ide: silence some underflow warnings (0860bf94) · Commits · 戴 / test

Back in the day we used to just say this code was root only so it was ok that the bounds checking was sloppy. These days it annoys static checkers so we fix it. In the original code "c > INT_MAX" was never true since "c" was an int. I am not sure what was intended so I left it alone. But because I made "c" unsigned it means we don't have a warning any more. The second warning is that we cap "i" but allow negatives leading to an underflow of the ide_disks_chs[] array. The third set of warnings is because these values come from the user and we cap most of the upper bounds but allow negative values. Negative cylinders doesn't make sense. drivers/ide/ide.c:262 ide_set_disk_chs() warn: impossible condition '(c > ((~0 >> 1))) => (s32min-s32max > s32max)' drivers/ide/ide.c:270 ide_set_disk_chs() warn: check 'ide_disks_chs[i]' for negative offsets 'i' = s32min. extra = 's32min-19' drivers/ide/ide.c:271 ide_set_disk_chs() warn: no lower bound on 'h' Signed-off-by:

Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/ide/ide.c

+8 −8

Original line number	Diff line number	Diff line
		@@ -178,17 +178,17 @@ MODULE_PARM_DESC(pci_clock, "PCI bus clock frequency (in MHz)");

		static int ide_set_dev_param_mask(const char s, const struct kernel_param kp)
		{
		int a, b, i, j = 1;
		unsigned int a, b, i, j = 1;
		unsigned int dev_param_mask = (unsigned int )kp->arg;

		/* controller . device (0 or 1) [ : 1 (set) \| 0 (clear) ] */
		if (sscanf(s, "%d.%d:%d", &a, &b, &j) != 3 &&
		sscanf(s, "%d.%d", &a, &b) != 2)
		if (sscanf(s, "%u.%u:%u", &a, &b, &j) != 3 &&
		sscanf(s, "%u.%u", &a, &b) != 2)
		return -EINVAL;

		i = a * MAX_DRIVES + b;

		if (i >= MAX_HWIFS * MAX_DRIVES \|\| j < 0 \|\| j > 1)
		if (i >= MAX_HWIFS * MAX_DRIVES \|\| j > 1)
		return -EINVAL;

		if (j)
		@@ -246,17 +246,17 @@ static struct chs_geom ide_disks_chs[MAX_HWIFS * MAX_DRIVES];

		static int ide_set_disk_chs(const char str, struct kernel_param kp)
		{
		int a, b, c = 0, h = 0, s = 0, i, j = 1;
		unsigned int a, b, c = 0, h = 0, s = 0, i, j = 1;

		/* controller . device (0 or 1) : Cylinders , Heads , Sectors */
		/* controller . device (0 or 1) : 1 (use CHS) \| 0 (ignore CHS) */
		if (sscanf(str, "%d.%d:%d,%d,%d", &a, &b, &c, &h, &s) != 5 &&
		sscanf(str, "%d.%d:%d", &a, &b, &j) != 3)
		if (sscanf(str, "%u.%u:%u,%u,%u", &a, &b, &c, &h, &s) != 5 &&
		sscanf(str, "%u.%u:%u", &a, &b, &j) != 3)
		return -EINVAL;

		i = a * MAX_DRIVES + b;

		if (i >= MAX_HWIFS * MAX_DRIVES \|\| j < 0 \|\| j > 1)
		if (i >= MAX_HWIFS * MAX_DRIVES \|\| j > 1)
		return -EINVAL;

		if (c > INT_MAX \|\| h > 255 \|\| s > 255)

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