clk: bcm2835: Remove casting to bcm2835_clk_register

There are four different callback functions that are used for the
clk_register callback that all have different second parameter types.

bcm2835_register_pll -> struct bcm2835_pll_data
bcm2835_register_pll_divider -> struct bcm2835_pll_divider_data
bcm2835_register_clock -> struct bcm2835_clock_data
bcm2835_register_date -> struct bcm2835_gate_data

These callbacks are cast to bcm2835_clk_register so that there is no
error about incompatible pointer types. Unfortunately, this is a control
flow integrity violation, which verifies that the callback function's
types match the prototypes exactly before jumping.

[    0.857913] CFI failure (target: 0xffffff9334a81820):
[    0.857977] WARNING: CPU: 3 PID: 35 at kernel/cfi.c:29 __cfi_check_fail+0x50/0x58
[    0.857985] Modules linked in:
[    0.858007] CPU: 3 PID: 35 Comm: kworker/3:1 Not tainted 4.19.123-v8-01301-gdbb48f16956e4-dirty #1
[    0.858015] Hardware name: Raspberry Pi 3 Model B Rev 1.2 (DT)
[    0.858031] Workqueue: events 0xffffff9334a925c8
[    0.858046] pstate: 60000005 (nZCv daif -PAN -UAO)
[    0.858058] pc : __cfi_check_fail+0x50/0x58
[    0.858070] lr : __cfi_check_fail+0x50/0x58
[    0.858078] sp : ffffff800814ba90
[    0.858086] x29: ffffff800814ba90 x28: 000fffffffdfff3d
[    0.858101] x27: 00000000002000c2 x26: ffffff93355fdb18
[    0.858116] x25: 0000000000000000 x24: ffffff9334a81820
[    0.858131] x23: ffffff93357f3580 x22: ffffff9334af1000
[    0.858146] x21: a79b57e88f8ebc81 x20: ffffff93357f3580
[    0.858161] x19: ffffff9334a81820 x18: fffffff679769070
[    0.858175] x17: 0000000000000000 x16: 0000000000000000
[    0.858190] x15: 0000000000000004 x14: 000000000000003c
[    0.858205] x13: 0000000000003044 x12: 0000000000000000
[    0.858220] x11: b57e91cd641bae00 x10: b57e91cd641bae00
[    0.858235] x9 : b57e91cd641bae00 x8 : b57e91cd641bae00
[    0.858250] x7 : 0000000000000000 x6 : ffffff933591d4e5
[    0.858264] x5 : 0000000000000000 x4 : 0000000000000000
[    0.858279] x3 : ffffff800814b718 x2 : ffffff9334a84818
[    0.858293] x1 : ffffff9334bba66c x0 : 0000000000000029
[    0.858308] Call trace:
[    0.858321]  __cfi_check_fail+0x50/0x58
[    0.858337]  __cfi_check+0x3ab3c/0x4467c
[    0.858351]  bcm2835_clk_probe+0x210/0x2dc
[    0.858369]  platform_drv_probe+0xb0/0xfc
[    0.858380]  really_probe+0x4a0/0x5a8
[    0.858391]  driver_probe_device+0x68/0x104
[    0.858403]  __device_attach_driver+0x100/0x148
[    0.858418]  bus_for_each_drv+0xb0/0x12c
[    0.858431]  __device_attach.llvm.17225159516306086099+0xc0/0x168
[    0.858443]  bus_probe_device+0x44/0xfc
[    0.858455]  deferred_probe_work_func+0xa0/0xe0
[    0.858472]  process_one_work+0x210/0x538
[    0.858485]  worker_thread+0x2e8/0x478
[    0.858500]  kthread+0x154/0x164
[    0.858515]  ret_from_fork+0x10/0x18

To fix this, change the second parameter of all functions void * and use
a local variable with the correct type so that everything works
properly. With this, the only use of bcm2835_clk_register is in struct
bcm2835_clk_desc so we can just remove it and use the type directly.

Fixes: 56eb3a2ed972 ("clk: bcm2835: remove use of BCM2835_CLOCK_COUNT in driver")
Link: https://github.com/ClangBuiltLinux/linux/issues/1028
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lkml.kernel.org/r/20200516080806.1459784-2-natechancellor@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 7c845c2..0d0eeb3 100644 (file)
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1296,8 +1296,9 @@ static const struct clk_ops bcm2835_vpu_clock_clk_ops = {
 };
 
 static struct clk_hw *bcm2835_register_pll(struct bcm2835_cprman *cprman,
-                                          const struct bcm2835_pll_data *data)
+                                          const void *data)
 {
+       const struct bcm2835_pll_data *pll_data = data;
        struct bcm2835_pll *pll;
        struct clk_init_data init;
        int ret;
@@ -1307,7 +1308,7 @@ static struct clk_hw *bcm2835_register_pll(struct bcm2835_cprman *cprman,
        /* All of the PLLs derive from the external oscillator. */
        init.parent_names = &cprman->real_parent_names[0];
        init.num_parents = 1;
-       init.name = data->name;
+       init.name = pll_data->name;
        init.ops = &bcm2835_pll_clk_ops;
        init.flags = CLK_IGNORE_UNUSED;
 
@@ -1316,7 +1317,7 @@ static struct clk_hw *bcm2835_register_pll(struct bcm2835_cprman *cprman,
                return NULL;
 
        pll->cprman = cprman;
-       pll->data = data;
+       pll->data = pll_data;
        pll->hw.init = &init;
 
        ret = devm_clk_hw_register(cprman->dev, &pll->hw);
@@ -1327,35 +1328,36 @@ static struct clk_hw *bcm2835_register_pll(struct bcm2835_cprman *cprman,
 
 static struct clk_hw *
 bcm2835_register_pll_divider(struct bcm2835_cprman *cprman,
-                            const struct bcm2835_pll_divider_data *data)
+                            const void *data)
 {
+       const struct bcm2835_pll_divider_data *divider_data = data;
        struct bcm2835_pll_divider *divider;
        struct clk_init_data init;
        const char *divider_name;
        int ret;
 
-       if (data->fixed_divider != 1) {
+       if (divider_data->fixed_divider != 1) {
                divider_name = devm_kasprintf(cprman->dev, GFP_KERNEL,
-                                             "%s_prediv", data->name);
+                                             "%s_prediv", divider_data->name);
                if (!divider_name)
                        return NULL;
        } else {
-               divider_name = data->name;
+               divider_name = divider_data->name;
        }
 
        memset(&init, 0, sizeof(init));
 
-       init.parent_names = &data->source_pll;
+       init.parent_names = &divider_data->source_pll;
        init.num_parents = 1;
        init.name = divider_name;
        init.ops = &bcm2835_pll_divider_clk_ops;
-       init.flags = data->flags | CLK_IGNORE_UNUSED;
+       init.flags = divider_data->flags | CLK_IGNORE_UNUSED;
 
        divider = devm_kzalloc(cprman->dev, sizeof(*divider), GFP_KERNEL);
        if (!divider)
                return NULL;
 
-       divider->div.reg = cprman->regs + data->a2w_reg;
+       divider->div.reg = cprman->regs + divider_data->a2w_reg;
        divider->div.shift = A2W_PLL_DIV_SHIFT;
        divider->div.width = A2W_PLL_DIV_BITS;
        divider->div.flags = CLK_DIVIDER_MAX_AT_ZERO;
@@ -1364,7 +1366,7 @@ bcm2835_register_pll_divider(struct bcm2835_cprman *cprman,
        divider->div.table = NULL;
 
        divider->cprman = cprman;
-       divider->data = data;
+       divider->data = divider_data;
 
        ret = devm_clk_hw_register(cprman->dev, &divider->div.hw);
        if (ret)
@@ -1374,20 +1376,22 @@ bcm2835_register_pll_divider(struct bcm2835_cprman *cprman,
         * PLLH's channels have a fixed divide by 10 afterwards, which
         * is what our consumers are actually using.
         */
-       if (data->fixed_divider != 1) {
-               return clk_hw_register_fixed_factor(cprman->dev, data->name,
+       if (divider_data->fixed_divider != 1) {
+               return clk_hw_register_fixed_factor(cprman->dev,
+                                                   divider_data->name,
                                                    divider_name,
                                                    CLK_SET_RATE_PARENT,
                                                    1,
-                                                   data->fixed_divider);
+                                                   divider_data->fixed_divider);
        }
 
        return &divider->div.hw;
 }
 
 static struct clk_hw *bcm2835_register_clock(struct bcm2835_cprman *cprman,
-                                         const struct bcm2835_clock_data *data)
+                                            const void *data)
 {
+       const struct bcm2835_clock_data *clock_data = data;
        struct bcm2835_clock *clock;
        struct clk_init_data init;
        const char *parents[1 << CM_SRC_BITS];
@@ -1398,8 +1402,8 @@ static struct clk_hw *bcm2835_register_clock(struct bcm2835_cprman *cprman,
         * Replace our strings referencing parent clocks with the
         * actual clock-output-name of the parent.
         */
-       for (i = 0; i < data->num_mux_parents; i++) {
-               parents[i] = data->parents[i];
+       for (i = 0; i < clock_data->num_mux_parents; i++) {
+               parents[i] = clock_data->parents[i];
 
                ret = match_string(cprman_parent_names,
                                   ARRAY_SIZE(cprman_parent_names),
@@ -1410,18 +1414,18 @@ static struct clk_hw *bcm2835_register_clock(struct bcm2835_cprman *cprman,
 
        memset(&init, 0, sizeof(init));
        init.parent_names = parents;
-       init.num_parents = data->num_mux_parents;
-       init.name = data->name;
-       init.flags = data->flags | CLK_IGNORE_UNUSED;
+       init.num_parents = clock_data->num_mux_parents;
+       init.name = clock_data->name;
+       init.flags = clock_data->flags | CLK_IGNORE_UNUSED;
 
        /*
         * Pass the CLK_SET_RATE_PARENT flag if we are allowed to propagate
         * rate changes on at least of the parents.
         */
-       if (data->set_rate_parent)
+       if (clock_data->set_rate_parent)
                init.flags |= CLK_SET_RATE_PARENT;
 
-       if (data->is_vpu_clock) {
+       if (clock_data->is_vpu_clock) {
                init.ops = &bcm2835_vpu_clock_clk_ops;
        } else {
                init.ops = &bcm2835_clock_clk_ops;
@@ -1430,7 +1434,7 @@ static struct clk_hw *bcm2835_register_clock(struct bcm2835_cprman *cprman,
                /* If the clock wasn't actually enabled at boot, it's not
                 * critical.
                 */
-               if (!(cprman_read(cprman, data->ctl_reg) & CM_ENABLE))
+               if (!(cprman_read(cprman, clock_data->ctl_reg) & CM_ENABLE))
                        init.flags &= ~CLK_IS_CRITICAL;
        }
 
@@ -1439,7 +1443,7 @@ static struct clk_hw *bcm2835_register_clock(struct bcm2835_cprman *cprman,
                return NULL;
 
        clock->cprman = cprman;
-       clock->data = data;
+       clock->data = clock_data;
        clock->hw.init = &init;
 
        ret = devm_clk_hw_register(cprman->dev, &clock->hw);
@@ -1449,24 +1453,26 @@ static struct clk_hw *bcm2835_register_clock(struct bcm2835_cprman *cprman,
 }
 
 static struct clk_hw *bcm2835_register_gate(struct bcm2835_cprman *cprman,
-                                        const struct bcm2835_gate_data *data)
+                                           const void *data)
 {
-       return clk_hw_register_gate(cprman->dev, data->name, data->parent,
+       const struct bcm2835_gate_data *gate_data = data;
+
+       return clk_hw_register_gate(cprman->dev, gate_data->name,
+                                   gate_data->parent,
                                    CLK_IGNORE_UNUSED | CLK_SET_RATE_GATE,
-                                   cprman->regs + data->ctl_reg,
+                                   cprman->regs + gate_data->ctl_reg,
                                    CM_GATE_BIT, 0, &cprman->regs_lock);
 }
 
-typedef struct clk_hw *(*bcm2835_clk_register)(struct bcm2835_cprman *cprman,
-                                              const void *data);
 struct bcm2835_clk_desc {
-       bcm2835_clk_register clk_register;
+       struct clk_hw *(*clk_register)(struct bcm2835_cprman *cprman,
+                                      const void *data);
        unsigned int supported;
        const void *data;
 };
 
 /* assignment helper macros for different clock types */
-#define _REGISTER(f, s, ...) { .clk_register = (bcm2835_clk_register)f, \
+#define _REGISTER(f, s, ...) { .clk_register = f, \
                               .supported = s,                          \
                               .data = __VA_ARGS__ }
 #define REGISTER_PLL(s, ...)   _REGISTER(&bcm2835_register_pll,        \