Add test cases for ASHMEM_GET_PROT_MASK and ASHMEM_SET_PROT_MASK ioctls.

1 files changed, 88 insertions, 0 deletions

diff --git a/ashmemtest-basic/ashmemtest.c b/ashmemtest-basic/ashmemtest.c
index eb83986..23d83d1 100644
--- a/ashmemtest-basic/ashmemtest.c
+++ b/ashmemtest-basic/ashmemtest.c
@@ -394,6 +394,93 @@ void ashmem_mmap (char *ashmemdev, size_t pagesize)
     printf ("%d [%s]: test passed\n", testno, __func__);
 }
 
+/* Stolen from the kernel */
+#define DEFAULT_PROT_MASK (PROT_READ | PROT_WRITE | PROT_EXEC)
+
+void ashmem_prot (char *ashmemdev, size_t pagesize)
+{
+    void *mem;
+    int fd, ret;
+
+    testno++;
+
+    /* check whether default protection is read/write/exec */
+    fd = test_open (ashmemdev, O_RDWR);
+    ret = ioctl (fd, ASHMEM_SET_SIZE, pagesize);
+    if (ret < 0)
+	fatal (errno, "can't allocate %ld-bytes read-only region");
+    ret = ioctl (fd, ASHMEM_GET_PROT_MASK);
+    if (ret != DEFAULT_PROT_MASK)
+	fatal (0, "default protection mask mismatch (got %x expect %x)",
+	       ret, DEFAULT_PROT_MASK);
+    test_close (fd);
+
+    /* check whether we can remove some protection bits */
+    fd = test_open (ashmemdev, O_RDWR);
+    ret = ioctl (fd, ASHMEM_SET_SIZE, pagesize);
+    if (ret < 0)
+	fatal (errno, "can't allocate %ld-bytes read-only region");
+    ret = ioctl (fd, ASHMEM_GET_PROT_MASK);
+    if (ret != DEFAULT_PROT_MASK)
+	fatal (errno, "can't get protection mask or unexpected mask");
+    ret &= ~(PROT_READ | PROT_WRITE);
+    ret = ioctl (fd, ASHMEM_SET_PROT_MASK, ret);
+    if (ret < 0)
+	fatal (errno, "can't remove protection bits");
+    ret = ioctl (fd, ASHMEM_GET_PROT_MASK);
+    if (ret != PROT_EXEC)
+	fatal (errno, "protection mask mismatch (expect %x got %x)", PROT_EXEC, ret);
+    test_close (fd);
+
+    /* check whether we can't map read/write after removing PROT_READ... */
+    fd = test_open (ashmemdev, O_RDWR);
+    ret = ioctl (fd, ASHMEM_SET_SIZE, pagesize);
+    if (ret < 0)
+	fatal (errno, "can't allocate %ld-bytes read-only region");
+    ret = ioctl (fd, ASHMEM_GET_PROT_MASK);
+    if (ret != DEFAULT_PROT_MASK)
+	fatal (errno, "can't get protection mask or unexpected mask");
+    ret &= ~PROT_READ;
+    ret = ioctl (fd, ASHMEM_SET_PROT_MASK, ret);
+    if (ret < 0)
+	fatal (errno, "can't remove protection bits");
+    mem = mmap (NULL, pagesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+    if (mem != MAP_FAILED || errno != EPERM)
+	fatal (errno, "should not allow read/write map after removing PROT_READ");
+    /* ...but can map write-only */
+    mem = mmap (NULL, pagesize, PROT_WRITE, MAP_SHARED, fd, 0);
+    if (mem == MAP_FAILED)
+	fatal (errno, "should allow write-only map after removing PROT_READ");
+    if (munmap (mem, pagesize))
+	fatal (errno, "can't unmap ashmem region");
+    test_close (fd);
+
+    /* likewise after removing PROT_WRITE... */
+    fd = test_open (ashmemdev, O_RDWR);
+    ret = ioctl (fd, ASHMEM_SET_SIZE, pagesize);
+    if (ret < 0)
+	fatal (errno, "can't allocate %ld-bytes read-only region");
+    ret = ioctl (fd, ASHMEM_GET_PROT_MASK);
+    if (ret != DEFAULT_PROT_MASK)
+	fatal (errno, "can't get protection mask or unexpected mask");
+    ret &= ~PROT_WRITE;
+    ret = ioctl (fd, ASHMEM_SET_PROT_MASK, ret);
+    if (ret < 0)
+	fatal (errno, "can't remove protection bits");
+    mem = mmap (NULL, pagesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+    if (mem != MAP_FAILED || errno != EPERM)
+	fatal (errno, "should not allow read/write map after removing PROT_WRITE");
+    /* ...still can map read-only */
+    mem = mmap (NULL, pagesize, PROT_READ, MAP_SHARED, fd, 0);
+    if (mem == MAP_FAILED)
+	fatal (errno, "should allow read-only map after removing PROT_WRITE");
+    if (munmap (mem, pagesize))
+	fatal (errno, "can't unmap ashmem region");
+    test_close (fd);
+
+    printf ("%d [%s]: test passed\n", testno, __func__);
+}
+
 int main(int argc, char *argv[])
 {
     char ashmemdev[64];
@@ -407,5 +494,6 @@ int main(int argc, char *argv[])
     ashmem_pin_status (ashmemdev, pagesize);
     ashmem_size (ashmemdev, pagesize);
     ashmem_mmap (ashmemdev, pagesize);
+    ashmem_prot (ashmemdev, pagesize);
     return 0;
 }