Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
firmware: exynos-acpm: Drop fake 'const' on handle pointer
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: a88927b534ba ("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>
authored by
Krzysztof Kozlowski
and committed by
Krzysztof Kozlowski
a2be37ee
f2e83070
+48
-52
+2
-2
drivers/clk/samsung/clk-acpm.c
+2
-2
drivers/clk/samsung/clk-acpm.c
···
20
20
u32 id;
21
21
struct clk_hw hw;
22
22
unsigned int mbox_chan_id;
23
-
const struct acpm_handle *handle;
23
+
struct acpm_handle *handle;
24
24
};
25
25
26
26
struct acpm_clk_variant {
···
113
113
114
114
static int acpm_clk_probe(struct platform_device *pdev)
115
115
{
116
-
const struct acpm_handle *acpm_handle;
116
+
struct acpm_handle *acpm_handle;
117
117
struct clk_hw_onecell_data *clk_data;
118
118
struct clk_hw **hws;
119
119
struct device *dev = &pdev->dev;
+2
-2
drivers/firmware/samsung/exynos-acpm-dvfs.c
+2
-2
drivers/firmware/samsung/exynos-acpm-dvfs.c
···
43
43
cmd[3] = ktime_to_ms(ktime_get());
44
44
}
45
45
46
-
int acpm_dvfs_set_rate(const struct acpm_handle *handle,
46
+
int acpm_dvfs_set_rate(struct acpm_handle *handle,
47
47
unsigned int acpm_chan_id, unsigned int clk_id,
48
48
unsigned long rate)
49
49
{
···
63
63
cmd[3] = ktime_to_ms(ktime_get());
64
64
}
65
65
66
-
unsigned long acpm_dvfs_get_rate(const struct acpm_handle *handle,
66
+
unsigned long acpm_dvfs_get_rate(struct acpm_handle *handle,
67
67
unsigned int acpm_chan_id, unsigned int clk_id)
68
68
{
69
69
struct acpm_xfer xfer;
+2
-2
drivers/firmware/samsung/exynos-acpm-dvfs.h
+2
-2
drivers/firmware/samsung/exynos-acpm-dvfs.h
···
11
11
12
12
struct acpm_handle;
13
13
14
-
int acpm_dvfs_set_rate(const struct acpm_handle *handle,
14
+
int acpm_dvfs_set_rate(struct acpm_handle *handle,
15
15
unsigned int acpm_chan_id, unsigned int id,
16
16
unsigned long rate);
17
-
unsigned long acpm_dvfs_get_rate(const struct acpm_handle *handle,
17
+
unsigned long acpm_dvfs_get_rate(struct acpm_handle *handle,
18
18
unsigned int acpm_chan_id,
19
19
unsigned int clk_id);
20
20
+5
-5
drivers/firmware/samsung/exynos-acpm-pmic.c
+5
-5
drivers/firmware/samsung/exynos-acpm-pmic.c
···
77
77
cmd[3] = ktime_to_ms(ktime_get());
78
78
}
79
79
80
-
int acpm_pmic_read_reg(const struct acpm_handle *handle,
80
+
int acpm_pmic_read_reg(struct acpm_handle *handle,
81
81
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
82
82
u8 *buf)
83
83
{
···
107
107
FIELD_PREP(ACPM_PMIC_VALUE, count);
108
108
}
109
109
110
-
int acpm_pmic_bulk_read(const struct acpm_handle *handle,
110
+
int acpm_pmic_bulk_read(struct acpm_handle *handle,
111
111
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
112
112
u8 count, u8 *buf)
113
113
{
···
150
150
cmd[3] = ktime_to_ms(ktime_get());
151
151
}
152
152
153
-
int acpm_pmic_write_reg(const struct acpm_handle *handle,
153
+
int acpm_pmic_write_reg(struct acpm_handle *handle,
154
154
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
155
155
u8 value)
156
156
{
···
187
187
}
188
188
}
189
189
190
-
int acpm_pmic_bulk_write(const struct acpm_handle *handle,
190
+
int acpm_pmic_bulk_write(struct acpm_handle *handle,
191
191
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
192
192
u8 count, const u8 *buf)
193
193
{
···
220
220
cmd[3] = ktime_to_ms(ktime_get());
221
221
}
222
222
223
-
int acpm_pmic_update_reg(const struct acpm_handle *handle,
223
+
int acpm_pmic_update_reg(struct acpm_handle *handle,
224
224
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
225
225
u8 value, u8 mask)
226
226
{
+5
-5
drivers/firmware/samsung/exynos-acpm-pmic.h
+5
-5
drivers/firmware/samsung/exynos-acpm-pmic.h
···
11
11
12
12
struct acpm_handle;
13
13
14
-
int acpm_pmic_read_reg(const struct acpm_handle *handle,
14
+
int acpm_pmic_read_reg(struct acpm_handle *handle,
15
15
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
16
16
u8 *buf);
17
-
int acpm_pmic_bulk_read(const struct acpm_handle *handle,
17
+
int acpm_pmic_bulk_read(struct acpm_handle *handle,
18
18
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
19
19
u8 count, u8 *buf);
20
-
int acpm_pmic_write_reg(const struct acpm_handle *handle,
20
+
int acpm_pmic_write_reg(struct acpm_handle *handle,
21
21
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
22
22
u8 value);
23
-
int acpm_pmic_bulk_write(const struct acpm_handle *handle,
23
+
int acpm_pmic_bulk_write(struct acpm_handle *handle,
24
24
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
25
25
u8 count, const u8 *buf);
26
-
int acpm_pmic_update_reg(const struct acpm_handle *handle,
26
+
int acpm_pmic_update_reg(struct acpm_handle *handle,
27
27
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
28
28
u8 value, u8 mask);
29
29
#endif /* __EXYNOS_ACPM_PMIC_H__ */
+9
-7
drivers/firmware/samsung/exynos-acpm.c
+9
-7
drivers/firmware/samsung/exynos-acpm.c
···
410
410
*
411
411
* Return: 0 on success, -errno otherwise.
412
412
*/
413
-
int acpm_do_xfer(const struct acpm_handle *handle, const struct acpm_xfer *xfer)
413
+
int acpm_do_xfer(struct acpm_handle *handle, const struct acpm_xfer *xfer)
414
414
{
415
415
struct acpm_info *acpm = handle_to_acpm_info(handle);
416
416
struct exynos_mbox_msg msg;
···
674
674
* acpm_handle_put() - release the handle acquired by acpm_get_by_phandle.
675
675
* @handle: Handle acquired by acpm_get_by_phandle.
676
676
*/
677
-
static void acpm_handle_put(const struct acpm_handle *handle)
677
+
static void acpm_handle_put(struct acpm_handle *handle)
678
678
{
679
679
struct acpm_info *acpm = handle_to_acpm_info(handle);
680
680
struct device *dev = acpm->dev;
···
700
700
* @np: ACPM device tree node.
701
701
*
702
702
* Return: pointer to handle on success, ERR_PTR(-errno) otherwise.
703
+
*
704
+
* Note: handle CANNOT be pointer to const
703
705
*/
704
-
static const struct acpm_handle *acpm_get_by_node(struct device *dev,
705
-
struct device_node *np)
706
+
static struct acpm_handle *acpm_get_by_node(struct device *dev,
707
+
struct device_node *np)
706
708
{
707
709
struct platform_device *pdev;
708
710
struct device_link *link;
···
745
743
*
746
744
* Return: pointer to handle on success, ERR_PTR(-errno) otherwise.
747
745
*/
748
-
const struct acpm_handle *devm_acpm_get_by_node(struct device *dev,
749
-
struct device_node *np)
746
+
struct acpm_handle *devm_acpm_get_by_node(struct device *dev,
747
+
struct device_node *np)
750
748
{
751
-
const struct acpm_handle **ptr, *handle;
749
+
struct acpm_handle **ptr, *handle;
752
750
753
751
ptr = devres_alloc(devm_acpm_release, sizeof(*ptr), GFP_KERNEL);
754
752
if (!ptr)
+1
-1
drivers/firmware/samsung/exynos-acpm.h
+1
-1
drivers/firmware/samsung/exynos-acpm.h
+5
-5
drivers/mfd/sec-acpm.c
+5
-5
drivers/mfd/sec-acpm.c
···
367
367
};
368
368
369
369
struct sec_pmic_acpm_shared_bus_context {
370
-
const struct acpm_handle *acpm;
370
+
struct acpm_handle *acpm;
371
371
unsigned int acpm_chan_id;
372
372
u8 speedy_channel;
373
373
};
···
390
390
size_t count)
391
391
{
392
392
struct sec_pmic_acpm_bus_context *ctx = context;
393
-
const struct acpm_handle *acpm = ctx->shared->acpm;
393
+
struct acpm_handle *acpm = ctx->shared->acpm;
394
394
const struct acpm_pmic_ops *pmic_ops = &acpm->ops.pmic_ops;
395
395
size_t val_count = count - BITS_TO_BYTES(ACPM_ADDR_BITS);
396
396
const u8 *d = data;
···
410
410
void *val_buf, size_t val_size)
411
411
{
412
412
struct sec_pmic_acpm_bus_context *ctx = context;
413
-
const struct acpm_handle *acpm = ctx->shared->acpm;
413
+
struct acpm_handle *acpm = ctx->shared->acpm;
414
414
const struct acpm_pmic_ops *pmic_ops = &acpm->ops.pmic_ops;
415
415
const u8 *r = reg_buf;
416
416
u8 reg;
···
429
429
unsigned int val)
430
430
{
431
431
struct sec_pmic_acpm_bus_context *ctx = context;
432
-
const struct acpm_handle *acpm = ctx->shared->acpm;
432
+
struct acpm_handle *acpm = ctx->shared->acpm;
433
433
const struct acpm_pmic_ops *pmic_ops = &acpm->ops.pmic_ops;
434
434
435
435
return pmic_ops->update_reg(acpm, ctx->shared->acpm_chan_id, ctx->type, reg & 0xff,
···
480
480
struct regmap *regmap_common, *regmap_pmic, *regmap;
481
481
const struct sec_pmic_acpm_platform_data *pdata;
482
482
struct sec_pmic_acpm_shared_bus_context *shared_ctx;
483
-
const struct acpm_handle *acpm;
483
+
struct acpm_handle *acpm;
484
484
struct device *dev = &pdev->dev;
485
485
int ret, irq;
486
486
+17
-23
include/linux/firmware/samsung/exynos-acpm-protocol.h
+17
-23
include/linux/firmware/samsung/exynos-acpm-protocol.h
···
14
14
struct device_node;
15
15
16
16
struct acpm_dvfs_ops {
17
-
int (*set_rate)(const struct acpm_handle *handle,
18
-
unsigned int acpm_chan_id, unsigned int clk_id,
19
-
unsigned long rate);
20
-
unsigned long (*get_rate)(const struct acpm_handle *handle,
17
+
int (*set_rate)(struct acpm_handle *handle, unsigned int acpm_chan_id,
18
+
unsigned int clk_id, unsigned long rate);
19
+
unsigned long (*get_rate)(struct acpm_handle *handle,
21
20
unsigned int acpm_chan_id,
22
21
unsigned int clk_id);
23
22
};
24
23
25
24
struct acpm_pmic_ops {
26
-
int (*read_reg)(const struct acpm_handle *handle,
27
-
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
28
-
u8 *buf);
29
-
int (*bulk_read)(const struct acpm_handle *handle,
30
-
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
31
-
u8 count, u8 *buf);
32
-
int (*write_reg)(const struct acpm_handle *handle,
33
-
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
34
-
u8 value);
35
-
int (*bulk_write)(const struct acpm_handle *handle,
36
-
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
37
-
u8 count, const u8 *buf);
38
-
int (*update_reg)(const struct acpm_handle *handle,
39
-
unsigned int acpm_chan_id, u8 type, u8 reg, u8 chan,
40
-
u8 value, u8 mask);
25
+
int (*read_reg)(struct acpm_handle *handle, unsigned int acpm_chan_id,
26
+
u8 type, u8 reg, u8 chan, u8 *buf);
27
+
int (*bulk_read)(struct acpm_handle *handle, unsigned int acpm_chan_id,
28
+
u8 type, u8 reg, u8 chan, u8 count, u8 *buf);
29
+
int (*write_reg)(struct acpm_handle *handle, unsigned int acpm_chan_id,
30
+
u8 type, u8 reg, u8 chan, u8 value);
31
+
int (*bulk_write)(struct acpm_handle *handle, unsigned int acpm_chan_id,
32
+
u8 type, u8 reg, u8 chan, u8 count, const u8 *buf);
33
+
int (*update_reg)(struct acpm_handle *handle, unsigned int acpm_chan_id,
34
+
u8 type, u8 reg, u8 chan, u8 value, u8 mask);
41
35
};
42
36
43
37
struct acpm_ops {
···
50
56
struct device;
51
57
52
58
#if IS_ENABLED(CONFIG_EXYNOS_ACPM_PROTOCOL)
53
-
const struct acpm_handle *devm_acpm_get_by_node(struct device *dev,
54
-
struct device_node *np);
59
+
struct acpm_handle *devm_acpm_get_by_node(struct device *dev,
60
+
struct device_node *np);
55
61
#else
56
62
57
-
static inline const struct acpm_handle *devm_acpm_get_by_node(struct device *dev,
58
-
struct device_node *np)
63
+
static inline struct acpm_handle *devm_acpm_get_by_node(struct device *dev,
64
+
struct device_node *np)
59
65
{
60
66
return NULL;
61
67
}