Re: PATCH: BZ #14557: __kernel_vsyscall unwind info is incorrect

[Roland McGrath <roland at hack dot frob dot com>]

> The _ns_loaded list is for ld.so and doesn't support libc.a.  For
> example, ld.so calls its own malloc routines to manage memory before
> entering main.  We can't easily do that in libc.a since we need to set up
> a few things for malloc first.  Unless there is a specific issue we need
> to address, I'd like to use the existing patch.  OK to install?

If statically-linked programs are going to know about the vDSO at all,
then they should support it fully.  That means a static program can use
-ldl and use dlsym to access the vDSO, for example.

The rtld.c code that sets up dl_sysinfo_map can move into a new internal
function in a new dl-foo.c file built both for ld.so and for libc.a.  For
static, that function can be called by some __attribute__((constructor))
function that is defined in the same file as the definition of some data
variables that only -ldl code or dl_iterate_phdr will use, so it's not
included in a static link that doesn't need it.  Surely a static program's
__attribute__((constructor)) functions can call malloc (if they can't, then
that's a preexisting bug we should fix first).


Thanks,
Roland