[bug report] mtd: parsers: Add Qcom SMEM parser

[Dan Carpenter]

Hello Manivannan Sadhasivam,

The patch 803eb124e1a6: "mtd: parsers: Add Qcom SMEM parser" from Jan
4, 2021, leads to the following static checker warning:

	drivers/mtd/parsers/qcomsmempart.c:109 parse_qcomsmem_part()
	warn: passing zero to 'PTR_ERR'

drivers/mtd/parsers/qcomsmempart.c
    68          pr_debug("Parsing partition table info from SMEM\n");
    69          ptable = qcom_smem_get(SMEM_APPS, SMEM_AARM_PARTITION_TABLE, &len);
    70          if (IS_ERR(ptable)) {

Can "ptable" be NULL here?

    71                  pr_err("Error reading partition table header\n");
    72                  return PTR_ERR(ptable);
    73          }
    74  
    75          /* Verify ptable magic */
    76          if (le32_to_cpu(ptable->magic1) != SMEM_FLASH_PART_MAGIC1 ||
    77              le32_to_cpu(ptable->magic2) != SMEM_FLASH_PART_MAGIC2) {
    78                  pr_err("Partition table magic verification failed\n");
    79                  return -EINVAL;
    80          }
    81  
    82          /* Ensure that # of partitions is less than the max we have allocated */
    83          numparts = le32_to_cpu(ptable->numparts);
    84          if (numparts > SMEM_FLASH_PTABLE_MAX_PARTS_V4) {
    85                  pr_err("Partition numbers exceed the max limit\n");
    86                  return -EINVAL;
    87          }
    88  
    89          /* Find out length of partition data based on table version */
    90          if (le32_to_cpu(ptable->version) <= SMEM_FLASH_PTABLE_V3) {
    91                  len = SMEM_FLASH_PTABLE_HDR_LEN + SMEM_FLASH_PTABLE_MAX_PARTS_V3 *
    92                          sizeof(struct smem_flash_pentry);
    93          } else if (le32_to_cpu(ptable->version) == SMEM_FLASH_PTABLE_V4) {
    94                  len = SMEM_FLASH_PTABLE_HDR_LEN + SMEM_FLASH_PTABLE_MAX_PARTS_V4 *
    95                          sizeof(struct smem_flash_pentry);
    96          } else {
    97                  pr_err("Unknown ptable version (%d)", le32_to_cpu(ptable->version));
    98                  return -EINVAL;
    99          }
   100  
   101          /*
   102           * Now that the partition table header has been parsed, verified
   103           * and the length of the partition table calculated, read the
   104           * complete partition table
   105           */
   106          ptable = qcom_smem_get(SMEM_APPS, SMEM_AARM_PARTITION_TABLE, &len);
   107          if (IS_ERR_OR_NULL(ptable)) {
   108                  pr_err("Error reading partition table\n");
   109                  return PTR_ERR(ptable);

If "ptable" is NULL then this code returns success.  It's not clear if
that's intentional.  If it is then just ignore this email.  Thanks!

   110          }
   111  
   112          parts = kcalloc(numparts, sizeof(*parts), GFP_KERNEL);

regards,
dan carpenter