tpm: fix alignment issues

The new tpm-crb-test fails on sparc host:

TEST: tests/tpm-crb-test... (pid=230409)
  /i386/tpm-crb/test:
Broken pipe
FAIL
GTester: last random seed: R02S29cea50247fe1efa59ee885a26d51a85
(pid=230423)
FAIL: tests/tpm-crb-test

and generates a new clang sanitizer runtime warning:

/home/petmay01/linaro/qemu-for-merges/hw/tpm/tpm_util.h:36:24: runtime
error: load of misaligned address 0x7fdc24c00002 for type 'const
uint32_t' (aka 'const unsigned int'), which requires 4 byte alignment
0x7fdc24c00002: note: pointer points here
<memory cannot be printed>

The sparc architecture does not allow misaligned loads and will
segfault if you try them.  For example, this function:

static inline uint32_t tpm_cmd_get_size(const void *b)
{
    return be32_to_cpu(*(const uint32_t *)(b + 2));
}

Should read,
    return ldl_be_p(b + 2);

As a general rule you can't take an arbitrary pointer into a byte
buffer and try to interpret it as a structure or a pointer to a
larger-than-bytesize-data simply by casting the pointer.

Use this clean up as an opportunity to remove unnecessary temporary
buffers and casts.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>

1 files changed, 16 insertions, 1 deletions

diff --git a/hw/tpm/tpm_util.h b/hw/tpm/tpm_util.h
index 19b2847..f003d15 100644
--- a/hw/tpm/tpm_util.h
+++ b/hw/tpm/tpm_util.h
@@ -31,9 +31,24 @@ bool tpm_util_is_selftest(const uint8_t *in, uint32_t in_len);
 
 int tpm_util_test_tpmdev(int tpm_fd, TPMVersion *tpm_version);
 
+static inline uint16_t tpm_cmd_get_tag(const void *b)
+{
+    return lduw_be_p(b);
+}
+
 static inline uint32_t tpm_cmd_get_size(const void *b)
 {
-    return be32_to_cpu(*(const uint32_t *)(b + 2));
+    return ldl_be_p(b + 2);
+}
+
+static inline uint32_t tpm_cmd_get_ordinal(const void *b)
+{
+    return ldl_be_p(b + 6);
+}
+
+static inline uint32_t tpm_cmd_get_errcode(const void *b)
+{
+    return ldl_be_p(b + 6);
 }
 
 int tpm_util_get_buffer_size(int tpm_fd, TPMVersion tpm_version,