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Re: [PATCH] [PR libc/18801] PIE binary with STT_GNU_IFUNC symbol and TEXTREL segfaults on x86_64
- From: Paul Pluzhnikov <ppluzhnikov at google dot com>
- To: "H.J. Lu" <hjl dot tools at gmail dot com>
- Cc: Sriraman Tallam <tmsriram at google dot com>, GLIBC Devel <libc-alpha at sourceware dot org>, Ian Lance Taylor <iant at google dot com>, David Li <davidxl at google dot com>
- Date: Tue, 11 Aug 2015 15:37:36 -0700
- Subject: Re: [PATCH] [PR libc/18801] PIE binary with STT_GNU_IFUNC symbol and TEXTREL segfaults on x86_64
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On Tue, Aug 11, 2015 at 3:31 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> No. I am proposing that linker issues an error if there is TEXTREL
> with IFUNC unless "-z now'" is used, assuming that this doesn't
> require changes to ld.so nor SELinux.
Ah, ok. But that *doesn't* help current crash at all: "-z now" will
force IFUNC resolver (if any) to be called, and that call will fail
since we are currently removing execute protections.
(This is in fact the situation we've discovered the crash in originally.)
--
Paul Pluzhnikov