for Go 1.17 + 2021-06-09 1402b27d46 strconv: document parsing of leading +/- + 2021-06-09 df35ade067 doc/go1.17: document //go:build lines + 2021-06-09 e4e7807d24 net/http: add AllowQuerySemicolons + 2021-06-09 ec3026d032 doc/go1.17: remove TODO for ports section + 2021-06-09 e6dda19888 net/url: reject query values with semicolons + 2021-06-09 139e935d3c math/big: comment division + 2021-06-09 aa5540cd82 cmd/compile: make map.zero symbol content-addressable + 2021-06-09 07ca28d529 cmd/link: fix bug in -strictdups checking of BSS symbols + 2021-06-08 bcecae2af6 doc/go1.17: mention new possibility of type conversion panicking + 2021-06-08 63dcab2e91 doc/go1.17: mention new vet checks sigchanyzer and stdmethods. + 2021-06-08 6551763a60 doc/go1.17: mention block profile bias fix + 2021-06-08 cb80937bf6 Revert "doc/go1.17: mention block profile bias fix" + 2021-06-08 d3e3d03666 net: reject leading zeros in IP address parsers + 2021-06-08 da4a640141 doc/go1.17: revise OpenBSD release notes + 2021-06-08 689f4c7415 doc/go1.17: mention block profile bias fix + 2021-06-08 9afe071c60 doc/go1.17: remove TODO for Tools section + 2021-06-08 f753d7223e doc/go1.17: resolve TODO for cmd/cover + 2021-06-08 9498b0155d cmd/go: in Go 1.17+ modules, add indirect go.mod dependencies separately from direct ones + 2021-06-08 949f00cebe doc/go1.17: add release notes for crypto packages + 2021-06-08 0fb3e2c184 doc/go1.17: add a release note for the '-compat' flag to 'go mod tidy' + 2021-06-08 2169deb352 cmd/compile: use t.AllMethods when sorting typesByString + 2021-06-08 c20bcb6488 runtime: remove out-of-date comments about frame skipping + 2021-06-07 39c39ae52f doc: document Go 1.17 language changes + 2021-06-07 dc8b558951 cmd/dist: pass -Wno-lto-type-mismatch in swig_callback_lto + 2021-06-07 909dd5e010 strconv: ParseFloat: always return ErrSyntax for bad syntax Change-Id: Iffdf379d0275bbd12d50149ce38634773ced481d
2021-06-08[dev.typeparams] runtime: remove tracebackdefersCherry Mui
tracebackdefers is used for scanning/copying deferred functions' arguments. Now that deferred functions are always argumentless, it does nothing. Remove. Change-Id: I55bedabe5584ea41a12cdb03d55ec9692a5aacd9 Reviewed-on: https://go-review.googlesource.com/c/go/+/325916 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>
2021-06-08[dev.typeparams] runtime: remove variadic defer/go callsCherry Mui
Now that defer/go wrapping is used, deferred/go'd functions are always argumentless. Remove the code handling arguments. This CL is mostly removing the fallback code path. There are more cleanups to be done, in later CLs. Change-Id: I87bfd3fb2d759fbeb6487b8125c0f6992863d6e5 Reviewed-on: https://go-review.googlesource.com/c/go/+/325915 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>
2021-06-08runtime: remove out-of-date comments about frame skippingMatthew Dempsky
skipPleaseUseCallersFrames was removed in CL 152537. Change-Id: Ide47feec85a33a6fb6882e16baf9e21492521640 Reviewed-on: https://go-review.googlesource.com/c/go/+/325949 Trust: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2021-05-12runtime: fix handling of SPWRITE functions in tracebackRuss Cox
It is valid to see SPWRITE functions at the top of a GC stack traceback, in the case where they self-preempted during the stack growth check and haven't actually modified SP in a traceback-unfriendly manner yet. The current check is therefore too aggressive. isAsyncSafePoint is taking care of not async-preempting SPWRITE functions because it doesn't async-preempt any assembly functions at all. But perhaps it will in the future. To keep a check that SPWRITE assembly functions are not async-preempted, add one in preemptPark. Then relax the check in traceback to avoid triggering on self-preempted SPWRITE functions. The long and short of this is that the assembly we corrected in x/crypto issue #44269 was incredibly dodgy but not technically incompatible with the Go runtime. After this change, the original x/crypto assembly no longer causes GC traceback crashes during "GOGC=1 go test -count=1000". But we'll still leave the corrected assembly. This also means that we don't need to worry about diagnosing SPWRITE assembly functions that may exist in the wild. They will be skipped for async preemption and no harm no foul. Fixes #44269, which was open pending some kind of check for bad SPWRITE functions in the wild. (No longer needed.) Change-Id: I6000197b62812bbd2cd92da28eab422634cf75a8 Reviewed-on: https://go-review.googlesource.com/c/go/+/317669 Trust: Russ Cox <rsc@golang.org> Run-TryBot: Russ Cox <rsc@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>
2021-04-22cmd/compile, runtime: add metadata for argument printing in tracebackCherry Zhang
Currently, when the runtime printing a stack track (at panic, or when runtime.Stack is called), it prints the function arguments as words in memory. With a register-based calling convention, the layout of argument area of the memory changes, so the printing also needs to change. In particular, the memory order and the syntax order of the arguments may differ. To address that, this CL lets the compiler to emit some metadata about the memory layout of the arguments, and the runtime will use this information to print arguments in syntax order. Previously we print the memory contents of the results along with the arguments. The results are likely uninitialized when the traceback is taken, so that information is rarely useful. Also, with a register-based calling convention the results may not have corresponding locations in memory. This CL changes it to not print results. Previously the runtime simply prints the memory contents as pointer-sized words. With a register-based calling convention, as the layout changes, arguments that were packed in one word may no longer be in one word. Also, as the spill slots are not always initialized, it is possible that some part of a word contains useful informationwhile the rest contains garbage. Instead of letting the runtime recreating the ABI0 layout and print them as words, we now print each component separately. Aggregate-typed argument/component is surrounded by "{}". For example, for a function F(int, [3]byte, byte) int when called as F(1, [3]byte{2, 3, 4}, 5), it used to print F(0x1, 0x5040302, 0xXXXXXXXX) // assuming little endian, 0xXXXXXXXX is uninitilized result Now prints F(0x1, {0x2, 0x3, 0x4}, 0x5). Note: the liveness tracking of the spill splots has not been implemented in this CL. Currently the runtime just assumes all the slots are live and print them all. Increase binary sizes by ~1.5%. old new hello (println) 1171328 1187712 (+1.4%) hello (fmt) 1877024 1901600 (+1.3%) cmd/compile 22326928 22662800 (+1.5%) cmd/go 13505024 13726208 (+1.6%) Updates #40724. Change-Id: I351e0bf497f99bdbb3f91df2fb17e3c2c5c316dc Reviewed-on: https://go-review.googlesource.com/c/go/+/304470 Trust: Cherry Zhang <cherryyz@google.com> Run-TryBot: Cherry Zhang <cherryyz@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>
2021-04-02reflect: add register ABI support for makeFuncStub and methodValueCallMichael Anthony Knyszek
This change finishes off functionality register ABI for the reflect package. Specifically, it implements a call on a MakeFunc'd value by performing the reverse process that reflect.Value.Call does, using the same ABI steps. It implements a call on a method value created by reflect by translating between the method value's ABI to the method's ABI. Tests are added for both cases. For #40724. Change-Id: I302820b61fc0a8f94c5525a002bc02776aef41af Reviewed-on: https://go-review.googlesource.com/c/go/+/298670 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>
2021-03-05runtime: encapsulate access to allgsMichael Pratt
Correctly accessing allgs is a bit hairy. Some paths need to lock allglock, some don't. Those that don't are safest using atomicAllG, but usage is not consistent. Rather than doing this ad-hoc, move all access* through forEachG / forEachGRace, the locking and atomic versions, respectively. This will make it easier to ensure safe access. * markroot is the only exception, as it has a far-removed guarantee of safe access via an atomic load of allglen far before actual use. Change-Id: Ie1c7a8243e155ae2b4bc3143577380c695680e89 Reviewed-on: https://go-review.googlesource.com/c/go/+/279994 Trust: Michael Pratt <mpratt@google.com> Run-TryBot: Michael Pratt <mpratt@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Michael Knyszek <mknyszek@google.com>