[RFC PATCH 2/7] rslib: Fix decoding of shortened codes

From: Ferdinand Blomqvist
Date: Sat Mar 30 2019 - 14:30:20 EST


The decoder is broken. It only works with full length codes.

Signed-off-by: Ferdinand Blomqvist <ferdinand.blomqvist@xxxxxxxxx>
---
lib/reed_solomon/decode_rs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/reed_solomon/decode_rs.c b/lib/reed_solomon/decode_rs.c
index 1db74eb098d0..3313bf944ff1 100644
--- a/lib/reed_solomon/decode_rs.c
+++ b/lib/reed_solomon/decode_rs.c
@@ -99,9 +99,9 @@
if (no_eras > 0) {
/* Init lambda to be the erasure locator polynomial */
lambda[1] = alpha_to[rs_modnn(rs,
- prim * (nn - 1 - eras_pos[0]))];
+ prim * (nn - 1 - (eras_pos[0] + pad)))];
for (i = 1; i < no_eras; i++) {
- u = rs_modnn(rs, prim * (nn - 1 - eras_pos[i]));
+ u = rs_modnn(rs, prim * (nn - 1 - (eras_pos[i] + pad)));
for (j = i + 1; j > 0; j--) {
tmp = index_of[lambda[j - 1]];
if (tmp != nn) {
--
2.17.2