10.0-RC1, armv6: "pfctl -s state" crashes on BeagleBone Black due to unaligned access

[Warner Losh]

I think this was changed in later RC versions.

Warner

On Jan 4, 2014, at 6:06 AM, Guy Yur wrote:

> Hi,
> 
> I am running 10.0-RC1 arm.armv6 on the BeagleBone Black.
> The "pfctl -s state" command is crashing when trying to print the
> second entry.
> 
> struct pfsync_state has a size that is not divisiable by 4 or 8 leading to the
> second entry in the returned state array not being aligned and pfctl
> core dumps on Bus error when trying to access a uint32_t field.
> 
> (gdb) bt
> #0  print_host (addr=0x2085a11a, port=7660, af=2 '\002', opts=1024) at
> /usr/src/sbin/pfctl/pf_print_state.c:178
> #1  0x00021c4c in print_state (s=0x2085a0f2, opts=1024) at
> /usr/src/sbin/pfctl/pf_print_state.c:236
> #2  0x0000c664 in pfctl_show_states (dev=<value optimized out>,
> iface=0x0, opts=1024) at /usr/src/sbin/pfctl/pfctl.c:1095
> 
> sizeof(struct pfsync_state_key) is 36
> sizeof(struct pfsync_state_peer) is 32
> sizeof(struct pf_addr) is 16
> sizeof(struct pfsync_state) is 242
> 
> Removing the __spare[2] field will allow the struct to be aligned on 8 bytes
> for the u_int64_t id field and also cover the uint32_t fields alignment
> but this will break KBI.
> 
> I am currently using an inefficient workaround in pfctl_show_states
> that memcpy each entry to a struct pfsync_state on the stack
> ensuring each call to print_state receives an aligned struct.
> 
> 
> 10.0-RC1 World and kernel were compiled in a VirtualBox VM running
> 9.2-RELEASE-p2 i386.
> clang and ARM_EABI used as the default make options.
> 
> 
> Regards,
> Guy
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