am fdd6dfa8: am 2c5153b0: libc: add getauxval()
* commit 'fdd6dfa863ea73251b5d59990e239854c31ecee3':
libc: add getauxval()
diff --git a/libc/Android.mk b/libc/Android.mk
index 804a09c..4bf996b 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -275,6 +275,7 @@
bionic/dirent.cpp \
bionic/eventfd.cpp \
bionic/__fgets_chk.cpp \
+ bionic/getauxval.cpp \
bionic/getcwd.cpp \
bionic/libgen.cpp \
bionic/__memcpy_chk.cpp \
diff --git a/libc/bionic/getauxval.cpp b/libc/bionic/getauxval.cpp
new file mode 100644
index 0000000..38a05fc
--- /dev/null
+++ b/libc/bionic/getauxval.cpp
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <stddef.h>
+#include <sys/cdefs.h>
+#include <sys/auxv.h>
+#include <private/bionic_auxv.h>
+#include <elf.h>
+
+__LIBC_HIDDEN__
+Elf32_auxv_t* __libc_auxv = NULL;
+
+extern "C" unsigned long int getauxval(unsigned long int type) {
+ Elf32_auxv_t* v;
+
+ for (v = __libc_auxv; v->a_type != AT_NULL; v++) {
+ if (v->a_type == type) {
+ return v->a_un.a_val;
+ }
+ }
+
+ return 0;
+}
diff --git a/libc/bionic/libc_init_common.c b/libc/bionic/libc_init_common.c
index fb164f4..86e1eb5 100644
--- a/libc/bionic/libc_init_common.c
+++ b/libc/bionic/libc_init_common.c
@@ -38,6 +38,7 @@
#include <bionic_tls.h>
#include <errno.h>
+#include <private/bionic_auxv.h>
extern unsigned __get_sp(void);
extern pid_t gettid(void);
@@ -95,6 +96,15 @@
__progname = argv[0] ? argv[0] : "<unknown>";
environ = envp;
+ // The auxiliary vector is at the end of the environment block
+ while(*envp != NULL) {
+ envp++;
+ }
+ /* The end of the environment block is marked by two NULL pointers */
+ envp++;
+
+ __libc_auxv = (Elf32_auxv_t*) envp;
+
__system_properties_init(); // Requires 'environ'.
}
diff --git a/libc/bionic/libc_init_static.c b/libc/bionic/libc_init_static.c
index ba7f008..bb3a410 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 @@
}
}
-/*
- * 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 @@
{
int argc;
char **argv, **envp;
- unsigned *vecs;
__libc_init_tls(NULL);
@@ -129,14 +115,6 @@
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 @@
if (structors->fini_array)
__cxa_atexit(__libc_fini,structors->fini_array,NULL);
- apply_gnu_relro(vecs);
+ apply_gnu_relro();
exit(slingshot(argc, argv, envp));
}
diff --git a/libc/include/elf.h b/libc/include/elf.h
index c3e3226..ac0f1d2 100644
--- a/libc/include/elf.h
+++ b/libc/include/elf.h
@@ -28,8 +28,23 @@
#ifndef _ELF_H
#define _ELF_H
+#include <stdint.h>
#include <linux/auxvec.h>
#include <sys/exec_elf.h>
+typedef struct {
+ uint32_t a_type;
+ union {
+ uint32_t a_val;
+ } a_un;
+} Elf32_auxv_t;
+
+typedef struct {
+ uint64_t a_type;
+ union {
+ uint64_t a_val;
+ } a_un;
+} Elf64_auxv_t;
+
#endif /* _ELF_H */
diff --git a/libc/include/sys/auxv.h b/libc/include/sys/auxv.h
new file mode 100644
index 0000000..918442f
--- /dev/null
+++ b/libc/include/sys/auxv.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+#ifndef _SYS_AUXV_H_
+#define _SYS_AUXV_H_
+
+#include <linux/auxvec.h>
+
+__BEGIN_DECLS
+
+unsigned long int getauxval(unsigned long int type);
+
+__END_DECLS
+
+#endif /* _SYS_AUXV_H_ */
diff --git a/libc/private/bionic_auxv.h b/libc/private/bionic_auxv.h
new file mode 100644
index 0000000..d3b0038
--- /dev/null
+++ b/libc/private/bionic_auxv.h
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+#ifndef _SYS_AUXV_H_
+#define _SYS_AUXV_H_
+
+#include <elf.h>
+
+__BEGIN_DECLS
+
+extern Elf32_auxv_t* __libc_auxv;
+
+__END_DECLS
+
+#endif /* _SYS_AUXV_H_ */
diff --git a/tests/Android.mk b/tests/Android.mk
index 635c021..25da120 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -55,6 +55,7 @@
test_src_files = \
dirent_test.cpp \
fenv_test.cpp \
+ getauxval_test.cpp \
getcwd_test.cpp \
libgen_test.cpp \
pthread_test.cpp \
diff --git a/tests/getauxval_test.cpp b/tests/getauxval_test.cpp
new file mode 100644
index 0000000..01c11c3
--- /dev/null
+++ b/tests/getauxval_test.cpp
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <sys/cdefs.h>
+#include <features.h>
+#include <gtest/gtest.h>
+
+// getauxval() was only added as of glibc version 2.16.
+// See: http://lwn.net/Articles/519085/
+// Don't try to compile this code on older glibc versions.
+
+#if defined(__BIONIC__)
+ #define GETAUXVAL_CAN_COMPILE 1
+#elif defined(__GLIBC_PREREQ)
+ #if __GLIBC_PREREQ(2, 16)
+ #define GETAUXVAL_CAN_COMPILE 1
+ #endif
+#endif
+
+#if defined(GETAUXVAL_CAN_COMPILE)
+
+#include <sys/auxv.h>
+
+TEST(getauxval, expected_values) {
+ ASSERT_EQ((unsigned long int) 0, getauxval(AT_SECURE));
+ ASSERT_EQ(getuid(), getauxval(AT_UID));
+ ASSERT_EQ(geteuid(), getauxval(AT_EUID));
+ ASSERT_EQ(getgid(), getauxval(AT_GID));
+ ASSERT_EQ(getegid(), getauxval(AT_EGID));
+ ASSERT_EQ((unsigned long int) getpagesize(), getauxval(AT_PAGESZ));
+
+ ASSERT_NE((unsigned long int) 0, getauxval(AT_PHDR));
+ ASSERT_NE((unsigned long int) 0, getauxval(AT_PHNUM));
+ ASSERT_NE((unsigned long int) 0, getauxval(AT_ENTRY));
+ ASSERT_NE((unsigned long int) 0, getauxval(AT_PAGESZ));
+}
+
+TEST(getauxval, unexpected_values) {
+ ASSERT_EQ((unsigned long int) 0, getauxval(0xdeadbeef));
+}
+
+#endif /* GETAUXVAL_CAN_COMPILE */