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The SO_ATTACH_FILTER option is set only. I propose to add the get ability by using SO_ATTACH_FILTER in getsockopt. To be less irritating to eyes the SO_GET_FILTER alias to it is declared. This ability is required by checkpoint-restore project to be able to save full state of a socket. There are two issues with getting filter back. First, kernel modifies the sock_filter->code on filter load, thus in order to return the filter element back to user we have to decode it into user-visible constants. Fortunately the modification in question is interconvertible. Second, the BPF_S_ALU_DIV_K code modifies the command argument k to speed up the run-time division by doing kernel_k = reciprocal(user_k). Bad news is that different user_k may result in same kernel_k, so we can't get the original user_k back. Good news is that we don't have to do it. What we need to is calculate a user2_k so, that reciprocal(user2_k) == reciprocal(user_k) == kernel_k i.e. if it's re-loaded back the compiled again value will be exactly the same as it was. That said, the user2_k can be calculated like this user2_k = reciprocal(kernel_k) with an exception, that if kernel_k == 0, then user2_k == 1. The optlen argument is treated like this -- when zero, kernel returns the amount of sock_fprog elements in filter, otherwise it should be large enough for the sock_fprog array. changes since v1: * Declared SO_GET_FILTER in all arch headers * Added decode of vlan-tag codes Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| README | ||
linux-2.6 for H8/300 README
Yoshinori Sato <ysato@users.sourceforge.jp>
* Supported CPU
H8/300H and H8S
* Supported Target
1.simulator of GDB
require patches.
2.AE 3068/AE 3069
more information
MICROTRONIQUE <http://www.microtronique.com/>
Akizuki Denshi Tsusho Ltd. <http://www.akizuki.ne.jp> (Japanese Only)
3.H8MAX
see http://ip-sol.jp/h8max/ (Japanese Only)
4.EDOSK2674
see http://www.eu.renesas.com/products/mpumcu/tool/edk/support/edosk2674.html
http://www.uclinux.org/pub/uClinux/ports/h8/HITACHI-EDOSK2674-HOWTO
http://www.azpower.com/H8-uClinux/
* Toolchain Version
gcc-3.1 or higher and patch
see arch/h8300/tools_patch/README
binutils-2.12 or higher
gdb-5.2 or higher
The environment that can compile a h8300-elf binary is necessary.
* Userland Develop environment
used h8300-elf toolchains.
see http://www.uclinux.org/pub/uClinux/ports/h8/
* A few words of thanks
Porting to H8/300 serieses is support of Information-technology Promotion Agency, Japan.
I thank support.
and All developer/user.