id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
9734	Wrong check of mmap() return value in coroutine stack allocator	Tianlong Wu <rockuw@…>	olli	"In boost source /libs/coroutine/detail/standard_stack_allocator_posix.cpp:120, it has the following snippet:
{{{#!c
    void * limit =
# if defined(macintosh) || defined(__APPLE__) || defined(__APPLE_CC__)
    ::mmap( 0, size_, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
# else
    ::mmap( 0, size_, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
# endif
    ::close( fd);
    if ( ! limit) throw std::bad_alloc();

}}}

It assumes that mmap() returns 0 on fail. However when mmap() fails, the return value is NOT 0, but (void*)-1 instead. This wrong check will bypass the throw and let the error pass down, leading to confusing error message seen by the user."	Bugs	closed	To Be Determined	coroutine	Boost 1.55.0	Problem	fixed