On Fri, 2 Feb 2018 23:02:20 +0000 Sergei Trofimovich <slyfox@xxxxxxxxxx> wrote: > On Fri, 2 Feb 2018 14:22:32 -0800 > "Luck, Tony" <tony.luck@xxxxxxxxx> wrote: > > > On Fri, Feb 02, 2018 at 10:12:24PM +0000, Sergei Trofimovich wrote: > > > The strace breakage looks like that: > > > ./strace: get_regs: get_regs_error: Input/output error > > > > > > It happens because ia64 needs to load unwind tables > > > to read certain registers. Unwind tables fail to load > > > due to GCC quirk on the following code: > > > > > > extern char __end_unwind[]; > > > const struct unw_table_entry *end = (struct unw_table_entry *)table_end; > > > table->end = segment_base + end[-1].end_offset; > > > > > > GCC does not generate correct code for this single memory > > > reference after constant propagation (see https://gcc.gnu.org/PR84184). > > > > I'm not seeing this ... probably because I build with > > a pre-historic 4.3.4 version of gcc. > > > > Do you know which version(s) are affected? I'm not looking > > for an exhaustive list, just the one on which you found this > > would be good. > > > > -Tony > > Original bug https://bugs.gentoo.org/518130 claims regression appeared > around gcc-4.5. Locally am seeing the problem with gcc-6.4.0, gcc-7.2.0 and > gcc-8 (HEAD). Another report on the positive patch effect: rx2600 boots successfully with this patch (did not without, my guess is due to early access fault at bad address): https://bugs.gentoo.org/579278#c13 Tested-by: stanton_arch@xxxxxxxx -- Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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