diff options
Diffstat (limited to 'kernel/kcsan/core.c')
| -rw-r--r-- | kernel/kcsan/core.c | 59 |
1 files changed, 27 insertions, 32 deletions
diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c index d9410d58c93e..3314fc29e236 100644 --- a/kernel/kcsan/core.c +++ b/kernel/kcsan/core.c @@ -19,10 +19,10 @@ bool kcsan_enabled; /* Per-CPU kcsan_ctx for interrupts */ static DEFINE_PER_CPU(struct kcsan_ctx, kcsan_cpu_ctx) = { - .disable_count = 0, - .atomic_next = 0, - .atomic_nest_count = 0, - .in_flat_atomic = false, + .disable_count = 0, + .atomic_next = 0, + .atomic_nest_count = 0, + .in_flat_atomic = false, }; /* @@ -50,11 +50,11 @@ static DEFINE_PER_CPU(struct kcsan_ctx, kcsan_cpu_ctx) = { * slot=9: [10, 11, 9] * slot=63: [64, 65, 63] */ -#define NUM_SLOTS (1 + 2 * KCSAN_CHECK_ADJACENT) +#define NUM_SLOTS (1 + 2*KCSAN_CHECK_ADJACENT) #define SLOT_IDX(slot, i) (slot + ((i + KCSAN_CHECK_ADJACENT) % NUM_SLOTS)) /* - * SLOT_IDX_FAST is used in fast-path. Not first checking the address's primary + * SLOT_IDX_FAST is used in the fast-path. Not first checking the address's primary * slot (middle) is fine if we assume that data races occur rarely. The set of * indices {SLOT_IDX(slot, i) | i in [0, NUM_SLOTS)} is equivalent to * {SLOT_IDX_FAST(slot, i) | i in [0, NUM_SLOTS)}. @@ -68,9 +68,9 @@ static DEFINE_PER_CPU(struct kcsan_ctx, kcsan_cpu_ctx) = { * zero-initialized state matches INVALID_WATCHPOINT. * * Add NUM_SLOTS-1 entries to account for overflow; this helps avoid having to - * use more complicated SLOT_IDX_FAST calculation with modulo in fast-path. + * use more complicated SLOT_IDX_FAST calculation with modulo in the fast-path. */ -static atomic_long_t watchpoints[CONFIG_KCSAN_NUM_WATCHPOINTS + NUM_SLOTS - 1]; +static atomic_long_t watchpoints[CONFIG_KCSAN_NUM_WATCHPOINTS + NUM_SLOTS-1]; /* * Instructions to skip watching counter, used in should_watch(). We use a @@ -78,7 +78,8 @@ static atomic_long_t watchpoints[CONFIG_KCSAN_NUM_WATCHPOINTS + NUM_SLOTS - 1]; */ static DEFINE_PER_CPU(long, kcsan_skip); -static inline atomic_long_t *find_watchpoint(unsigned long addr, size_t size, +static inline atomic_long_t *find_watchpoint(unsigned long addr, + size_t size, bool expect_write, long *encoded_watchpoint) { @@ -110,8 +111,8 @@ static inline atomic_long_t *find_watchpoint(unsigned long addr, size_t size, return NULL; } -static inline atomic_long_t *insert_watchpoint(unsigned long addr, size_t size, - bool is_write) +static inline atomic_long_t * +insert_watchpoint(unsigned long addr, size_t size, bool is_write) { const int slot = watchpoint_slot(addr); const long encoded_watchpoint = encode_watchpoint(addr, size, is_write); @@ -120,21 +121,16 @@ static inline atomic_long_t *insert_watchpoint(unsigned long addr, size_t size, /* Check slot index logic, ensuring we stay within array bounds. */ BUILD_BUG_ON(SLOT_IDX(0, 0) != KCSAN_CHECK_ADJACENT); - BUILD_BUG_ON(SLOT_IDX(0, KCSAN_CHECK_ADJACENT + 1) != 0); - BUILD_BUG_ON(SLOT_IDX(CONFIG_KCSAN_NUM_WATCHPOINTS - 1, - KCSAN_CHECK_ADJACENT) != - ARRAY_SIZE(watchpoints) - 1); - BUILD_BUG_ON(SLOT_IDX(CONFIG_KCSAN_NUM_WATCHPOINTS - 1, - KCSAN_CHECK_ADJACENT + 1) != - ARRAY_SIZE(watchpoints) - NUM_SLOTS); + BUILD_BUG_ON(SLOT_IDX(0, KCSAN_CHECK_ADJACENT+1) != 0); + BUILD_BUG_ON(SLOT_IDX(CONFIG_KCSAN_NUM_WATCHPOINTS-1, KCSAN_CHECK_ADJACENT) != ARRAY_SIZE(watchpoints)-1); + BUILD_BUG_ON(SLOT_IDX(CONFIG_KCSAN_NUM_WATCHPOINTS-1, KCSAN_CHECK_ADJACENT+1) != ARRAY_SIZE(watchpoints) - NUM_SLOTS); for (i = 0; i < NUM_SLOTS; ++i) { long expect_val = INVALID_WATCHPOINT; /* Try to acquire this slot. */ watchpoint = &watchpoints[SLOT_IDX(slot, i)]; - if (atomic_long_try_cmpxchg_relaxed(watchpoint, &expect_val, - encoded_watchpoint)) + if (atomic_long_try_cmpxchg_relaxed(watchpoint, &expect_val, encoded_watchpoint)) return watchpoint; } @@ -150,11 +146,10 @@ static inline atomic_long_t *insert_watchpoint(unsigned long addr, size_t size, * 2. the thread that set up the watchpoint already removed it; * 3. the watchpoint was removed and then re-used. */ -static inline bool try_consume_watchpoint(atomic_long_t *watchpoint, - long encoded_watchpoint) +static inline bool +try_consume_watchpoint(atomic_long_t *watchpoint, long encoded_watchpoint) { - return atomic_long_try_cmpxchg_relaxed(watchpoint, &encoded_watchpoint, - CONSUMED_WATCHPOINT); + return atomic_long_try_cmpxchg_relaxed(watchpoint, &encoded_watchpoint, CONSUMED_WATCHPOINT); } /* @@ -162,14 +157,13 @@ static inline bool try_consume_watchpoint(atomic_long_t *watchpoint, */ static inline bool remove_watchpoint(atomic_long_t *watchpoint) { - return atomic_long_xchg_relaxed(watchpoint, INVALID_WATCHPOINT) != - CONSUMED_WATCHPOINT; + return atomic_long_xchg_relaxed(watchpoint, INVALID_WATCHPOINT) != CONSUMED_WATCHPOINT; } static inline struct kcsan_ctx *get_ctx(void) { /* - * In interrupt, use raw_cpu_ptr to avoid unnecessary checks, that would + * In interrupts, use raw_cpu_ptr to avoid unnecessary checks, that would * also result in calls that generate warnings in uaccess regions. */ return in_task() ? ¤t->kcsan_ctx : raw_cpu_ptr(&kcsan_cpu_ctx); @@ -260,7 +254,8 @@ static inline unsigned int get_delay(void) */ static noinline void kcsan_found_watchpoint(const volatile void *ptr, - size_t size, bool is_write, + size_t size, + bool is_write, atomic_long_t *watchpoint, long encoded_watchpoint) { @@ -296,8 +291,8 @@ static noinline void kcsan_found_watchpoint(const volatile void *ptr, user_access_restore(flags); } -static noinline void kcsan_setup_watchpoint(const volatile void *ptr, - size_t size, bool is_write) +static noinline void +kcsan_setup_watchpoint(const volatile void *ptr, size_t size, bool is_write) { atomic_long_t *watchpoint; union { @@ -346,8 +341,8 @@ static noinline void kcsan_setup_watchpoint(const volatile void *ptr, watchpoint = insert_watchpoint((unsigned long)ptr, size, is_write); if (watchpoint == NULL) { /* - * Out of capacity: the size of `watchpoints`, and the frequency - * with which `should_watch()` returns true should be tweaked so + * Out of capacity: the size of 'watchpoints', and the frequency + * with which should_watch() returns true should be tweaked so * that this case happens very rarely. */ kcsan_counter_inc(KCSAN_COUNTER_NO_CAPACITY); |