linux-kernel - [RFC 08/14] dept: Apply Dept to seqlock

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1643078204-12663-9-git-send-email-byungchul.park@lge.com>
Date:   Tue, 25 Jan 2022 11:36:38 +0900
From:   Byungchul Park <byungchul.park@....com>
To:     torvalds@...ux-foundation.org, mingo@...hat.com,
        linux-kernel@...r.kernel.org
Cc:     peterz@...radead.org, will@...nel.org, tglx@...utronix.de,
        rostedt@...dmis.org, joel@...lfernandes.org, sashal@...nel.org,
        daniel.vetter@...ll.ch, chris@...is-wilson.co.uk,
        duyuyang@...il.com, johannes.berg@...el.com, tj@...nel.org,
        tytso@....edu, willy@...radead.org, david@...morbit.com,
        amir73il@...il.com, bfields@...ldses.org,
        gregkh@...uxfoundation.org, kernel-team@....com
Subject: [RFC 08/14] dept: Apply Dept to seqlock

Makes Dept able to track dependencies by seqlock with adding wait
annotation on read side of seqlock.

Signed-off-by: Byungchul Park <byungchul.park@....com>
---
 include/linux/seqlock.h | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index cbfc78b..622267f 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -23,6 +23,13 @@
 
 #include <asm/processor.h>
 
+#ifdef CONFIG_DEPT
+#define DEPT_EVT_ALL		((1UL << DEPT_MAX_SUBCLASSES_EVT) - 1)
+#define dept_seq_wait(m, ip)	dept_wait(m, DEPT_EVT_ALL, ip, __func__, 0)
+#else
+#define dept_seq_wait(m, ip)	do { } while (0)
+#endif
+
 /*
  * The seqlock seqcount_t interface does not prescribe a precise sequence of
  * read begin/retry/end. For readers, typically there is a call to
@@ -148,7 +155,7 @@ static inline void seqcount_lockdep_reader_access(const seqcount_t *s)
  * This lock-unlock technique must be implemented for all of PREEMPT_RT
  * sleeping locks.  See Documentation/locking/locktypes.rst
  */
-#if defined(CONFIG_LOCKDEP) || defined(CONFIG_PREEMPT_RT)
+#if defined(CONFIG_LOCKDEP) || defined(CONFIG_DEPT) || defined(CONFIG_PREEMPT_RT)
 #define __SEQ_LOCK(expr)	expr
 #else
 #define __SEQ_LOCK(expr)
@@ -203,6 +210,12 @@ static inline void seqcount_lockdep_reader_access(const seqcount_t *s)
 	__SEQ_LOCK(locktype	*lock);					\
 } seqcount_##lockname##_t;						\
 									\
+static __always_inline void						\
+__seqprop_##lockname##_wait(const seqcount_##lockname##_t *s)		\
+{									\
+	__SEQ_LOCK(dept_seq_wait(&(lockmember)->dep_map.dmap, _RET_IP_));\
+}									\
+									\
 static __always_inline seqcount_t *					\
 __seqprop_##lockname##_ptr(seqcount_##lockname##_t *s)			\
 {									\
@@ -271,6 +284,8 @@ static inline void __seqprop_assert(const seqcount_t *s)
 	lockdep_assert_preemption_disabled();
 }
 
+static inline void __seqprop_wait(const seqcount_t *s) { }
+
 #define __SEQ_RT	IS_ENABLED(CONFIG_PREEMPT_RT)
 
 SEQCOUNT_LOCKNAME(raw_spinlock, raw_spinlock_t,  false,    s->lock,        raw_spin, raw_spin_lock(s->lock))
@@ -311,6 +326,7 @@ static inline void __seqprop_assert(const seqcount_t *s)
 #define __seqcount_sequence(s)		__seqprop(s, sequence)
 #define __seqcount_lock_preemptible(s)	__seqprop(s, preemptible)
 #define __seqcount_assert_lock_held(s)	__seqprop(s, assert)
+#define __seqcount_dept_wait(s)		__seqprop(s, wait)
 
 /**
  * __read_seqcount_begin() - begin a seqcount_t read section w/o barrier
@@ -360,6 +376,7 @@ static inline void __seqprop_assert(const seqcount_t *s)
 #define read_seqcount_begin(s)						\
 ({									\
 	seqcount_lockdep_reader_access(__seqcount_ptr(s));		\
+	__seqcount_dept_wait(s);					\
 	raw_read_seqcount_begin(s);					\
 })
 
-- 
1.9.1