Merge "Fix orthography of GetTestLibRoot()." into main
diff --git a/libc/arch-arm64/bionic/vfork.S b/libc/arch-arm64/bionic/vfork.S
index addb775..dd16349 100644
--- a/libc/arch-arm64/bionic/vfork.S
+++ b/libc/arch-arm64/bionic/vfork.S
@@ -28,7 +28,6 @@
#include <platform/bionic/tls_defines.h>
#include <private/bionic_asm.h>
-#include <private/bionic_asm_offsets.h>
#include <asm/signal.h>
#include <linux/sched.h>
@@ -58,8 +57,8 @@
// [1] https://cs.android.com/android/platform/superproject/+/master:system/extras/simpleperf/app_api/cpp/simpleperf.cpp;drc=788fa4183441f4977ddbd5a055e42a7fe7691d21;l=308
#if !__has_feature(hwaddress_sanitizer)
// if (!__libc_globals->memtag_stack) x0 |= CLONE_VM | CLONE_VFORK;
- adrp x1, __libc_globals + OFFSETOF_libc_globals_memtag_stack
- ldrb w1, [x1, :lo12:__libc_globals + OFFSETOF_libc_globals_memtag_stack]
+ adrp x1, __libc_memtag_stack
+ ldrb w1, [x1, :lo12:__libc_memtag_stack]
cbnz w1, 1f
orr x0, x0, #CLONE_VM
orr x0, x0, #CLONE_VFORK
diff --git a/libc/bionic/heap_tagging.cpp b/libc/bionic/heap_tagging.cpp
index b6c9fe5..c4347e8 100644
--- a/libc/bionic/heap_tagging.cpp
+++ b/libc/bionic/heap_tagging.cpp
@@ -58,7 +58,7 @@
case M_HEAP_TAGGING_LEVEL_SYNC:
case M_HEAP_TAGGING_LEVEL_ASYNC:
atomic_store(&globals->memtag, true);
- atomic_store(&globals->memtag_stack, __libc_shared_globals()->initial_memtag_stack);
+ atomic_store(&__libc_memtag_stack, __libc_shared_globals()->initial_memtag_stack);
break;
default:
break;
@@ -113,7 +113,7 @@
// tagged and checks no longer happen.
globals->heap_pointer_tag = static_cast<uintptr_t>(0xffull << UNTAG_SHIFT);
}
- atomic_store(&globals->memtag_stack, false);
+ atomic_store(&__libc_memtag_stack, false);
atomic_store(&globals->memtag, false);
});
@@ -207,7 +207,7 @@
// │memtag_handle_longjmp│ │
// └─────────────────────┘ ▼
#ifdef __aarch64__
- if (__libc_globals->memtag_stack) {
+ if (atomic_load(&__libc_memtag_stack)) {
size_t distance = reinterpret_cast<uintptr_t>(sp_dst) - reinterpret_cast<uintptr_t>(sp_src);
if (distance > kUntagLimit) {
async_safe_fatal(
diff --git a/libc/bionic/libc_init_common.cpp b/libc/bionic/libc_init_common.cpp
index 51f7ce9..944098f 100644
--- a/libc/bionic/libc_init_common.cpp
+++ b/libc/bionic/libc_init_common.cpp
@@ -57,6 +57,7 @@
extern "C" void scudo_malloc_set_pattern_fill_contents(int);
__LIBC_HIDDEN__ constinit WriteProtected<libc_globals> __libc_globals;
+__LIBC_HIDDEN__ constinit _Atomic(bool) __libc_memtag_stack;
// Not public, but well-known in the BSDs.
__BIONIC_WEAK_VARIABLE_FOR_NATIVE_BRIDGE
diff --git a/libc/bionic/malloc_common.cpp b/libc/bionic/malloc_common.cpp
index 3c4884b..9932e3e 100644
--- a/libc/bionic/malloc_common.cpp
+++ b/libc/bionic/malloc_common.cpp
@@ -353,7 +353,7 @@
errno = EINVAL;
return false;
}
- *reinterpret_cast<bool*>(arg) = atomic_load(&__libc_globals->memtag_stack);
+ *reinterpret_cast<bool*>(arg) = atomic_load(&__libc_memtag_stack);
return true;
}
if (opcode == M_GET_DECAY_TIME_ENABLED) {
diff --git a/libc/bionic/malloc_common_dynamic.cpp b/libc/bionic/malloc_common_dynamic.cpp
index a6bf7a7..8858178 100644
--- a/libc/bionic/malloc_common_dynamic.cpp
+++ b/libc/bionic/malloc_common_dynamic.cpp
@@ -542,7 +542,7 @@
errno = EINVAL;
return false;
}
- *reinterpret_cast<bool*>(arg) = atomic_load(&__libc_globals->memtag_stack);
+ *reinterpret_cast<bool*>(arg) = atomic_load(&__libc_memtag_stack);
return true;
}
if (opcode == M_GET_DECAY_TIME_ENABLED) {
diff --git a/libc/bionic/pthread_create.cpp b/libc/bionic/pthread_create.cpp
index 194db18..5bd4f16 100644
--- a/libc/bionic/pthread_create.cpp
+++ b/libc/bionic/pthread_create.cpp
@@ -91,7 +91,7 @@
// Create and set an alternate signal stack.
int prot = PROT_READ | PROT_WRITE;
#ifdef __aarch64__
- if (atomic_load(&__libc_globals->memtag_stack)) {
+ if (atomic_load(&__libc_memtag_stack)) {
prot |= PROT_MTE;
}
#endif
@@ -237,7 +237,7 @@
int prot = PROT_READ | PROT_WRITE;
const char* prot_str = "R+W";
#ifdef __aarch64__
- if (atomic_load(&__libc_globals->memtag_stack)) {
+ if (atomic_load(&__libc_memtag_stack)) {
prot |= PROT_MTE;
prot_str = "R+W+MTE";
}
diff --git a/libc/bionic/pthread_internal.cpp b/libc/bionic/pthread_internal.cpp
index bfe2f98..2342aff 100644
--- a/libc/bionic/pthread_internal.cpp
+++ b/libc/bionic/pthread_internal.cpp
@@ -179,10 +179,8 @@
void __pthread_internal_remap_stack_with_mte() {
#if defined(__aarch64__)
// If process doesn't have MTE enabled, we don't need to do anything.
- if (!__libc_globals->memtag) return;
- bool prev = true;
- __libc_globals.mutate(
- [&prev](libc_globals* globals) { prev = atomic_exchange(&globals->memtag_stack, true); });
+ if (!atomic_load(&__libc_globals->memtag)) return;
+ bool prev = atomic_exchange(&__libc_memtag_stack, true);
if (prev) return;
uintptr_t lo, hi;
__find_main_stack_limits(&lo, &hi);
diff --git a/libc/include/dlfcn.h b/libc/include/dlfcn.h
index 0425031..a506dc1 100644
--- a/libc/include/dlfcn.h
+++ b/libc/include/dlfcn.h
@@ -26,25 +26,35 @@
* SUCH DAMAGE.
*/
-#ifndef __DLFCN_H__
-#define __DLFCN_H__
+#pragma once
#include <stdint.h>
#include <sys/cdefs.h>
__BEGIN_DECLS
+/**
+ * dladdr() returns information using this structure.
+ */
typedef struct {
- /* Pathname of shared object that contains address. */
+ /** Pathname of the shared object that contains the given address. */
const char* _Nullable dli_fname;
- /* Address at which shared object is loaded. */
+ /** Address at which the shared object is loaded. */
void* _Nullable dli_fbase;
- /* Name of nearest symbol with address lower than addr. */
+ /** Name of the nearest symbol with an address lower than the given address. */
const char* _Nullable dli_sname;
- /* Exact address of symbol named in dli_sname. */
+ /** Exact address of the symbol named in `dli_sname`. */
void* _Nullable dli_saddr;
} Dl_info;
+/**
+ * [dlopen(3)](http://man7.org/linux/man-pages/man3/dlopen.3.html)
+ * loads the given shared library.
+ *
+ * Returns a pointer to an opaque handle for use with other <dlfcn.h> functions
+ * on success, and returns NULL on failure, in which case dlerror() can be used
+ * to retrieve the specific error.
+ */
void* _Nullable dlopen(const char* _Nullable __filename, int __flag);
/**
@@ -64,42 +74,109 @@
* a child process which can later be killed by the parent or call
* exit() itself.
*
+ * Note also that dlclose() interacts badly with thread local variables
+ * with non-trivial destructors, with the
+ * (exact behavior varying by API level)[https://android.googlesource.com/platform/bionic/+/main/android-changes-for-ndk-developers.md#dlclose-interacts-badly-with-thread-local-variables-with-non_trivial-destructors].
+ *
* Returns 0 on success, and returns -1 on failure, in which case
* dlerror() can be used to retrieve the specific error.
*/
int dlclose(void* _Nonnull __handle);
+/**
+ * [dlerror(3)](http://man7.org/linux/man-pages/man3/dlerror.3.html)
+ * returns a human-readable error message describing the most recent
+ * failure from one of the <dlfcn.h> functions on the calling thread.
+ *
+ * This function also clears the error, so a second call (or a call
+ * before any failure) will return NULL.
+ *
+ * Returns a pointer to an error on success, and returns NULL if no
+ * error is pending.
+ */
char* _Nullable dlerror(void);
-/* (RTLD_DEFAULT is null for LP64, but -1 for LP32) */
+/**
+ * [dlsym(3)](http://man7.org/linux/man-pages/man3/dlsym.3.html)
+ * returns a pointer to the symbol with the given name in the shared
+ * library represented by the given handle.
+ *
+ * Returns the address of the symbol on success, and returns NULL on failure,
+ * in which case dlerror() can be used to retrieve the specific error.
+ */
void* _Nullable dlsym(void* __BIONIC_COMPLICATED_NULLNESS __handle, const char* _Nullable __symbol);
-/* (RTLD_DEFAULT is null for LP64, but -1 for LP32) */
+
+/**
+ * [dlvsym(3)](http://man7.org/linux/man-pages/man3/dlvsym.3.html)
+ * returns a pointer to the symbol with the given name and version in the shared
+ * library represented by the given handle.
+ *
+ * Returns the address of the symbol on success, and returns NULL on failure,
+ * in which case dlerror() can be used to retrieve the specific error.
+ */
void* _Nullable dlvsym(void* __BIONIC_COMPLICATED_NULLNESS __handle, const char* _Nullable __symbol, const char* _Nullable __version) __INTRODUCED_IN(24);
+
+/**
+ * [dladdr(3)](http://man7.org/linux/man-pages/man3/dladdr.3.html)
+ * returns information about the symbol at the given address.
+ *
+ * Returns non-zero on success, and returns 0 on failure. Note that unlike
+ * the other <dlfcn.h> functions, in this case dlerror() will _not_ have
+ * more information.
+ */
int dladdr(const void* _Nonnull __addr, Dl_info* _Nonnull __info);
+/**
+ * A dlsym()/dlvsym() handle that returns the first symbol found in any
+ * shared library using the default search order.
+ */
+#define RTLD_DEFAULT __BIONIC_CAST(reinterpret_cast, void*, 0)
+
+/**
+ * A dlsym()/dlvsym() handle that returns the first symbol found in any
+ * shared library that appears _after_ the object containing the caller.
+ */
+#define RTLD_NEXT __BIONIC_CAST(reinterpret_cast, void*, -1L)
+
+/**
+ * A dlopen() flag to not make symbols from this library available to later
+ * libraries. See also RTLD_GLOBAL.
+ */
#define RTLD_LOCAL 0
+
+/** Not supported on Android; Android always uses RTLD_NOW. */
#define RTLD_LAZY 0x00001
+
+/** A dlopen() flag to resolve all undefined symbols before dlopen() returns. */
#define RTLD_NOW 0x00002
+
+/**
+ * A dlopen() flag to not actually load the given library;
+ * used to test whether the library is already loaded.
+ */
#define RTLD_NOLOAD 0x00004
+
+/**
+ * A dlopen() flag to make symbols from this library available to later
+ * libraries. See also RTLD_LOCAL.
+ */
#define RTLD_GLOBAL 0x00100
+
+/**
+ * A dlopen() flag to ignore later dlclose() calls on this library.
+ */
#define RTLD_NODELETE 0x01000
+/* LP32 has historical ABI breakage. */
#if !defined(__LP64__)
-/* LP32 is broken for historical reasons. */
+#undef RTLD_DEFAULT
+#define RTLD_DEFAULT __BIONIC_CAST(reinterpret_cast, void*, 0xffffffff)
+#undef RTLD_NEXT
+#define RTLD_NEXT __BIONIC_CAST(reinterpret_cast, void*, 0xfffffffe)
#undef RTLD_NOW
#define RTLD_NOW 0x00000
#undef RTLD_GLOBAL
#define RTLD_GLOBAL 0x00002
#endif
-#if defined (__LP64__)
-#define RTLD_DEFAULT __BIONIC_CAST(reinterpret_cast, void*, 0)
-#define RTLD_NEXT __BIONIC_CAST(reinterpret_cast, void*, -1L)
-#else
-#define RTLD_DEFAULT __BIONIC_CAST(reinterpret_cast, void*, 0xffffffff)
-#define RTLD_NEXT __BIONIC_CAST(reinterpret_cast, void*, 0xfffffffe)
-#endif
-
__END_DECLS
-
-#endif
diff --git a/libc/private/bionic_asm_offsets.h b/libc/private/bionic_asm_offsets.h
deleted file mode 100644
index e72adda..0000000
--- a/libc/private/bionic_asm_offsets.h
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * Copyright (C) 2023 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.
- */
-
-#pragma once
-
-#if defined(__aarch64__)
-#define OFFSETOF_libc_globals_memtag_stack 64
-#endif
diff --git a/libc/private/bionic_globals.h b/libc/private/bionic_globals.h
index 6f1e389..0949056 100644
--- a/libc/private/bionic_globals.h
+++ b/libc/private/bionic_globals.h
@@ -38,7 +38,6 @@
#include "private/WriteProtected.h"
#include "private/bionic_allocator.h"
-#include "private/bionic_asm_offsets.h"
#include "private/bionic_elf_tls.h"
#include "private/bionic_fdsan.h"
#include "private/bionic_malloc_dispatch.h"
@@ -48,7 +47,6 @@
vdso_entry vdso[VDSO_END];
long setjmp_cookie;
uintptr_t heap_pointer_tag;
- _Atomic(bool) memtag_stack;
_Atomic(bool) decay_time_enabled;
_Atomic(bool) memtag;
@@ -77,11 +75,11 @@
bool memtag_stack;
};
-#ifdef __aarch64__
-static_assert(OFFSETOF_libc_globals_memtag_stack == offsetof(libc_globals, memtag_stack));
-#endif
-
__LIBC_HIDDEN__ extern WriteProtected<libc_globals> __libc_globals;
+// This cannot be in __libc_globals, because we cannot access the
+// WriteProtected in a thread-safe way.
+// See b/328256432.
+__LIBC_HIDDEN__ extern _Atomic(bool) __libc_memtag_stack;
struct abort_msg_t;
struct crash_detail_page_t;