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| author | Russ Cox <rsc@golang.org> | 2009-10-12 10:26:38 -0700 |
|---|---|---|
| committer | Russ Cox <rsc@golang.org> | 2009-10-12 10:26:38 -0700 |
| commit | add89dd1bae04b641944d082467375f1dc787cd2 (patch) | |
| tree | da51e7592c895d32c8acf0bed84cdd5cfa1dbc01 /src/pkg/runtime/amd64 | |
| parent | fd76b4f3851c70a083991d8e86d7432d9157737b (diff) | |
| download | go-add89dd1bae04b641944d082467375f1dc787cd2.tar.xz | |
stack overflow debugging and fix.
* in 6l, -K already meant check for stack underflow.
add -KK to mean double-check stack overflows
even in nosplit functions.
* comment out print locks; they deadlock too easily
but are still useful to put back for special occasions.
* let runcgo assembly switch to scheduler stack
without involving scheduler directly. because runcgo
gets called from matchmg, it is too hard to keep it
from being called on other stacks.
R=r
DELTA=94 (65 added, 18 deleted, 11 changed)
OCL=35591
CL=35604
Diffstat (limited to 'src/pkg/runtime/amd64')
| -rw-r--r-- | src/pkg/runtime/amd64/asm.s | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/src/pkg/runtime/amd64/asm.s b/src/pkg/runtime/amd64/asm.s index 6cb6d5c77a..87bc222e14 100644 --- a/src/pkg/runtime/amd64/asm.s +++ b/src/pkg/runtime/amd64/asm.s @@ -272,20 +272,32 @@ TEXT jmpdefer(SB), 7, $0 JMP AX // but first run the deferred function // runcgo(void(*fn)(void*), void *arg) -// Call fn(arg), but align the stack -// appropriately for the gcc ABI -// and also save g and m across the call, +// Call fn(arg) on the scheduler stack, +// aligned appropriately for the gcc ABI. +// Save g and m across the call, // since the foreign code might reuse them. TEXT runcgo(SB),7,$32 + // Save old registers. MOVQ fn+0(FP),AX MOVQ arg+8(FP),DI // DI = first argument in AMD64 ABI MOVQ SP, CX + + // Figure out if we need to switch to m->g0 stack. + MOVQ m_g0(m), R8 + CMPQ R8, g + JEQ 2(PC) + MOVQ (m_sched+gobuf_sp)(m), SP + + // Now on a scheduling stack (a pthread-created stack). + SUBQ $32, SP ANDQ $~15, SP // alignment for gcc ABI MOVQ g, 24(SP) // save old g, m, SP MOVQ m, 16(SP) MOVQ CX, 8(SP) CALL AX - MOVQ 16(SP), m // restore + + // Restore registers, stack pointer. + MOVQ 16(SP), m MOVQ 24(SP), g MOVQ 8(SP), SP RET |