From 78e5a3399421ad79fc024e6d78e2deb7809d26af Mon Sep 17 00:00:00 2001
From: Yury Norov <yury.norov@gmail.com>
Date: Mon, 19 Sep 2022 14:05:53 -0700
Subject: [PATCH] cpumask: fix checking valid cpu range
The range of valid CPUs is [0, nr_cpu_ids). Some cpumask functions are
passed with a shifted CPU index, and for them, the valid range is
[-1, nr_cpu_ids-1). Currently for those functions, we check the index
against [-1, nr_cpu_ids), which is wrong.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
include/linux/cpumask.h | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 13b32dd9803b9..286804bfe3b72 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -174,9 +174,8 @@ static inline unsigned int cpumask_last(const struct cpumask *srcp)
static inline
unsigned int cpumask_next(int n, const struct cpumask *srcp)
{
- /* -1 is a legal arg here. */
- if (n != -1)
- cpumask_check(n);
+ /* n is a prior cpu */
+ cpumask_check(n + 1);
return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n + 1);
}
@@ -189,9 +188,8 @@ unsigned int cpumask_next(int n, const struct cpumask *srcp)
*/
static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
{
- /* -1 is a legal arg here. */
- if (n != -1)
- cpumask_check(n);
+ /* n is a prior cpu */
+ cpumask_check(n + 1);
return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
}
@@ -231,9 +229,8 @@ static inline
unsigned int cpumask_next_and(int n, const struct cpumask *src1p,
const struct cpumask *src2p)
{
- /* -1 is a legal arg here. */
- if (n != -1)
- cpumask_check(n);
+ /* n is a prior cpu */
+ cpumask_check(n + 1);
return find_next_and_bit(cpumask_bits(src1p), cpumask_bits(src2p),
nr_cpumask_bits, n + 1);
}
@@ -263,8 +260,8 @@ static inline
unsigned int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap)
{
cpumask_check(start);
- if (n != -1)
- cpumask_check(n);
+ /* n is a prior cpu */
+ cpumask_check(n + 1);
/*
* Return the first available CPU when wrapping, or when starting before cpu0,
--
GitLab