[PATCH 1/1] [v2] drivers: edac: Fix bad bit shift operations

From: Priyanka Singh
Date: Wed Apr 13 2022 - 00:48:43 EST


Fix possible bad bit shift operations in fsl_mc_check()

Signed-off-by: Priyanka Singh <priyanka.singh@xxxxxxx>
Reviewed-by: Sherry Sun <sherry.sun@xxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
---
Changes for v2:
Fixed compilation warning

drivers/edac/fsl_ddr_edac.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/edac/fsl_ddr_edac.c b/drivers/edac/fsl_ddr_edac.c
index 6d8ea226010d..747c52b019a2 100644
--- a/drivers/edac/fsl_ddr_edac.c
+++ b/drivers/edac/fsl_ddr_edac.c
@@ -6,7 +6,7 @@
* split out from mpc85xx_edac EDAC driver.
*
* Parts Copyrighted (c) 2013 by Freescale Semiconductor, Inc.
- *
+ * Parts Copyrighted (c) 2022 NXP
* Author: Dave Jiang <djiang@xxxxxxxxxx>
*
* 2006-2007 (c) MontaVista Software, Inc. This file is licensed under
@@ -334,18 +334,24 @@ static void fsl_mc_check(struct mem_ctl_info *mci)
sbe_ecc_decode(cap_high, cap_low, syndrome,
&bad_data_bit, &bad_ecc_bit);

- if (bad_data_bit != -1)
+ if (bad_data_bit >= 0)
fsl_mc_printk(mci, KERN_ERR,
"Faulty Data bit: %d\n", bad_data_bit);
- if (bad_ecc_bit != -1)
+ if (bad_ecc_bit >= 0)
fsl_mc_printk(mci, KERN_ERR,
- "Faulty ECC bit: %d\n", bad_ecc_bit);
-
- fsl_mc_printk(mci, KERN_ERR,
- "Expected Data / ECC:\t%#8.8x_%08x / %#2.2x\n",
- cap_high ^ (1 << (bad_data_bit - 32)),
- cap_low ^ (1 << bad_data_bit),
- syndrome ^ (1 << bad_ecc_bit));
+ "Faulty ECC bit: %d\n", bad_ecc_bit);
+ if ((bad_data_bit > 0 && bad_data_bit < 32) && bad_ecc_bit > 0) {
+ fsl_mc_printk(mci, KERN_ERR,
+ "Expected Data / ECC:\t%#8.8x_%08x / %#2.2x\n",
+ cap_high, cap_low ^ (1 << bad_data_bit),
+ syndrome ^ (1 << bad_ecc_bit));
+ }
+ if (bad_data_bit >= 32 && bad_ecc_bit > 0) {
+ fsl_mc_printk(mci, KERN_ERR,
+ "Expected Data / ECC:\t%#8.8x_%08x / %#2.2x\n",
+ cap_high ^ (1 << (bad_data_bit - 32)),
+ cap_low, syndrome ^ (1 << bad_ecc_bit));
+ }
}

fsl_mc_printk(mci, KERN_ERR,

base-commit: f6695af7ac79f92d80a7c20fc86a236d1784562f
--
2.17.1