tpm: sandbox: fix wrong assignment with a simplification

The recv variable in sandbox_tpm2_fill_buf() is a pointer on a pointer
of a char array. It means accessing *recv is the char array pointer
itself while **recv is the first character of that array. There is no
need for such indirection here, so simplify the code.

Simplifying things will make the last assignment right: "*recv = NULL"
is now correct. The issue has been found by the following Coverity
Scan report:

    CID 183371:  Incorrect expression  (UNUSED_VALUE)
    Assigning value "4UL" to "*recv" here, but that stored value is overwritten before it can be used.
    232             *recv += sizeof(rc);
    233
    234             /* Add trailing \0 */
    235             *recv = NULL;

While at simplifying things, use '\0' instead of NULL when adding an
empty char at the end of the buffer.

Reported-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Miquel Raynal 2018-08-05 18:53:07 +02:00 committed by Tom Rini
parent fd973ca696
commit 46703cd9f3

View file

@ -215,24 +215,24 @@ static int sandbox_tpm2_check_readyness(struct udevice *dev, int command)
return 0;
}
static int sandbox_tpm2_fill_buf(u8 **recv, size_t *recv_len, u16 tag, u32 rc)
static int sandbox_tpm2_fill_buf(u8 *recv, size_t *recv_len, u16 tag, u32 rc)
{
*recv_len = sizeof(tag) + sizeof(u32) + sizeof(rc);
/* Write tag */
put_unaligned_be16(tag, *recv);
*recv += sizeof(tag);
put_unaligned_be16(tag, recv);
recv += sizeof(tag);
/* Write length */
put_unaligned_be32(*recv_len, *recv);
*recv += sizeof(u32);
put_unaligned_be32(*recv_len, recv);
recv += sizeof(u32);
/* Write return code */
put_unaligned_be32(rc, *recv);
*recv += sizeof(rc);
put_unaligned_be32(rc, recv);
recv += sizeof(rc);
/* Add trailing \0 */
*recv = NULL;
*recv = '\0';
return 0;
}
@ -287,7 +287,7 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
printf("TPM2: Unmatching length, received: %ld, expected: %d\n",
send_size, length);
rc = TPM2_RC_SIZE;
sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
return 0;
}
@ -295,13 +295,13 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
sent += sizeof(command);
rc = sandbox_tpm2_check_readyness(dev, command);
if (rc) {
sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
return 0;
}
rc = sandbox_tpm2_check_session(dev, command, tag, &sent, &hierarchy);
if (rc) {
sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
return 0;
}
@ -319,7 +319,7 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
tpm->startup_done = true;
sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
break;
case TPM2_CC_SELF_TEST:
@ -335,7 +335,7 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
tpm->tests_done = true;
sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
break;
case TPM2_CC_CLEAR:
@ -358,7 +358,7 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
tpm->pcr[i][j] = 0;
}
sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
break;
case TPM2_CC_HIERCHANGEAUTH:
@ -372,7 +372,7 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
sent += new_pw_sz;
}
sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
break;
case TPM2_CC_GET_CAPABILITY:
@ -392,7 +392,7 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
if (!property_count ||
property + property_count > TPM2_PROPERTY_NB) {
rc = TPM2_RC_HANDLE;
return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
return sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
}
/* Write tag */
@ -445,7 +445,7 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
tpm->properties[TPM2_LOCKOUT_RECOVERY] = get_unaligned_be32(sent);
sent += sizeof(*tpm->properties);
sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
break;
case TPM2_CC_PCR_READ:
@ -454,7 +454,7 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
if (selections != 1) {
printf("Sandbox cannot handle more than one PCR\n");
rc = TPM2_RC_VALUE;
return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
return sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
}
alg = get_unaligned_be16(sent);
@ -462,7 +462,7 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
if (alg != TPM2_ALG_SHA256) {
printf("Sandbox TPM only handle SHA256 algorithm\n");
rc = TPM2_RC_VALUE;
return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
return sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
}
pcr_array_sz = *sent;
@ -470,7 +470,7 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
if (!pcr_array_sz || pcr_array_sz > 8) {
printf("Sandbox TPM cannot handle so much PCRs\n");
rc = TPM2_RC_VALUE;
return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
return sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
}
for (i = 0; i < pcr_array_sz; i++)
@ -480,13 +480,13 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
printf("Sandbox TPM handles up to %d PCR(s)\n",
SANDBOX_TPM_PCR_NB);
rc = TPM2_RC_VALUE;
return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
return sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
}
if (!pcr_map) {
printf("Empty PCR map.\n");
rc = TPM2_RC_VALUE;
return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
return sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
}
for (i = 0; i < SANDBOX_TPM_PCR_NB; i++)
@ -538,7 +538,7 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
if (pcr_nb != 1) {
printf("Sandbox cannot handle more than one PCR\n");
rc = TPM2_RC_VALUE;
return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
return sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
}
/* Check the hash algorithm */
@ -547,19 +547,19 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
if (alg != TPM2_ALG_SHA256) {
printf("Sandbox TPM only handle SHA256 algorithm\n");
rc = TPM2_RC_VALUE;
return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
return sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
}
/* Extend the PCR */
rc = sandbox_tpm2_extend(dev, pcr_index, sent);
sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
break;
default:
printf("TPM2 command %02x unknown in Sandbox\n", command);
rc = TPM2_RC_COMMAND_CODE;
sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
}
return 0;