mtd: nand: silence some shift wrap warnings

There are static checkers which complain when we declare variables as

64 bit bitfields but only use the lower 32 bits because of shift wrapping. In this case "len" is declared as u64 as opposed to unsigned long or something which might be 32 bits.

Signed-off-by Dan Carpenter<[email protected]>

drivers/mtd/nand/nand_base.c +4 -4

index 9a48758..3eddd04 100644
@@ -108,13 +108,13 @@ static int check_offs_len(struct mtd_info *mtd,
  	int ret = 0;
 
  	/* Start address must align on block boundary */
-	if (ofs&  ((1<<  chip->phys_erase_shift) - 1)) {
+	if (ofs&  ((1ULL<<  chip->phys_erase_shift) - 1)) {
  		pr_debug("%s: unaligned address\n", __func__);
  		ret = -EINVAL;
  	}
 
  	/* Length must align on block boundary */
-	if (len&  ((1<<  chip->phys_erase_shift) - 1)) {
+	if (len&  ((1ULL<<  chip->phys_erase_shift) - 1)) {
  		pr_debug("%s: length not block aligned\n", __func__);
  		ret = -EINVAL;
  	}

@@ -394,7 +394,7 @@ static int nand_block_markbad_lowlevel(struct mtd_info *mtd, loff_t ofs)
  		memset(&einfo, 0, sizeof(einfo));
  		einfo.mtd = mtd;
  		einfo.addr = ofs;
-		einfo.len = 1<<  chip->phys_erase_shift;
+		einfo.len = 1ULL<<  chip->phys_erase_shift;
  		nand_erase_nand(mtd,&einfo, 0);
 
  		/* Write bad block marker to OOB */

@@ -2630,7 +2630,7 @@ int nand_erase_nand(struct mtd_info *mtd, struct erase_info *instr,
  		}
 
  		/* Increment page address and decrement length */
-		len -= (1<<  chip->phys_erase_shift);
+		len -= (1ULL<<  chip->phys_erase_shift);
  		page += pages_per_block;
 
  		/* Check, if we cross a chip boundary */

Quoted 1 line · Dan Carpenter

There are static checkers which complain when we declare variables as

could you tell me which "checker" and how do you test it?

you'd better post the warning message here.

Quoted 7 lines · Huang Shijie

Quoted 1 line · Dan Carpenter

There are static checkers which complain when we declare variables as

could you tell me which "checker" and how do you test it?

you'd better post the warning message here.

It's some stuff I'm working on but haven't released yet. But "len"

and "ofs" are declared as u64 and loff_t. If they were declared as unsigned long then maybe the current code would be fine because the code would be correct-ish on 32 bit arches.

So this is definitely the right thing to do.

There are static checkers which complain when we declare variables as 64 bit bitfields but only use the lower 32 bits because of shift wrapping. In this case "len" is declared as u64 as opposed to unsigned long or something which might be 32 bits.

Signed-off-by Dan Carpenter <[email protected]>