Messages in this thread | | | Date | Fri, 20 Mar 2015 15:04:19 +0300 | From | Cyrill Gorcunov <> | Subject | Re: [PATCH v3 1/2] x86_64,signal: Fix SS handling for signals delivered to 64-bit programs |
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On Fri, Mar 20, 2015 at 02:56:22PM +0300, Cyrill Gorcunov wrote: > > > > > > fwiw currently we're passing zero in this __pad0 (replying to your > > > previous email, so we can workaround in the kernel assuming zero > > > as a special case, not that good but better than nothing). > > > > Special-casing zero sounds not that bad to me. > > It can be removed after a few years - just don't forget > > to document it in a good comment: why we have special > > case? What software required it? > > In which version of that software the need to have this hack > > was eliminated? > > To be fair, such special case would be ideal for us, so that > if noone object against such hack, i would cook a patch.
Denys, note though that Andy pointed a downside for such approach as well:
| The only real down side I can see to special casing zero is that it | really is possible to end up with zero in there. For example, the | SIGSEGV you get do to the failed sigreturn probably has sigcontext->ss | == 0 :)
which I don't know how to resolve.
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