The newly added support for high-resolution pps rates introduced multiple 64-bit
division operations in one function, which fails on all 32-bit architectures:
net/netfilter/xt_hashlimit.o: In function `user2credits':
xt_hashlimit.c:(.text.user2credits+0x3c): undefined reference to `__aeabi_uldivmod'
xt_hashlimit.c:(.text.user2credits+0x68): undefined reference to `__aeabi_uldivmod'
xt_hashlimit.c:(.text.user2credits+0x88): undefined reference to `__aeabi_uldivmod'
This replaces the division with an explicit call to div_u64 for version 2
to documents that this is a slow operation, and reverts back to 32-bit arguments
for the version 1 data to restore the original faster 32-bit division.
With both changes combined, we no longer get a link error.
Fixes: 11d5f15723c9 ("netfilter: xt_hashlimit: Create revision 2 to support higher pps rates")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
Vishwanath Pai already sent a patch for this, and I did my version independently.
The difference is that his version also the more expensive division for the
version 1 variant that doesn't need it.
See also http://patchwork.ozlabs.org/patch/676713/
---
net/netfilter/xt_hashlimit.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index 44a095ecc7b7..3d5525df6eb3 100644
--- a/net/netfilter/xt_hashlimit.c
+++ b/net/netfilter/xt_hashlimit.c
@@ -464,20 +464,23 @@ static u32 xt_hashlimit_len_to_chunks(u32 len)
static u64 user2credits(u64 user, int revision)
{
if (revision == 1) {
+ u32 user32 = user; /* use 32-bit division */
+
/* If multiplying would overflow... */
- if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY_v1))
+ if (user32 > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY_v1))
/* Divide first. */
- return (user / XT_HASHLIMIT_SCALE) *\
+ return (user32 / XT_HASHLIMIT_SCALE) *
HZ * CREDITS_PER_JIFFY_v1;
- return (user * HZ * CREDITS_PER_JIFFY_v1) \
- / XT_HASHLIMIT_SCALE;
+ return (user32 * HZ * CREDITS_PER_JIFFY_v1) /
+ XT_HASHLIMIT_SCALE;
} else {
if (user > 0xFFFFFFFFFFFFFFFF / (HZ*CREDITS_PER_JIFFY))
- return (user / XT_HASHLIMIT_SCALE_v2) *\
- HZ * CREDITS_PER_JIFFY;
+ return div_u64_u64(user, XT_HASHLIMIT_SCALE_v2) *
+ HZ * CREDITS_PER_JIFFY;
- return (user * HZ * CREDITS_PER_JIFFY) / XT_HASHLIMIT_SCALE_v2;
+ return div_u64_u64(user * HZ * CREDITS_PER_JIFFY,
+ XT_HASHLIMIT_SCALE_v2);
}
}
--
2.9.0
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