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Based on 1 normalized pattern(s):
this file is part of the linux kernel and is made available under
the terms of the gnu general public license version 2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 28 file(s).
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Enrico Weigelt <[email protected]>
Reviewed-by: Allison Randal <[email protected]>
Reviewed-by: Kate Stewart <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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This reverts commit ed68d7e9b9cfb64f3045ffbcb108df03c09a0f98.
The patch wasn't quite correct -- there are non-Intel (and hence
non-486) CPUs that we support that don't have CPUID. Since we no
longer require CPUID for sync_core(), just revert the patch.
I think the relevant CPUs are Geode and Elan, but I'm not sure.
In principle, we should try to do better at identifying CPUID-less
CPUs in early boot, but that's more complicated.
Reported-by: One Thousand Gnomes <[email protected]>
Signed-off-by: Andy Lutomirski <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Matthew Whitehead <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Henrique de Moraes Holschuh <[email protected]>
Cc: Andrew Cooper <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: xen-devel <[email protected]>
Cc: Linus Torvalds <[email protected]>
Link: http://lkml.kernel.org/r/82acde18a108b8e353180dd6febcc2876df33f24.1481307769.git.luto@kernel.org
Signed-off-by: Thomas Gleixner <[email protected]>
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Linux will have all kinds of sporadic problems on systems that don't
have the CPUID instruction unless CONFIG_M486=y. In particular,
sync_core() will explode.
I believe that these kernels had a better chance of working before
commit 05fb3c199bb0 ("x86/boot: Initialize FPU and X86_FEATURE_ALWAYS
even if we don't have CPUID"). That commit inadvertently fixed a
serious bug: we used to fail to detect the FPU if CPUID wasn't
present. Because we also used to forget to set X86_FEATURE_ALWAYS, we
end up with no cpu feature bits set at all. This meant that
alternative patching didn't do anything and, if paravirt was disabled,
we could plausibly finish the entire boot process without calling
sync_core().
Rather than trying to work around these issues, just have the kernel
fail loudly if it's running on a CPUID-less 486, doesn't have CPUID,
and doesn't have CONFIG_M486 set.
Reported-by: Matthew Whitehead <[email protected]>
Signed-off-by: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/70eac6639f23df8be5fe03fa1984aedd5d40077a.1479598603.git.luto@kernel.org
Signed-off-by: Ingo Molnar <[email protected]>
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The Intel(R) Xeon Phi(TM) Processor x200 Family (codename: Knights
Landing) has an erratum where a processor thread setting the Accessed
or Dirty bits may not do so atomically against its checks for the
Present bit. This may cause a thread (which is about to page fault)
to set A and/or D, even though the Present bit had already been
atomically cleared.
These bits are truly "stray". In the case of the Dirty bit, the
thread associated with the stray set was *not* allowed to write to
the page. This means that we do not have to launder the bit(s); we
can simply ignore them.
If the PTE is used for storing a swap index or a NUMA migration index,
the A bit could be misinterpreted as part of the swap type. The stray
bits being set cause a software-cleared PTE to be interpreted as a
swap entry. In some cases (like when the swap index ends up being
for a non-existent swapfile), the kernel detects the stray value
and WARN()s about it, but there is no guarantee that the kernel can
always detect it.
When we have 64-bit PTEs (64-bit mode or 32-bit PAE), we were able
to move the swap PTE format around to avoid these troublesome bits.
But, 32-bit non-PAE is tight on bits. So, disallow it from running
on this hardware. I can't imagine anyone wanting to run 32-bit
non-highmem kernels on this hardware, but disallowing them from
running entirely is surely the safe thing to do.
Signed-off-by: Dave Hansen <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Luis R. Rodriguez <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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The table mapping CPUID bits to human-readable strings takes up a
non-trivial amount of space, and only exists to support /proc/cpuinfo
and a couple of kernel messages. Since programs depend on the format of
/proc/cpuinfo, force inclusion of the table when building with /proc
support; otherwise, support omitting that table to save space, in which
case the kernel messages will print features numerically instead.
In addition to saving 1408 bytes out of vmlinux, this also saves 1373
bytes out of the uncompressed setup code, which contributes directly to
the size of bzImage.
Signed-off-by: Josh Triplett <[email protected]>
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Checkin e38e05a85828dac23540cd007df5f20985388afc added a 9th CPU flag
word, but didn't adjust the boot code to match. This patch adds the
necessary boot code support.
Note: due to a typo in an #if statement, it didn't trigger the #error
this was supposed to do.
Signed-off-by: H. Peter Anvin <[email protected]>
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Clean up the code for crashes during SpeedStep probing on older
machines.
Signed-off-by: H. Peter Anvin <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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Trying to boot a 64-bit kernel on a 32bit Pentium 4 gets
you an amusing message along the lines of.
"you need an x86-64, but you only have an i1586"
due to the P4 being family F. Munge it to be 686.
Signed-off-by: Dave Jones <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
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Instead of obscure numbers, print the list of missing CPU features in
cleartext. To conserve space, use a host program (mkcpustr.c) to
produce a compact list of mandatory features only.
Signed-off-by: H. Peter Anvin <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
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Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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