From: "Luck, Tony" <tony.luck@intel.com>
To: Sergei Trofimovich <slyfox@gentoo.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>,
linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ia64: fix ptrace(PTRACE_GETREGS) (unbreaks strace, gdb)
Date: Fri, 02 Feb 2018 22:22:32 +0000 [thread overview]
Message-ID: <20180202222231.23favlxecnxcencr@agluck-desk> (raw)
In-Reply-To: <20180202221224.16597-1-slyfox@gentoo.org>
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
next prev parent reply other threads:[~2018-02-02 22:22 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-02 22:12 [PATCH] ia64: fix ptrace(PTRACE_GETREGS) (unbreaks strace, gdb) Sergei Trofimovich
2018-02-02 22:22 ` Luck, Tony [this message]
2018-02-02 23:02 ` Sergei Trofimovich
2018-02-11 18:51 ` Sergei Trofimovich
2018-03-09 23:15 ` [PATCH v2, simpler] " Sergei Trofimovich
2018-08-04 21:33 ` Sergei Trofimovich
2019-04-29 10:38 ` [PATCH] " John Paul Adrian Glaubitz
2019-04-29 11:34 ` John Paul Adrian Glaubitz
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