[patch 14/76] IPCOMP: Disable BH on output when using shared tfm

From: Chris Wright
Date: Fri Mar 21 2008 - 19:01:38 EST


-stable review patch. If anyone has any objections, please let us know.
---------------------

From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>

Upstream commit: 21e43188f272c7fd9efc84b8244c0b1dfccaa105

Because we use shared tfm objects in order to conserve memory,
(each tfm requires 128K of vmalloc memory), BH needs to be turned
off on output as that can occur in process context.

Previously this was done implicitly by the xfrm output code.
That was lost when it became lockless. So we need to add the
BH disabling to IPComp directly.

Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>

---
net/ipv4/ipcomp.c | 5 ++++-
net/ipv6/ipcomp6.c | 2 ++
2 files changed, 6 insertions(+), 1 deletion(-)

--- a/net/ipv4/ipcomp.c
+++ b/net/ipv4/ipcomp.c
@@ -108,8 +108,11 @@ static int ipcomp_compress(struct xfrm_s
const int cpu = get_cpu();
u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
- int err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
+ int err;

+ local_bh_disable();
+ err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
+ local_bh_enable();
if (err)
goto out;

--- a/net/ipv6/ipcomp6.c
+++ b/net/ipv6/ipcomp6.c
@@ -146,7 +146,9 @@ static int ipcomp6_output(struct xfrm_st
scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
tfm = *per_cpu_ptr(ipcd->tfms, cpu);

+ local_bh_disable();
err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
+ local_bh_enable();
if (err || (dlen + sizeof(*ipch)) >= plen) {
put_cpu();
goto out_ok;

--
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/