The kmalloc could crash if allocation fails. Add the __GFP_NOFAIL flag
to ensure that allocation succeeds every time.
Signed-off-by: Li zeming <[email protected]>
---
drivers/clk/zynq/clkc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/clk/zynq/clkc.c b/drivers/clk/zynq/clkc.c
index 7bdeaff2bfd6..7621c2f00468 100644
--- a/drivers/clk/zynq/clkc.c
+++ b/drivers/clk/zynq/clkc.c
@@ -427,7 +427,7 @@ static void __init zynq_clk_setup(struct device_node *np)
SLCR_GEM1_CLK_CTRL, 0, 0, &gem1clk_lock);
tmp = strlen("mio_clk_00x");
- clk_name = kmalloc(tmp, GFP_KERNEL);
+ clk_name = kmalloc(tmp, GFP_KERNEL | __GFP_NOFAIL);
for (i = 0; i < NUM_MIO_PINS; i++) {
int idx;
--
2.18.2
Quoting Li zeming (2023-02-22 13:58:34)
> The kmalloc could crash if allocation fails. Add the __GFP_NOFAIL flag
> to ensure that allocation succeeds every time.
>
> Signed-off-by: Li zeming <[email protected]>
> ---
> drivers/clk/zynq/clkc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/clk/zynq/clkc.c b/drivers/clk/zynq/clkc.c
> index 7bdeaff2bfd6..7621c2f00468 100644
> --- a/drivers/clk/zynq/clkc.c
> +++ b/drivers/clk/zynq/clkc.c
> @@ -427,7 +427,7 @@ static void __init zynq_clk_setup(struct device_node *np)
> SLCR_GEM1_CLK_CTRL, 0, 0, &gem1clk_lock);
>
> tmp = strlen("mio_clk_00x");
> - clk_name = kmalloc(tmp, GFP_KERNEL);
> + clk_name = kmalloc(tmp, GFP_KERNEL | __GFP_NOFAIL);
There are so many more allocations happening in this function and they
aren't marked nofail. Why is this one special?
I could see a patch moving mio_clk_00x to the stack and then printing to
it. But it is also fine like this, so I don't see any reason to change
this.
hello senior:
I observed that some other variable assignments in this function are basically judged by the if statement, while clk_name does not make an if branch statement, and I think clk_name is also relatively important, increasing __GFP_NOFAIL flag ensures that the assignment can succeed under any circumstances.
Hi,
On 2/23/23 19:33, Li zeming wrote:
>
> hello senior:
> I observed that some other variable assignments in this function are basically judged by the if statement, while clk_name does not make an if branch statement, and I think clk_name is also relatively important, increasing __GFP_NOFAIL flag ensures that the assignment can succeed under any circumstances.
>
I think that solution with array on stack would be better choice.
It will be faster and you can completely skip the whole allocation code for it.
Thanks,
Michal