[PATCH] zcache: fix "zcache=" kernel parameter

From: Piotr Sarna
Date: Thu Jul 18 2013 - 07:09:53 EST


Commit 835f2f5 ("staging: zcache: enable zcache to be built/loaded as
a module") introduced an incorrect handling of "zcache=" parameter.

Inside zcache_comp_init() function, zcache_comp_name variable is
checked for being empty. If not empty, the above variable is tested
for being compatible with Crypto API. Unfortunately, after that
function ends unconditionally (by the "goto out" directive) and returns:
- non-zero value if verification succeeded, wrongly indicating an error
- zero value if verification failed, falsely informing that function
zcache_comp_init() ended properly.

A solution to this problem is as following:
1. Move the "goto out" directive inside the "if (!ret)" statement
2. In case that crypto_has_comp() returned 0, change the value of ret
to non-zero before "goto out" to indicate an error.

Signed-off-by: Piotr Sarna <p.sarna@xxxxxxxxxxxxxxxxxxx>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
drivers/staging/zcache/zcache-main.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index dcceed2..81972fa 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -1811,10 +1811,12 @@ static int zcache_comp_init(void)
#else
if (*zcache_comp_name != '\0') {
ret = crypto_has_comp(zcache_comp_name, 0, 0);
- if (!ret)
+ if (!ret) {
pr_info("zcache: %s not supported\n",
zcache_comp_name);
- goto out;
+ ret = 1;
+ goto out;
+ }
}
if (!ret)
strcpy(zcache_comp_name, "lzo");
--
1.7.9.5

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