ARM: ux500: do not directly dereference __iomem

commit 65b0e307a1a9193571db12910f382f84195a3d29 upstream.

Sparse reports that calling add_device_randomness() on `uid` is a
violation of address spaces. And indeed the next usage uses readl()
properly, but that was left out when passing it toadd_device_
randomness(). So instead copy the whole thing to the stack first.

Fixes: 4040d10a3d ("ARM: ux500: add DB serial number to entropy pool")
Cc: Linus Walleij <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/all/[email protected]/
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Jason A. Donenfeld <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Linus Walleij <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
This commit is contained in:
Jason A. Donenfeld 2022-11-08 13:37:55 +01:00 • committed by Greg Kroah-Hartman
commit b22d683c90

View file

@ -159,20 +159,18 @@ static ssize_t ux500_get_process(struct device *dev,
static const char *db8500_read_soc_id(struct device_node *backupram)
{
void __iomem *base;
void __iomem *uid;
const char *retstr;
u32 uid[5];
base = of_iomap(backupram, 0);
if (!base)
return NULL;
uid = base + 0x1fc0;
memcpy_fromio(uid, base + 0x1fc0, sizeof(uid));
/* Throw these device-specific numbers into the entropy pool */
add_device_randomness(uid, 0x14);
add_device_randomness(uid, sizeof(uid));
retstr = kasprintf(GFP_KERNEL, "%08x%08x%08x%08x%08x",
readl((u32 *)uid+0),
readl((u32 *)uid+1), readl((u32 *)uid+2),
readl((u32 *)uid+3), readl((u32 *)uid+4));
uid[0], uid[1], uid[2], uid[3], uid[4]);
iounmap(base);
return retstr;
}