On Mon, 12 Aug 2024, Felix Lechner via "Developers list for Guile, the GNU extensibility library" <guile-devel@gnu.org> wrote: > Hi, [...]
> The warning probably originates here: > > ret = madvise ((void *) lo, hi - lo, MADV_DONTNEED); [4] > > From my reading, that call is meant to return stack space back to the > operating system. According to the madvise(2) manual page [5] the > variable 'lo' must be page-aligned, but apparently isn't. > > Why would the 'stack_bottom' not be page aligned, please? Could it be > mitigated by alignment instructions in my ELF shared object? The argument passed to `madvise(2)' is page aligned correcly. See the round down with `lo &= ~(page_size - 1U); /* round down */' just above the call. The following is possible for EINVAL to be returned: 1) hi - lo < page_size 2) lenght = hi - lo; lo + lenght < lo => Unsigned integer overflow 3) The memory range is locked. See mlock(2) 4) The variable `page_size' is zero for some reason (highly doubt) You can check for all of the above with a debugger or `strace(1)' easily. Regards, Olivier -- Olivier Dion oldiob.ca
