From: Georg Kotheimer georg.kotheimer@kernkonzept.com
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 | 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
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++) {
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 georg.kotheimer@kernkonzept.com
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 | 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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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 georg.kotheimer@kernkonzept.com
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 | 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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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 georg.kotheimer@kernkonzept.com
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 | 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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Hi Marcus, Marcus Hähnel wrote,
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.
I pushed your hotfix, but would also like to include any follow up cleanup patch.
best regards Waldemar
Thanks Waldemar,
I sent another patch that I would say is a cleaner solution since it separates the _dl_auxvt logic, which is needed in static and shared builds due to getauxval, from the ldso specific things.
But I'm not sure if you have any policy regarding the addition of new headers, or if I am missing something. So I would welcome any feedback.
Best regards,
- Marcus
On Thu, 2025-03-06 at 16:44 +0100, Waldemar Brodkorb wrote:
Hi Marcus, Marcus Hähnel wrote,
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.
I pushed your hotfix, but would also like to include any follow up cleanup patch.
best regards Waldemar _______________________________________________ devel mailing list -- devel@uclibc-ng.org To unsubscribe send an email to devel-leave@uclibc-ng.org
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Marcus Haehnel -
Marcus Hähnel
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Waldemar Brodkorb