From 3e97294663d978bf8abb7acec7cc615ef2f1ea75 Mon Sep 17 00:00:00 2001 From: Cherry Mui Date: Mon, 25 Jul 2022 11:02:56 -0400 Subject: [PATCH] runtime/cgo: use frame address to set g0 stack bound For a cgo binary, at startup we set g0's stack bounds using the address of a local variable (&size) in a C function x_cgo_init and the stack size from pthread_attr_getstacksize. Normally, &size is an address within the current stack frame. However, when it is compiled with ASAN, it may be instrumented to __asan_stack_malloc_0 and the address may not live in the current stack frame, causing the stack bound to be set incorrectly, e.g. lo > hi. Using __builtin_frame_address(0) to get the stack address instead. Change-Id: I41df929e5ed24d8bbf3e15027af6dcdfc3736e37 Reviewed-on: https://go-review.googlesource.com/c/go/+/419434 Run-TryBot: Cherry Mui TryBot-Result: Gopher Robot Reviewed-by: Ian Lance Taylor --- src/runtime/cgo/gcc_linux_amd64.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/src/runtime/cgo/gcc_linux_amd64.c b/src/runtime/cgo/gcc_linux_amd64.c index c25e7e769ba23..fb164c1a1df03 100644 --- a/src/runtime/cgo/gcc_linux_amd64.c +++ b/src/runtime/cgo/gcc_linux_amd64.c @@ -44,7 +44,9 @@ x_cgo_init(G *g, void (*setg)(void*), void **tlsg, void **tlsbase) } pthread_attr_init(attr); pthread_attr_getstacksize(attr, &size); - g->stacklo = (uintptr)&size - size + 4096; + g->stacklo = (uintptr)__builtin_frame_address(0) - size + 4096; + if (g->stacklo >= g->stackhi) + fatalf("bad stack bounds: lo=%p hi=%p\n", g->stacklo, g->stackhi); pthread_attr_destroy(attr); free(attr);