This is a note to let you know that I've just added the patch titled
staging: zcache: fix "zcache=" kernel parameter
to my staging git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 02073798a6b081bf74e6c10d6f7e7a693c067ecd Mon Sep 17 00:00:00 2001
From: Piotr Sarna <p.sarna@xxxxxxxxxxxxxxxxxxx>
Date: Mon, 29 Jul 2013 12:25:20 +0200
Subject: 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 <p.sarna@xxxxxxxxxxxxxxxxxxx>
[bzolnier: updated patch description]
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx> # 3.10
Cc: Cristian Rodriguez <crrodriguez@xxxxxxxxxxxx>
Cc: Bob Liu <bob.liu@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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 dcceed29..81972fa4 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");
--
1.8.3.rc0.20.gb99dd2e
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