clk: get matching entry under lock in of_clk_init()
PATCH 1/1 clk: get matching entry under lock in of_clk_init()
Currently of_clk_init() finds a matching device node while holding the device tree spinlock. When a matching device node is found, the lock is dropped and then re-acquired in order to get a reference to the matching device id structure.
Acquiring the spinlock twice is unnecessary (and it opens a vulnerable window that could conceivably lead to errors).
There already exists an interface for both finding and taking a reference to a device id under lock, so use it.
--- drivers/clk/clk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
drivers/clk/clk.c +2 -2
@@ -2116,13 +2116,13 @@ EXPORT_SYMBOL_GPL(of_clk_get_parent_name);*/ void __init of_clk_init (const struct of_device_id *matches) { +const struct of_device_id *match;struct device_node *np;if (!matches) matches = __clk_of_table; -for_each_matching_node (np, matches) { -const struct of_device_id *match =of_match_node (matches, np); +for_each_matching_node_and_match (np, matches, &match) {of_clk_init_cb_t clk_init_cb = match->data;clk_init_cb (np); }
Signature · 1 line
1.7.9.5
PATCH RESEND 1/1 clk: get matching entry under lock in of_clk_init()
Currently of_clk_init() finds a matching device node while holding the device tree spinlock. When a matching device node is found, the lock is dropped and then re-acquired in order to get a reference to the matching device id structure.
Acquiring the spinlock twice is unnecessary (and it opens a vulnerable window that could conceivably lead to errors).
There already exists an interface for both finding and taking a reference to a device id under lock, so use it.
--- drivers/clk/clk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
drivers/clk/clk.c +2 -2
@@ -2116,13 +2116,13 @@ EXPORT_SYMBOL_GPL(of_clk_get_parent_name);*/ void __init of_clk_init (const struct of_device_id *matches) { +const struct of_device_id *match;struct device_node *np;if (!matches) matches = __clk_of_table; -for_each_matching_node (np, matches) { -const struct of_device_id *match =of_match_node (matches, np); +for_each_matching_node_and_match (np, matches, &match) {of_clk_init_cb_t clk_init_cb = match->data;clk_init_cb (np); }
Signature · 1 line
1.7.9.5
PATCH RESEND 1/1 clk: get matching entry under lock in of_clk_init()
Quoting Alex Elder (2013-08-22 09:31:31)
Quoted 8 lines
Currently
of_clk_init()finds a matching device node while holding the device tree spinlock. When a matching device node is found, the lock is dropped and then re-acquired in order to get a reference to the matching device id structure.Acquiring the spinlock twice is unnecessary (and it opens a vulnerable window that could conceivably lead to errors).
Quoted 7 lines
There already exists an interface for both finding and taking a reference to a device id under lock, so use it.
Signed-off-by Alex Elder <[email protected]>Reviewed-by Christian Daudt <[email protected]>Reviewed-by Markus Mayer <[email protected]>Reviewed-by Matt Porter <[email protected]>
Thanks for the fix. Taken into clk-next.
Regards,
Mike
Quoted 26 lines
--- drivers/clk/clk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)drivers/clk/clk.c +2
-2@@ -2116,13 +2116,13 @@ EXPORT_SYMBOL_GPL(of_clk_get_parent_name);*/ void __init of_clk_init (const struct of_device_id *matches) { +const struct of_device_id *match;struct device_node *np;if (!matches) matches = __clk_of_table; -for_each_matching_node (np, matches) { -const struct of_device_id *match =of_match_node (matches, np); +for_each_matching_node_and_match (np, matches, &match) {of_clk_init_cb_t clk_init_cb = match->data;clk_init_cb (np); }Signature · 1 line
1.7.9.5