From d5622a9c13752be46e6fcde9d31391ce0bb0598b Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 2 Mar 2015 15:45:41 +0000 Subject: clkdev: use clk_hw internally clk_add_alias() calls clk_get() followed by clk_put() but in between those two calls it saves away the struct clk pointer to a clk_lookup structure. This leaves the 'clk' member of the clk_lookup pointing at freed memory on configurations where CONFIG_COMMON_CLK=y. This is a problem because clk_get_sys() will eventually try to dereference the freed pointer by calling __clk_get_hw() on it. Fix this by saving away the struct clk_hw pointer instead of the struct clk pointer so that when we try to create a per-user struct clk in clk_get_sys() we don't dereference a junk pointer. Signed-off-by: Russell King --- drivers/clk/clkdev.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) (limited to 'drivers') diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c index 1fcb6ef2cdac..1bb120a3855f 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -177,7 +177,7 @@ struct clk *clk_get_sys(const char *dev_id, const char *con_id) if (!cl) goto out; - clk = __clk_create_clk(__clk_get_hw(cl->clk), dev_id, con_id); + clk = __clk_create_clk(cl->clk_hw, dev_id, con_id); if (IS_ERR(clk)) goto out; @@ -215,18 +215,26 @@ void clk_put(struct clk *clk) } EXPORT_SYMBOL(clk_put); -void clkdev_add(struct clk_lookup *cl) +static void __clkdev_add(struct clk_lookup *cl) { mutex_lock(&clocks_mutex); list_add_tail(&cl->node, &clocks); mutex_unlock(&clocks_mutex); } + +void clkdev_add(struct clk_lookup *cl) +{ + if (!cl->clk_hw) + cl->clk_hw = __clk_get_hw(cl->clk); + __clkdev_add(cl); +} EXPORT_SYMBOL(clkdev_add); void __init clkdev_add_table(struct clk_lookup *cl, size_t num) { mutex_lock(&clocks_mutex); while (num--) { + cl->clk_hw = __clk_get_hw(cl->clk); list_add_tail(&cl->node, &clocks); cl++; } @@ -243,7 +251,7 @@ struct clk_lookup_alloc { }; static struct clk_lookup * __init_refok -vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, +vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt, va_list ap) { struct clk_lookup_alloc *cla; @@ -252,7 +260,7 @@ vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, if (!cla) return NULL; - cla->cl.clk = clk; + cla->cl.clk_hw = hw; if (con_id) { strlcpy(cla->con_id, con_id, sizeof(cla->con_id)); cla->cl.con_id = cla->con_id; @@ -273,7 +281,7 @@ clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...) va_list ap; va_start(ap, dev_fmt); - cl = vclkdev_alloc(clk, con_id, dev_fmt, ap); + cl = vclkdev_alloc(__clk_get_hw(clk), con_id, dev_fmt, ap); va_end(ap); return cl; @@ -334,7 +342,7 @@ int clk_register_clkdev(struct clk *clk, const char *con_id, return PTR_ERR(clk); va_start(ap, dev_fmt); - cl = vclkdev_alloc(clk, con_id, dev_fmt, ap); + cl = vclkdev_alloc(__clk_get_hw(clk), con_id, dev_fmt, ap); va_end(ap); if (!cl) @@ -365,8 +373,8 @@ int clk_register_clkdevs(struct clk *clk, struct clk_lookup *cl, size_t num) return PTR_ERR(clk); for (i = 0; i < num; i++, cl++) { - cl->clk = clk; - clkdev_add(cl); + cl->clk_hw = __clk_get_hw(clk); + __clkdev_add(cl); } return 0; -- cgit v1.2.3-59-g8ed1b From fba3acd961ee167a5ffe4c094deccb7d99a0e963 Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 10 Mar 2015 14:34:00 +0000 Subject: clkdev: drop __init from clkdev_add_table() We want to be able to call clkdev_add_table() from non-init code, so we need to drop the __init marker from it. Signed-off-by: Russell King --- drivers/clk/clkdev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c index 1bb120a3855f..04b59ad6d852 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -230,7 +230,7 @@ void clkdev_add(struct clk_lookup *cl) } EXPORT_SYMBOL(clkdev_add); -void __init clkdev_add_table(struct clk_lookup *cl, size_t num) +void clkdev_add_table(struct clk_lookup *cl, size_t num) { mutex_lock(&clocks_mutex); while (num--) { -- cgit v1.2.3-59-g8ed1b From b3d8d7e89fab374d731dfb46fe048f09766ca9c8 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 9 Mar 2015 10:43:04 +0000 Subject: clkdev: const-ify connection id to clk_add_alias() The connection id is only passed to clk_get() which is already const. Const-ify this argument too. Signed-off-by: Russell King --- drivers/clk/clkdev.c | 6 +++--- include/linux/clkdev.h | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers') diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c index 04b59ad6d852..e112e13af760 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -288,10 +288,10 @@ clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...) } EXPORT_SYMBOL(clkdev_alloc); -int clk_add_alias(const char *alias, const char *alias_dev_name, char *id, - struct device *dev) +int clk_add_alias(const char *alias, const char *alias_dev_name, + const char *con_id, struct device *dev) { - struct clk *r = clk_get(dev, id); + struct clk *r = clk_get(dev, con_id); struct clk_lookup *l; if (IS_ERR(r)) diff --git a/include/linux/clkdev.h b/include/linux/clkdev.h index 3003afad46c9..cd93b215e3af 100644 --- a/include/linux/clkdev.h +++ b/include/linux/clkdev.h @@ -39,7 +39,7 @@ void clkdev_add(struct clk_lookup *cl); void clkdev_drop(struct clk_lookup *cl); void clkdev_add_table(struct clk_lookup *, size_t); -int clk_add_alias(const char *, const char *, char *, struct device *); +int clk_add_alias(const char *, const char *, const char *, struct device *); int clk_register_clkdev(struct clk *, const char *, const char *, ...); int clk_register_clkdevs(struct clk *, struct clk_lookup *, size_t); -- cgit v1.2.3-59-g8ed1b From 2568999835d7797afce3dcc3a3f368051ffcaf1f Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 2 Mar 2015 15:40:29 +0000 Subject: clkdev: add clkdev_create() helper Add a helper to allocate and add a clk_lookup structure. This can not only be used in several places in clkdev.c to simplify the code, but more importantly, can be used by callers of the clkdev code to simplify their clkdev creation and registration. Signed-off-by: Russell King --- drivers/clk/clkdev.c | 53 ++++++++++++++++++++++++++++++++++++++------------ include/linux/clkdev.h | 3 +++ 2 files changed, 44 insertions(+), 12 deletions(-) (limited to 'drivers') diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c index e112e13af760..c0eaf0973bd2 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -274,6 +274,19 @@ vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt, return &cla->cl; } +static struct clk_lookup * +vclkdev_create(struct clk_hw *hw, const char *con_id, const char *dev_fmt, + va_list ap) +{ + struct clk_lookup *cl; + + cl = vclkdev_alloc(hw, con_id, dev_fmt, ap); + if (cl) + __clkdev_add(cl); + + return cl; +} + struct clk_lookup * __init_refok clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...) { @@ -288,6 +301,29 @@ clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...) } EXPORT_SYMBOL(clkdev_alloc); +/** + * clkdev_create - allocate and add a clkdev lookup structure + * @clk: struct clk to associate with all clk_lookups + * @con_id: connection ID string on device + * @dev_fmt: format string describing device name + * + * Returns a clk_lookup structure, which can be later unregistered and + * freed. + */ +struct clk_lookup *clkdev_create(struct clk *clk, const char *con_id, + const char *dev_fmt, ...) +{ + struct clk_lookup *cl; + va_list ap; + + va_start(ap, dev_fmt); + cl = vclkdev_create(__clk_get_hw(clk), con_id, dev_fmt, ap); + va_end(ap); + + return cl; +} +EXPORT_SYMBOL_GPL(clkdev_create); + int clk_add_alias(const char *alias, const char *alias_dev_name, const char *con_id, struct device *dev) { @@ -297,12 +333,10 @@ int clk_add_alias(const char *alias, const char *alias_dev_name, if (IS_ERR(r)) return PTR_ERR(r); - l = clkdev_alloc(r, alias, alias_dev_name); + l = clkdev_create(r, alias, "%s", alias_dev_name); clk_put(r); - if (!l) - return -ENODEV; - clkdev_add(l); - return 0; + + return l ? 0 : -ENODEV; } EXPORT_SYMBOL(clk_add_alias); @@ -342,15 +376,10 @@ int clk_register_clkdev(struct clk *clk, const char *con_id, return PTR_ERR(clk); va_start(ap, dev_fmt); - cl = vclkdev_alloc(__clk_get_hw(clk), con_id, dev_fmt, ap); + cl = vclkdev_create(__clk_get_hw(clk), con_id, dev_fmt, ap); va_end(ap); - if (!cl) - return -ENOMEM; - - clkdev_add(cl); - - return 0; + return cl ? 0 : -ENOMEM; } EXPORT_SYMBOL(clk_register_clkdev); diff --git a/include/linux/clkdev.h b/include/linux/clkdev.h index cd93b215e3af..a240b18e86fa 100644 --- a/include/linux/clkdev.h +++ b/include/linux/clkdev.h @@ -38,6 +38,9 @@ struct clk_lookup *clkdev_alloc(struct clk *clk, const char *con_id, void clkdev_add(struct clk_lookup *cl); void clkdev_drop(struct clk_lookup *cl); +struct clk_lookup *clkdev_create(struct clk *clk, const char *con_id, + const char *dev_fmt, ...); + void clkdev_add_table(struct clk_lookup *, size_t); int clk_add_alias(const char *, const char *, const char *, struct device *); -- cgit v1.2.3-59-g8ed1b From 079ed3681d748523e50c3947ca59507a7a181260 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 2 Mar 2015 15:35:22 +0000 Subject: clk: s2mps11: use clkdev_create() clkdev_create() is a shorter way to write clkdev_alloc() followed by clkdev_add(). Use this instead. Signed-off-by: Russell King --- drivers/clk/clk-s2mps11.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/clk/clk-s2mps11.c b/drivers/clk/clk-s2mps11.c index bfa1e64e267d..9b13a303d3f8 100644 --- a/drivers/clk/clk-s2mps11.c +++ b/drivers/clk/clk-s2mps11.c @@ -242,14 +242,12 @@ static int s2mps11_clk_probe(struct platform_device *pdev) goto err_reg; } - s2mps11_clk->lookup = clkdev_alloc(s2mps11_clk->clk, + s2mps11_clk->lookup = clkdev_create(s2mps11_clk->clk, s2mps11_name(s2mps11_clk), NULL); if (!s2mps11_clk->lookup) { ret = -ENOMEM; goto err_lup; } - - clkdev_add(s2mps11_clk->lookup); } for (i = 0; i < S2MPS11_CLKS_NUM; i++) { -- cgit v1.2.3-59-g8ed1b