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| author | Helge Deller <deller@kernel.org> | 2024-01-26 09:32:20 +0100 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2024-01-30 12:43:18 +0100 |
| commit | 60365049ccbacd101654a66ddcb299abfabd4fc5 (patch) | |
| tree | 188301b262de1c2f1de58202bae8511012b3fcc9 /net | |
| parent | selftests: net: add missing config for nftables-backed iptables (diff) | |
| download | linux-60365049ccbacd101654a66ddcb299abfabd4fc5.tar.xz linux-60365049ccbacd101654a66ddcb299abfabd4fc5.zip | |
ipv6: Ensure natural alignment of const ipv6 loopback and router addresses
On a parisc64 kernel I sometimes notice this kernel warning:
Kernel unaligned access to 0x40ff8814 at ndisc_send_skb+0xc0/0x4d8
The address 0x40ff8814 points to the in6addr_linklocal_allrouters
variable and the warning simply means that some ipv6 function tries to
read a 64-bit word directly from the not-64-bit aligned
in6addr_linklocal_allrouters variable.
Unaligned accesses are non-critical as the architecture or exception
handlers usually will fix it up at runtime. Nevertheless it may trigger
a performance penality for some architectures. For details read the
"unaligned-memory-access" kernel documentation.
The patch below ensures that the ipv6 loopback and router addresses will
always be naturally aligned. This prevents the unaligned accesses for
all architectures.
Signed-off-by: Helge Deller <deller@gmx.de>
Fixes: 034dfc5df99eb ("ipv6: export in6addr_loopback to modules")
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/ZbNuFM1bFqoH-UoY@p100
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv6/addrconf_core.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/net/ipv6/addrconf_core.c b/net/ipv6/addrconf_core.c index 507a8353a6bd..c008d21925d7 100644 --- a/net/ipv6/addrconf_core.c +++ b/net/ipv6/addrconf_core.c @@ -220,19 +220,26 @@ const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) { EXPORT_SYMBOL_GPL(ipv6_stub); /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */ -const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT; +const struct in6_addr in6addr_loopback __aligned(BITS_PER_LONG/8) + = IN6ADDR_LOOPBACK_INIT; EXPORT_SYMBOL(in6addr_loopback); -const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT; +const struct in6_addr in6addr_any __aligned(BITS_PER_LONG/8) + = IN6ADDR_ANY_INIT; EXPORT_SYMBOL(in6addr_any); -const struct in6_addr in6addr_linklocal_allnodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT; +const struct in6_addr in6addr_linklocal_allnodes __aligned(BITS_PER_LONG/8) + = IN6ADDR_LINKLOCAL_ALLNODES_INIT; EXPORT_SYMBOL(in6addr_linklocal_allnodes); -const struct in6_addr in6addr_linklocal_allrouters = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; +const struct in6_addr in6addr_linklocal_allrouters __aligned(BITS_PER_LONG/8) + = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT; EXPORT_SYMBOL(in6addr_linklocal_allrouters); -const struct in6_addr in6addr_interfacelocal_allnodes = IN6ADDR_INTERFACELOCAL_ALLNODES_INIT; +const struct in6_addr in6addr_interfacelocal_allnodes __aligned(BITS_PER_LONG/8) + = IN6ADDR_INTERFACELOCAL_ALLNODES_INIT; EXPORT_SYMBOL(in6addr_interfacelocal_allnodes); -const struct in6_addr in6addr_interfacelocal_allrouters = IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT; +const struct in6_addr in6addr_interfacelocal_allrouters __aligned(BITS_PER_LONG/8) + = IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT; EXPORT_SYMBOL(in6addr_interfacelocal_allrouters); -const struct in6_addr in6addr_sitelocal_allrouters = IN6ADDR_SITELOCAL_ALLROUTERS_INIT; +const struct in6_addr in6addr_sitelocal_allrouters __aligned(BITS_PER_LONG/8) + = IN6ADDR_SITELOCAL_ALLROUTERS_INIT; EXPORT_SYMBOL(in6addr_sitelocal_allrouters); static void snmp6_free_dev(struct inet6_dev *idev) |