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hwrng: geode - fix accessing registers

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[ Upstream commit 464bd8ec2f06707f3773676a1bd2c64832a3c805 ]

When the membase and pci_dev pointer were moved to a new struct in priv,
the actual membase users were left untouched, and they started reading
out arbitrary memory behind the struct instead of registers. This
unfortunately turned the RNG into a constant number generator, depending
on the content of what was at that offset.

To fix this, update geode_rng_data_{read,present}() to also get the
membase via amd_geode_priv, and properly read from the right addresses
again.

Fixes: 9f6ec8dc574e ("hwrng: geode - Fix PCI device refcount leak")
Reported-by: Timur I. Davletshin <timur.davletshin@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217882
Tested-by: Timur I. Davletshin <timur.davletshin@gmail.com>
Suggested-by: Jo-Philipp Wich <jo@mein.io>
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jonas Gorski 2023-09-10 10:34:17 +02:00 committed by Greg Kroah-Hartman
parent e4e4d4abb8
commit f5d95a3968
1 changed files with 4 additions and 2 deletions
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6
drivers/char/hw_random/geode-rng.c
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@ -58,7 +58,8 @@ struct amd_geode_priv {
static int geode_rng_data_read(struct hwrng *rng, u32 *data)
{
void __iomem *mem = (void __iomem *)rng->priv;
struct amd_geode_priv *priv = (struct amd_geode_priv *)rng->priv;
void __iomem *mem = priv->membase;
*data = readl(mem + GEODE_RNG_DATA_REG);
@ -67,7 +68,8 @@ static int geode_rng_data_read(struct hwrng *rng, u32 *data)
static int geode_rng_data_present(struct hwrng *rng, int wait)
{
void __iomem *mem = (void __iomem *)rng->priv;
struct amd_geode_priv *priv = (struct amd_geode_priv *)rng->priv;
void __iomem *mem = priv->membase;
int data, i;
for (i = 0; i < 20; i++) {