Merge tag 'locking-urgent-2024-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Ingo Molnar:
 "lockdep:
    - Fix potential deadlock between lockdep and RCU (Zhiguo Niu)
    - Use str_plural() to address Coccinelle warning (Thorsten Blum)
    - Add debuggability enhancement (Luis Claudio R. Goncalves)

  static keys & calls:
    - Fix static_key_slow_dec() yet again (Peter Zijlstra)
    - Handle module init failure correctly in static_call_del_module()
      (Thomas Gleixner)
    - Replace pointless WARN_ON() in static_call_module_notify() (Thomas
      Gleixner)

  <linux/cleanup.h>:
    - Add usage and style documentation (Dan Williams)

  rwsems:
    - Move is_rwsem_reader_owned() and rwsem_owner() under
      CONFIG_DEBUG_RWSEMS (Waiman Long)

  atomic ops, x86:
    - Redeclare x86_32 arch_atomic64_{add,sub}() as void (Uros Bizjak)
    - Introduce the read64_nonatomic macro to x86_32 with cx8 (Uros
      Bizjak)"

Signed-off-by: Ingo Molnar <mingo@kernel.org>

* tag 'locking-urgent-2024-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwsem: Move is_rwsem_reader_owned() and rwsem_owner() under CONFIG_DEBUG_RWSEMS
  jump_label: Fix static_key_slow_dec() yet again
  static_call: Replace pointless WARN_ON() in static_call_module_notify()
  static_call: Handle module init failure correctly in static_call_del_module()
  locking/lockdep: Simplify character output in seq_line()
  lockdep: fix deadlock issue between lockdep and rcu
  lockdep: Use str_plural() to fix Coccinelle warning
  cleanup: Add usage and style documentation
  lockdep: suggest the fix for "lockdep bfs error:-1" on print_bfs_bug
  locking/atomic/x86: Redeclare x86_32 arch_atomic64_{add,sub}() as void
  locking/atomic/x86: Introduce the read64_nonatomic macro to x86_32 with cx8

2 files changed, 9 insertions, 6 deletions

diff --git a/arch/x86/include/asm/atomic64_32.h b/arch/x86/include/asm/atomic64_32.h
index 8db2ec4d6cda..1f650b4dde50 100644
--- a/arch/x86/include/asm/atomic64_32.h
+++ b/arch/x86/include/asm/atomic64_32.h
@@ -163,20 +163,18 @@ static __always_inline s64 arch_atomic64_dec_return(atomic64_t *v)
 }
 #define arch_atomic64_dec_return arch_atomic64_dec_return
 
-static __always_inline s64 arch_atomic64_add(s64 i, atomic64_t *v)
+static __always_inline void arch_atomic64_add(s64 i, atomic64_t *v)
 {
 	__alternative_atomic64(add, add_return,
 			       ASM_OUTPUT2("+A" (i), "+c" (v)),
 			       ASM_NO_INPUT_CLOBBER("memory"));
-	return i;
 }
 
-static __always_inline s64 arch_atomic64_sub(s64 i, atomic64_t *v)
+static __always_inline void arch_atomic64_sub(s64 i, atomic64_t *v)
 {
 	__alternative_atomic64(sub, sub_return,
 			       ASM_OUTPUT2("+A" (i), "+c" (v)),
 			       ASM_NO_INPUT_CLOBBER("memory"));
-	return i;
 }
 
 static __always_inline void arch_atomic64_inc(atomic64_t *v)
diff --git a/arch/x86/lib/atomic64_cx8_32.S b/arch/x86/lib/atomic64_cx8_32.S
index 90afb488b396..b2eff07d65e4 100644
--- a/arch/x86/lib/atomic64_cx8_32.S
+++ b/arch/x86/lib/atomic64_cx8_32.S
@@ -16,6 +16,11 @@
 	cmpxchg8b (\reg)
 .endm
 
+.macro read64_nonatomic reg
+	movl (\reg), %eax
+	movl 4(\reg), %edx
+.endm
+
 SYM_FUNC_START(atomic64_read_cx8)
 	read64 %ecx
 	RET
@@ -51,7 +56,7 @@ SYM_FUNC_START(atomic64_\func\()_return_cx8)
 	movl %edx, %edi
 	movl %ecx, %ebp
 
-	read64 %ecx
+	read64_nonatomic %ecx
 1:
 	movl %eax, %ebx
 	movl %edx, %ecx
@@ -79,7 +84,7 @@ addsub_return sub sub sbb
 SYM_FUNC_START(atomic64_\func\()_return_cx8)
 	pushl %ebx
 
-	read64 %esi
+	read64_nonatomic %esi
 1:
 	movl %eax, %ebx
 	movl %edx, %ecx