runtime: use default system stack size, not 64 kB, on non-cgo macOS

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>

diff --git a/src/runtime/os_darwin.go b/src/runtime/os_darwin.go
index 18c15ad89ee48a7ad370aa821c7f87654a08c08b..819aaaca70f845d9d8d7e44434485f1526f108ef 100644 (file)
--- a/src/runtime/os_darwin.go
+++ b/src/runtime/os_darwin.go
@@ -145,14 +145,14 @@ func newosproc(mp *m) {
                exit(1)
        }
 
-       // Set the stack size we want to use.  64KB for now.
-       // TODO: just use OS default size?
-       const stackSize = 1 << 16
-       if pthread_attr_setstacksize(&attr, stackSize) != 0 {
+       // Find out OS stack size for our own stack guard.
+       var stacksize uintptr
+       if pthread_attr_getstacksize(&attr, &stacksize) != 0 {
                write(2, unsafe.Pointer(&failthreadcreate[0]), int32(len(failthreadcreate)))
                exit(1)
        }
-       //mSysStatInc(&memstats.stacks_sys, stackSize) //TODO: do this?
+       mp.g0.stack.hi = stacksize // for mstart
+       //mSysStatInc(&memstats.stacks_sys, stacksize) //TODO: do this?
 
        // Tell the pthread library we won't join with this thread.
        if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
@@ -191,11 +191,16 @@ func newosproc0(stacksize uintptr, fn uintptr) {
                exit(1)
        }
 
-       // Set the stack we want to use.
-       if pthread_attr_setstacksize(&attr, stacksize) != 0 {
+       // The caller passes in a suggested stack size,
+       // from when we allocated the stack and thread ourselves,
+       // without libpthread. Now that we're using libpthread,
+       // we use the OS default stack size instead of the suggestion.
+       // Find out that stack size for our own stack guard.
+       if pthread_attr_getstacksize(&attr, &stacksize) != 0 {
                write(2, unsafe.Pointer(&failthreadcreate[0]), int32(len(failthreadcreate)))
                exit(1)
        }
+       g0.stack.hi = stacksize // for mstart
        mSysStatInc(&memstats.stacks_sys, stacksize)
 
        // Tell the pthread library we won't join with this thread.

diff --git a/src/runtime/sys_darwin.go b/src/runtime/sys_darwin.go
index 434fa5f5882a1c82915b54ee491988d229d32216..0bf17c47af2a02054db40c320fb7e548ea75b022 100644 (file)
--- a/src/runtime/sys_darwin.go
+++ b/src/runtime/sys_darwin.go
@@ -128,10 +128,10 @@ func pthread_attr_init_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
-func pthread_attr_setstacksize(attr *pthreadattr, size uintptr) int32 {
-       return libcCall(unsafe.Pointer(funcPC(pthread_attr_setstacksize_trampoline)), unsafe.Pointer(&attr))
+func pthread_attr_getstacksize(attr *pthreadattr, size *uintptr) int32 {
+       return libcCall(unsafe.Pointer(funcPC(pthread_attr_getstacksize_trampoline)), unsafe.Pointer(&attr))
 }
-func pthread_attr_setstacksize_trampoline()
+func pthread_attr_getstacksize_trampoline()
 
 //go:nosplit
 //go:cgo_unsafe_args
@@ -396,7 +396,7 @@ func closeonexec(fd int32) {
 // in a system library, with the libc_ prefix missing.
 
 //go:cgo_import_dynamic libc_pthread_attr_init pthread_attr_init "/usr/lib/libSystem.B.dylib"
-//go:cgo_import_dynamic libc_pthread_attr_setstacksize pthread_attr_setstacksize "/usr/lib/libSystem.B.dylib"
+//go:cgo_import_dynamic libc_pthread_attr_getstacksize pthread_attr_getstacksize "/usr/lib/libSystem.B.dylib"
 //go:cgo_import_dynamic libc_pthread_attr_setdetachstate pthread_attr_setdetachstate "/usr/lib/libSystem.B.dylib"
 //go:cgo_import_dynamic libc_pthread_create pthread_create "/usr/lib/libSystem.B.dylib"
 //go:cgo_import_dynamic libc_exit exit "/usr/lib/libSystem.B.dylib"

diff --git a/src/runtime/sys_darwin_386.s b/src/runtime/sys_darwin_386.s
index d318509e0a520ec886943c702ff38d8ce73268e8..9a0b3607c2d1e70678d232d0f4fb8b00f4c18284 100644 (file)
--- a/src/runtime/sys_darwin_386.s
+++ b/src/runtime/sys_darwin_386.s
@@ -474,7 +474,7 @@ TEXT runtime·pthread_attr_init_trampoline(SB),NOSPLIT,$0
        POPL    BP
        RET
 
-TEXT runtime·pthread_attr_setstacksize_trampoline(SB),NOSPLIT,$0
+TEXT runtime·pthread_attr_getstacksize_trampoline(SB),NOSPLIT,$0
        PUSHL   BP
        MOVL    SP, BP
        SUBL    $8, SP
@@ -483,7 +483,7 @@ TEXT runtime·pthread_attr_setstacksize_trampoline(SB),NOSPLIT,$0
        MOVL    AX, 0(SP)
        MOVL    4(CX), AX       // arg 2 size
        MOVL    AX, 4(SP)
-       CALL    libc_pthread_attr_setstacksize(SB)
+       CALL    libc_pthread_attr_getstacksize(SB)
        MOVL    BP, SP
        POPL    BP
        RET

diff --git a/src/runtime/sys_darwin_amd64.s b/src/runtime/sys_darwin_amd64.s
index 934c510b88e738f92f48418037a77ea1430e662b..016b056eb34dd99e9308e5697643e8501a54e462 100644 (file)
--- a/src/runtime/sys_darwin_amd64.s
+++ b/src/runtime/sys_darwin_amd64.s
@@ -443,12 +443,12 @@ TEXT runtime·pthread_attr_init_trampoline(SB),NOSPLIT,$0
        POPQ    BP
        RET
 
-TEXT runtime·pthread_attr_setstacksize_trampoline(SB),NOSPLIT,$0
+TEXT runtime·pthread_attr_getstacksize_trampoline(SB),NOSPLIT,$0
        PUSHQ   BP
        MOVQ    SP, BP
        MOVQ    8(DI), SI       // arg 2 size
        MOVQ    0(DI), DI       // arg 1 attr
-       CALL    libc_pthread_attr_setstacksize(SB)
+       CALL    libc_pthread_attr_getstacksize(SB)
        POPQ    BP
        RET
 

diff --git a/src/runtime/sys_darwin_arm.s b/src/runtime/sys_darwin_arm.s
index 6c3fa0739d7505f9426a87f3d5235b01dfe86a03..82470bc4df2b3704eed7b36627a82e1d41bd2bf8 100644 (file)
--- a/src/runtime/sys_darwin_arm.s
+++ b/src/runtime/sys_darwin_arm.s
@@ -323,7 +323,7 @@ TEXT runtime·pthread_attr_init_trampoline(SB),NOSPLIT,$0
        BL      libc_exit(SB)
        RET
 
-TEXT runtime·pthread_attr_setstacksize_trampoline(SB),NOSPLIT,$0
+TEXT runtime·pthread_attr_getstacksize_trampoline(SB),NOSPLIT,$0
        MOVW    $46, R0
        BL      libc_exit(SB)
        RET

diff --git a/src/runtime/sys_darwin_arm64.s b/src/runtime/sys_darwin_arm64.s
index 79dd009f6fd11abdc26421c7d0a9e586e2b0c2b3..af03af37bba26486ed32387125dbb58a87c27e14 100644 (file)
--- a/src/runtime/sys_darwin_arm64.s
+++ b/src/runtime/sys_darwin_arm64.s
@@ -382,10 +382,10 @@ TEXT runtime·pthread_attr_init_trampoline(SB),NOSPLIT,$0
        BL      libc_pthread_attr_init(SB)
        RET
 
-TEXT runtime·pthread_attr_setstacksize_trampoline(SB),NOSPLIT,$0
+TEXT runtime·pthread_attr_getstacksize_trampoline(SB),NOSPLIT,$0
        MOVD    8(R0), R1       // arg 2 size
        MOVD    0(R0), R0       // arg 1 attr
-       BL      libc_pthread_attr_setstacksize(SB)
+       BL      libc_pthread_attr_getstacksize(SB)
        RET
 
 TEXT runtime·pthread_attr_setdetachstate_trampoline(SB),NOSPLIT,$0