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On 2010-04-06T17:28:18+00:00 Dan wrote:

F-13 userspace can't be booted in system with AMD Geode LX CPU. Per
http://fedoraproject.org/wiki/Features/F12X86Support it is a supported
CPU for the x86 Fedora. Because the panic or "Illegal instruction"
exception appears so early when userspace binaries should be run leads
me to think that something is wrong in libc.

The symptoms are
- when booted F-13 kernel + F-13 initramfs => kernel panic when code from 
initramfs should be executed
- when booted F-12 kernel + F-12 initramfs => unable to chroot to the F-13 
userspace, see the attachments for boot logs in 2 situations - first is with 
init=/bin/bash on the kernel command line, second is with rdbreak=pre-pivot and 
manual chroot

Version-Release number of selected component (if applicable):
glibc-2.11.90-16

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/0

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On 2010-04-06T17:28:57+00:00 Dan wrote:

Created attachment 404757
f12kernel-f13userspace-1

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/1

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On 2010-04-06T17:29:25+00:00 Dan wrote:

Created attachment 404758
f12kernel-f13userspace-2

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/2

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On 2010-04-06T17:29:51+00:00 Dan wrote:

Created attachment 404759
f13kernel-f13userspace

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/3

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On 2010-04-07T07:43:40+00:00 Dan wrote:

Created attachment 404857
disassembly

I have installed gdb into the initramfs and now I can see the exact
place of the crash. The NOPL instruction throws the exception and it's
really unknown on the Geode LX per
http://support.amd.com/us/Embedded_TechDocs/33234H_LX_databook.pdf.

Buildroot used to build this glibc is
http://koji.fedoraproject.org/koji/buildrootinfo?buildrootID=742936 and
gcc is gcc-4.4.3-8.fc13.i686.rpm

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/4

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On 2010-04-07T07:48:56+00:00 Jakub wrote:

So the CPU isn't i686 compatible and thus isn't supported.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/5

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On 2010-04-07T08:41:38+00:00 Dan wrote:

Ok, then we should write a new release note for F-13 about the changed
CPU support.

Just for curiosity, where can I get the definition of i686 architecture?
I have "Intel® 64 and IA-32 Architectures Software Developer’s Manual",
but how can one find there what's i686 and what was added in later CPUs?

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/6

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On 2010-04-07T11:15:39+00:00 Andreas wrote:

That should eventually be fixed in the kernel, see <http://marc.info/?l
=linux-kernel&m=126748102722641&w=2>.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/7

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On 2010-06-02T09:50:28+00:00 Till wrote:

(In reply to comment #5)
> So the CPU isn't i686 compatible and thus isn't supported.    

I opened a Fesco ticket to clarify which CPUs are supported by Fedora:
https://fedorahosted.org/fesco/ticket/387

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/22

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On 2010-06-08T04:26:30+00:00 Dont wrote:

There is no clarification needed by FESCo.  The release was intended to
support the Geode LX -- whether or not it is an "i686" (it isn't).
Nothing in the F13 release specifications says anything about changing
the set of supported CPUs from F12, which clearly supported the Geode LX
(see Comment 1).

Further investigation in the released Fedora 13 i686 LiveCD reveals that
NOPL instructions only occur in binaries produced from glibc, and in a
couple of statically linked binaries (/sbin/sln and /sbin/mdadm.static)
linked with glibc.

NOPL instructions can be generated by the GNU Assembler for .align
commands that occur in executable sections.  GCC can generate .align
when optimizing, to align loop starts on cache line boundaries.  Gas
only generates NOPL when instructed that the machine architecture
supports it.  Apparently, sometime between F12 and F13, either gas's
.align support was improved or enbugged, or the arguments to gas when
compiling glibc were changed to an inappropriate value that excluded the
Geode LX.

This is not a generic problem with every package in the release -- it's
a bug in the build configuration or Makefiles of glibc.  This should be
fixable by rebuilding the binary packages derived from glibc.  This
won't fix the release CDs and DVDs, but will fix the repos, which is key
for the largest affected Fedora customer, OLPC.  However, this problem
HAS been reported by other users on other Geode LX hardware; see:

  http://sharkcz.livejournal.com/5708.html

This bug was timely reported, but the report was ignored while there was
plenty of time to fix the release.

This bug should be reopened -- but bugzilla.redhat.com does not seem to
offer me a user interface with which to do that.

The priority of this bug should be increased, because it causes the
release media to fail to boot and fail to install on supported hardware.
For the same reason, it should also be documented in the release notes
here:

  http://fedoraproject.org/wiki/Common_F13_bugs#Hardware-related_issues

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/33

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On 2010-06-08T21:28:40+00:00 Daniel wrote:

It's true that Geode LX is not-quite i686 and we seem to be aware of
some other places in which it is lacking (in addition to nopl).

This time around it does appear that the only problematic package we
know about is glibc, so I'll focus on that case.

The reason that glibc is the only affected package is because glibc's
build system checks if the assembler supports the "-mtune" option, and
if so, when building for i686 it passes -mtune=i686.

Normally gcc does not pass -mtune or -march to the assembler (surprised
me, too). But glibc explicitly checks if the assembler accepts it, and
if so, it passes -Wa,-mtune=i686 to gcc, causing gcc to pass -mtune=i686
to the assembler. (the assembler's -march option remains unused)

Passing -mtune=i686 to the assembler causes nopl to be used. This
indicates an assembler bug, because mtune should produce enhanced code
for a certain arch without breaking compat, but in this case using nopl
instructions *will* break compat. This is
http://sourceware.org/bugzilla/show_bug.cgi?id=6957 (looks like the
developer wants a test case before continuing, I'll try and come up with
one now)

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/34

------------------------------------------------------------------------
On 2010-06-08T22:26:45+00:00 Daniel wrote:

Alright. Posted some test cases on the upstream bug and already got a
response.

Invoking "as -mtune=i686" is effectively equivalent to invoking "as
-march=i686 -mtune=i686" (a small behavioural difference when compared
to gcc). So it will look to produce optimized code for i686, with the
whole of the i686 instruction set at its disposition.

So there is no glibc or assembler bug here. We're asking glibc to build
for i686, and glibc is doing a better job than most packages of
communicating the target architecture through the whole build chain. (by
default the optimization flags do not reach the assembler, but glibc
makes this happen)

If we want to fix F13, we have a number of options available:
 - build glibc for target arch i586
 - hack glibc build system to use -Wa,-mtune=i586 (i.e. we ask all parts of the 
build chain to optimize for i686, except for the assembler which we ask to 
optimize for i586)
 - hack glibc build system to use -Wa,-mtune=i686 -Wa,-march=i586 (i.e. ask the 
assembler to optimize for i686, but never going outside of the instruction set 
supported by i586 processes)
 - hack glibc build system so that we don't ask assembler to do any 
optimizations (like the rest of the world)


In the FESCO meeting, we decided that we should gain a full understanding of 
this issue before coming up with a decision (do we hack glibc in F13 to fix 
this? Do we change target arch for F14? or both? or...?). I think with my 
analysis we have now gained an understanding.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/35

------------------------------------------------------------------------
On 2010-06-09T06:32:49+00:00 Dan wrote:

And there is also the NOPL emulator for kernel, that seems to be simple
enough. I would use this (the Geode LX is very close to i686) and do
iX86 < i686 as secondary arch where other people would profit too.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/36

------------------------------------------------------------------------
On 2010-06-09T07:02:29+00:00 Jakub wrote:

The NOPL emulator or letting Geode LX use a secondary i586 (or i486) arch is 
the only reasonable way to resolve this.  All packages are built with 
-march=i686, so
even if as -mtune=i686 perhaps shouldn't use automatically i686 insns, 
-march=i686 certainly should.  gcc should switch to telling as to use i686 
optimized code for -march=i686, so all packages will eventually have i686 nops.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/37

------------------------------------------------------------------------
On 2010-06-09T07:54:23+00:00 Andreas wrote:

(In reply to comment #11)
> If we want to fix F13, we have a number of options available:
>  - hack glibc build system to use -Wa,-mtune=i686 -Wa,-march=i586 (i.e. ask 
> the
> assembler to optimize for i686, but never going outside of the instruction set
> supported by i586 processes)

$ echo 'cmove %eax,%edx' | as -32 -march=i586 -mtune=i686
{standard input}: Assembler messages:
{standard input}:1: Error: `cmove' is not supported on `i586'

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/38

------------------------------------------------------------------------
On 2010-06-09T17:29:00+00:00 Dont wrote:

Having somebody else fix the bug in some other software component always
"seems to be simple enough".  In this case, it isn't; there is serious
dissent in the kernel team about whether, and how, to make this "simple"
instruction emulation work.  Independent of the kernel-architecture
disagreement, nobody has yet posted a correct patch for "simply"
emulating it in the kernel (the best patch opens security holes by
peeking at userspace without appropriate permission checks).  And if
NOPL is going to become common in every program, as Jakub suggested, the
last thing we want is for it to take thousands of cycles because it has
to trap into the kernel every time it wants to do a no-op!

Perhaps another way to look at the problem is that gcc and gas do not
provide a way to target the instruction set of the Geode LX processor.
Fedora definitely wants to target these processors, because they are a
significant part of the installed base of Fedora - 1.5 million machines
to date.  (Here's the Fedora Feature notice for the change in F11 that
made i586 support the base:
http://fedoraproject.org/wiki/Features/ArchitectureSupport .  And here's
the F12 change that was supposed to support both the i686 AND the Geode
LX while desupporting the i586:
http://fedoraproject.org/wiki/Features/F12X86Support )

Yet there are no compiler/gas switches that let the full instruction set
of the Geode LX processor be used without also including instructions
that the processor doesn't implement.  This may be a result of the
unfortunate Intel-Corporation orientation of the instruction set (in
general they like to ignore their competition).  Intel did not document
the NOPL instruction for the i686, yet all their 686 processors happened
to implement it, so it crept into the tools even though it was not part
of the documented spec.  But other vendors who merely implemented the
spec did not implement it.  Here is the 1997 "Intel Architecture
Software Developer's Manual: Volume 2: Instruction Set Reference" from
the Pentium Pro era, as retrieved by the Internet Archive:
http://web.archive.org/web/20070221130324/http://developer.intel.com/design/pentium/manuals/24319101.pdf
.  It does not document NOPL, only the 1-byte NOP instruction.  Contrast
this with the current "Intel 64 and IA-32 Architectures Software
Developers Manual, Volume 2", which does document long NOP instructions:
http://www.intel.com/Assets/PDF/manual/253667.pdf .

So one possible resolution is to keep the "i686" designation for this
instruction set, but to remove NOPL from the "i686" instruction set,
making the GNU tools match the i686 (Pentium Pro and successors)
documentation.

What is the actual performance impact of altering GAS to avoid the use
of NOPL on the i686 while aligning in executable sections?  Since GAS
already knows how to align on every kind of processor (it picks from
among four or five different alternative NOP selections already),
patching gas's NOP selection on i686 seems to be the least intrusive
change that would result in long-term support for both the i686 and the
Geode LX.

A more intrusive change would be to define an instruction set "geodelx"
and for Fedora to supply -march=geodelx -mtune=atom (rather than
-march=i686 -mtune=atom).  This would allow the use of long NOPs on
-march=i686 (real Intel i686s) while avoiding them in the Fedora
distribution.

We (the community) may want to do one thing to patch F13, and another
thing in the long term (for F14 and other distros).  This is because the
F13 issue is confined to a small number of packages and yet kills 1.5M
customers.  We can afford to recompile the world for F14, but if we
decide that that's the only fix possible, F13 is dead on Geodes.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/39

------------------------------------------------------------------------
On 2010-06-09T18:50:37+00:00 Richard wrote:

Comment 15: Well argued.

Another way to look at this is that 32 bit x86 is already a legacy
architecture.  No one who cares about performance should be using
it -- all those power users long switched to x86-64.  If you accept
this argument then what we in Fedora should be doing is not making
much effort to optimize 32 bit legacy systems at all.  Rather, we should
work on broadening support to as many old systems as possible by
compiling for the lowest common denominator (i486 or i586 systems
were probably the oldest ones that would have had enough memory to
run mini Fedora spins).

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/40

------------------------------------------------------------------------
On 2010-06-10T00:52:27+00:00 Dont wrote:

I don't think the 36.3 million people who bought Atom netbooks in 2009
think their system is "legacy" -- nor the 58 million expected to buy in
2010 (estimated May 2010:
http://www.abiresearch.com/press/1656-2009+Netbook+Shipments+Pass+Expectations%2C+58+Million+Forecast+for+2010).
All CPU vendors are still selling high and growing volumes of 32-bit-
only x86 chips.  Their users do care about performance, though the issue
is much more about performance-per-watt than about raw performance.  X86
chips without amd64 support are mostly used either in mobile
applications where battery life matters, or in embedded boards with
limited heat budgets (or fanless operation).

Given the higher penetration of Linux in netbooks (and OLPCs) than on
desktops, there may well be more people running Fedora on x86 than on
amd64.  Indeed that's exactly what smolt shows:
http://smolt.fedoraproject.org/static/stats/stats.html, with 69% on x86
and 30% on 64-bit, out of about 203,000 reporting hosts.  (Smolt never
runs on 1.5 million Fedora OLPCs that are Geode LX's.  XO-1.5's will
replace XO-1 sales this year; they use the Via C7-M ULV processor which
is also only 32-bit x86 compatible, and all of them will run Fedora.)

Unfortunately the web and repo stats aren't broken out by architecture:
http://fedoraproject.org/wiki/Statistics .  Perhaps this page can be
improved to tell us how many accesses are happening to x86 versus x64
repos?

The overall picture is clear:  32-bit x86 is still the dominant
architecture in use in Fedora.  We shouldn't break high volume 32-bit
chips in Fedora, nor should we stop optimizing for 32-bit systems.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/41

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On 2010-06-10T09:01:05+00:00 Andreas wrote:

*** Bug 594660 has been marked as a duplicate of this bug. ***

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/42

------------------------------------------------------------------------
On 2010-06-21T03:58:47+00:00 Daniel wrote:

Created attachment 425520
Disable assembler optimizations

in the FESCO meeting it was decided to patch glibc for F13. Here is an
appropriate patch.

The response for F14+ is not yet clear, but will be continue to be
discussed in tuesdays meeting.

https://fedorahosted.org/fesco/ticket/387

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/51

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On 2010-06-23T21:50:23+00:00 Chuck wrote:

*** Bug 607186 has been marked as a duplicate of this bug. ***

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/53

------------------------------------------------------------------------
On 2010-06-30T19:56:06+00:00 John wrote:

Not to be impatient, but is there an estimate of when we might see a
patched glibc for F13 hitting the testing repo?

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/59

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On 2010-07-06T14:14:26+00:00 Fedora wrote:

glibc-2.12-3 has been submitted as an update for Fedora 13.
http://admin.fedoraproject.org/updates/glibc-2.12-3

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/60

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On 2010-07-07T17:51:20+00:00 Fedora wrote:

glibc-2.12-3 has been pushed to the Fedora 13 testing repository.  If problems 
still persist, please make note of it in this bug report.
 If you want to test the update, you can install it with 
 su -c 'yum --enablerepo=updates-testing update glibc'.  You can provide 
feedback for this update here: 
http://admin.fedoraproject.org/updates/glibc-2.12-3

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/61

------------------------------------------------------------------------
On 2010-07-08T21:50:34+00:00 Dennis wrote:

(In reply to comment #16)
> Comment 15: Well argued.
> 
> Another way to look at this is that 32 bit x86 is already a legacy
> architecture.  No one who cares about performance should be using
> it -- all those power users long switched to x86-64.  If you accept
> this argument then what we in Fedora should be doing is not making
> much effort to optimize 32 bit legacy systems at all.  Rather, we should
> work on broadening support to as many old systems as possible by
> compiling for the lowest common denominator (i486 or i586 systems
> were probably the oldest ones that would have had enough memory to
> run mini Fedora spins).    

hear, hear. I was proud of Linux in the "old days" when it truely
supported old hardware. With my Via C3 and C3-2, I have to look at other
solutions, perhaps even NetBSD.

I mean this will still support the Atom netbooks. I really dont think
"the up to one percentage" gained by going from i586 to i686 was a good
choice. I also have a Atom netbook.

Doesn't most newer Intel Atoms have the 64 bit extension?

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/62

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On 2010-07-10T00:11:26+00:00 Fran wrote:

Soekris 5501 with Geode LX processor boots and runs OK after installing
this test build.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/63

------------------------------------------------------------------------
On 2010-07-13T07:33:42+00:00 Fedora wrote:

glibc-2.12-3 has been pushed to the Fedora 13 stable repository.  If
problems still persist, please make note of it in this bug report.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/64

------------------------------------------------------------------------
On 2010-07-27T14:50:37+00:00 Chuck wrote:

*** Bug 618592 has been marked as a duplicate of this bug. ***

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/65

------------------------------------------------------------------------
On 2010-07-27T14:59:49+00:00 Peter wrote:

I've just started testing this on my Fit-PC1 which has a geode (I would
have tested it sooner but its been packed in boxes moving since March
and i've only just recovered it. The initial upgrade of "yum upgrade yum
rpm glibc" from F-12 has worked and its currently around 50% of the way
through the rest of the yum upgrade for the rest of the distro. I'll be
doing further testing over the coming days. Looks good so far.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/66

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On 2010-07-27T15:02:29+00:00 Glen wrote:

I can verify that doing a rebuild of the Fedora13 livecd with the
livecd-creator results in an image that's bootable on my Via C3-2
hardware.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/67

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On 2010-09-03T04:38:02+00:00 Quentin wrote:

FYI the Linux binutils 2.20.51.0.11 release contains a fix that no
longer generates the offending NOPs for i686.

2010/08/06 patch
   http://sourceware.org/ml/binutils-cvs/2010-08/msg00057.html
2010/08/11 release
   http://gcc.gnu.org/ml/gcc/2010-08/msg00194.html

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/69

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On 2010-09-06T01:08:36+00:00 frank wrote:

Is there any formal FC13 CD/DVD I can download to install on geode? I
need a full installtion that is likely Fedora-13-i386-DVD.iso?

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/72

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On 2010-09-07T18:41:20+00:00 Nick wrote:

This should really be revisited.

The basic semantics for choosing the NOP sequence were completely wrong. This 
has been fixed now.
The NOPL instruction is not supported by all i686 processors, the coded 
assumption was that they all did. This has been changed by the recent AMD 
patches linked to by Quentin Neill so that it is not assumed and it's specified 
as an extension where it is supported.

(NOPL is not standard i686, it was undocumented and has just been de
facto supported since the Pentium Pro.)

The benefit of full i686 optimisation, which do have real performance
implications, are things like bswap (useful in networking), cmpxchg/xadd
(used in atomics) and cmov (useful in compiler generated code).

The correct solution is surely to ensure that when something is compiled
for generic i686, NOPL is nowhere to be seen...

Once the AMD patches that fix the bad semantics for NOPL and i686 in
binutils (GAS) have been applied, the build of eglibc should be changed
to restore i686 optimisation.

The frustrating thing is that broken semantics for i686 have led to
absurd patches such as the following being proposed as a workaround:

http://groups.google.com/group/linux.kernel/browse_thread/thread/c1ec68f5498236dc/617726bec31595ed?show_docid=617726bec31595ed

The point that gets missed there is that, abstractly, a NOP is meant to
be exactly as it says on the tin, a No Operation.

It's meant to do nothing at all - for a predefined number of clock cycles.
A NOP is commonly used for timing purposes, that completely breaks that 
contract.

Again, NOPL is not standard i686 - it's an extension supported by the
vast, vast majority of i686 class processors. If you're compiling
generically for i686, you cannot assume that it is present.

Bad patches like the above to work around broken compilation cause more
harm than good, plastering over the real problem.

I've also had a brief look at the kernel.

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=arch/x86/Makefile_32.cpu;hb=HEAD

… special cases the GX1 to -march=pentium-mmx and the LX to
-march=geode,-march=pentium-mmx.

There is also a special case for the bug in binutils for
!CONFIG_X86_P6_NOP where -mtune=generic32 is set.

And what about [x86: do not promote TM3x00/TM5x00 to i686-class]
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=a7ef94e6889186848573a10c5bdb8271405f44de
- that patch is based on the bad assumption that i686 includes NOPL when
it does not.

I haven't looked thoroughly, there might be more places!

Cheers,

Nick

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/87

------------------------------------------------------------------------
On 2011-02-04T07:31:39+00:00 Andre wrote:

The most recent glibc.i686 build for Rawhide (
http://koji.fedoraproject.org/koji/buildinfo?buildID=215507 ) appears to
have reintroduced the NOPL instruction. See
http://lists.fedoraproject.org/pipermail/test/2011-February/096805.html
.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/111

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On 2011-02-04T08:06:02+00:00 Peter wrote:

Re-opening and adding as a F15 Alpha blocker

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/112

------------------------------------------------------------------------
On 2011-02-07T14:40:19+00:00 Daniel wrote:

Is there a risk that this new binutils version will spit NOPLs into a
whole range of packages, not just glibc?

If so this should ideally be given attention this week, as the F15
rebuild is due.

I had a quick look at the changelog and NEWS files of the newest
releases and nothing stood out. I took a look at the patches that fixed
this originally against the current code, but I don't have the
background knowledge to make any meaningful observations.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/113

------------------------------------------------------------------------
On 2011-02-07T19:10:54+00:00 Jan wrote:

There is now:

* Mon Feb  7 2011 Jan Kratochvil <jan.kratoch...@redhat.com> - 2.13.90-2
- Put back the assembler "workaround" - to disable the nopl instruction.

which just reverts:
* Tue Jan 25 2011 Andreas Schwab <sch...@redhat.com> - 2.13.90-1
[...]
- Remove no longer needed assembler workaround

so that nopl/nopw are no longer generated on i686.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/114

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On 2011-02-07T21:27:21+00:00 Daniel wrote:

Great. Thanks so much for addressing this at short notice :)

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/115

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On 2011-02-08T19:03:11+00:00 Jan wrote:

http://sourceware.org/ml/binutils/2011-02/msg00071.html
->
I believe glibc should therefore use -march=something, probably -march=i686.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/116

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On 2011-02-11T08:34:00+00:00 Adam wrote:

Leaving notes on proposed blockers as I won't be at the meeting tomorrow
most likely:

This hits "The installer must boot (if appropriate) and run on all
primary architectures from default live image, DVD, and boot.iso install
media", IMO, so is an Alpha blocker. +1

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/117

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On 2011-02-11T17:41:38+00:00 Dennis wrote:

fixed is in glibc-2.13.90-2

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/118

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On 2011-02-11T19:19:39+00:00 Robyn wrote:

AGREED: 579838 - accepted as Alpha blocker as this impacts all XO's and
is already fixed.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/119

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On 2011-02-14T08:06:48+00:00 Andreas wrote:

This is *not* a glibc bug.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/120

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On 2011-02-14T13:48:21+00:00 Jared wrote:

(In reply to comment #42)
> This is *not* a glibc bug.

Andreas, can you be more specific?  I'd like to get as many details as
possible on this, so we can get it assigned to the proper component.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/121

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On 2011-02-14T14:28:45+00:00 Nick wrote:

(In reply to comment #43)
> (In reply to comment #42)
> > This is *not* a glibc bug.
> 
> Andreas, can you be more specific?  I'd like to get as many details as 
> possible
> on this, so we can get it assigned to the proper component.

glibc should not contain NOPL instructions when compiled with
-march=i686 against a recent binutils (GAS) version. A workaround in
glibc should not be needed.

Refer to my previous comment.

Cheers,

Nick

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/122

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On 2011-02-16T15:25:47+00:00 James wrote:

@nickc - Any thoughts on how to proceed.  This is currently listed as a
F15Alpha release blocker.  THe Alpha release candidate compose is
scheduled for this friday (02-18).  For this bug, we'll need either a
workaround, a fix, or proof it does not qualify as an F15Alpha release
blocker.  Thanks!

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/123

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On 2011-02-16T16:12:35+00:00 Nick wrote:

With the workaround reapplied, it is clearly not a blocker. The fix is
merely applied in the wrong place. It is just bandaid, if you like.

The longer term view should be to correct things so that the optimal
compilation options are used.

Now that binutils has been fixed, i686 is a sane baseline for a 32-bit build.
In my view, the entire 32-bit build of FC15 should be targeted for i686 with 
-march=i686 with a fixed version of binutils (GAS) that does not make bad 
assumption over the presence of NOPL.

As far as compatibility impact of compiling for i686, which need to be
understood and digested:

VIA Edens based on the 'Samuel 2' design do not support CMOV or NOPL. (These 
would break.)
All VIA Edens based on the 'Nehemiah' design support CMOV but not NOPL. 
(Introduced in 2003. These would not break.)

Via C3s based on the 'Samuel 2'or 'Ezra'/'Ezra-T' design do not support CMOV or 
NOPL. (These would break.)
All C3s based on the 'Nehemiah' design support CMOV but not NOPL. (Introduced 
in 2003. These would not break.)

National Semi's GXm, GXLV and GX1 do not support CMOV or NOPL. (These would 
break.)
All Geodes since and including National Semi's GX2 support CMOV but not NOPL. 
(Introduced in 2002. These would not break.) 
The AMD branded Geodes (GX and LX) support CMOV but not NOPL. (These would not 
break.)

The Cyrix 6x86 processors do not support CMOV or NOPL. (These would break.)
The Cyrix 8x86MX / Cyrix MII do support CMOV but not NOPL. (These would not 
break.)

The AMD K6 and K6-2 do not support CMOV or NOPL. (These would break.)

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/124

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On 2011-02-16T16:30:33+00:00 Adam wrote:

This bug is for NOPL instructions existing in glibc. That bug is clearly
now fixed, hence this should be closed. Nick, if you think that working
around the issue in glibc is the wrong fix, can you please file a new
bug against whichever component should be fixed so that glibc does not
need to include a workaround (I'm guessing binutils)? It would be easier
to track the correct issues that way; we should close this one so it's
no longer blocking the Alpha release. Thanks.

Reply at:
https://bugs.launchpad.net/ubuntu/+source/eglibc/+bug/587186/comments/125


** Changed in: binutils (Fedora)
       Status: Unknown => Fix Released

** Changed in: binutils (Fedora)
   Importance: Unknown => Medium

** Bug watch added: fedorahosted.org/fesco/ #387
   https://fedorahosted.org/fesco/ticket/387

** Bug watch added: Sourceware.org Bugzilla #6957
   https://sourceware.org/bugzilla/show_bug.cgi?id=6957

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Title:
  libc6 upgrade fails: illegal instruction

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