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runtime: add crash stack support for wasm

Currently if morestack on g0 happens the wasm runtime prints
"RuntimeError: memory access out of bounds", which is quite misleading.
By switching to a crash stack we can get better stacktraces
for the error.

There is no way to automate tests for this feature on wasm, since
TestG0StackOverflow relies on spawning a subprocess which is not
supported by the wasm port.

The way I got this tested manually is to comment everything in
TestG0StackOverflow, leaving just runtime.G0StackOverflow().

Then it is a matter of invoking the test:

    GOOS=js GOARCH=wasm go test runtime -v -run=TestG0StackOverflow

Change-Id: If450f3ee5209bb32efc1abd0a34b1cc4a29d0c46
GitHub-Last-Rev: 0d7c396e4c
GitHub-Pull-Request: golang/go#63956
Reviewed-on: https://go-review.googlesource.com/c/go/+/539995
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
This commit is contained in:
Mauri de Souza Meneguzzo 2023-11-19 20:21:22 +00:00 committed by Cherry Mui
parent ddb38c3f54
commit 369ce90d2c
3 changed files with 42 additions and 7 deletions

View File

@ -20,6 +20,7 @@ TEXT ·mapinitnoop<ABIInternal>(SB),NOSPLIT,$0-0
#ifndef GOARCH_ppc64
#ifndef GOARCH_ppc64le
#ifndef GOARCH_riscv64
#ifndef GOARCH_wasm
// stub to appease shared build mode.
TEXT ·switchToCrashStack0<ABIInternal>(SB),NOSPLIT,$0-0
UNDEF
@ -30,3 +31,4 @@ TEXT ·switchToCrashStack0<ABIInternal>(SB),NOSPLIT,$0-0
#endif
#endif
#endif
#endif

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@ -140,6 +140,7 @@ TEXT runtime·systemstack(SB), NOSPLIT, $0-8
I64Ne
If
CALLNORESUME runtime·badsystemstack(SB)
CALLNORESUME runtime·abort(SB)
End
// switch:
@ -181,6 +182,9 @@ TEXT runtime·systemstack(SB), NOSPLIT, $0-8
TEXT runtime·systemstack_switch(SB), NOSPLIT, $0-0
RET
TEXT runtime·abort(SB),NOSPLIT|NOFRAME,$0-0
UNDEF
// AES hashing not implemented for wasm
TEXT runtime·memhash(SB),NOSPLIT|NOFRAME,$0-32
JMP runtime·memhashFallback(SB)
@ -208,6 +212,33 @@ TEXT runtime·procyield(SB), NOSPLIT, $0-0 // FIXME
TEXT runtime·breakpoint(SB), NOSPLIT, $0-0
UNDEF
// func switchToCrashStack0(fn func())
TEXT runtime·switchToCrashStack0(SB), NOSPLIT, $0-8
MOVD fn+0(FP), CTXT // context register
MOVD g_m(g), R2 // curm
// set g to gcrash
MOVD $runtime·gcrash(SB), g // g = &gcrash
MOVD R2, g_m(g) // g.m = curm
MOVD g, m_g0(R2) // curm.g0 = g
// switch to crashstack
I64Load (g_stack+stack_hi)(g)
I64Const $(-4*8)
I64Add
I32WrapI64
Set SP
// call target function
Get CTXT
I32WrapI64
I64Load $0
CALL
// should never return
CALL runtime·abort(SB)
UNDEF
// Called during function prolog when more stack is needed.
//
// The traceback routines see morestack on a g0 as being
@ -221,12 +252,19 @@ TEXT runtime·morestack(SB), NOSPLIT, $0-0
// R2 = g0
MOVD m_g0(R1), R2
// Set g->sched to context in f.
NOP SP // tell vet SP changed - stop checking offsets
MOVD 0(SP), g_sched+gobuf_pc(g)
MOVD $8(SP), g_sched+gobuf_sp(g) // f's SP
MOVD CTXT, g_sched+gobuf_ctxt(g)
// Cannot grow scheduler stack (m->g0).
Get g
Get R2
I64Eq
If
CALLNORESUME runtime·badmorestackg0(SB)
CALLNORESUME runtime·abort(SB)
End
// Cannot grow signal stack (m->gsignal).
@ -235,20 +273,15 @@ TEXT runtime·morestack(SB), NOSPLIT, $0-0
I64Eq
If
CALLNORESUME runtime·badmorestackgsignal(SB)
CALLNORESUME runtime·abort(SB)
End
// Called from f.
// Set m->morebuf to f's caller.
NOP SP // tell vet SP changed - stop checking offsets
MOVD 8(SP), m_morebuf+gobuf_pc(R1)
MOVD $16(SP), m_morebuf+gobuf_sp(R1) // f's caller's SP
MOVD g, m_morebuf+gobuf_g(R1)
// Set g->sched to context in f.
MOVD 0(SP), g_sched+gobuf_pc(g)
MOVD $8(SP), g_sched+gobuf_sp(g) // f's SP
MOVD CTXT, g_sched+gobuf_ctxt(g)
// Call newstack on m->g0's stack.
MOVD R2, g
MOVD g_sched+gobuf_sp(R2), SP

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@ -576,7 +576,7 @@ func switchToCrashStack(fn func()) {
abort()
}
const crashStackImplemented = GOARCH == "amd64" || GOARCH == "arm64" || GOARCH == "mips64" || GOARCH == "mips64le" || GOARCH == "ppc64" || GOARCH == "ppc64le" || GOARCH == "riscv64"
const crashStackImplemented = GOARCH == "amd64" || GOARCH == "arm64" || GOARCH == "mips64" || GOARCH == "mips64le" || GOARCH == "ppc64" || GOARCH == "ppc64le" || GOARCH == "riscv64" || GOARCH == "wasm"
//go:noescape
func switchToCrashStack0(fn func()) // in assembly