From 7e8b93a750d1c0fe6993ae80584d30ae513cd6f1 Mon Sep 17 00:00:00 2001
From: Todd Frederick <tfred@google.com>
Date: Wed, 16 Oct 2024 02:10:02 +0000
Subject: Revert "Use MappedFile for mmap-related operations in CursorWindow"

This reverts commit e28dd9f756fd7df72e39260e82a7569a3636d0af.

Reason for revert: Breaks STS

Bug: 372629475
Change-Id: I708ac6e193b1b4cc0adfc0875e075fe5fd5d7191
---
 libs/androidfw/CursorWindow.cpp                 | 21 ++++++++-------------
 libs/androidfw/include/androidfw/CursorWindow.h |  4 ----
 2 files changed, 8 insertions(+), 17 deletions(-)

(limited to 'libs/androidfw')

diff --git a/libs/androidfw/CursorWindow.cpp b/libs/androidfw/CursorWindow.cpp
index cbb1e8f82838..5e645cceea2d 100644
--- a/libs/androidfw/CursorWindow.cpp
+++ b/libs/androidfw/CursorWindow.cpp
@@ -18,12 +18,11 @@
 
 #include <androidfw/CursorWindow.h>
 
+#include <sys/mman.h>
+
 #include "android-base/logging.h"
-#include "android-base/mapped_file.h"
 #include "cutils/ashmem.h"
 
-using android::base::MappedFile;
-
 namespace android {
 
 /**
@@ -40,7 +39,7 @@ CursorWindow::CursorWindow() {
 
 CursorWindow::~CursorWindow() {
     if (mAshmemFd != -1) {
-        mMappedFile.reset();
+        ::munmap(mData, mSize);
         ::close(mAshmemFd);
     } else {
         free(mData);
@@ -76,7 +75,6 @@ fail_silent:
 status_t CursorWindow::maybeInflate() {
     int ashmemFd = 0;
     void* newData = nullptr;
-    std::unique_ptr<MappedFile> mappedFile;
 
     // Bail early when we can't expand any further
     if (mReadOnly || mSize == mInflatedSize) {
@@ -97,12 +95,11 @@ status_t CursorWindow::maybeInflate() {
         goto fail_silent;
     }
 
-    mappedFile = MappedFile::FromFd(ashmemFd, 0, mInflatedSize, PROT_READ | PROT_WRITE);
-    if (mappedFile == nullptr) {
+    newData = ::mmap(nullptr, mInflatedSize, PROT_READ | PROT_WRITE, MAP_SHARED, ashmemFd, 0);
+    if (newData == MAP_FAILED) {
         PLOG(ERROR) << "Failed mmap";
         goto fail_silent;
     }
-    newData = mappedFile->data();
 
     if (ashmem_set_prot_region(ashmemFd, PROT_READ) < 0) {
         PLOG(ERROR) << "Failed ashmem_set_prot_region";
@@ -123,7 +120,6 @@ status_t CursorWindow::maybeInflate() {
         mData = newData;
         mSize = mInflatedSize;
         mSlotsOffset = newSlotsOffset;
-        mMappedFile = std::move(mappedFile);
 
         updateSlotsData();
     }
@@ -134,7 +130,7 @@ status_t CursorWindow::maybeInflate() {
 fail:
     LOG(ERROR) << "Failed maybeInflate";
 fail_silent:
-    mappedFile.reset();
+    ::munmap(newData, mInflatedSize);
     ::close(ashmemFd);
     return UNKNOWN_ERROR;
 }
@@ -171,12 +167,11 @@ status_t CursorWindow::createFromParcel(Parcel* parcel, CursorWindow** outWindow
             goto fail_silent;
         }
 
-        window->mMappedFile = MappedFile::FromFd(window->mAshmemFd, 0, window->mSize, PROT_READ);
-        if (window->mMappedFile == nullptr) {
+        window->mData = ::mmap(nullptr, window->mSize, PROT_READ, MAP_SHARED, window->mAshmemFd, 0);
+        if (window->mData == MAP_FAILED) {
             PLOG(ERROR) << "Failed mmap";
             goto fail_silent;
         }
-        window->mData = window->mMappedFile->data();
     } else {
         window->mAshmemFd = -1;
 
diff --git a/libs/androidfw/include/androidfw/CursorWindow.h b/libs/androidfw/include/androidfw/CursorWindow.h
index c2eac12eb77d..9ec026a19c4c 100644
--- a/libs/androidfw/include/androidfw/CursorWindow.h
+++ b/libs/androidfw/include/androidfw/CursorWindow.h
@@ -26,8 +26,6 @@
 #include "binder/Parcel.h"
 #include "utils/String8.h"
 
-#include "android-base/mapped_file.h"
-
 #define LOG_WINDOW(...)
 
 namespace android {
@@ -151,8 +149,6 @@ private:
     String8 mName;
     int mAshmemFd = -1;
     void* mData = nullptr;
-    std::unique_ptr<android::base::MappedFile> mMappedFile;
-
     /**
      * Pointer to the first FieldSlot, used to optimize the extremely
      * hot code path of getFieldSlot().
-- 
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