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android-8.1.0_r81 patches

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This commit is contained in:
Ziyang Zhou
2023-10-05 22:44:10 +08:00
parent da422ab6de
commit 81ef272d21
20 changed files with 1232 additions and 0 deletions
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318
android-8.1.0_r81/system/core/0005-memfd-support.patch Normal file
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@@ -0,0 +1,318 @@
From 5f3272be10ea27866e5e0b30bfc921befde70ab2 Mon Sep 17 00:00:00 2001
From: Ziyang Zhou <ziyang.zhou@outlook.com>
Date: Sun, 3 Jul 2022 11:22:31 +0800
Subject: [PATCH 5/6] memfd support
---
libcutils/Android.bp | 4 +-
libcutils/{ashmem-dev.c => ashmem-dev.cpp} | 51 +++++-
libcutils/ashmem-hack.inc | 172 +++++++++++++++++++++
3 files changed, 223 insertions(+), 4 deletions(-)
rename libcutils/{ashmem-dev.c => ashmem-dev.cpp} (79%)
create mode 100644 libcutils/ashmem-hack.inc
diff --git a/libcutils/Android.bp b/libcutils/Android.bp
index d00ff5f96..93f2658c7 100644
--- a/libcutils/Android.bp
+++ b/libcutils/Android.bp
@@ -106,7 +106,7 @@ cc_library {
android: {
srcs: libcutils_nonwindows_sources + [
"android_reboot.c",
- "ashmem-dev.c",
+ "ashmem-dev.cpp",
"klog.cpp",
"partition_utils.c",
"properties.cpp",
@@ -148,7 +148,7 @@ cc_library {
},
},
- shared_libs: ["liblog"],
+ shared_libs: ["liblog", "libbase"],
header_libs: [
"libcutils_headers",
"libutils_headers",
diff --git a/libcutils/ashmem-dev.c b/libcutils/ashmem-dev.cpp
similarity index 79%
rename from libcutils/ashmem-dev.c
rename to libcutils/ashmem-dev.cpp
index b4abb79d8..137c0280c 100644
--- a/libcutils/ashmem-dev.c
+++ b/libcutils/ashmem-dev.cpp
@@ -135,8 +135,14 @@ static int __ashmem_is_ashmem(int fd, int fatal)
return -1;
}
+#include "ashmem-hack.inc"
+
int ashmem_valid(int fd)
{
+ if (has_memfd_support() && !memfd_is_ashmem(fd)) {
+ return 1;
+ }
+
return __ashmem_is_ashmem(fd, 0) >= 0;
}
@@ -151,6 +157,10 @@ int ashmem_create_region(const char *name, size_t size)
{
int ret, save_errno;
+ if (has_memfd_support()) {
+ return memfd_create_region(name ? name : "none", size);
+ }
+
int fd = __ashmem_open();
if (fd < 0) {
return fd;
@@ -182,6 +192,10 @@ error:
int ashmem_set_prot_region(int fd, int prot)
{
+ if (has_memfd_support() && !memfd_is_ashmem(fd)) {
+ return memfd_set_prot_region(fd, prot);
+ }
+
int ret = __ashmem_is_ashmem(fd, 1);
if (ret < 0) {
return ret;
@@ -192,7 +206,16 @@ int ashmem_set_prot_region(int fd, int prot)
int ashmem_pin_region(int fd, size_t offset, size_t len)
{
- struct ashmem_pin pin = { offset, len };
+ if (!pin_deprecation_warn || debug_log) {
+ ALOGE("Pinning is deprecated since Android Q. Please use trim or other methods.\n");
+ pin_deprecation_warn = true;
+ }
+
+ if (has_memfd_support() && !memfd_is_ashmem(fd)) {
+ return 0;
+ }
+
+ struct ashmem_pin pin = { static_cast<uint32_t>(offset), static_cast<uint32_t>(len) };
int ret = __ashmem_is_ashmem(fd, 1);
if (ret < 0) {
@@ -204,7 +227,16 @@ int ashmem_pin_region(int fd, size_t offset, size_t len)
int ashmem_unpin_region(int fd, size_t offset, size_t len)
{
- struct ashmem_pin pin = { offset, len };
+ if (!pin_deprecation_warn || debug_log) {
+ ALOGE("Pinning is deprecated since Android Q. Please use trim or other methods.\n");
+ pin_deprecation_warn = true;
+ }
+
+ if (has_memfd_support() && !memfd_is_ashmem(fd)) {
+ return 0;
+ }
+
+ struct ashmem_pin pin = { static_cast<uint32_t>(offset), static_cast<uint32_t>(len) };
int ret = __ashmem_is_ashmem(fd, 1);
if (ret < 0) {
@@ -216,6 +248,21 @@ int ashmem_unpin_region(int fd, size_t offset, size_t len)
int ashmem_get_size_region(int fd)
{
+ if (has_memfd_support() && !memfd_is_ashmem(fd)) {
+ struct stat sb;
+
+ if (fstat(fd, &sb) == -1) {
+ ALOGE("ashmem_get_size_region(%d): fstat failed: %s\n", fd, strerror(errno));
+ return -1;
+ }
+
+ if (debug_log) {
+ ALOGD("ashmem_get_size_region(%d): %d\n", fd, static_cast<int>(sb.st_size));
+ }
+
+ return sb.st_size;
+ }
+
int ret = __ashmem_is_ashmem(fd, 1);
if (ret < 0) {
return ret;
diff --git a/libcutils/ashmem-hack.inc b/libcutils/ashmem-hack.inc
new file mode 100644
index 000000000..8526c85be
--- /dev/null
+++ b/libcutils/ashmem-hack.inc
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2008 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 <cutils/ashmem.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/ashmem.h>
+#include <linux/memfd.h>
+#include <log/log.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/sysmacros.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <android-base/file.h>
+#include <android-base/properties.h>
+#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
+
+/* Will be added to UAPI once upstream change is merged */
+#define F_SEAL_FUTURE_WRITE 0x0010
+
+/*
+ * The minimum vendor API level at and after which it is safe to use memfd.
+ * This is to facilitate deprecation of ashmem.
+ */
+#define MIN_MEMFD_VENDOR_API_LEVEL 29
+#define MIN_MEMFD_VENDOR_API_LEVEL_CHAR 'Q'
+
+/*
+ * has_memfd_support() determines if the device can use memfd. memfd support
+ * has been there for long time, but certain things in it may be missing. We
+ * check for needed support in it. Also we check if the VNDK version of
+ * libcutils being used is new enough, if its not, then we cannot use memfd
+ * since the older copies may be using ashmem so we just use ashmem. Once all
+ * Android devices that are getting updates are new enough (ex, they were
+ * originally shipped with Android release > P), then we can just use memfd and
+ * delete all ashmem code from libcutils (while preserving the interface).
+ *
+ * NOTE:
+ * The sys.use_memfd property is set by default to false in Android
+ * to temporarily disable memfd, till vendor and apps are ready for it.
+ * The main issue: either apps or vendor processes can directly make ashmem
+ * IOCTLs on FDs they receive by assuming they are ashmem, without going
+ * through libcutils. Such fds could have very well be originally created with
+ * libcutils hence they could be memfd. Thus the IOCTLs will break.
+ *
+ * Set default value of sys.use_memfd property to true once the issue is
+ * resolved, so that the code can then self-detect if kernel support is present
+ * on the device. The property can also set to true from adb shell, for
+ * debugging.
+ */
+
+static bool debug_log = false; /* set to true for verbose logging and other debug */
+static bool pin_deprecation_warn = true; /* Log the pin deprecation warning only once */
+
+
+/* Determine if memfd can be supported. This is just one-time hardwork
+ * which will be cached by the caller.
+ */
+static bool __has_memfd_support() {
+ /* Used to turn on/off the detection at runtime, in the future this
+ * property will be removed once we switch everything over to ashmem.
+ * Currently it is used only for debugging to switch the system over.
+ */
+ if (!android::base::GetBoolProperty("sys.use_memfd", false)) {
+ if (debug_log) {
+ ALOGD("sys.use_memfd=false so memfd disabled\n");
+ }
+ return false;
+ }
+
+ // Check if kernel support exists, otherwise fall back to ashmem.
+ // This code needs to build on old API levels, so we can't use the libc
+ // wrapper.
+ android::base::unique_fd fd(
+ syscall(__NR_memfd_create, "test_android_memfd", MFD_CLOEXEC | MFD_ALLOW_SEALING));
+ if (fd == -1) {
+ ALOGE("memfd_create failed: %s, no memfd support.\n", strerror(errno));
+ return false;
+ }
+
+ if (fcntl(fd, F_ADD_SEALS, F_SEAL_FUTURE_WRITE) == -1) {
+ ALOGE("fcntl(F_ADD_SEALS) failed: %s, no memfd support.\n", strerror(errno));
+ return false;
+ }
+
+ if (debug_log) {
+ ALOGD("memfd: device has memfd support, using it\n");
+ }
+ return true;
+}
+
+static bool has_memfd_support() {
+ /* memfd_supported is the initial global per-process state of what is known
+ * about memfd.
+ */
+ static bool memfd_supported = __has_memfd_support();
+
+ return memfd_supported;
+}
+
+static bool memfd_is_ashmem(int fd) {
+ static bool fd_check_error_once = false;
+
+ if (__ashmem_is_ashmem(fd, 0) == 0) {
+ if (!fd_check_error_once) {
+ ALOGE("memfd: memfd expected but ashmem fd used - please use libcutils.\n");
+ fd_check_error_once = true;
+ }
+
+ return true;
+ }
+
+ return false;
+}
+
+static int memfd_create_region(const char* name, size_t size) {
+ // This code needs to build on old API levels, so we can't use the libc
+ // wrapper.
+ android::base::unique_fd fd(syscall(__NR_memfd_create, name, MFD_CLOEXEC | MFD_ALLOW_SEALING));
+
+ if (fd == -1) {
+ ALOGE("memfd_create(%s, %zd) failed: %s\n", name, size, strerror(errno));
+ return -1;
+ }
+
+ if (ftruncate(fd, size) == -1) {
+ ALOGE("ftruncate(%s, %zd) failed for memfd creation: %s\n", name, size, strerror(errno));
+ return -1;
+ }
+
+ if (debug_log) {
+ ALOGE("memfd_create(%s, %zd) success. fd=%d\n", name, size, fd.get());
+ }
+ return fd.release();
+}
+
+static int memfd_set_prot_region(int fd, int prot) {
+ /* Only proceed if an fd needs to be write-protected */
+ if (prot & PROT_WRITE) {
+ return 0;
+ }
+
+ if (fcntl(fd, F_ADD_SEALS, F_SEAL_FUTURE_WRITE) == -1) {
+ ALOGE("memfd_set_prot_region(%d, %d): F_SEAL_FUTURE_WRITE seal failed: %s\n", fd, prot,
+ strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
--
2.34.1