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firmware: exynos-acpm: Drop fake 'const' on handle pointer

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All the functions operating on the 'handle' pointer are claiming it is a
pointer to const thus they should not modify the handle.  In fact that's
a false statement, because first thing these functions do is drop the
cast to const with container_of:

  struct acpm_info *acpm = handle_to_acpm_info(handle);

And with such cast the handle is easily writable with simple:

  acpm->handle.ops.pmic_ops.read_reg = NULL;

The code is not correct logically, either, because functions like
acpm_get_by_node() and acpm_handle_put() are meant to modify the handle
reference counting, thus they must modify the handle.  Modification here
happens anyway, even if the reference counting is stored in the
container which the handle is part of.

The code does not have actual visible bug, but incorrect 'const'
annotations could lead to incorrect compiler decisions.

Fixes: a88927b534 ("firmware: add Exynos ACPM protocol driver")
Cc: stable@vger.kernel.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Link: https://patch.msgid.link/20260224104203.42950-2-krzysztof.kozlowski@oss.qualcomm.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
This commit is contained in:
Krzysztof Kozlowski
2026-02-24 11:42:04 +01:00
committed by Krzysztof Kozlowski
parent f2e83070fe
commit a2be37eedb
9 changed files with 48 additions and 52 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/firmware/samsung/exynos-acpm-pmic.c
View File

@@ -77,7 +77,7 @@ static void acpm_pmic_init_read_cmd(u32 cmd[4], u8 type, u8 reg, u8 chan)
cmd[3] = ktime_to_ms(ktime_get());
}
int acpm_pmic_read_reg(const struct acpm_handle *handle,
int acpm_pmic_read_reg(struct acpm_handle *handle,
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
u8 *buf)
{
@@ -107,7 +107,7 @@ static void acpm_pmic_init_bulk_read_cmd(u32 cmd[4], u8 type, u8 reg, u8 chan,
FIELD_PREP(ACPM_PMIC_VALUE, count);
}
int acpm_pmic_bulk_read(const struct acpm_handle *handle,
int acpm_pmic_bulk_read(struct acpm_handle *handle,
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
u8 count, u8 *buf)
{
@@ -150,7 +150,7 @@ static void acpm_pmic_init_write_cmd(u32 cmd[4], u8 type, u8 reg, u8 chan,
cmd[3] = ktime_to_ms(ktime_get());
}
int acpm_pmic_write_reg(const struct acpm_handle *handle,
int acpm_pmic_write_reg(struct acpm_handle *handle,
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
u8 value)
{
@@ -187,7 +187,7 @@ static void acpm_pmic_init_bulk_write_cmd(u32 cmd[4], u8 type, u8 reg, u8 chan,
}
}
int acpm_pmic_bulk_write(const struct acpm_handle *handle,
int acpm_pmic_bulk_write(struct acpm_handle *handle,
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
u8 count, const u8 *buf)
{
@@ -220,7 +220,7 @@ static void acpm_pmic_init_update_cmd(u32 cmd[4], u8 type, u8 reg, u8 chan,
cmd[3] = ktime_to_ms(ktime_get());
}
int acpm_pmic_update_reg(const struct acpm_handle *handle,
int acpm_pmic_update_reg(struct acpm_handle *handle,
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
u8 value, u8 mask)
{