On Thu, Apr 27, 2017 at 03:30:24PM -0700, Florian Fainelli wrote:
> After commit 6d684e54690c ("rhashtable: Cap total number of
> entries to 2^31"), we would be hitting a panic() in net/core/rtnetlink.c
> during initialization. The call stack would look like this:
Thanks for the patch. I think we could just fold it into the
previous if clause, like this:
---8<---
The commit 6d684e54690c ("rhashtable: Cap total number of entries
to 2^31") breaks rhashtable users that do not set max_size. This
is because when max_size is zero max_elems is also incorrectly set
to zero instead of 2^31.
This patch fixes it by only lowering max_elems when max_size is not
zero.
Fixes: 6d684e54690c ("rhashtable: Cap total number of entries to 2^31")
Reported-by: Florian Fainelli <f.faine...@gmail.com>
Reported-by: kernel test robot <fengguang...@intel.com>
Signed-off-by: Herbert Xu <herb...@gondor.apana.org.au>
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 751630b..3895486 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -958,13 +958,14 @@ int rhashtable_init(struct rhashtable *ht,
if (params->min_size)
ht->p.min_size = roundup_pow_of_two(params->min_size);
- if (params->max_size)
- ht->p.max_size = rounddown_pow_of_two(params->max_size);
-
/* Cap total entries at 2^31 to avoid nelems overflow. */
ht->max_elems = 1u << 31;
- if (ht->p.max_size < ht->max_elems / 2)
- ht->max_elems = ht->p.max_size * 2;
+
+ if (params->max_size) {
+ ht->p.max_size = rounddown_pow_of_two(params->max_size);
+ if (ht->p.max_size < ht->max_elems / 2)
+ ht->max_elems = ht->p.max_size * 2;
+ }
ht->p.min_size = max(ht->p.min_size, HASH_MIN_SIZE);
--
Email: Herbert Xu <herb...@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
