Make getauxval work with static linking

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 <marcus.haehnel@kernkonzept.com>

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

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