Hi, Based on my test, it works well even if you keep this mips patch, upstream already update libtommath and libtomcrypt to latest, and I can confirm the update to these two libs fixes dropbear misbehavior on mips.
https://github.com/mkj/dropbear/commit/a79b61517bc7123250d0e2dc21dc18deccf0bb64 https://github.com/mkj/dropbear/commit/364fb6019c1931de3d181f21ea491ec112161577 Best Regards, Syrone Wong On Wed, Aug 23, 2017 at 4:50 PM, Kevin Darbyshire-Bryant <ke...@darbyshire-bryant.me.uk> wrote: > > > On 23/08/17 09:20, Felix Fietkau wrote: >> >> On 2017-08-22 12:01, Kevin Darbyshire-Bryant wrote: >>> >>> Drop 300-mips_Os_cpu_rtx_cost_model.patch for gcc 7.2 >>> >>> This was causing mis-compilation of dropbear with the default '-Os' size >>> optimization as reported in FS#814 >>> >>> Tested on ar71xx, archer C7 v2. For size comparison of my whole build: >>> >>> 12058628 O2-withoutpatch-dropbearworks.bin >>> 12058628 O2-withpatch-dropbearworks.bin >>> 11468804 Os-withoutpatch-dropbearworks.bin >>> 11468804 Os-withpatch-dropbearfails.bin >>> >>> Signed-off-by: Kevin Darbyshire-Bryant <ke...@darbyshire-bryant.me.uk> >> >> I strongly suspect that this change is hiding the real bug instead of >> fixing it. Please double-check that the mis-compilation also does not >> happen with -O2 instead of -Os. > > > Hi Felix, > > The symptom of dropbear not responding (it goes into a tight loop) *only* > occurs for me with the patch installed and with '-Os'. As documented in the > FS report, starting with gcc 7.1, dropbear (and for some uhttpd) go AWOL > when built with '-Os'. Initially I did not experience that issue because I > always build with '-O2', however by switching to '-Os' I was able to > reproduce the behaviour. > > As part of my bump to gcc 7.2 and 'cargo culting/refreshing' the 7.1 patches > across, I thought I would investigate if the same erroneous behaviour > existed - it did. So questions: Why MIPS only, why only with '-Os' and not > '-O2', why is no one else screaming about this? Many experiments and 'make > dirclean' (to ensure gcc and the whole router image rebuilt) later I reached > my conclusions with 300-mips_Os_cpu_rtx_cost_model.patch. > > What I have not done is check to see if removal of > 300-mips_Os_cpu_rtx_cost_model.patch on gcc 7.1 solves the problem there, it > could be that gcc 7.1 also had a bug. > > Cheers, > > Kevin > > > > >> >> - Felix >> > > _______________________________________________ > Lede-dev mailing list > Lede-dev@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/lede-dev _______________________________________________ Lede-dev mailing list Lede-dev@lists.infradead.org http://lists.infradead.org/mailman/listinfo/lede-dev
