From 99a1ae29360980e79fa2d616819a6fe7411e4eda Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Sat, 16 May 2020 01:08:07 -0700 Subject: [PATCH] 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 Link: https://lkml.kernel.org/r/20200516080806.1459784-2-natechancellor@gmail.com Signed-off-by: Stephen Boyd --- drivers/clk/bcm/clk-bcm2835.c | 68 +++++++++++++++++++---------------- 1 file changed, 37 insertions(+), 31 deletions(-) diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c index 7c845c293af0..0d0eeb3b0dd5 100644 --- 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 = ÷r_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, ÷r->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 ÷r->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, \ -- 2.20.1