linux-kernel - [PATCH v2 1/2] nfit: Fix the abuse of COMPLETION_INITIALIZER

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: <20170824142239.15178-1-boqun.feng@gmail.com>
Date:   Thu, 24 Aug 2017 22:22:36 +0800
From:   Boqun Feng <boqun.feng@...il.com>
To:     linux-kernel@...r.kernel.org, linux-mm@...ck.org
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>, walken@...gle.com,
        Byungchul Park <byungchul.park@....com>,
        Arnd Bergmann <arnd@...db.de>,
        Andrew Morton <akpm@...ux-foundation.org>, willy@...radead.org,
        Nicholas Piggin <npiggin@...il.com>, kernel-team@....com,
        Boqun Feng <boqun.feng@...il.com>,
        Dan Williams <dan.j.williams@...el.com>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Len Brown <lenb@...nel.org>, linux-nvdimm@...ts.01.org,
        linux-acpi@...r.kernel.org
Subject: [PATCH v2 1/2] nfit: Fix the abuse of COMPLETION_INITIALIZER_ONSTACK()

COMPLETION_INITIALIZER_ONSTACK() is supposed to used as an initializer,
in other words, it should only be used in assignment expressions or
compound literals. So the usage in drivers/acpi/nfit/core.c:

	COMPLETION_INITIALIZER_ONSTACK(flush.cmp);

, is inappropriate.

Besides, this usage could also break compilations for another fix to
reduce stack sizes caused by COMPLETION_INITIALIZER_ONSTACK(), because
that fix changes COMPLETION_INITIALIZER_ONSTACK() from rvalue to lvalue,
and usage as above will report error:

	drivers/acpi/nfit/core.c: In function 'acpi_nfit_flush_probe':
	include/linux/completion.h:77:3: error: value computed is not used [-Werror=unused-value]
	  (*({ init_completion(&work); &work; }))

This patch fixes this by replacing COMPLETION_INITIALIZER_ONSTACK() with
init_completion() in acpi_nfit_flush_probe(), which does the same
initialization without any other problem.

Signed-off-by: Boqun Feng <boqun.feng@...il.com>
---
 drivers/acpi/nfit/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 19182d091587..1893e416e7c0 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -2884,7 +2884,7 @@ static int acpi_nfit_flush_probe(struct nvdimm_bus_descriptor *nd_desc)
 	 * need to be interruptible while waiting.
 	 */
 	INIT_WORK_ONSTACK(&flush.work, flush_probe);
-	COMPLETION_INITIALIZER_ONSTACK(flush.cmp);
+	init_completion(&flush.cmp);
 	queue_work(nfit_wq, &flush.work);
 	mutex_unlock(&acpi_desc->init_mutex);
 
-- 
2.14.1