kernel.git/drivers/clk/clk.c, branch linux-4.4.y

clk: fix invalid usage of list cursor in unregister

2021-04-16T10:00:21Z

[ Upstream commit 7045465500e465b09f09d6e5bdc260a9f1aab97b ] Fix invalid usage of a list_for_each_entry cursor in clk_notifier_unregister(). When list is empty or if the list is completely traversed (without breaking from the loop on one of the entries) then the list cursor does not point to a valid entry and therefore should not be used. The patch fixes a logical bug that hasn't been seen in pratice however it is analogus to the bug fixed in clk_notifier_register(). The issue was dicovered when running 5.12-rc1 kernel on x86_64 with KASAN enabled: BUG: KASAN: global-out-of-bounds in clk_notifier_register+0xab/0x230 Read of size 8 at addr ffffffffa0d10588 by task swapper/0/1 CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc1 #1 Hardware name: Google Caroline/Caroline, BIOS Google_Caroline.7820.430.0 07/20/2018 Call Trace: dump_stack+0xee/0x15c print_address_description+0x1e/0x2dc kasan_report+0x188/0x1ce ? clk_notifier_register+0xab/0x230 ? clk_prepare_lock+0x15/0x7b ? clk_notifier_register+0xab/0x230 clk_notifier_register+0xab/0x230 dw8250_probe+0xc01/0x10d4 ... Memory state around the buggy address: ffffffffa0d10480: 00 00 00 00 00 03 f9 f9 f9 f9 f9 f9 00 00 00 00 ffffffffa0d10500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f9 f9 >ffffffffa0d10580: f9 f9 f9 f9 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffffffffa0d10600: 00 00 00 00 00 00 f9 f9 f9 f9 f9 f9 00 00 00 00 ffffffffa0d10680: 00 00 00 00 00 00 00 00 f9 f9 f9 f9 00 00 00 00 ================================================================== Fixes: b2476490ef11 ("clk: introduce the common clock framework") Reported-by: Lukasz Majczak Signed-off-by: Lukasz Bartosik Link: https://lore.kernel.org/r/20210401225149.18826-2-lb@semihalf.com Signed-off-by: Stephen Boyd Signed-off-by: Sasha Levin

clk: Don't show the incorrect clock phase

2018-05-30T05:49:11Z

[ Upstream commit 1f9c63e8de3d7b377c9d74e4a17524cfb60e6384 ] It's found that the clock phase output from clk_summary is wrong compared to the actual phase reading from the register. cat /sys/kernel/debug/clk/clk_summary | grep sdio_sample sdio_sample 0 1 0 50000000 0 -22 It exposes an issue that clk core, clk_core_get_phase, always returns the cached core->phase which should be either updated by calling clk_set_phase or directly from the first place the clk was registered. When registering the clk, the core->phase geting from ->get_phase() may return negative value indicating error. This is quite common since the clk's phase may be highly related to its parent chain, but it was temporarily orphan when registered, since its parent chains hadn't be ready at that time, so the clk drivers decide to return error in this case. However, if no clk_set_phase is called or maybe the ->set_phase() isn't even implemented, the core->phase would never be updated. This is wrong, and we should try to update it when all its parent chains are settled down, like the way of updating clock rate for that. But it's not deserved to complicate the code now and just update it anyway when calling clk_core_get_phase, which would be much simple and enough. Signed-off-by: Shawn Lin Acked-by: Jerome Brunet Signed-off-by: Stephen Boyd Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

clk: Add clk_hw_is_enabled() for use by clk providers

2015-10-26T19:36:55Z

Add clk_hw_is_enabled() to the provider APIs so clk providers can use a struct clk_hw instead of a struct clk to check if a clk is enabled or not. Signed-off-by: Joachim Eastwood Signed-off-by: Stephen Boyd

clk: add missing of_node_put

2015-10-21T23:16:32Z

for_each_matching_node_and_match performs an of_node_get on each iteration, so a break out of the loop requires an of_node_put. A simplified version of the semantic patch that fixes this problem is as follows (http://coccinelle.lip6.fr): // @@ expression e1,e2,e; local idexpression np; @@ for_each_matching_node_and_match(np, e1, e2) { ... when != of_node_put(np) when != e = np ( return np; | + of_node_put(np); ? return ...; ) ... } // Besides the problem identified by the semantic patch, this patch adds an of_node_get in front of saving np in a field of parent, to account for the fact that this value will be put on going on to the next element in the iteration, and then adds of_node_puts in the two loops where the parent pointer can be freed. Signed-off-by: Julia Lawall Signed-off-by: Stephen Boyd

clk: Make clk input parameter of __clk_get_name() const

2015-10-16T18:56:19Z

When calling __clk_get_name() on a const clock: warning: passing argument 1 of '__clk_get_name' discards 'const' qualifier from pointer target type include/linux/clk-provider.h:613:13: note: expected 'struct clk *' but argument is of type 'const struct clk *' __clk_get_name() does not modify the passed clock, hence make it const. Signed-off-by: Geert Uytterhoeven Signed-off-by: Stephen Boyd

clk: Use %u to format unsigned int in of_clk_src_onecell_get()

2015-10-16T18:49:01Z

Signed-off-by: Geert Uytterhoeven Signed-off-by: Stephen Boyd

clk: Make of_clk_get_parent_name() robust with #clock-cells = 1

2015-10-15T23:17:03Z

If a clock provider has #clock-cells = 1 and we call of_clk_get_parent_name() on it we may end up returning the name of the provider node if the provider doesn't have a clock-output-names property. This doesn't make sense, especially when you consider that calling of_clk_get_parent_name() on such a node with different indices will return the same name each time. Let's try getting the clock from the framework via of_clk_get() instead, and only fallback to the node name if we have a provider with #clock-cells = 0. This way, we can't hand out the same name for different clocks when we don't actually know their names. Cc: Thomas Petazzoni Signed-off-by: Stephen Boyd

Merge branch 'clk-fixes' into clk-next

2015-09-17T19:28:41Z

* clk-fixes: drivers: clk: st: Rename st_pll3200c32_407_c0_x into st_pll3200c32_cx_x clk: check for invalid parent index of orphans in __clk_init()

clk: Remove unneeded semicolons

2015-09-17T18:15:14Z

There are cleary typo errors so can be removed. Signed-off-by: Javier Martinez Canillas Acked-by: Leo Yan Signed-off-by: Stephen Boyd

clk: check for invalid parent index of orphans in __clk_init()

2015-09-16T22:35:18Z

If a mux clock is initialised (by hardware or firmware) with an invalid parent, its ->get_parent() can return an out of range index. For example, the generic mux clock attempts to return -EINVAL, which due to the u8 return type ends up a rather large number. Using this index with the parent_names[] array results in an invalid pointer and (usually) a crash in the following strcmp(). This patch adds a check for the parent index being in range, ignoring clocks reporting invalid values. Signed-off-by: Mans Rullgard Tested-by: Rhyland Klein Signed-off-by: Stephen Boyd