From: Byungchul Park <byungchul.park@lge.com> To: torvalds@linux-foundation.org Cc: damien.lemoal@opensource.wdc.com, linux-ide@vger.kernel.org, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, mingo@redhat.com, linux-kernel@vger.kernel.org, peterz@infradead.org, will@kernel.org, tglx@linutronix.de, rostedt@goodmis.org, joel@joelfernandes.org, sashal@kernel.org, daniel.vetter@ffwll.ch, chris@chris-wilson.co.uk, duyuyang@gmail.com, johannes.berg@intel.com, tj@kernel.org, tytso@mit.edu, willy@infradead.org, david@fromorbit.com, amir73il@gmail.com, bfields@fieldses.org, gregkh@linuxfoundation.org, kernel-team@lge.com, linux-mm@kvack.org, akpm@linux-foundation.org, mhocko@kernel.org, minchan@kernel.org, hannes@cmpxchg.org, vdavydov.dev@gmail.com, sj@kernel.org, jglisse@redhat.com, dennis@kernel.org, cl@linux.com, penberg@kernel.org, rientjes@google.com, vbabka@suse.cz, ngupta@vflare.org, linux-block@vger.kernel.org, paolo.valente@linaro.org, josef@toxicpanda.com, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, jack@suse.cz, jack@suse.com, jlayton@kernel.org, dan.j.williams@intel.com, hch@infradead.org, djwong@kernel.org, dri-devel@lists.freedesktop.org, airlied@linux.ie, rodrigosiqueiramelo@gmail.com, melissa.srw@gmail.com, hamohammed.sa@gmail.com Subject: [PATCH v4 22/24] dept: Don't create dependencies between different depths in any case Date: Fri, 4 Mar 2022 16:06:41 +0900 [thread overview] Message-ID: <1646377603-19730-23-git-send-email-byungchul.park@lge.com> (raw) In-Reply-To: <1646377603-19730-1-git-send-email-byungchul.park@lge.com> Dept already prevents creating dependencies between different depths of the class indicated by *_lock_nested() when the lock acquisitions happen consecutively. lock A0 with depth lock_nested A1 with depth + 1 ... unlock A1 unlock A0 Dept does not create A0 -> A1 dependency in this case, either. However, once another class cut in, the code becomes problematic. When Dept tries to create real dependencies, it does not only create real ones but also wrong ones between different depths of the class. lock A0 with depth lock B lock_nested A1 with depth + 1 ... unlock A1 unlock B unlock A0 Even in this case, Dept should not create A0 -> A1 dependency. So let Dept not create wrong dependencies between different depths of the class in any case. Reported-by: 42.hyeyoo@gmail.com Signed-off-by: Byungchul Park <byungchul.park@lge.com> --- kernel/dependency/dept.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/kernel/dependency/dept.c b/kernel/dependency/dept.c index 5d4efc3..cc1b3a3 100644 --- a/kernel/dependency/dept.c +++ b/kernel/dependency/dept.c @@ -1458,14 +1458,7 @@ static void add_wait(struct dept_class *c, unsigned long ip, eh = dt->ecxt_held + i; if (eh->ecxt->class != c || eh->nest == ne) - break; - } - - for (; i >= 0; i--) { - struct dept_ecxt_held *eh; - - eh = dt->ecxt_held + i; - add_dep(eh->ecxt, w); + add_dep(eh->ecxt, w); } if (!wait_consumed(w) && !rich_stack) { -- 1.9.1
WARNING: multiple messages have this Message-ID (diff)
From: Byungchul Park <byungchul.park@lge.com> To: torvalds@linux-foundation.org Cc: hamohammed.sa@gmail.com, jack@suse.cz, peterz@infradead.org, daniel.vetter@ffwll.ch, amir73il@gmail.com, david@fromorbit.com, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, bfields@fieldses.org, linux-ide@vger.kernel.org, adilger.kernel@dilger.ca, joel@joelfernandes.org, cl@linux.com, will@kernel.org, duyuyang@gmail.com, sashal@kernel.org, paolo.valente@linaro.org, damien.lemoal@opensource.wdc.com, willy@infradead.org, hch@infradead.org, airlied@linux.ie, mingo@redhat.com, djwong@kernel.org, vdavydov.dev@gmail.com, rientjes@google.com, dennis@kernel.org, linux-ext4@vger.kernel.org, linux-mm@kvack.org, ngupta@vflare.org, johannes.berg@intel.com, jack@suse.com, dan.j.williams@intel.com, josef@toxicpanda.com, rostedt@goodmis.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, jglisse@redhat.com, viro@zeniv.linux.org.uk, tglx@linutronix.de, mhocko@kernel.org, vbabka@suse.cz, melissa.srw@gmail.com, sj@kernel.org, tytso@mit.edu, rodrigosiqueiramelo@gmail.com, kernel-team@lge.com, gregkh@linuxfoundation.org, jlayton@kernel.org, linux-kernel@vger.kernel.org, penberg@kernel.org, minchan@kernel.org, hannes@cmpxchg.org, tj@kernel.org, akpm@linux-foundation.org Subject: [PATCH v4 22/24] dept: Don't create dependencies between different depths in any case Date: Fri, 4 Mar 2022 16:06:41 +0900 [thread overview] Message-ID: <1646377603-19730-23-git-send-email-byungchul.park@lge.com> (raw) In-Reply-To: <1646377603-19730-1-git-send-email-byungchul.park@lge.com> Dept already prevents creating dependencies between different depths of the class indicated by *_lock_nested() when the lock acquisitions happen consecutively. lock A0 with depth lock_nested A1 with depth + 1 ... unlock A1 unlock A0 Dept does not create A0 -> A1 dependency in this case, either. However, once another class cut in, the code becomes problematic. When Dept tries to create real dependencies, it does not only create real ones but also wrong ones between different depths of the class. lock A0 with depth lock B lock_nested A1 with depth + 1 ... unlock A1 unlock B unlock A0 Even in this case, Dept should not create A0 -> A1 dependency. So let Dept not create wrong dependencies between different depths of the class in any case. Reported-by: 42.hyeyoo@gmail.com Signed-off-by: Byungchul Park <byungchul.park@lge.com> --- kernel/dependency/dept.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/kernel/dependency/dept.c b/kernel/dependency/dept.c index 5d4efc3..cc1b3a3 100644 --- a/kernel/dependency/dept.c +++ b/kernel/dependency/dept.c @@ -1458,14 +1458,7 @@ static void add_wait(struct dept_class *c, unsigned long ip, eh = dt->ecxt_held + i; if (eh->ecxt->class != c || eh->nest == ne) - break; - } - - for (; i >= 0; i--) { - struct dept_ecxt_held *eh; - - eh = dt->ecxt_held + i; - add_dep(eh->ecxt, w); + add_dep(eh->ecxt, w); } if (!wait_consumed(w) && !rich_stack) { -- 1.9.1
next prev parent reply other threads:[~2022-03-04 7:08 UTC|newest] Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-03-04 7:06 [PATCH v4 00/24] DEPT(Dependency Tracker) Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 01/24] llist: Move llist_{head,node} definition to types.h Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 02/24] dept: Implement Dept(Dependency Tracker) Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-09 7:21 ` kernel test robot 2022-03-09 23:43 ` kernel test robot 2022-03-04 7:06 ` [PATCH v4 03/24] dept: Embed Dept data in Lockdep Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 04/24] dept: Add a API for skipping dependency check temporarily Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 05/24] dept: Apply Dept to spinlock Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 06/24] dept: Apply Dept to mutex families Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 07/24] dept: Apply Dept to rwlock Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 08/24] dept: Apply Dept to wait_for_completion()/complete() Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 09/24] dept: Apply Dept to seqlock Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 10/24] dept: Apply Dept to rwsem Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 11/24] dept: Add proc knobs to show stats and dependency graph Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-10 7:43 ` kernel test robot 2022-03-04 7:06 ` [PATCH v4 12/24] dept: Introduce split map concept and new APIs for them Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 13/24] dept: Apply Dept to wait/event of PG_{locked,writeback} Byungchul Park 2022-03-04 7:06 ` [PATCH v4 13/24] dept: Apply Dept to wait/event of PG_{locked, writeback} Byungchul Park 2022-03-04 7:06 ` [PATCH v4 14/24] dept: Apply SDT to swait Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-09 9:14 ` kernel test robot 2022-03-04 7:06 ` [PATCH v4 15/24] dept: Apply SDT to wait(waitqueue) Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 16/24] locking/lockdep, cpu/hotplus: Use a weaker annotation in AP thread Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 19:28 ` Sergei Shtylyov 2022-03-04 19:28 ` Sergei Shtylyov 2022-03-04 23:36 ` Byungchul Park 2022-03-04 23:36 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 17/24] dept: Distinguish each syscall context from another Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 18/24] dept: Distinguish each work " Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 19/24] dept: Disable Dept within the wait_bit layer by default Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 20/24] dept: Add nocheck version of init_completion() Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 21/24] dept: Disable Dept on struct crypto_larval's completion for now Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` Byungchul Park [this message] 2022-03-04 7:06 ` [PATCH v4 22/24] dept: Don't create dependencies between different depths in any case Byungchul Park 2022-03-04 11:39 ` Hyeonggon Yoo 2022-03-04 11:39 ` Hyeonggon Yoo 2022-03-04 23:38 ` Byungchul Park 2022-03-04 23:38 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 23/24] dept: Let it work with real sleeps in __schedule() Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-04 7:06 ` [PATCH v4 24/24] dept: Disable Dept on that map once it's been handled until next turn Byungchul Park 2022-03-04 7:06 ` Byungchul Park 2022-03-12 1:53 ` [PATCH v4 00/24] DEPT(Dependency Tracker) Hyeonggon Yoo 2022-03-12 1:53 ` Hyeonggon Yoo 2022-03-14 6:59 ` Byungchul Park 2022-03-14 6:59 ` Byungchul Park 2022-03-15 12:04 ` Hyeonggon Yoo 2022-03-15 12:04 ` Hyeonggon Yoo 2022-03-16 4:32 ` Byungchul Park 2022-03-16 4:32 ` Byungchul Park 2022-03-16 9:30 ` Hyeonggon Yoo 2022-03-16 9:30 ` Hyeonggon Yoo 2022-03-18 7:51 ` Byungchul Park 2022-03-18 7:51 ` Byungchul Park 2022-03-20 10:57 ` Byungchul Park 2022-03-20 10:57 ` Byungchul Park
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