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Groups > linux.kernel > #1201367
| From | Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v4 3/3] MIPS: set stack/data protection as non-executable |
| Date | 2015-08-06 02:30 +0200 |
| Message-ID | <pUheh-BC-1@gated-at.bofh.it> (permalink) |
| References | <pUgBz-84f-5@gated-at.bofh.it> <pUgBA-84f-11@gated-at.bofh.it> <pUgLg-8fz-1@gated-at.bofh.it> <pUgUW-eG-19@gated-at.bofh.it> <pUheh-BC-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 08/05/2015 05:14 PM, David Daney wrote: > On 08/05/2015 05:06 PM, Leonid Yegoshin wrote: >> On 08/05/2015 04:55 PM, Paul Burton wrote: >>> >>> >>> As was pointed out last time you posted this, it breaks backwards >>> compatibility with userland & thus cannot be applied. >> >> Never observed since first version. >> >> In other side, the problem with apps like ssh_keygen is observed in >> absence of executable stack protection. > > You cannot change the default. > > If your ssh_keygen is broken, get a working version. It is actually any application which requests non-executable stack protection and needs some emulation BEFORE GLIBC cancels that non-executable stack protection due to libraries. If you build all libraries with PT_GNU_STACK 'non-executable' and use application with the same protection then you can't emulate even a single instruction - it crashes immediately. So, it is not a bad application, it is a bad choice for emulation space in past. > > I have never had a problem running ssh_keygen (on platforms requiring > emulation). Create a buildroot FS with PT_GNU_STACK 'non-executable' libraries. Then run ssh_keygen on CPU without FPU and look. You also may try to run MIPS R2 Debian on MIPS R6 CPU, and see a spectacular failure of ssh_keygen (it tries to emulate MIPS R2 instruction before first library is loaded and that fails due to non-executable stack protection. - Leonid. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH v4 3/3] MIPS: set stack/data protection as non-executable Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> - 2015-08-06 01:50 +0200
Re: [PATCH v4 3/3] MIPS: set stack/data protection as non-executable Paul Burton <paul.burton@imgtec.com> - 2015-08-06 02:00 +0200
Re: [PATCH v4 3/3] MIPS: set stack/data protection as non-executable Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> - 2015-08-06 02:10 +0200
Re: [PATCH v4 3/3] MIPS: set stack/data protection as non-executable Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> - 2015-08-06 02:30 +0200
Re: [PATCH v4 3/3] MIPS: set stack/data protection as non-executable Paul Burton <paul.burton@imgtec.com> - 2015-08-06 02:50 +0200
Re: [PATCH v4 3/3] MIPS: set stack/data protection as non-executable Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> - 2015-08-06 02:50 +0200
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