From 73e0e496afdac9a5190eb3b9c51fdfebcc14ebd4 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Fri, 6 Feb 2015 11:42:43 -0800 Subject: [PATCH] clkdev: Always allocate a struct clk and call __clk_get() w/ CCF of_clk_get_by_clkspec() returns a struct clk pointer but it doesn't create a new handle for the consumers when we're using the common clock framework. Instead it just returns whatever the clk provider hands out. When the consumers go to call clk_put() we get an Oops. Unable to handle kernel paging request at virtual address 00200200 pgd = c0004000 [00200200] *pgd=00000000 Internal error: Oops: 805 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.19.0-rc1-00104-ga251361a-dirty #992 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) task: ee00b000 ti: ee088000 task.ti: ee088000 PC is at __clk_put+0x24/0xd0 LR is at clk_prepare_lock+0xc/0xec pc : [] lr : [] psr: 20000153 sp : ee089de8 ip : 00000000 fp : 00000000 r10: ee02f480 r9 : 00000001 r8 : 00000000 r7 : ee031cc0 r6 : ee089e08 r5 : 00000000 r4 : ee02f480 r3 : 00100100 r2 : 00200200 r1 : 0000091e r0 : 00000001 Flags: nzCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 4000404a DAC: 00000015 Process swapper/0 (pid: 1, stack limit = 0xee088238) Stack: (0xee089de8 to 0xee08a000) 9de0: ee7c8f14 c03f0ec8 ee089e08 00000000 c0718dc8 00000001 9e00: 00000000 c04ee0f0 ee7e0844 00000001 00000181 c04edb58 ee2bd320 00000000 9e20: 00000000 c011dc5c ee16a1e0 00000000 00000000 c0718dc8 ee16a1e0 ee2bd1e0 9e40: c0641740 ee16a1e0 00000000 ee2bd320 c0718dc8 ee1d3e10 ee1d3e10 00000000 9e60: c0769a88 00000000 c0718dc8 00000000 00000000 c02c3124 c02c310c ee1d3e10 9e80: c07b4eec 00000000 c0769a88 c02c1d0c ee1d3e10 c0769a88 ee1d3e44 00000000 9ea0: c07091dc c02c1eb8 00000000 c0769a88 c02c1e2c c02c0544 ee005478 ee1676c0 9ec0: c0769a88 ee3a4e80 c0760ce8 c02c150c c0669b90 c0769a88 c0746cd8 c0769a88 9ee0: c0746cd8 ee2bc4c0 c0778c00 c02c24e0 00000000 c0746cd8 c0746cd8 c07091f0 9f00: 00000000 c0008944 c04f405c 00000025 ee00b000 60000153 c074ab00 00000000 9f20: 00000000 c074ab90 60000153 00000000 ef7fca5d c050860c 000000b6 c0036b88 9f40: c065ecc4 c06bc728 00000006 00000006 c074ab30 ef7fca40 c0739bdc 00000006 9f60: c0718dbc c0778c00 000000b6 c0718dc8 c06ed598 c06edd64 00000006 00000006 9f80: c06ed598 c003b438 00000000 c04e64f4 00000000 00000000 00000000 00000000 9fa0: 00000000 c04e64fc 00000000 c000e838 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 c0c0c0c0 c0c0c0c0 [] (__clk_put) from [] (of_clk_set_defaults+0xe0/0x2c0) [] (of_clk_set_defaults) from [] (platform_drv_probe+0x18/0xa4) [] (platform_drv_probe) from [] (driver_probe_device+0x10c/0x22c) [] (driver_probe_device) from [] (__driver_attach+0x8c/0x90) [] (__driver_attach) from [] (bus_for_each_dev+0x54/0x88) [] (bus_for_each_dev) from [] (bus_add_driver+0xd4/0x1d0) [] (bus_add_driver) from [] (driver_register+0x78/0xf4) [] (driver_register) from [] (fimc_md_init+0x14/0x30) [] (fimc_md_init) from [] (do_one_initcall+0x80/0x1d0) [] (do_one_initcall) from [] (kernel_init_freeable+0x108/0x1d4) [] (kernel_init_freeable) from [] (kernel_init+0x8/0xec) [] (kernel_init) from [] (ret_from_fork+0x14/0x3c) Code: ebfff4ae e5943014 e5942018 e3530000 (e5823000) Let's create a per-user handle here so that clk_put() can properly unlink it and free the handle. Now that we allocate a clk structure here we need to free it if __clk_get() fails so bury the __clk_get() call in __of_clk_get_from_provider(). We need to handle the same problem in clk_get_sys() so export __clk_free_clk() to clkdev.c and do the same thing, except let's use a union to make this code #ifdef free. This fixes the above crash, properly calls __clk_get() when of_clk_get_from_provider() is called, and cleans up the clk structure on the error path of clk_get_sys(). Fixes: 035a61c314eb "clk: Make clk API return per-user struct clk instances" Reported-by: Sylwester Nawrocki Reported-by: Alban Browaeys Tested-by: Sylwester Nawrocki Tested-by: Alban Browaeys Reviewed-by: Tomeu Vizoso Signed-off-by: Stephen Boyd Signed-off-by: Michael Turquette --- drivers/clk/clk.c | 18 +++++++++++--- drivers/clk/clk.h | 19 +++++++++++++- drivers/clk/clkdev.c | 59 ++++++++++++++++++++------------------------ 3 files changed, 59 insertions(+), 37 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 113456030d66..5469d7714f5d 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2382,7 +2382,7 @@ struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id, return clk; } -static void __clk_free_clk(struct clk *clk) +void __clk_free_clk(struct clk *clk) { clk_prepare_lock(); hlist_del(&clk->child_node); @@ -2894,7 +2894,8 @@ void of_clk_del_provider(struct device_node *np) } EXPORT_SYMBOL_GPL(of_clk_del_provider); -struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec) +struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec, + const char *dev_id, const char *con_id) { struct of_clk_provider *provider; struct clk *clk = ERR_PTR(-EPROBE_DEFER); @@ -2903,8 +2904,17 @@ struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec) list_for_each_entry(provider, &of_clk_providers, link) { if (provider->node == clkspec->np) clk = provider->get(clkspec, provider->data); - if (!IS_ERR(clk)) + if (!IS_ERR(clk)) { + clk = __clk_create_clk(__clk_get_hw(clk), dev_id, + con_id); + + if (!IS_ERR(clk) && !__clk_get(clk)) { + __clk_free_clk(clk); + clk = ERR_PTR(-ENOENT); + } + break; + } } return clk; @@ -2915,7 +2925,7 @@ struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) struct clk *clk; mutex_lock(&of_clk_mutex); - clk = __of_clk_get_from_provider(clkspec); + clk = __of_clk_get_from_provider(clkspec, NULL, __func__); mutex_unlock(&of_clk_mutex); return clk; diff --git a/drivers/clk/clk.h b/drivers/clk/clk.h index 23c44e51df69..ba845408cc3e 100644 --- a/drivers/clk/clk.h +++ b/drivers/clk/clk.h @@ -13,10 +13,27 @@ struct clk_hw; #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) struct clk *of_clk_get_by_clkspec(struct of_phandle_args *clkspec); -struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec); +struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec, + const char *dev_id, const char *con_id); void of_clk_lock(void); void of_clk_unlock(void); #endif +#ifdef CONFIG_COMMON_CLK struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id, const char *con_id); +void __clk_free_clk(struct clk *clk); +#else +/* All these casts to avoid ifdefs in clkdev... */ +static inline struct clk * +__clk_create_clk(struct clk_hw *hw, const char *dev_id, const char *con_id) +{ + return (struct clk *)hw; +} +static inline void __clk_free_clk(struct clk *clk) { } +static struct clk_hw *__clk_get_hw(struct clk *clk) +{ + return (struct clk_hw *)clk; +} + +#endif diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c index 29a1ab7af4b8..043fd3633373 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -29,6 +29,20 @@ static DEFINE_MUTEX(clocks_mutex); #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) +static struct clk *__of_clk_get_by_clkspec(struct of_phandle_args *clkspec, + const char *dev_id, const char *con_id) +{ + struct clk *clk; + + if (!clkspec) + return ERR_PTR(-EINVAL); + + of_clk_lock(); + clk = __of_clk_get_from_provider(clkspec, dev_id, con_id); + of_clk_unlock(); + return clk; +} + /** * of_clk_get_by_clkspec() - Lookup a clock form a clock provider * @clkspec: pointer to a clock specifier data structure @@ -39,22 +53,11 @@ static DEFINE_MUTEX(clocks_mutex); */ struct clk *of_clk_get_by_clkspec(struct of_phandle_args *clkspec) { - struct clk *clk; - - if (!clkspec) - return ERR_PTR(-EINVAL); - - of_clk_lock(); - clk = __of_clk_get_from_provider(clkspec); - - if (!IS_ERR(clk) && !__clk_get(clk)) - clk = ERR_PTR(-ENOENT); - - of_clk_unlock(); - return clk; + return __of_clk_get_by_clkspec(clkspec, NULL, __func__); } -static struct clk *__of_clk_get(struct device_node *np, int index) +static struct clk *__of_clk_get(struct device_node *np, int index, + const char *dev_id, const char *con_id) { struct of_phandle_args clkspec; struct clk *clk; @@ -68,7 +71,7 @@ static struct clk *__of_clk_get(struct device_node *np, int index) if (rc) return ERR_PTR(rc); - clk = of_clk_get_by_clkspec(&clkspec); + clk = __of_clk_get_by_clkspec(&clkspec, dev_id, con_id); of_node_put(clkspec.np); return clk; @@ -76,12 +79,7 @@ static struct clk *__of_clk_get(struct device_node *np, int index) struct clk *of_clk_get(struct device_node *np, int index) { - struct clk *clk = __of_clk_get(np, index); - - if (!IS_ERR(clk)) - clk = __clk_create_clk(__clk_get_hw(clk), np->full_name, NULL); - - return clk; + return __of_clk_get(np, index, np->full_name, NULL); } EXPORT_SYMBOL(of_clk_get); @@ -102,12 +100,10 @@ static struct clk *__of_clk_get_by_name(struct device_node *np, */ if (name) index = of_property_match_string(np, "clock-names", name); - clk = __of_clk_get(np, index); + clk = __of_clk_get(np, index, dev_id, name); if (!IS_ERR(clk)) { - clk = __clk_create_clk(__clk_get_hw(clk), dev_id, name); break; - } - else if (name && index >= 0) { + } else if (name && index >= 0) { if (PTR_ERR(clk) != -EPROBE_DEFER) pr_err("ERROR: could not get clock %s:%s(%i)\n", np->full_name, name ? name : "", index); @@ -209,17 +205,16 @@ struct clk *clk_get_sys(const char *dev_id, const char *con_id) if (!cl) goto out; - if (!__clk_get(cl->clk)) { + clk = __clk_create_clk(__clk_get_hw(cl->clk), dev_id, con_id); + if (IS_ERR(clk)) + goto out; + + if (!__clk_get(clk)) { + __clk_free_clk(clk); cl = NULL; goto out; } -#if defined(CONFIG_COMMON_CLK) - clk = __clk_create_clk(__clk_get_hw(cl->clk), dev_id, con_id); -#else - clk = cl->clk; -#endif - out: mutex_unlock(&clocks_mutex); -- GitLab