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From: Yury Norov <yury.norov@gmail.com>
To: linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	"David S . Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	Yury Norov <yury.norov@gmail.com>
Subject: [PATCH 1/7] cpumask: fix checking valid cpu range
Date: Mon, 19 Sep 2022 14:05:53 -0700	[thread overview]
Message-ID: <20220919210559.1509179-2-yury.norov@gmail.com> (raw)
In-Reply-To: <20220919210559.1509179-1-yury.norov@gmail.com>

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 e4f9136a4a63..a1cd4eb1a3d6 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);
 }
@@ -267,8 +264,8 @@ 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,
-- 
2.34.1


  reply	other threads:[~2022-09-19 21:06 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-19 21:05 [PATCH 0/7] cpumask: repair cpumask_check() Yury Norov
2022-09-19 21:05 ` Yury Norov [this message]
2022-09-28 12:18   ` [PATCH 1/7] cpumask: fix checking valid cpu range Valentin Schneider
2022-09-28 14:49     ` Yury Norov
2022-09-30 17:04       ` Valentin Schneider
2022-10-01  2:02         ` Yury Norov
2022-09-19 21:05 ` [PATCH 2/7] net: fix cpu_max_bits_warn() usage in netif_attrmask_next{,_and} Yury Norov
2022-09-26 17:34   ` Jakub Kicinski
2022-09-26 17:47     ` Yury Norov
2022-09-19 21:05 ` [PATCH 3/7] cpumask: switch for_each_cpu{,_not} to use for_each_bit() Yury Norov
2022-09-19 21:05 ` [PATCH 4/7] lib/find_bit: add find_next{,_and}_bit_wrap Yury Norov
2022-09-19 21:05 ` [PATCH 5/7] lib/bitmap: introduce for_each_set_bit_wrap() macro Yury Norov
2022-09-19 21:05 ` [PATCH 6/7] lib/find: optimize for_each() macros Yury Norov
2022-09-19 21:05 ` [PATCH 7/7] lib/bitmap: add tests for for_each() loops Yury Norov
2022-09-25 15:47 ` [PATCH 0/7] cpumask: repair cpumask_check() Yury Norov
2022-09-26 15:09   ` Jakub Kicinski
2022-09-26 16:27     ` Yury Norov

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