PR 1098: "struct ipovly" notpacked.

Ralf Corsepius ralf.corsepius at rtems.org
Tue Jul 11 14:57:39 UTC 2006


On Tue, 2006-07-11 at 21:27 +0800, ray wrote:
> In fact, the PR works for the ARM board.
In fact the patch attached to the PR is wrong.

> And the __attribute__((packed)) do really convert the 32bit load/store
> instruction to 2 16bit load/store instruction(or 4 8bit load/store).
> The struct may seems well format, but after packing and copying, the
> head point of tcpiphdr is not 32bit aligned, which may cause data
> access abort. And in the new version of BSD, the mal-aligned members
> (ti_next, ti_prev) have gone.
You are playing with symptoms. The fact it might pamper over the symtoms
probably isn't much more than a random accident.

So far, nobody has found the actual cause (I have a suspect, but it's
too early to pronounce it in public.)

Ralf






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