x86: geode: fix hwrng register accesses
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.
Closes #13417.
Reported-by: Timur I. Davletshin <timur.davletshin@gmail.com>
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>
(cherry picked from commit 09d13cd8d8)
			
			
This commit is contained in:
		| @@ -0,0 +1,47 @@ | |||||||
|  | From 859bd2e0c0052967536f3f902716f204d5a978b1 Mon Sep 17 00:00:00 2001 | ||||||
|  | From: Jonas Gorski <jonas.gorski@gmail.com> | ||||||
|  | Date: Fri, 8 Sep 2023 22:48:33 +0200 | ||||||
|  | Subject: [PATCH] hwrng: geode: fix accessing registers | ||||||
|  |  | ||||||
|  | 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> | ||||||
|  | --- | ||||||
|  |  drivers/char/hw_random/geode-rng.c | 6 ++++-- | ||||||
|  |  1 file changed, 4 insertions(+), 2 deletions(-) | ||||||
|  |  | ||||||
|  | --- a/drivers/char/hw_random/geode-rng.c | ||||||
|  | +++ b/drivers/char/hw_random/geode-rng.c | ||||||
|  | @@ -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 hw | ||||||
|  |   | ||||||
|  |  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++) { | ||||||
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