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-rw-r--r--libc/bionic/libc_init_static.c34
1 files changed, 6 insertions, 28 deletions
diff --git a/libc/bionic/libc_init_static.c b/libc/bionic/libc_init_static.c
index ba7f008e9..bb3a41021 100644
--- a/libc/bionic/libc_init_static.c
+++ b/libc/bionic/libc_init_static.c
@@ -49,6 +49,7 @@
#include <bionic_tls.h>
#include <errno.h>
#include <sys/mman.h>
+#include <sys/auxv.h>
// Returns the address of the page containing address 'x'.
#define PAGE_START(x) ((x) & PAGE_MASK)
@@ -65,27 +66,13 @@ static void call_array(void(**list)())
}
}
-/*
- * Find the value of the AT_* variable passed to us by the kernel.
- */
-static unsigned find_aux(unsigned *vecs, unsigned type) {
- while (vecs[0]) {
- if (vecs[0] == type) {
- return vecs[1];
- }
- vecs += 2;
- }
-
- return 0; // should never happen
-}
-
-static void apply_gnu_relro(unsigned *vecs) {
+static void apply_gnu_relro() {
Elf32_Phdr *phdr_start;
- unsigned phdr_ct;
+ unsigned long int phdr_ct;
Elf32_Phdr *phdr;
- phdr_start = (Elf32_Phdr *) find_aux(vecs, AT_PHDR);
- phdr_ct = find_aux(vecs, AT_PHNUM);
+ phdr_start = (Elf32_Phdr *) getauxval(AT_PHDR);
+ phdr_ct = getauxval(AT_PHNUM);
for (phdr = phdr_start; phdr < (phdr_start + phdr_ct); phdr++) {
if (phdr->p_type != PT_GNU_RELRO)
@@ -108,7 +95,6 @@ __noreturn void __libc_init(uintptr_t *elfdata,
{
int argc;
char **argv, **envp;
- unsigned *vecs;
__libc_init_tls(NULL);
@@ -129,14 +115,6 @@ __noreturn void __libc_init(uintptr_t *elfdata,
argv = (char**)(elfdata + 1);
envp = argv + argc + 1;
- // The auxiliary vector is at the end of the environment block
- vecs = (unsigned *) envp;
- while (vecs[0] != 0) {
- vecs++;
- }
- /* The end of the environment block is marked by two NULL pointers */
- vecs++;
-
/* The executable may have its own destructors listed in its .fini_array
* so we need to ensure that these are called when the program exits
* normally.
@@ -144,6 +122,6 @@ __noreturn void __libc_init(uintptr_t *elfdata,
if (structors->fini_array)
__cxa_atexit(__libc_fini,structors->fini_array,NULL);
- apply_gnu_relro(vecs);
+ apply_gnu_relro();
exit(slingshot(argc, argv, envp));
}