On Tue, 3 Dec 2019 at 17:01, Paul E. McKenney <paulmck@xxxxxxxxxx> wrote: > > On Mon, Dec 02, 2019 at 09:30:22PM -0800, Randy Dunlap wrote: > > On 11/26/19 6:04 AM, Marco Elver wrote: > > > Prefer __always_inline for fast-path functions that are called outside > > > of user_access_save, to avoid generating UACCESS warnings when > > > optimizing for size (CC_OPTIMIZE_FOR_SIZE). It will also avoid future > > > surprises with compiler versions that change the inlining heuristic even > > > when optimizing for performance. > > > > > > Report: http://lkml.kernel.org/r/58708908-84a0-0a81-a836-ad97e33dbb62@xxxxxxxxxxxxx > > > Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> > > > Signed-off-by: Marco Elver <elver@xxxxxxxxxx> > > > > Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> # build-tested > > Thank you, Randy! Hoped this would have applied by now, but since KCSAN isn't in mainline yet, should I send a version of this patch rebased on -rcu/kcsan? It will just conflict with the style cleanup that is in -tip/locking/kcsan when another eventual merge happens. Alternatively, we can delay it for now and just have to remember to apply eventually (and have to live with things being messy for a bit longer :-)). The version as-is here applies on -tip/locking/kcsan and -next (which merged -tip/locking/kcsan). Thanks, -- Marco > Thanx, Paul > > > Thanks. > > > > > --- > > > Rebased on: locking/kcsan branch of tip tree. > > > --- > > > kernel/kcsan/atomic.h | 2 +- > > > kernel/kcsan/core.c | 16 +++++++--------- > > > kernel/kcsan/encoding.h | 14 +++++++------- > > > 3 files changed, 15 insertions(+), 17 deletions(-) > > > > > > diff --git a/kernel/kcsan/atomic.h b/kernel/kcsan/atomic.h > > > index 576e03ddd6a3..a9c193053491 100644 > > > --- a/kernel/kcsan/atomic.h > > > +++ b/kernel/kcsan/atomic.h > > > @@ -18,7 +18,7 @@ > > > * than cast to volatile. Eventually, we hope to be able to remove this > > > * function. > > > */ > > > -static inline bool kcsan_is_atomic(const volatile void *ptr) > > > +static __always_inline bool kcsan_is_atomic(const volatile void *ptr) > > > { > > > /* only jiffies for now */ > > > return ptr == &jiffies; > > > diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c > > > index 3314fc29e236..c616fec639cd 100644 > > > --- a/kernel/kcsan/core.c > > > +++ b/kernel/kcsan/core.c > > > @@ -78,10 +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, > > > - bool expect_write, > > > - long *encoded_watchpoint) > > > +static __always_inline atomic_long_t * > > > +find_watchpoint(unsigned long addr, size_t size, bool expect_write, long *encoded_watchpoint) > > > { > > > const int slot = watchpoint_slot(addr); > > > const unsigned long addr_masked = addr & WATCHPOINT_ADDR_MASK; > > > @@ -146,7 +144,7 @@ insert_watchpoint(unsigned long addr, size_t size, bool is_write) > > > * 2. the thread that set up the watchpoint already removed it; > > > * 3. the watchpoint was removed and then re-used. > > > */ > > > -static inline bool > > > +static __always_inline bool > > > try_consume_watchpoint(atomic_long_t *watchpoint, long encoded_watchpoint) > > > { > > > return atomic_long_try_cmpxchg_relaxed(watchpoint, &encoded_watchpoint, CONSUMED_WATCHPOINT); > > > @@ -160,7 +158,7 @@ static inline bool remove_watchpoint(atomic_long_t *watchpoint) > > > return atomic_long_xchg_relaxed(watchpoint, INVALID_WATCHPOINT) != CONSUMED_WATCHPOINT; > > > } > > > > > > -static inline struct kcsan_ctx *get_ctx(void) > > > +static __always_inline struct kcsan_ctx *get_ctx(void) > > > { > > > /* > > > * In interrupts, use raw_cpu_ptr to avoid unnecessary checks, that would > > > @@ -169,7 +167,7 @@ static inline struct kcsan_ctx *get_ctx(void) > > > return in_task() ? ¤t->kcsan_ctx : raw_cpu_ptr(&kcsan_cpu_ctx); > > > } > > > > > > -static inline bool is_atomic(const volatile void *ptr) > > > +static __always_inline bool is_atomic(const volatile void *ptr) > > > { > > > struct kcsan_ctx *ctx = get_ctx(); > > > > > > @@ -193,7 +191,7 @@ static inline bool is_atomic(const volatile void *ptr) > > > return kcsan_is_atomic(ptr); > > > } > > > > > > -static inline bool should_watch(const volatile void *ptr, int type) > > > +static __always_inline bool should_watch(const volatile void *ptr, int type) > > > { > > > /* > > > * Never set up watchpoints when memory operations are atomic. > > > @@ -226,7 +224,7 @@ static inline void reset_kcsan_skip(void) > > > this_cpu_write(kcsan_skip, skip_count); > > > } > > > > > > -static inline bool kcsan_is_enabled(void) > > > +static __always_inline bool kcsan_is_enabled(void) > > > { > > > return READ_ONCE(kcsan_enabled) && get_ctx()->disable_count == 0; > > > } > > > diff --git a/kernel/kcsan/encoding.h b/kernel/kcsan/encoding.h > > > index b63890e86449..f03562aaf2eb 100644 > > > --- a/kernel/kcsan/encoding.h > > > +++ b/kernel/kcsan/encoding.h > > > @@ -59,10 +59,10 @@ encode_watchpoint(unsigned long addr, size_t size, bool is_write) > > > (addr & WATCHPOINT_ADDR_MASK)); > > > } > > > > > > -static inline bool decode_watchpoint(long watchpoint, > > > - unsigned long *addr_masked, > > > - size_t *size, > > > - bool *is_write) > > > +static __always_inline bool decode_watchpoint(long watchpoint, > > > + unsigned long *addr_masked, > > > + size_t *size, > > > + bool *is_write) > > > { > > > if (watchpoint == INVALID_WATCHPOINT || > > > watchpoint == CONSUMED_WATCHPOINT) > > > @@ -78,13 +78,13 @@ static inline bool decode_watchpoint(long watchpoint, > > > /* > > > * Return watchpoint slot for an address. > > > */ > > > -static inline int watchpoint_slot(unsigned long addr) > > > +static __always_inline int watchpoint_slot(unsigned long addr) > > > { > > > return (addr / PAGE_SIZE) % CONFIG_KCSAN_NUM_WATCHPOINTS; > > > } > > > > > > -static inline bool matching_access(unsigned long addr1, size_t size1, > > > - unsigned long addr2, size_t size2) > > > +static __always_inline bool matching_access(unsigned long addr1, size_t size1, > > > + unsigned long addr2, size_t size2) > > > { > > > unsigned long end_range1 = addr1 + size1 - 1; > > > unsigned long end_range2 = addr2 + size2 - 1; > > > > > > > > > -- > > ~Randy > >
