Patrick McHardy wrote on 2009-06-02 12:20:45: >Jan Engelhardt wrote: >> On Friday 2009-05-29 18:20, Bart De Schuymer wrote: >> >>> I think it's best to fix this in the kernel if it's possible, since >>> we don't >>> want to break compatibility. >>> If the fix has to be in userspace, then it must be a fix that still >>> works for >>> older kernels. >> >> Since the kernel uses xt_align already, it's best for userspace to do >> the same. > >But that doesn't work for older kernels. Please don't dismiss >compatibility issues that easily. Sometimes things unfortunately >do slip through, but I expect people to do their best to fix the >problem properly when this happens. I compiled myself an ARM crosscompiler, just to see what's going on. Not that I could run the binaries, but I could at least look at the objdump output. The first impression was: "the state before the supposed regression was introduced could not have worked on ARM in the first place had I run this". It turns out that ebtables is completely unusable on at least three arches with given ABI configurations even if things were still calculated against ebt_replace instead of _xt_align. One case has been verified by me since it's consumer hardware, and it surprises me the Debian project has not found this earlier, because they actually produced one affected binary distribution in the past (x86 with k64_u32). Affected arches are all with k64_u32. (Perhaps almost all — I did not recall seeing it on sparc64, and, as I am just checking up on ebtables's Makefile, it has a hack for sparc.) The other configuration I see problems in is a (rather normal) k32_u32 ARM setup with a kernel compiled with CONFIG_EABI=no. The userspace patch proposed by Sachin Nasap is, IMHO, one to fix the alignment problems (both old and recent) in one clap. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
