commit 95c357244c36d62c3bc67db3ff70ce43e07e9765
author Isaac J. Manjarres <isaacmanjarres@google.com> Fri Dec 27 13:36:35 2024 -0800
committer Isaac J. Manjarres <isaacmanjarres@google.com> Wed Jan 15 14:35:47 2025 -0800
tree 5f1d2af277d5dc9a68a4fbf949ca614654914a80
parent 86c1d55226dc3a5cab91382ac50a428d56d67f04

ashmem_test: Remove tests that remove read access

Memfds are always readable, and there is no way to restrict them
from being mapped as readable. There is also no known usecase for
which read access needs to be revoked. Therefore, remove tests that
rely on being able to remove read-access to ashmem buffers, since
those will fail when ashmem moves to using memfd.

Bug: 111903542
Change-Id: I9ef7c82f9dcf641b0bad997b7ca3d06f0344fb32
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>

libcutils/ashmem_test.cpp

diff --git a/libcutils/ashmem_test.cpp b/libcutils/ashmem_test.cpp
index e78934f..9876914 100644
--- a/libcutils/ashmem_test.cpp
+++ b/libcutils/ashmem_test.cpp
@@ -187,12 +187,6 @@
     ASSERT_NO_FATAL_FAILURE(TestMmap(fd, size, PROT_READ, &region));
     EXPECT_EQ(0, munmap(region, size));
 
-    ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_WRITE));
-    TestProtDenied(fd, size, PROT_READ);
-    TestProtIs(fd, PROT_WRITE);
-    ASSERT_NO_FATAL_FAILURE(TestMmap(fd, size, PROT_WRITE, &region));
-    EXPECT_EQ(0, munmap(region, size));
-
     ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_READ | PROT_WRITE));
     TestProtIs(fd, PROT_READ | PROT_WRITE);
     ASSERT_EQ(0, ashmem_set_prot_region(fd, PROT_READ));
@@ -208,32 +202,29 @@
     unique_fd fd;
     const size_t size = getpagesize();
 
-    int protFlags[] = { PROT_READ, PROT_WRITE };
-    for (size_t i = 0; i < arraysize(protFlags); i++) {
-        ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_READ | PROT_WRITE));
+    ASSERT_NO_FATAL_FAILURE(TestCreateRegion(size, fd, PROT_READ | PROT_WRITE));
 
-        // This part of the test forks a process via ASSERT_EXIT()
-        // and has the child process change the mapping permissions of the
-        // buffer.
-        //
-        // The intent of this is to ensure that updates to the buffer's
-        // mapping permissions are visible across processes that reference the
-        // buffer.
-        //
-        // In this case, the parent process attempts to map the buffer with a
-        // permission that is denied, which should fail.
-        ASSERT_EXIT(
-            {
-                if (!ashmem_valid(fd)) {
-                    _exit(3);
-                } else if (ashmem_set_prot_region(fd, protFlags[i]) == -1) {
-                    _exit(1);
-                }
-                _exit(0);
-            },
-            ::testing::ExitedWithCode(0), "");
-        ASSERT_NO_FATAL_FAILURE(TestProtDenied(fd, size, protFlags[1-i]));
-    }
+    // This part of the test forks a process via ASSERT_EXIT()
+    // and has the child process change the mapping permissions of the
+    // buffer to read-only.
+    //
+    // The intent of this is to ensure that updates to the buffer's
+    // mapping permissions are visible across processes that reference the
+    // buffer.
+    //
+    // In this case, the parent process attempts to map the buffer with write
+    // permission, which should fail.
+    ASSERT_EXIT(
+        {
+            if (!ashmem_valid(fd)) {
+                _exit(3);
+            } else if (ashmem_set_prot_region(fd, PROT_READ) == -1) {
+                _exit(1);
+            }
+            _exit(0);
+        },
+        ::testing::ExitedWithCode(0), "");
+    ASSERT_NO_FATAL_FAILURE(TestProtDenied(fd, size, PROT_WRITE));
 }
 
 TEST(AshmemTest, ForkMultiRegionTest) {