I haven't had a chance to test this yet, but the original decision of
placing it in reloc_static_pie.c was to ensure that when reloc_static_pie()
accessed _dl_load_base it would do so without relying on relocations.

Do you mind letting me know which architecture you are building on? On one
or two architectures I do make use of _DYNAMIC in _start() and I wonder if
maybe that is leaking into static builds?

Also it doesn't look like you are 0 initializing _dl_load_base in its new
location. This is a requirement since non-pie static binaries will hit the
code path and expect _dl_load_base to be 0.

On Fri, Sep 2, 2022, 1:24 AM Max Filippov <[email protected]> wrote:

> When uclibc is built with static PIE support the _dl_load_base variable
> shared between the libc-tls.c and reloc_static_pie.c creates the
> dependency that requires linking reloc_static_pie.o into static
> position-dependent executables resulting in the following build errors:
>   gcc -static test.c -o test
>   ...ld:
>   ...usr/lib/libc.a(reloc_static_pie.os):(.text+0x0):
>         undefined reference to `_DYNAMIC'
>
> Move _dl_load_base definition to libc-tls.c to resolve this dependency
> and fix static PDE build.
>
> Signed-off-by: Max Filippov <[email protected]>
> ---
>  libc/misc/internals/reloc_static_pie.c     | 2 +-
>  libpthread/nptl/sysdeps/generic/libc-tls.c | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/libc/misc/internals/reloc_static_pie.c
> b/libc/misc/internals/reloc_static_pie.c
> index 578202d235a1..f66f7a4236c9 100644
> --- a/libc/misc/internals/reloc_static_pie.c
> +++ b/libc/misc/internals/reloc_static_pie.c
> @@ -20,7 +20,7 @@
>  #include <elf.h>
>  #include <dl-elf.h>
>
> -ElfW(Addr) _dl_load_base = NULL;
> +extern ElfW(Addr) _dl_load_base;
>
>  void
>  reloc_static_pie (ElfW(Addr) load_addr);
> diff --git a/libpthread/nptl/sysdeps/generic/libc-tls.c
> b/libpthread/nptl/sysdeps/generic/libc-tls.c
> index 0c8c558d05d3..e0e272e01dae 100644
> --- a/libpthread/nptl/sysdeps/generic/libc-tls.c
> +++ b/libpthread/nptl/sysdeps/generic/libc-tls.c
> @@ -117,6 +117,7 @@ init_static_tls (size_t memsz, size_t align)
>    GL(dl_tls_static_nelem) = GL(dl_tls_max_dtv_idx);
>  }
>
> +ElfW(Addr) _dl_load_base;
>  void __libc_setup_tls (size_t tcbsize, size_t tcbalign);
>  void
>  __libc_setup_tls (size_t tcbsize, size_t tcbalign)
> @@ -143,8 +144,7 @@ __libc_setup_tls (size_t tcbsize, size_t tcbalign)
>  #else
>           initimage = (void *) phdr->p_vaddr;
>  #if !defined(SHARED) && defined(STATIC_PIE)
> -    extern ElfW(Addr) _dl_load_base;
> -    initimage += _dl_load_base;
> +         initimage += _dl_load_base;
>  #endif
>  #endif
>           align = phdr->p_align;
> --
> 2.30.2
>
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