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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/mfd/sec-acpm.c
View File

@@ -367,7 +367,7 @@ static const struct regmap_config s2mpg11_regmap_config_meter = {
};
struct sec_pmic_acpm_shared_bus_context {
const struct acpm_handle *acpm;
struct acpm_handle *acpm;
unsigned int acpm_chan_id;
u8 speedy_channel;
};
@@ -390,7 +390,7 @@ static int sec_pmic_acpm_bus_write(void *context, const void *data,
size_t count)
{
struct sec_pmic_acpm_bus_context *ctx = context;
const struct acpm_handle *acpm = ctx->shared->acpm;
struct acpm_handle *acpm = ctx->shared->acpm;
const struct acpm_pmic_ops *pmic_ops = &acpm->ops.pmic_ops;
size_t val_count = count - BITS_TO_BYTES(ACPM_ADDR_BITS);
const u8 *d = data;
@@ -410,7 +410,7 @@ static int sec_pmic_acpm_bus_read(void *context, const void *reg_buf, size_t reg
void *val_buf, size_t val_size)
{
struct sec_pmic_acpm_bus_context *ctx = context;
const struct acpm_handle *acpm = ctx->shared->acpm;
struct acpm_handle *acpm = ctx->shared->acpm;
const struct acpm_pmic_ops *pmic_ops = &acpm->ops.pmic_ops;
const u8 *r = reg_buf;
u8 reg;
@@ -429,7 +429,7 @@ static int sec_pmic_acpm_bus_reg_update_bits(void *context, unsigned int reg, un
unsigned int val)
{
struct sec_pmic_acpm_bus_context *ctx = context;
const struct acpm_handle *acpm = ctx->shared->acpm;
struct acpm_handle *acpm = ctx->shared->acpm;
const struct acpm_pmic_ops *pmic_ops = &acpm->ops.pmic_ops;
return pmic_ops->update_reg(acpm, ctx->shared->acpm_chan_id, ctx->type, reg & 0xff,
@@ -480,7 +480,7 @@ static int sec_pmic_acpm_probe(struct platform_device *pdev)
struct regmap *regmap_common, *regmap_pmic, *regmap;
const struct sec_pmic_acpm_platform_data *pdata;
struct sec_pmic_acpm_shared_bus_context *shared_ctx;
const struct acpm_handle *acpm;
struct acpm_handle *acpm;
struct device *dev = &pdev->dev;
int ret, irq;