commit 2abb0d5268ae7b5ddf82099b1f8d5aa8414637d4 upstream.

There is no locking in this sysfs show function so stats printing can
race with a devfreq_update_status called as part of freq switching or
with initialization.

Also add an assert in devfreq_update_status to make it clear that lock
must be held by caller.

Fixes: 39688ce6facd ("PM / devfreq: account suspend/resume for stats")
Cc: stable@vger.kernel.org
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 7544fd7f384591038646d3cd9efb311ab4509e24 upstream.

A bit unexpectedly (but still documented), request_module may
return a positive value, in case of a modprobe error.
This is currently causing issues in the devfreq framework.

When a request_module exits with a positive value, we currently
return that via ERR_PTR. However, because the value is positive,
it's not a ERR_VALUE proper, and is therefore treated as a
valid struct devfreq_governor pointer, leading to a kernel oops.

Fix this by returning -EINVAL if request_module returns a positive
value.

Fixes: b53b0128052ff ("PM / devfreq: Fix static checker warning in try_then_request_governor")
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit b53b0128052ffd687797d5f4deeb76327e7b5711 ]

The patch 23c7b54ca1cd: "PM / devfreq: Fix devfreq_add_device() when
drivers are built as modules." leads to the following static checker
warning:

    drivers/devfreq/devfreq.c:1043 governor_store()
    warn: 'governor' can also be NULL

The reason is that the try_then_request_governor() function returns both
error pointers and NULL. It should just return error pointers, so fix
this by returning a ERR_PTR to the error intead of returning NULL.

Fixes: 23c7b54ca1cd ("PM / devfreq: Fix devfreq_add_device() when drivers are built as modules.")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 2f061fd0c2d852e32e03a903fccd810663c5c31e ]

device_release() is freeing the resources before calling the device
specific release callback which is, in the case of devfreq, stopping
the governor.

It is a problem as some governors are using the device resources. e.g.
simpleondemand which is using the devfreq deferrable monitoring work. If it
is not stopped before the resources are freed, it might lead to a use after
free.

Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Reviewed-by: John Einar Reitan <john.reitan@arm.com>
[cw00.choi: Fix merge conflict]
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit df5cf4a36178c5d4f2b8b9469cb2f722e64cd102 ]

Commit ab8f58ad72c4 ("PM / devfreq: Set min/max_freq when adding the
devfreq device") initializes df->min/max_freq with the min/max OPP when
the device is added. Later commit f1d981eaecf8 ("PM / devfreq: Use the
available min/max frequency") adds df->scaling_min/max_freq and the
following to the frequency adjustment code:

  max_freq = MIN(devfreq->scaling_max_freq, devfreq->max_freq);

With the current handling of min/max_freq this is incorrect:

Even though df->max_freq is now initialized to a value != 0 user space
can still set it to 0, in this case max_freq would be 0 instead of
df->scaling_max_freq as intended. In consequence the frequency adjustment
is not performed:

  if (max_freq && freq > max_freq) {
	freq = max_freq;

To fix this set df->min/max freq to the min/max OPP in max/max_freq_store,
when the user passes a value of 0. This also prevents df->max_freq from
being set below the min OPP when df->min_freq is 0, and similar for
min_freq. Since it is now guaranteed that df->min/max_freq can't be 0 the
checks for this case can be removed.

Fixes: f1d981eaecf8 ("PM / devfreq: Use the available min/max frequency")
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 23c7b54ca1cd1797ef39169ab85e6d46f1c2d061 ]

When the devfreq driver and the governor driver are built as modules,
the call to devfreq_add_device() or governor_store() fails because the
governor driver is not loaded at the time the devfreq driver loads. The
devfreq driver has a build dependency on the governor but also should
have a runtime dependency. We need to make sure that the governor driver
is loaded before the devfreq driver.

This patch fixes this bug by adding a try_then_request_governor()
function. First tries to find the governor, and then, if it is not found,
it requests the module and tries again.

Fixes: 1b5c1be2c88e (PM / devfreq: map devfreq drivers to governor using name)
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Commit ab8f58ad72c4 ("PM / devfreq: Set min/max_freq when adding
the devfreq device") introduced the initialization of the user
limits min/max_freq from the lowest/highest available OPPs. Later
commit f1d981eaecf8 ("PM / devfreq: Use the available min/max
frequency") added scaling_min/max_freq, which actually represent
the frequencies of the lowest/highest available OPP. scaling_min/
max_freq are initialized with the values from min/max_freq, which
is totally correct in the context, but a bit awkward to read.

Swap the initialization and assign scaling_min/max_freq with the
OPP freqs and then the user limts min/max_freq with scaling_min/
max_freq.

Needless to say that this change is a NOP, intended to improve
readability.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

Never directly free @dev after calling device_register() or
device_unregister(), even if device_register() returned an error.
Always use put_device() to give up the reference initialized.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

The devm_kzalloc() function has a 2-factor argument form, devm_kcalloc().
This patch replaces cases of:

        devm_kzalloc(handle, a * b, gfp)

with:
        devm_kcalloc(handle, a * b, gfp)

as well as handling cases of:

        devm_kzalloc(handle, a * b * c, gfp)

with:

        devm_kzalloc(handle, array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        devm_kcalloc(handle, array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        devm_kzalloc(handle, 4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

Some manual whitespace fixes were needed in this patch, as Coccinelle
really liked to write "=devm_kcalloc..." instead of "= devm_kcalloc...".

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
expression HANDLE;
type TYPE;
expression THING, E;
@@

(
  devm_kzalloc(HANDLE,
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  devm_kzalloc(HANDLE,
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression HANDLE;
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  devm_kzalloc(HANDLE,
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
expression HANDLE;
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
expression HANDLE;
identifier SIZE, COUNT;
@@

- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression HANDLE;
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  devm_kzalloc(HANDLE,
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression HANDLE;
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  devm_kzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
expression HANDLE;
identifier STRIDE, SIZE, COUNT;
@@

(
  devm_kzalloc(HANDLE,
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression HANDLE;
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  devm_kzalloc(HANDLE, C1 * C2 * C3, ...)
|
  devm_kzalloc(HANDLE,
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  devm_kzalloc(HANDLE,
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression HANDLE;
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  devm_kzalloc(HANDLE, sizeof(THING) * C2, ...)
|
  devm_kzalloc(HANDLE, sizeof(TYPE) * C2, ...)
|
  devm_kzalloc(HANDLE, C1 * C2 * C3, ...)
|
  devm_kzalloc(HANDLE, C1 * C2, ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	(E1) * E2
+	E1, E2
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>

df->governor is being dereferenced before it is null checked,
hence there is a potential null pointer dereference.

Notice that df->governor is being null checked at line 1004:
if (df->governor) {, which implies it might be null.

Fix this by null checking df->governor before dereferencing it.

Addresses-Coverity-ID: 1401988 ("Dereference before null check")
Fixes: bcf23c79c4e4 ("PM / devfreq: Fix available_governor sysfs")
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>