apparmor: Fix 8-byte alignment for initial dfa blob streams

The dfa blob stream for the aa_dfa_unpack() function is expected to be aligned
on a 8 byte boundary.

The static nulldfa_src[] and stacksplitdfa_src[] arrays store the initial
apparmor dfa blob streams, but since they are declared as an array-of-chars
the compiler and linker will only ensure a "char" (1-byte) alignment.

Add an __aligned(8) annotation to the arrays to tell the linker to always
align them on a 8-byte boundary. This avoids runtime warnings at startup on
alignment-sensitive platforms like parisc such as:

 Kernel: unaligned access to 0x7f2a584a in aa_dfa_unpack+0x124/0x788 (iir 0xca0109f)
 Kernel: unaligned access to 0x7f2a584e in aa_dfa_unpack+0x210/0x788 (iir 0xca8109c)
 Kernel: unaligned access to 0x7f2a586a in aa_dfa_unpack+0x278/0x788 (iir 0xcb01090)

Signed-off-by: Helge Deller <[email protected]>
Cc: [email protected]
Fixes: 98b824f ("apparmor: refcount the pdb")
Signed-off-by: John Johansen <[email protected]>

Author: hdeller

security/apparmor/lsm.c

@@ -2404,12 +2404,12 @@ static int __init apparmor_nf_ip_init(void)
 __initcall(apparmor_nf_ip_init);
 #endif
 
-static char nulldfa_src[] = {
+static char nulldfa_src[] __aligned(8) = {
 	#include "nulldfa.in"
 };
 static struct aa_dfa *nulldfa;
 
-static char stacksplitdfa_src[] = {
+static char stacksplitdfa_src[] __aligned(8) = {
 	#include "stacksplitdfa.in"
 };
 struct aa_dfa *stacksplitdfa;