[GIT pull] locking/urgent for v5.12-rc3

[Thomas Gleixner]

Linus,

please pull the latest locking/urgent branch from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 
locking-urgent-2021-03-14

up to:  4817a52b3061: seqlock,lockdep: Fix seqcount_latch_init()


A couple of locking fixes:
 
 - A fix for the static_call mechanism so it handles unaligned
   addresses correctly.

 - Make u64_stats_init() a macro so every instance gets a seperate lockdep
   key.

 - Make seqcount_latch_init() a macro as well to preserve the static
   variable which is used for the lockdep key.

Thanks,

        tglx

------------------>
Peter Zijlstra (3):
      static_call: Fix the module key fixup
      u64_stats,lockdep: Fix u64_stats_init() vs lockdep
      seqlock,lockdep: Fix seqcount_latch_init()


 include/linux/seqlock.h        | 5 +----
 include/linux/u64_stats_sync.h | 7 ++++---
 kernel/static_call.c           | 7 ++++---
 3 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index 2f7bb92b4c9e..f61e34fbaaea 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -664,10 +664,7 @@ typedef struct {
  * seqcount_latch_init() - runtime initializer for seqcount_latch_t
  * @s: Pointer to the seqcount_latch_t instance
  */
-static inline void seqcount_latch_init(seqcount_latch_t *s)
-{
-       seqcount_init(&s->seqcount);
-}
+#define seqcount_latch_init(s) seqcount_init(&(s)->seqcount)
 
 /**
  * raw_read_seqcount_latch() - pick even/odd latch data copy
diff --git a/include/linux/u64_stats_sync.h b/include/linux/u64_stats_sync.h
index c6abb79501b3..e81856c0ba13 100644
--- a/include/linux/u64_stats_sync.h
+++ b/include/linux/u64_stats_sync.h
@@ -115,12 +115,13 @@ static inline void u64_stats_inc(u64_stats_t *p)
 }
 #endif
 
+#if BITS_PER_LONG == 32 && defined(CONFIG_SMP)
+#define u64_stats_init(syncp)  seqcount_init(&(syncp)->seq)
+#else
 static inline void u64_stats_init(struct u64_stats_sync *syncp)
 {
-#if BITS_PER_LONG == 32 && defined(CONFIG_SMP)
-       seqcount_init(&syncp->seq);
-#endif
 }
+#endif
 
 static inline void u64_stats_update_begin(struct u64_stats_sync *syncp)
 {
diff --git a/kernel/static_call.c b/kernel/static_call.c
index 6906c6ec4c97..ae825295cf68 100644
--- a/kernel/static_call.c
+++ b/kernel/static_call.c
@@ -349,7 +349,8 @@ static int static_call_add_module(struct module *mod)
        struct static_call_site *site;
 
        for (site = start; site != stop; site++) {
-               unsigned long addr = (unsigned long)static_call_key(site);
+               unsigned long s_key = (long)site->key + (long)&site->key;
+               unsigned long addr = s_key & ~STATIC_CALL_SITE_FLAGS;
                unsigned long key;
 
                /*
@@ -373,8 +374,8 @@ static int static_call_add_module(struct module *mod)
                        return -EINVAL;
                }
 
-               site->key = (key - (long)&site->key) |
-                           (site->key & STATIC_CALL_SITE_FLAGS);
+               key |= s_key & STATIC_CALL_SITE_FLAGS;
+               site->key = key - (long)&site->key;
        }
 
        return __static_call_init(mod, start, stop);