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authorFerdinand Blomqvist <ferdinand.blomqvist@gmail.com>2019-06-20 17:10:37 +0300
committerThomas Gleixner <tglx@linutronix.de>2019-06-26 14:55:47 +0200
commitef4d6a8556b637ad27c8c2a2cff1dda3da38e9a9 (patch)
tree448b3b8cb09f14c3d3dca2069705e9b2def77c3b /lib
parent647cc9ece63fdba573a31bdafa54fb2d388c3c83 (diff)
downloadlinux-ef4d6a8556b637ad27c8c2a2cff1dda3da38e9a9.tar.gz
rslib: Fix handling of of caller provided syndrome
Check if the syndrome provided by the caller is zero, and act
accordingly.

Signed-off-by: Ferdinand Blomqvist <ferdinand.blomqvist@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190620141039.9874-6-ferdinand.blomqvist@gmail.com

Diffstat (limited to 'lib')
-rw-r--r--lib/reed_solomon/decode_rs.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/lib/reed_solomon/decode_rs.c b/lib/reed_solomon/decode_rs.c
index 78629bbe6590..b7264a712d46 100644
--- a/lib/reed_solomon/decode_rs.c
+++ b/lib/reed_solomon/decode_rs.c
@@ -42,8 +42,18 @@
 	BUG_ON(pad < 0 || pad >= nn - nroots);
 
 	/* Does the caller provide the syndrome ? */
-	if (s != NULL)
-		goto decode;
+	if (s != NULL) {
+		for (i = 0; i < nroots; i++) {
+			/* The syndrome is in index form,
+			 * so nn represents zero
+			 */
+			if (s[i] != nn)
+				goto decode;
+		}
+
+		/* syndrome is zero, no errors to correct  */
+		return 0;
+	}
 
 	/* form the syndromes; i.e., evaluate data(x) at roots of
 	 * g(x) */