From 02073798a6b081bf74e6c10d6f7e7a693c067ecd Mon Sep 17 00:00:00 2001 From: Piotr Sarna Date: Mon, 29 Jul 2013 12:25:20 +0200 Subject: [PATCH] staging: zcache: fix "zcache=" kernel parameter 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. This patch replaces an earlier one from Michal Hocko (based on report from Cristian Rodriguez): http://permalink.gmane.org/gmane.linux.kernel.mm/102484 It also addressed the same issue but didn't fix the zcache_comp_init() for case when the compressor data passed to "zcache=" option was invalid or unsupported. Signed-off-by: Piotr Sarna [bzolnier: updated patch description] Acked-by: Bartlomiej Zolnierkiewicz Signed-off-by: Kyungmin Park Acked-by: Konrad Rzeszutek Wilk Acked-by: Michal Hocko Cc: stable # 3.10 Cc: Cristian Rodriguez Cc: Bob Liu Signed-off-by: Greg Kroah-Hartman --- 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 dcceed29d31a..81972fa47beb 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"); -- 2.34.1