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authorLinus Torvalds <torvalds@linux-foundation.org>2026-09-25 15:55:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-09-25 15:55:03 -0700
commit75467f60a3d14f08f86f2b353298d2826382ff23 (patch)
treeacd8a7d5b5a675042449386efa5b42ec44d8bf81 /include/asm-generic/atomic.h
downloadlinux-stable-75467f60a3d14f08f86f2b353298d2826382ff23.tar.gz
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Merge tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipegrafted
Pull IPE fixes from Fan Wu: "Two fixes for use-after-free issues found by recent LLM-assisted code analysis. - move successful policy load auditing under the new policy directory's inode lock, preventing a concurrent policy deletion from freeing the policy while it is still being audited - protect the dm-verity root hash with RCU, preventing policy evaluation from racing with root hash replacement during preresume" * tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipe: ipe: protect the dm-verity root hash with RCU ipe: fix use-after-free when auditing a newly loaded policy
Diffstat (limited to 'include/asm-generic/atomic.h')
-rw-r--r--include/asm-generic/atomic.h133
1 files changed, 133 insertions, 0 deletions
diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h
new file mode 100644
index 000000000..22142c71d
--- /dev/null
+++ b/include/asm-generic/atomic.h
@@ -0,0 +1,133 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Generic C implementation of atomic counter operations. Do not include in
+ * machine independent code.
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+#ifndef __ASM_GENERIC_ATOMIC_H
+#define __ASM_GENERIC_ATOMIC_H
+
+#include <asm/cmpxchg.h>
+#include <asm/barrier.h>
+
+#ifdef CONFIG_SMP
+
+/* we can build all atomic primitives from cmpxchg */
+
+#define ATOMIC_OP(op, c_op) \
+static inline void generic_atomic_##op(int i, atomic_t *v) \
+{ \
+ int c, old; \
+ \
+ c = v->counter; \
+ while ((old = arch_cmpxchg(&v->counter, c, c c_op i)) != c) \
+ c = old; \
+}
+
+#define ATOMIC_OP_RETURN(op, c_op) \
+static inline int generic_atomic_##op##_return(int i, atomic_t *v) \
+{ \
+ int c, old; \
+ \
+ c = v->counter; \
+ while ((old = arch_cmpxchg(&v->counter, c, c c_op i)) != c) \
+ c = old; \
+ \
+ return c c_op i; \
+}
+
+#define ATOMIC_FETCH_OP(op, c_op) \
+static inline int generic_atomic_fetch_##op(int i, atomic_t *v) \
+{ \
+ int c, old; \
+ \
+ c = v->counter; \
+ while ((old = arch_cmpxchg(&v->counter, c, c c_op i)) != c) \
+ c = old; \
+ \
+ return c; \
+}
+
+#else
+
+#include <linux/irqflags.h>
+
+#define ATOMIC_OP(op, c_op) \
+static inline void generic_atomic_##op(int i, atomic_t *v) \
+{ \
+ unsigned long flags; \
+ \
+ raw_local_irq_save(flags); \
+ v->counter = v->counter c_op i; \
+ raw_local_irq_restore(flags); \
+}
+
+#define ATOMIC_OP_RETURN(op, c_op) \
+static inline int generic_atomic_##op##_return(int i, atomic_t *v) \
+{ \
+ unsigned long flags; \
+ int ret; \
+ \
+ raw_local_irq_save(flags); \
+ ret = (v->counter = v->counter c_op i); \
+ raw_local_irq_restore(flags); \
+ \
+ return ret; \
+}
+
+#define ATOMIC_FETCH_OP(op, c_op) \
+static inline int generic_atomic_fetch_##op(int i, atomic_t *v) \
+{ \
+ unsigned long flags; \
+ int ret; \
+ \
+ raw_local_irq_save(flags); \
+ ret = v->counter; \
+ v->counter = v->counter c_op i; \
+ raw_local_irq_restore(flags); \
+ \
+ return ret; \
+}
+
+#endif /* CONFIG_SMP */
+
+ATOMIC_OP_RETURN(add, +)
+ATOMIC_OP_RETURN(sub, -)
+
+ATOMIC_FETCH_OP(add, +)
+ATOMIC_FETCH_OP(sub, -)
+ATOMIC_FETCH_OP(and, &)
+ATOMIC_FETCH_OP(or, |)
+ATOMIC_FETCH_OP(xor, ^)
+
+ATOMIC_OP(add, +)
+ATOMIC_OP(sub, -)
+ATOMIC_OP(and, &)
+ATOMIC_OP(or, |)
+ATOMIC_OP(xor, ^)
+
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#define arch_atomic_add_return generic_atomic_add_return
+#define arch_atomic_sub_return generic_atomic_sub_return
+
+#define arch_atomic_fetch_add generic_atomic_fetch_add
+#define arch_atomic_fetch_sub generic_atomic_fetch_sub
+#define arch_atomic_fetch_and generic_atomic_fetch_and
+#define arch_atomic_fetch_or generic_atomic_fetch_or
+#define arch_atomic_fetch_xor generic_atomic_fetch_xor
+
+#define arch_atomic_add generic_atomic_add
+#define arch_atomic_sub generic_atomic_sub
+#define arch_atomic_and generic_atomic_and
+#define arch_atomic_or generic_atomic_or
+#define arch_atomic_xor generic_atomic_xor
+
+#define arch_atomic_read(v) READ_ONCE((v)->counter)
+#define arch_atomic_set(v, i) WRITE_ONCE(((v)->counter), (i))
+
+#endif /* __ASM_GENERIC_ATOMIC_H */