The function is_power_of_2() also do the check on nr_pages,
so the first check performed is unnecessary. On the other
hand, the key point is to ensure @nr_pages is a power-of-two
number and mostly @nr_pages is a nonzero value, so in the
most cases, the function is_power_of_2() will be called.
Signed-off-by: Kaixu Xia <xiaka...@huawei.com>
---
kernel/events/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 882f835..abb57c2 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4268,7 +4268,7 @@ static int perf_mmap(struct file *file, struct
vm_area_struct *vma)
* If we have rb pages ensure they're a power-of-two number, so we
* can do bitmasks instead of modulo.
*/
- if (nr_pages != 0 && !is_power_of_2(nr_pages))
+ if (!is_power_of_2(nr_pages))
return -EINVAL;
if (vma_size != PAGE_SIZE * (1 + nr_pages))
--
1.8.5.5
--
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