| Message ID | 20230222215834.3507-1-zeming@nfschina.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | zynq: clkc: Add kmalloc allocation flag | expand |
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 <zeming@nfschina.com> > --- > 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
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;
The kmalloc could crash if allocation fails. Add the __GFP_NOFAIL flag to ensure that allocation succeeds every time. Signed-off-by: Li zeming <zeming@nfschina.com> --- drivers/clk/zynq/clkc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)