I just sent a proposal to fix the issue. This needs a small modification to 
ldso.h however.

In my opinion the `AUX_MAX_AT_ID` and `_dl_auxvt` definitions are a bit 
misplaced in that file anyways. An alternative to
the sent patch would be to introduce a new header `dl-auxvt.h` that is included 
by `ldso.h` and by `__uClibc_main.c`
instead. However, that seems a bit more invasive. If you want I can try the 
alternative as well and submit an alternate
patch for that version.

Best regards and again apologies for the hassle,

- Marcus



On Thu, 2025-03-06 at 14:41 +0100, Marcus Hähnel wrote:
> Hi Waldemar,
> 
> our apologies. I only compiled this in our environment where the failing code 
> is not used.
> We can reproduce the issue and are looking for a fix.
> 
> - Marcus
> 
> On Thu, 2025-03-06 at 14:08 +0100, Waldemar Brodkorb wrote:
> > Hi Marcus,
> > 
> > I accidentally pushed the changes and now get following build error:
> > 
> > libc/misc/internals/__uClibc_main.c: In function '__uClibc_main':
> > libc/misc/internals/__uClibc_main.c:424:10: error: '_dl_auxvt' undeclared 
> > (first use in this function); did you mean '_dl_aux_init'?
> >   424 |     if ((_dl_auxvt[AT_UID].a_un.a_val == (size_t)-1 && 
> > __check_suid()) ||
> >       |          ^~~~~~~~~
> >       |          _dl_aux_init
> > libc/misc/internals/__uClibc_main.c:424:10: note: each undeclared 
> > identifier is reported only once for each function it appears in
> > gmake[6]: *** [Makerules:373: libc/misc/internals/__uClibc_main.os] Error 1
> > gmake[5]: *** [Makefile:353: 
> > /home/wbx/embedded-test/openadk/toolchain_build_qemu-aarch64_uclibc-ng_cortex_a53/w-uClibc-ng-1.0.51-1/uClibc-ng-1.0.51/.compiled]
> >  Error 2
> > gmake[4]: *** [Makefile:106: uclibc-ng-compile] Error 2
> > gmake[3]: *** [mk/build.mk:229: toolchain/final] Error 2
> > gmake[2]: *** [/home/wbx/embedded-test/openadk/mk/build.mk:174: world] 
> > Error 2
> > gmake[1]: *** [Makefile.adk:25: all] Error 2
> > make: *** [Makefile:22: all] Error 2
> > build failed
> > wbx@helium:~/embedded-test$  
> > 
> > Any idea why it fails for me and not for you?
> > Targeting aarch64 with uClibc-ng master.
> > 
> > best regards
> >  Waldemar
> > 
> > Marcus Haehnel wrote,
> > 
> > > From: Georg Kotheimer <[email protected]>
> > > 
> > > While for dynamic linking the _dl_auxvt array is provided in
> > > dl-startup.c as part of the ldso, is was undefined for statically
> > > linked binaries. This resulted in a corresponding linker error if
> > > a statically linked program used getauxval.
> > > 
> > > To provide _dl_auxvt also for statically linked binaries, a definition
> > > of _dl_auxvt is added to dl-support.c and initialized by _dl_aux_init().
> > > 
> > > Signed-off-by: Marcus Haehnel <[email protected]>
> > > ---
> > >  libc/misc/elf/dl-support.c          | 16 +++++++++++++---
> > >  libc/misc/internals/__uClibc_main.c | 22 ++++++----------------
> > >  2 files changed, 19 insertions(+), 19 deletions(-)
> > > 
> > > diff --git a/libc/misc/elf/dl-support.c b/libc/misc/elf/dl-support.c
> > > index 87cd1bb72..81c78fa55 100644
> > > --- a/libc/misc/elf/dl-support.c
> > > +++ b/libc/misc/elf/dl-support.c
> > > @@ -12,6 +12,7 @@
> > >   */
> > >  
> > >  #include <link.h>
> > > +#include <ldso.h>
> > >  #include <elf.h>
> > >  #if defined(USE_TLS) && USE_TLS
> > >  #include <assert.h>
> > > @@ -31,17 +32,26 @@ ElfW(Phdr) *_dl_phdr;
> > >  size_t _dl_phnum;
> > >  size_t _dl_pagesize;
> > >  
> > > +ElfW(auxv_t) _dl_auxvt[AUX_MAX_AT_ID];
> > > +
> > >  void internal_function _dl_aux_init (ElfW(auxv_t) *av);
> > >  void internal_function _dl_aux_init (ElfW(auxv_t) *av)
> > >  {
> > > +   memset(_dl_auxvt, 0x00, sizeof(_dl_auxvt));
> > > +   for (; av->a_type != AT_NULL; av++)
> > > +     {
> > > +       if (av->a_type < AUX_MAX_AT_ID)
> > > +         _dl_auxvt[av->a_type] = *av;
> > > +     }
> > > +
> > >     /* Get the program headers base address from the aux vect */
> > > -   _dl_phdr = (ElfW(Phdr) *) av[AT_PHDR].a_un.a_val;
> > > +   _dl_phdr = (ElfW(Phdr) *) _dl_auxvt[AT_PHDR].a_un.a_val;
> > >  
> > >     /* Get the number of program headers from the aux vect */
> > > -   _dl_phnum = (size_t) av[AT_PHNUM].a_un.a_val;
> > > +   _dl_phnum = (size_t) _dl_auxvt[AT_PHNUM].a_un.a_val;
> > >  
> > >     /* Get the pagesize from the aux vect */
> > > -   _dl_pagesize = (av[AT_PAGESZ].a_un.a_val) ? (size_t) 
> > > av[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
> > > +   _dl_pagesize = (_dl_auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) 
> > > _dl_auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
> > >  }
> > >  
> > >  #if defined(USE_TLS) && USE_TLS
> > > diff --git a/libc/misc/internals/__uClibc_main.c 
> > > b/libc/misc/internals/__uClibc_main.c
> > > index 64a9c8214..a84492248 100644
> > > --- a/libc/misc/internals/__uClibc_main.c
> > > +++ b/libc/misc/internals/__uClibc_main.c
> > > @@ -43,7 +43,7 @@
> > >  /* Are we in a secure process environment or are we dealing
> > >   * with setuid stuff?  If we are dynamically linked, then we
> > >   * already have _dl_secure, otherwise we need to re-examine
> > > - * auxvt[] below.
> > > + * _dl_auxvt[] below.
> > >   */
> > >  int _pe_secure = 0;
> > >  libc_hidden_data_def(_pe_secure)
> > > @@ -373,7 +373,6 @@ void __uClibc_main(int (*main)(int, char **, char 
> > > **), int argc,
> > >  {
> > >  #ifndef SHARED
> > >      unsigned long *aux_dat;
> > > -    ElfW(auxv_t) auxvt[AT_EGID + 1];
> > >  #endif
> > >  
> > >  #ifdef __UCLIBC_HAS_THREADS_NATIVE__
> > > @@ -399,23 +398,14 @@ void __uClibc_main(int (*main)(int, char **, char 
> > > **), int argc,
> > >  
> > >  #ifndef SHARED
> > >      /* Pull stuff from the ELF header when possible */
> > > -    memset(auxvt, 0x00, sizeof(auxvt));
> > >      aux_dat = (unsigned long*)__environ;
> > >      while (*aux_dat) {
> > >   aux_dat++;
> > >      }
> > >      aux_dat++;
> > > -    while (*aux_dat) {
> > > - ElfW(auxv_t) *auxv_entry = (ElfW(auxv_t) *) aux_dat;
> > > - if (auxv_entry->a_type <= AT_EGID) {
> > > -     memcpy(&(auxvt[auxv_entry->a_type]), auxv_entry, 
> > > sizeof(ElfW(auxv_t)));
> > > - }
> > > - aux_dat += 2;
> > > -    }
> > >      /* Get the program headers (_dl_phdr) from the aux vector
> > >         It will be used into __libc_setup_tls. */
> > > -
> > > -    _dl_aux_init (auxvt);
> > > +    _dl_aux_init ((ElfW(auxv_t) *)aux_dat);
> > >  #endif
> > >  
> > >      /* We need to initialize uClibc.  If we are dynamically linked this
> > > @@ -431,10 +421,10 @@ void __uClibc_main(int (*main)(int, char **, char 
> > > **), int argc,
> > >  #ifndef SHARED
> > >      /* Prevent starting SUID binaries where the stdin. stdout, and
> > >       * stderr file descriptors are not already opened. */
> > > -    if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && __check_suid()) ||
> > > -     (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
> > > -     (auxvt[AT_UID].a_un.a_val != auxvt[AT_EUID].a_un.a_val ||
> > > -      auxvt[AT_GID].a_un.a_val != auxvt[AT_EGID].a_un.a_val)))
> > > +    if ((_dl_auxvt[AT_UID].a_un.a_val == (size_t)-1 && __check_suid()) ||
> > > +     (_dl_auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
> > > +     (_dl_auxvt[AT_UID].a_un.a_val != _dl_auxvt[AT_EUID].a_un.a_val ||
> > > +      _dl_auxvt[AT_GID].a_un.a_val != _dl_auxvt[AT_EGID].a_un.a_val)))
> > >  #else
> > >      if (_dl_secure)
> > >  #endif
> > > -- 
> > > 2.47.1
> > > 
> > > _______________________________________________
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> > > To unsubscribe send an email to [email protected]
> > > 
> > _______________________________________________
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