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authorPriyanka Singh <priyanka.singh@nxp.com>2024-10-16 16:31:11 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-12-09 10:31:47 +0100
commit63a2d940c719fbded9d8fef94b5fb6a4933447f9 (patch)
treeb84faac77713730e5a3110445274cfd38443d2b0 /drivers
parentac7dfac639709c210ce667485c64c7a03cd3e02c (diff)
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EDAC/fsl_ddr: Fix bad bit shift operations
[ Upstream commit 9ec22ac4fe766c6abba845290d5139a3fbe0153b ] Fix undefined behavior caused by left-shifting a negative value in the expression: cap_high ^ (1 << (bad_data_bit - 32)) The variable bad_data_bit ranges from 0 to 63. When it is less than 32, bad_data_bit - 32 becomes negative, and left-shifting by a negative value in C is undefined behavior. Fix this by combining cap_high and cap_low into a 64-bit variable. [ bp: Massage commit message, simplify error bits handling. ] Fixes: ea2eb9a8b620 ("EDAC, fsl-ddr: Separate FSL DDR driver from MPC85xx") Signed-off-by: Priyanka Singh <priyanka.singh@nxp.com> Signed-off-by: Li Yang <leoyang.li@nxp.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20241016-imx95_edac-v3-3-86ae6fc2756a@nxp.com Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/edac/fsl_ddr_edac.c22
1 files changed, 13 insertions, 9 deletions
diff --git a/drivers/edac/fsl_ddr_edac.c b/drivers/edac/fsl_ddr_edac.c
index b81757555a8a..7809427c2dbe 100644
--- a/drivers/edac/fsl_ddr_edac.c
+++ b/drivers/edac/fsl_ddr_edac.c
@@ -328,21 +328,25 @@ static void fsl_mc_check(struct mem_ctl_info *mci)
* TODO: Add support for 32-bit wide buses
*/
if ((err_detect & DDR_EDE_SBE) && (bus_width == 64)) {
+ u64 cap = (u64)cap_high << 32 | cap_low;
+ u32 s = syndrome;
+
sbe_ecc_decode(cap_high, cap_low, syndrome,
&bad_data_bit, &bad_ecc_bit);
- if (bad_data_bit != -1)
- fsl_mc_printk(mci, KERN_ERR,
- "Faulty Data bit: %d\n", bad_data_bit);
- if (bad_ecc_bit != -1)
- fsl_mc_printk(mci, KERN_ERR,
- "Faulty ECC bit: %d\n", bad_ecc_bit);
+ if (bad_data_bit >= 0) {
+ fsl_mc_printk(mci, KERN_ERR, "Faulty Data bit: %d\n", bad_data_bit);
+ cap ^= 1ULL << bad_data_bit;
+ }
+
+ if (bad_ecc_bit >= 0) {
+ fsl_mc_printk(mci, KERN_ERR, "Faulty ECC bit: %d\n", bad_ecc_bit);
+ s ^= 1 << 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));
+ upper_32_bits(cap), lower_32_bits(cap), s);
}
fsl_mc_printk(mci, KERN_ERR,