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: 4040d10a3d44 ("ARM: ux500: add DB serial number to entropy pool")
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/202210230819.loF90KDh-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20221108123755.207438-1-Jason@zx2c4.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/soc/ux500/ux500-soc-id.c b/drivers/soc/ux500/ux500-soc-id.c
index 6c1be74..86a1a3c 100644
--- a/drivers/soc/ux500/ux500-soc-id.c
+++ b/drivers/soc/ux500/ux500-soc-id.c
@@ -159,20 +159,18 @@
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;
}