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// { dg-options "-O0" }
// { dg-shouldfail "segv or bus error" }
import core.thread;
import core.sys.posix.sys.mman;
// this should be true for most architectures
// (taken from core.thread)
version = StackGrowsDown;
enum stackSize = 4096;
// Simple method that causes a stack overflow
void stackMethod()
{
// Over the stack size, so it overflows the stack
int[stackSize/int.sizeof+100] x;
}
void main()
{
auto test_fiber = new Fiber(&stackMethod, stackSize);
// allocate a page below (above) the fiber's stack to make stack overflows possible (w/o segfaulting)
version (StackGrowsDown)
{
static assert(__traits(identifier, test_fiber.tupleof[8]) == "m_pmem");
auto stackBottom = test_fiber.tupleof[8];
auto p = mmap(stackBottom - 8 * stackSize, 8 * stackSize,
PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
assert(p !is null, "failed to allocate page");
}
else
{
auto m_sz = test_fiber.tupleof[7];
auto m_pmem = test_fiber.tupleof[8];
static assert(__traits(identifier, test_fiber.tupleof[7]) == "m_size");
static assert(__traits(identifier, test_fiber.tupleof[8]) == "m_pmem");
auto stackTop = m_pmem + m_sz;
auto p = mmap(stackTop, 8 * stackSize,
PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
assert(p !is null, "failed to allocate page");
}
// the guard page should prevent a mem corruption by stack
// overflow and cause a segfault instead (or generate SIGBUS on *BSD flavors)
test_fiber.call();
}
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