linux-kernel - [PATCH 3.16 42/63] mmc: mmc: fix switch timeout issue caused by jiffies precision

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: <lsq.1578512578.769610404@decadent.org.uk>
Date:   Wed, 08 Jan 2020 19:43:40 +0000
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, Denis Kirjanov <kda@...ux-powerpc.org>,
        "Chaotian Jing" <chaotian.jing@...iatek.com>,
        "Ulf Hansson" <ulf.hansson@...aro.org>,
        "Arnd Bergmann" <arnd@...db.de>
Subject: [PATCH 3.16 42/63] mmc: mmc: fix switch timeout issue caused by
 jiffies precision

3.16.81-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Chaotian Jing <chaotian.jing@...iatek.com>

commit 987aa5f8059613bf85cbb6f64ffbd34f5cb7a9d1 upstream.

with CONFIG_HZ=100, the precision of jiffies is 10ms, and the
generic_cmd6_time of some card is also 10ms. then, may be current
time is only 5ms, but already timed out caused by jiffies precision.

Signed-off-by: Chaotian Jing <chaotian.jing@...iatek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@...aro.org>
Cc: Arnd Bergmann <arnd@...db.de>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 drivers/mmc/core/mmc_ops.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -470,7 +470,7 @@ int __mmc_switch(struct mmc_card *card,
 		timeout_ms = MMC_OPS_TIMEOUT_MS;
 
 	/* Must check status to be sure of no errors. */
-	timeout = jiffies + msecs_to_jiffies(timeout_ms);
+	timeout = jiffies + msecs_to_jiffies(timeout_ms) + 1;
 	do {
 		if (send_status) {
 			err = __mmc_send_status(card, &status, ignore_crc);