linux-ext4 - [PATCH RFC v5 17/21] dept: Distinguish each work from another

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: <1647397593-16747-18-git-send-email-byungchul.park@lge.com>
Date:   Wed, 16 Mar 2022 11:26:29 +0900
From:   Byungchul Park <byungchul.park@....com>
To:     torvalds@...ux-foundation.org
Cc:     damien.lemoal@...nsource.wdc.com, linux-ide@...r.kernel.org,
        adilger.kernel@...ger.ca, linux-ext4@...r.kernel.org,
        mingo@...hat.com, linux-kernel@...r.kernel.org,
        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,
        linux-mm@...ck.org, akpm@...ux-foundation.org, mhocko@...nel.org,
        minchan@...nel.org, hannes@...xchg.org, vdavydov.dev@...il.com,
        sj@...nel.org, jglisse@...hat.com, dennis@...nel.org, cl@...ux.com,
        penberg@...nel.org, rientjes@...gle.com, vbabka@...e.cz,
        ngupta@...are.org, linux-block@...r.kernel.org,
        paolo.valente@...aro.org, josef@...icpanda.com,
        linux-fsdevel@...r.kernel.org, viro@...iv.linux.org.uk,
        jack@...e.cz, jack@...e.com, jlayton@...nel.org,
        dan.j.williams@...el.com, hch@...radead.org, djwong@...nel.org,
        dri-devel@...ts.freedesktop.org, airlied@...ux.ie,
        rodrigosiqueiramelo@...il.com, melissa.srw@...il.com,
        hamohammed.sa@...il.com
Subject: [PATCH RFC v5 17/21] dept: Distinguish each work from another

Workqueue already provides concurrency control. By that, any wait in a
work doesn't prevents events in other works with the control enabled.
Thus, each work would better be considered a different context.

So let Dept assign a different context id to each work.

Signed-off-by: Byungchul Park <byungchul.park@....com>
---
 include/linux/dept.h     |  2 ++
 kernel/dependency/dept.c | 10 ++++++++++
 kernel/workqueue.c       |  3 +++
 3 files changed, 15 insertions(+)

diff --git a/include/linux/dept.h b/include/linux/dept.h
index 672a762..3d24a52 100644
--- a/include/linux/dept.h
+++ b/include/linux/dept.h
@@ -491,6 +491,7 @@ struct dept_task {
 extern void dept_event_split_map(struct dept_map_each *me, struct dept_map_common *mc, unsigned long ip, const char *e_fn);
 extern void dept_ask_event_split_map(struct dept_map_each *me, struct dept_map_common *mc);
 extern void dept_kernel_enter(void);
+extern void dept_work_enter(void);
 
 static inline void dept_ecxt_enter_nokeep(struct dept_map *m)
 {
@@ -535,6 +536,7 @@ static inline void dept_ecxt_enter_nokeep(struct dept_map *m)
 #define dept_event_split_map(me, mc, ip, e_fn)		do { } while (0)
 #define dept_ask_event_split_map(me, mc)		do { } while (0)
 #define dept_kernel_enter()				do { } while (0)
+#define dept_work_enter()				do { } while (0)
 #define dept_ecxt_enter_nokeep(m)			do { } while (0)
 #define dept_key_init(k)				do { (void)(k); } while (0)
 #define dept_key_destroy(k)				do { (void)(k); } while (0)
diff --git a/kernel/dependency/dept.c b/kernel/dependency/dept.c
index 8d8d8eb..10801783 100644
--- a/kernel/dependency/dept.c
+++ b/kernel/dependency/dept.c
@@ -1886,6 +1886,16 @@ void dept_disable_hardirq(unsigned long ip)
 	dept_exit(flags);
 }
 
+/*
+ * Assign a different context id to each work.
+ */
+void dept_work_enter(void)
+{
+	struct dept_task *dt = dept_task();
+
+	dt->cxt_id[DEPT_CXT_PROCESS] += (1UL << DEPT_CXTS_NR);
+}
+
 void dept_kernel_enter(void)
 {
 	struct dept_task *dt = dept_task();
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 33f1106..f5d762c 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -51,6 +51,7 @@
 #include <linux/sched/isolation.h>
 #include <linux/nmi.h>
 #include <linux/kvm_para.h>
+#include <linux/dept.h>
 
 #include "workqueue_internal.h"
 
@@ -2217,6 +2218,8 @@ static void process_one_work(struct worker *worker, struct work_struct *work)
 
 	lockdep_copy_map(&lockdep_map, &work->lockdep_map);
 #endif
+	dept_work_enter();
+
 	/* ensure we're on the correct CPU */
 	WARN_ON_ONCE(!(pool->flags & POOL_DISASSOCIATED) &&
 		     raw_smp_processor_id() != pool->cpu);
-- 
1.9.1