From: Kees Cook <keescook@chromium.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Kees Cook <keescook@chromium.org>, Will Deacon <will@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Boqun Feng <boqun.feng@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Jakub Kicinski <kuba@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Arnd Bergmann <arnd@arndb.de>,
Andrew Morton <akpm@linux-foundation.org>,
"David S. Miller" <davem@davemloft.net>,
David Ahern <dsahern@kernel.org>,
Eric Dumazet <edumazet@google.com>,
Paolo Abeni <pabeni@redhat.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Uros Bizjak <ubizjak@gmail.com>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org,
netdev@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: [PATCH 1/4] locking/atomic/x86: Silence intentional wrapping addition
Date: Wed, 24 Apr 2024 12:17:34 -0700 [thread overview]
Message-ID: <20240424191740.3088894-1-keescook@chromium.org> (raw)
In-Reply-To: <20240424191225.work.780-kees@kernel.org>
Use add_wrap() to annotate the addition in atomic_add_return() as
expecting to wrap around.
Signed-off-by: Kees Cook <keescook@chromium.org>
---
Cc: Will Deacon <will@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
---
arch/x86/include/asm/atomic.h | 3 ++-
arch/x86/include/asm/atomic64_32.h | 2 +-
arch/x86/include/asm/atomic64_64.h | 2 +-
3 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h
index 55a55ec04350..a5862a258760 100644
--- a/arch/x86/include/asm/atomic.h
+++ b/arch/x86/include/asm/atomic.h
@@ -3,6 +3,7 @@
#define _ASM_X86_ATOMIC_H
#include <linux/compiler.h>
+#include <linux/overflow.h>
#include <linux/types.h>
#include <asm/alternative.h>
#include <asm/cmpxchg.h>
@@ -82,7 +83,7 @@ static __always_inline bool arch_atomic_add_negative(int i, atomic_t *v)
static __always_inline int arch_atomic_add_return(int i, atomic_t *v)
{
- return i + xadd(&v->counter, i);
+ return wrapping_add(int, i, xadd(&v->counter, i));
}
#define arch_atomic_add_return arch_atomic_add_return
diff --git a/arch/x86/include/asm/atomic64_32.h b/arch/x86/include/asm/atomic64_32.h
index 3486d91b8595..608b100e8ffe 100644
--- a/arch/x86/include/asm/atomic64_32.h
+++ b/arch/x86/include/asm/atomic64_32.h
@@ -254,7 +254,7 @@ static __always_inline s64 arch_atomic64_fetch_add(s64 i, atomic64_t *v)
{
s64 old, c = 0;
- while ((old = arch_atomic64_cmpxchg(v, c, c + i)) != c)
+ while ((old = arch_atomic64_cmpxchg(v, c, wrapping_add(s64, c, i))) != c)
c = old;
return old;
diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h
index 3165c0feedf7..f1dc8aa54b52 100644
--- a/arch/x86/include/asm/atomic64_64.h
+++ b/arch/x86/include/asm/atomic64_64.h
@@ -76,7 +76,7 @@ static __always_inline bool arch_atomic64_add_negative(s64 i, atomic64_t *v)
static __always_inline s64 arch_atomic64_add_return(s64 i, atomic64_t *v)
{
- return i + xadd(&v->counter, i);
+ return wrapping_add(s64, i, xadd(&v->counter, i));
}
#define arch_atomic64_add_return arch_atomic64_add_return
--
2.34.1
next prev parent reply other threads:[~2024-04-24 19:17 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-24 19:17 [PATCH 0/4] Annotate atomics for signed integer wrap-around Kees Cook
2024-04-24 19:17 ` Kees Cook [this message]
2024-04-24 22:41 ` [PATCH 1/4] locking/atomic/x86: Silence intentional wrapping addition Peter Zijlstra
2024-04-24 22:45 ` Kees Cook
2024-04-24 22:54 ` Peter Zijlstra
2024-04-24 23:05 ` Peter Zijlstra
2024-04-24 23:30 ` Kees Cook
2024-04-25 9:28 ` Peter Zijlstra
2024-04-25 10:19 ` Mark Rutland
2024-04-24 23:20 ` Kees Cook
2024-04-25 9:17 ` Peter Zijlstra
2024-04-25 17:39 ` Kees Cook
2024-04-25 10:15 ` Mark Rutland
2024-04-25 17:19 ` Kees Cook
2024-04-24 22:51 ` Peter Zijlstra
2024-04-24 19:17 ` [PATCH 2/4] arm64: atomics: lse: " Kees Cook
2024-05-02 11:21 ` Will Deacon
2024-05-02 15:00 ` Kees Cook
2024-04-24 19:17 ` [PATCH 3/4] locking/atomic: Annotate generic atomics with wrapping Kees Cook
2024-04-24 19:17 ` [PATCH 4/4] ipv4: Silence intentional wrapping addition Kees Cook
2024-04-26 7:40 ` [PATCH 1/4] locking/atomic/x86: " David Howells
2024-05-02 14:57 ` Kees Cook
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