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author | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-03-02 15:45:41 +0000 |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-05-06 11:58:02 +0100 |
commit | d5622a9c13752be46e6fcde9d31391ce0bb0598b (patch) | |
tree | 523015241b656260184db448979c8b2c11ece8ea /drivers/clk/clkdev.c | |
parent | b787f68c36d49bb1d9236f403813641efa74a031 (diff) | |
download | linux-d5622a9c13752be46e6fcde9d31391ce0bb0598b.tar.bz2 |
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 <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/clk/clkdev.c')
-rw-r--r-- | drivers/clk/clkdev.c | 24 |
1 files changed, 16 insertions, 8 deletions
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; |