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Diffstat (limited to 'include/linux/kcsan.h')
-rw-r--r-- | include/linux/kcsan.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/include/linux/kcsan.h b/include/linux/kcsan.h new file mode 100644 index 000000000..c07c71f5b --- /dev/null +++ b/include/linux/kcsan.h @@ -0,0 +1,75 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * The Kernel Concurrency Sanitizer (KCSAN) infrastructure. Public interface and + * data structures to set up runtime. See kcsan-checks.h for explicit checks and + * modifiers. For more info please see Documentation/dev-tools/kcsan.rst. + * + * Copyright (C) 2019, Google LLC. + */ + +#ifndef _LINUX_KCSAN_H +#define _LINUX_KCSAN_H + +#include <linux/kcsan-checks.h> +#include <linux/types.h> + +#ifdef CONFIG_KCSAN + +/* + * Context for each thread of execution: for tasks, this is stored in + * task_struct, and interrupts access internal per-CPU storage. + */ +struct kcsan_ctx { + int disable_count; /* disable counter */ + int disable_scoped; /* disable scoped access counter */ + int atomic_next; /* number of following atomic ops */ + + /* + * We distinguish between: (a) nestable atomic regions that may contain + * other nestable regions; and (b) flat atomic regions that do not keep + * track of nesting. Both (a) and (b) are entirely independent of each + * other, and a flat region may be started in a nestable region or + * vice-versa. + * + * This is required because, for example, in the annotations for + * seqlocks, we declare seqlock writer critical sections as (a) nestable + * atomic regions, but reader critical sections as (b) flat atomic + * regions, but have encountered cases where seqlock reader critical + * sections are contained within writer critical sections (the opposite + * may be possible, too). + * + * To support these cases, we independently track the depth of nesting + * for (a), and whether the leaf level is flat for (b). + */ + int atomic_nest_count; + bool in_flat_atomic; + + /* + * Access mask for all accesses if non-zero. + */ + unsigned long access_mask; + + /* List of scoped accesses; likely to be empty. */ + struct list_head scoped_accesses; + +#ifdef CONFIG_KCSAN_WEAK_MEMORY + /* + * Scoped access for modeling access reordering to detect missing memory + * barriers; only keep 1 to keep fast-path complexity manageable. + */ + struct kcsan_scoped_access reorder_access; +#endif +}; + +/** + * kcsan_init - initialize KCSAN runtime + */ +void kcsan_init(void); + +#else /* CONFIG_KCSAN */ + +static inline void kcsan_init(void) { } + +#endif /* CONFIG_KCSAN */ + +#endif /* _LINUX_KCSAN_H */ |