From: Georg Kotheimer georg.kotheimer@kernkonzept.com
Previously the getauxval implementation was limited to the auxiliary vector entries cached in _dl_auxvt. To also support entries outside of that cached subset, store the start address of the auxiliary vector, and if an uncached entry type is encountered search the entire auxiliary vector.
Signed-off-by: Marcus Haehnel marcus.haehnel@kernkonzept.com --- ldso/include/ldso.h | 3 ++- ldso/ldso/dl-startup.c | 4 ++++ libc/misc/auxvt/getauxval.c | 30 +++++++++++++----------------- libc/misc/elf/dl-support.c | 3 +++ 4 files changed, 22 insertions(+), 18 deletions(-)
diff --git a/ldso/include/ldso.h b/ldso/include/ldso.h index a397cce61..60e0a5bec 100755 --- a/ldso/include/ldso.h +++ b/ldso/include/ldso.h @@ -192,7 +192,8 @@ extern void *_dl_get_ready_to_run(struct elf_resolve *tpnt, DL_LOADADDR_TYPE loa #endif
#define AUX_MAX_AT_ID 40 -extern ElfW(auxv_t) _dl_auxvt[AUX_MAX_AT_ID]; +extern ElfW(auxv_t) _dl_auxvt[AUX_MAX_AT_ID]; /* Cache frequently accessed auxiliary vector entries */ +extern ElfW(auxv_t) *_dl_auxv_start; /* Start of the auxiliary vector */
void load_vdso(void *sys_info_ehdr, char **envp );
diff --git a/ldso/ldso/dl-startup.c b/ldso/ldso/dl-startup.c index e7000bd87..e0d8c8fff 100644 --- a/ldso/ldso/dl-startup.c +++ b/ldso/ldso/dl-startup.c @@ -100,6 +100,7 @@ extern ElfW(Addr) _begin[] attribute_hidden;
ElfW(auxv_t) _dl_auxvt[AUX_MAX_AT_ID]; +ElfW(auxv_t) *_dl_auxv_start;
#ifdef LDSO_NEED_DPNT ElfW(Dyn) *_dl_saved_dpnt = 0; @@ -131,6 +132,7 @@ DL_START(unsigned long args) struct elf_resolve tpnt_tmp; struct elf_resolve *tpnt = &tpnt_tmp; ElfW(auxv_t) _dl_auxvt_tmp[AUX_MAX_AT_ID]; + ElfW(auxv_t) *_dl_auxv_start_tmp; ElfW(Dyn) *dpnt; uint32_t *p32;
@@ -166,6 +168,7 @@ DL_START(unsigned long args) /* The junk on the stack immediately following the environment is * the Auxiliary Vector Table. Read out the elements of the auxvt, * sort and store them in auxvt for later use. */ + _dl_auxv_start_tmp = (ElfW(auxv_t) *)aux_dat; while (*aux_dat) { ElfW(auxv_t) *auxv_entry = (ElfW(auxv_t) *) aux_dat;
@@ -367,6 +370,7 @@ DL_START(unsigned long args) * now the globals work. so copy the aux vector */ _dl_memcpy( _dl_auxvt, _dl_auxvt_tmp, sizeof( ElfW(auxv_t) ) * AUX_MAX_AT_ID ); + _dl_auxv_start = _dl_auxv_start_tmp;
_dl_elf_main = (int (*)(int, char **, char **)) _dl_get_ready_to_run(tpnt, load_addr, envp, argv diff --git a/libc/misc/auxvt/getauxval.c b/libc/misc/auxvt/getauxval.c index 2bdffaf2c..7610b7e5c 100755 --- a/libc/misc/auxvt/getauxval.c +++ b/libc/misc/auxvt/getauxval.c @@ -17,32 +17,28 @@ * http://www.gnu.org/licenses/. */
-#include "errno.h" -#include "ldso.h" -#include "sys/auxv.h" +#include <errno.h> +#include <ldso.h> +#include <sys/auxv.h>
- -/* - * - * aarch64 gcc 11 uses __getauxval() in init_have_lse_atomics() - * - */ unsigned long int __getauxval (unsigned long int __type) { - if ( __type >= AUX_MAX_AT_ID ){ + // Requested value part of cached subset of auxiliary vector? + if (__type < AUX_MAX_AT_ID) { + if (_dl_auxvt[__type].a_type == __type) + return _dl_auxvt[__type].a_un.a_val; + __set_errno (ENOENT); return 0; }
- if ( _dl_auxvt[__type].a_type == __type){ - return _dl_auxvt[__type].a_un.a_val; - } + // Otherwise we have to iterate the auxiliary vector. + for (ElfW(auxv_t) *entry = _dl_auxv_start; entry->a_type != AT_NULL; entry++) + if (entry->a_type == __type) + return entry->a_un.a_val;
__set_errno (ENOENT); return 0; }
-unsigned long int getauxval (unsigned long int __type){ - return __getauxval( __type ); -} - +weak_alias(__getauxval, getauxval) diff --git a/libc/misc/elf/dl-support.c b/libc/misc/elf/dl-support.c index 81c78fa55..09cbefc18 100644 --- a/libc/misc/elf/dl-support.c +++ b/libc/misc/elf/dl-support.c @@ -33,10 +33,13 @@ size_t _dl_phnum; size_t _dl_pagesize;
ElfW(auxv_t) _dl_auxvt[AUX_MAX_AT_ID]; +ElfW(auxv_t) *_dl_auxv_start;
void internal_function _dl_aux_init (ElfW(auxv_t) *av); void internal_function _dl_aux_init (ElfW(auxv_t) *av) { + _dl_auxv_start = av; + memset(_dl_auxvt, 0x00, sizeof(_dl_auxvt)); for (; av->a_type != AT_NULL; av++) {