linux-kernel - [PATCH v2] tpm_tis_spi_main: set cs

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>] [day] [month] [year] [list]

Message-ID: <1612514469-4002-1-git-send-email-wanghongzhe@huawei.com>
Date:   Fri, 5 Feb 2021 16:41:09 +0800
From:   wanghongzhe <wanghongzhe@...wei.com>
To:     <peterhuewe@....de>, <jarkko@...nel.org>, <jgg@...pe.ca>
CC:     <linux-integrity@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: [PATCH v2] tpm_tis_spi_main: set cs_change = 0 when timesout

when i reach TPM_RETRY, the cs cannot  change back to 'high'.
So the TPM chips thinks this communication is not over.
And next times communication cannot be effective because
the communications mixed up with the last time.

v1 -> v2:
 - fix spi_xfer->cs_change error

Signed-off-by: wanghongzhe <wanghongzhe@...wei.com>
---
 drivers/char/tpm/tpm_tis_spi_main.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/char/tpm/tpm_tis_spi_main.c b/drivers/char/tpm/tpm_tis_spi_main.c
index 3856f6ebcb34..6c52cbb28881 100644
--- a/drivers/char/tpm/tpm_tis_spi_main.c
+++ b/drivers/char/tpm/tpm_tis_spi_main.c
@@ -64,8 +64,18 @@ static int tpm_tis_spi_flow_control(struct tpm_tis_spi_phy *phy,
 				break;
 		}
 
-		if (i == TPM_RETRY)
+		if (i == TPM_RETRY) {
+			/* change back to 'high',
+			 * So the TPM chips thinks the last communication
+			 * is done.
+			 */
+			spi_xfer->cs_change = 0;
+			spi_xfer->len = 1;
+			spi_message_init(&m);
+			spi_message_add_tail(spi_xfer, &m);
+			ret = spi_sync_locked(phy->spi_device, &m);
 			return -ETIMEDOUT;
+		}
 	}
 
 	return 0;
-- 
2.19.1