diff options
Diffstat (limited to 'kernel/kcsan')
| -rw-r--r-- | kernel/kcsan/core.c | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c index 64b30f7716a1..e3c7d8f34f2f 100644 --- a/kernel/kcsan/core.c +++ b/kernel/kcsan/core.c @@ -5,6 +5,7 @@ #include <linux/delay.h> #include <linux/export.h> #include <linux/init.h> +#include <linux/kernel.h> #include <linux/percpu.h> #include <linux/preempt.h> #include <linux/random.h> @@ -169,10 +170,20 @@ static __always_inline struct kcsan_ctx *get_ctx(void) return in_task() ? ¤t->kcsan_ctx : raw_cpu_ptr(&kcsan_cpu_ctx); } -static __always_inline bool is_atomic(const volatile void *ptr) +static __always_inline bool +is_atomic(const volatile void *ptr, size_t size, int type) { - struct kcsan_ctx *ctx = get_ctx(); + struct kcsan_ctx *ctx; + + if ((type & KCSAN_ACCESS_ATOMIC) != 0) + return true; + if (IS_ENABLED(CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC) && + (type & KCSAN_ACCESS_WRITE) != 0 && size <= sizeof(long) && + IS_ALIGNED((unsigned long)ptr, size)) + return true; /* Assume aligned writes up to word size are atomic. */ + + ctx = get_ctx(); if (unlikely(ctx->atomic_next > 0)) { /* * Because we do not have separate contexts for nested @@ -193,7 +204,8 @@ static __always_inline bool is_atomic(const volatile void *ptr) return kcsan_is_atomic(ptr); } -static __always_inline bool should_watch(const volatile void *ptr, int type) +static __always_inline bool +should_watch(const volatile void *ptr, size_t size, int type) { /* * Never set up watchpoints when memory operations are atomic. @@ -202,7 +214,7 @@ static __always_inline bool should_watch(const volatile void *ptr, int type) * should not count towards skipped instructions, and (2) to actually * decrement kcsan_atomic_next for consecutive instruction stream. */ - if ((type & KCSAN_ACCESS_ATOMIC) != 0 || is_atomic(ptr)) + if (is_atomic(ptr, size, type)) return false; if (this_cpu_dec_return(kcsan_skip) >= 0) @@ -460,7 +472,7 @@ static __always_inline void check_access(const volatile void *ptr, size_t size, if (unlikely(watchpoint != NULL)) kcsan_found_watchpoint(ptr, size, type, watchpoint, encoded_watchpoint); - else if (unlikely(should_watch(ptr, type))) + else if (unlikely(should_watch(ptr, size, type))) kcsan_setup_watchpoint(ptr, size, type); } |