This reverts commit 320d25b6a0.
This change was problematic for a couple of reasons:
1. It missed a some entry points (Xen things and 64-bit native).
2. The entry it changed can be executed more than once. This isn't
really a problem, but it conflated per-cpu state setup and global
state setup.
3. It broke 64-bit non-NX. 64-bit non-NX worked the other way around from
32-bit -- __supported_pte_mask had NX set initially and was *cleared*
in x86_configure_nx. With the patch applied, it never got cleared.
Reported-and-tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/59bd15f7f4b56b633a611b7f70876c6d2ad01a98.1461685884.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 mm updates from Ingo Molnar:
"The main changes in this cycle were:
- Enable full ASLR randomization for 32-bit programs (Hector
Marco-Gisbert)
- Add initial minimal INVPCI support, to flush global mappings (Andy
Lutomirski)
- Add KASAN enhancements (Andrey Ryabinin)
- Fix mmiotrace for huge pages (Karol Herbst)
- ... misc cleanups and small enhancements"
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm/32: Enable full randomization on i386 and X86_32
x86/mm/kmmio: Fix mmiotrace for hugepages
x86/mm: Avoid premature success when changing page attributes
x86/mm/ptdump: Remove paravirt_enabled()
x86/mm: Fix INVPCID asm constraint
x86/dmi: Switch dmi_remap() from ioremap() [uncached] to ioremap_cache()
x86/mm: If INVPCID is available, use it to flush global mappings
x86/mm: Add a 'noinvpcid' boot option to turn off INVPCID
x86/mm: Add INVPCID helpers
x86/kasan: Write protect kasan zero shadow
x86/kasan: Clear kasan_zero_page after TLB flush
x86/mm/numa: Check for failures in numa_clear_kernel_node_hotplug()
x86/mm/numa: Clean up numa_clear_kernel_node_hotplug()
x86/mm: Make kmap_prot into a #define
x86/mm/32: Set NX in __supported_pte_mask before enabling paging
x86/mm: Streamline and restore probe_memory_block_size()
Move them to a separate header and have the following
dependency:
x86/cpufeatures.h <- x86/processor.h <- x86/cpufeature.h
This makes it easier to use the header in asm code and not
include the whole cpufeature.h and add guards for asm.
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1453842730-28463-5-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There's a short window in which very early mappings can end up
with NX clear because they are created before we've noticed that
we have NX.
It turns out that we detect NX very early, so there's no need to
defer __supported_pte_mask setup.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/2b544627345f7110160545a3f47031eb45c3ad4f.1453239349.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge the early loader functionality into the driver proper. The
diff is huge but logically, it is simply moving code from the
_early.c files into the main driver.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1445334889-300-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 core updates from Ingo Molnar:
"There were so many changes in the x86/asm, x86/apic and x86/mm topics
in this cycle that the topical separation of -tip broke down somewhat -
so the result is a more traditional architecture pull request,
collected into the 'x86/core' topic.
The topics were still maintained separately as far as possible, so
bisectability and conceptual separation should still be pretty good -
but there were a handful of merge points to avoid excessive
dependencies (and conflicts) that would have been poorly tested in the
end.
The next cycle will hopefully be much more quiet (or at least will
have fewer dependencies).
The main changes in this cycle were:
* x86/apic changes, with related IRQ core changes: (Jiang Liu, Thomas
Gleixner)
- This is the second and most intrusive part of changes to the x86
interrupt handling - full conversion to hierarchical interrupt
domains:
[IOAPIC domain] -----
|
[MSI domain] --------[Remapping domain] ----- [ Vector domain ]
| (optional) |
[HPET MSI domain] ----- |
|
[DMAR domain] -----------------------------
|
[Legacy domain] -----------------------------
This now reflects the actual hardware and allowed us to distangle
the domain specific code from the underlying parent domain, which
can be optional in the case of interrupt remapping. It's a clear
separation of functionality and removes quite some duct tape
constructs which plugged the remap code between ioapic/msi/hpet
and the vector management.
- Intel IOMMU IRQ remapping enhancements, to allow direct interrupt
injection into guests (Feng Wu)
* x86/asm changes:
- Tons of cleanups and small speedups, micro-optimizations. This
is in preparation to move a good chunk of the low level entry
code from assembly to C code (Denys Vlasenko, Andy Lutomirski,
Brian Gerst)
- Moved all system entry related code to a new home under
arch/x86/entry/ (Ingo Molnar)
- Removal of the fragile and ugly CFI dwarf debuginfo annotations.
Conversion to C will reintroduce many of them - but meanwhile
they are only getting in the way, and the upstream kernel does
not rely on them (Ingo Molnar)
- NOP handling refinements. (Borislav Petkov)
* x86/mm changes:
- Big PAT and MTRR rework: making the code more robust and
preparing to phase out exposing direct MTRR interfaces to drivers -
in favor of using PAT driven interfaces (Toshi Kani, Luis R
Rodriguez, Borislav Petkov)
- New ioremap_wt()/set_memory_wt() interfaces to support
Write-Through cached memory mappings. This is especially
important for good performance on NVDIMM hardware (Toshi Kani)
* x86/ras changes:
- Add support for deferred errors on AMD (Aravind Gopalakrishnan)
This is an important RAS feature which adds hardware support for
poisoned data. That means roughly that the hardware marks data
which it has detected as corrupted but wasn't able to correct, as
poisoned data and raises an APIC interrupt to signal that in the
form of a deferred error. It is the OS's responsibility then to
take proper recovery action and thus prolonge system lifetime as
far as possible.
- Add support for Intel "Local MCE"s: upcoming CPUs will support
CPU-local MCE interrupts, as opposed to the traditional system-
wide broadcasted MCE interrupts (Ashok Raj)
- Misc cleanups (Borislav Petkov)
* x86/platform changes:
- Intel Atom SoC updates
... and lots of other cleanups, fixlets and other changes - see the
shortlog and the Git log for details"
* 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (222 commits)
x86/hpet: Use proper hpet device number for MSI allocation
x86/hpet: Check for irq==0 when allocating hpet MSI interrupts
x86/mm/pat, drivers/infiniband/ipath: Use arch_phys_wc_add() and require PAT disabled
x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled
x86/platform/intel/baytrail: Add comments about why we disabled HPET on Baytrail
genirq: Prevent crash in irq_move_irq()
genirq: Enhance irq_data_to_desc() to support hierarchy irqdomain
iommu, x86: Properly handle posted interrupts for IOMMU hotplug
iommu, x86: Provide irq_remapping_cap() interface
iommu, x86: Setup Posted-Interrupts capability for Intel iommu
iommu, x86: Add cap_pi_support() to detect VT-d PI capability
iommu, x86: Avoid migrating VT-d posted interrupts
iommu, x86: Save the mode (posted or remapped) of an IRTE
iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip
iommu: dmar: Provide helper to copy shared irte fields
iommu: dmar: Extend struct irte for VT-d Posted-Interrupts
iommu: Add new member capability to struct irq_remap_ops
x86/asm/entry/64: Disentangle error_entry/exit gsbase/ebx/usermode code
x86/asm/entry/32: Shorten __audit_syscall_entry() args preparation
x86/asm/entry/32: Explain reloading of registers after __audit_syscall_entry()
...
When building the kernel with 32-bit binutils built with support
only for the i386 target, we get the following warning:
arch/x86/kernel/head_32.S:66: Warning: shift count out of range (32 is not between 0 and 31)
The problem is that in that case, binutils' internal type
representation is 32-bit wide and the shift range overflows.
In order to fix this, manipulate the shift expression which
creates the 4GiB constant to not overflow the shift count.
Suggested-by: Michael Matz <matz@suse.de>
Reported-and-tested-by: Enrico Mioso <mrkiko.rs@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The early_idt_handlers asm code generates an array of entry
points spaced nine bytes apart. It's not really clear from that
code or from the places that reference it what's going on, and
the code only works in the first place because GAS never
generates two-byte JMP instructions when jumping to global
labels.
Clean up the code to generate the correct array stride (member size)
explicitly. This should be considerably more robust against
screw-ups, as GAS will warn if a .fill directive has a negative
count. Using '. =' to advance would have been even more robust
(it would generate an actual error if it tried to move
backwards), but it would pad with nulls, confusing anyone who
tries to disassemble the code. The new scheme should be much
clearer to future readers.
While we're at it, improve the comments and rename the array and
common code.
Binutils may start relaxing jumps to non-weak labels. If so,
this change will fix our build, and we may need to backport this
change.
Before, on x86_64:
0000000000000000 <early_idt_handlers>:
0: 6a 00 pushq $0x0
2: 6a 00 pushq $0x0
4: e9 00 00 00 00 jmpq 9 <early_idt_handlers+0x9>
5: R_X86_64_PC32 early_idt_handler-0x4
...
48: 66 90 xchg %ax,%ax
4a: 6a 08 pushq $0x8
4c: e9 00 00 00 00 jmpq 51 <early_idt_handlers+0x51>
4d: R_X86_64_PC32 early_idt_handler-0x4
...
117: 6a 00 pushq $0x0
119: 6a 1f pushq $0x1f
11b: e9 00 00 00 00 jmpq 120 <early_idt_handler>
11c: R_X86_64_PC32 early_idt_handler-0x4
After:
0000000000000000 <early_idt_handler_array>:
0: 6a 00 pushq $0x0
2: 6a 00 pushq $0x0
4: e9 14 01 00 00 jmpq 11d <early_idt_handler_common>
...
48: 6a 08 pushq $0x8
4a: e9 d1 00 00 00 jmpq 120 <early_idt_handler_common>
4f: cc int3
50: cc int3
...
117: 6a 00 pushq $0x0
119: 6a 1f pushq $0x1f
11b: eb 03 jmp 120 <early_idt_handler_common>
11d: cc int3
11e: cc int3
11f: cc int3
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Binutils <binutils@sourceware.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H.J. Lu <hjl.tools@gmail.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/ac027962af343b0c599cbfcf50b945ad2ef3d7a8.1432336324.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The early_idt_handlers asm code generates an array of entry
points spaced nine bytes apart. It's not really clear from that
code or from the places that reference it what's going on, and
the code only works in the first place because GAS never
generates two-byte JMP instructions when jumping to global
labels.
Clean up the code to generate the correct array stride (member size)
explicitly. This should be considerably more robust against
screw-ups, as GAS will warn if a .fill directive has a negative
count. Using '. =' to advance would have been even more robust
(it would generate an actual error if it tried to move
backwards), but it would pad with nulls, confusing anyone who
tries to disassemble the code. The new scheme should be much
clearer to future readers.
While we're at it, improve the comments and rename the array and
common code.
Binutils may start relaxing jumps to non-weak labels. If so,
this change will fix our build, and we may need to backport this
change.
Before, on x86_64:
0000000000000000 <early_idt_handlers>:
0: 6a 00 pushq $0x0
2: 6a 00 pushq $0x0
4: e9 00 00 00 00 jmpq 9 <early_idt_handlers+0x9>
5: R_X86_64_PC32 early_idt_handler-0x4
...
48: 66 90 xchg %ax,%ax
4a: 6a 08 pushq $0x8
4c: e9 00 00 00 00 jmpq 51 <early_idt_handlers+0x51>
4d: R_X86_64_PC32 early_idt_handler-0x4
...
117: 6a 00 pushq $0x0
119: 6a 1f pushq $0x1f
11b: e9 00 00 00 00 jmpq 120 <early_idt_handler>
11c: R_X86_64_PC32 early_idt_handler-0x4
After:
0000000000000000 <early_idt_handler_array>:
0: 6a 00 pushq $0x0
2: 6a 00 pushq $0x0
4: e9 14 01 00 00 jmpq 11d <early_idt_handler_common>
...
48: 6a 08 pushq $0x8
4a: e9 d1 00 00 00 jmpq 120 <early_idt_handler_common>
4f: cc int3
50: cc int3
...
117: 6a 00 pushq $0x0
119: 6a 1f pushq $0x1f
11b: eb 03 jmp 120 <early_idt_handler_common>
11d: cc int3
11e: cc int3
11f: cc int3
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Binutils <binutils@sourceware.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H.J. Lu <hjl.tools@gmail.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/ac027962af343b0c599cbfcf50b945ad2ef3d7a8.1432336324.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There is already defined macro KEEP_SEGMENTS in
<asm/bootparam.h>, let's use it instead of hardcoded
constants.
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1424331298-7456-1-git-send-email-kuleshovmail@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
It's an enum, not a #define, you can't use it in asm files.
Introduced in commit 5fa10196bd ("x86: Ignore NMIs that come in during
early boot"), and sadly I didn't compile-test things like I should have
before pushing out.
My weak excuse is that the x86 tree generally doesn't introduce stupid
things like this (and the ARM pull afterwards doesn't cause me to do a
compile-test either, since I don't cross-compile).
Cc: Don Zickus <dzickus@redhat.com>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Don Zickus reports:
A customer generated an external NMI using their iLO to test kdump
worked. Unfortunately, the machine hung. Disabling the nmi_watchdog
made things work.
I speculated the external NMI fired, caused the machine to panic (as
expected) and the perf NMI from the watchdog came in and was latched.
My guess was this somehow caused the hang.
----
It appears that the latched NMI stays latched until the early page
table generation on 64 bits, which causes exceptions to happen which
end in IRET, which re-enable NMI. Therefore, ignore NMIs that come in
during early execution, until we have proper exception handling.
Reported-and-tested-by: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/r/1394221143-29713-1-git-send-email-dzickus@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.5+, older with some backport effort
Pull x86 cpu feature fixes from Ingo Molnar:
"Two small cpufeature support updates"
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Fix override new_cpu_data.x86 with 486
x86, cpufeature: Use new CC_HAVE_ASM_GOTO
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings. In any case, they are temporary and harmless.
This removes all the arch/x86 uses of the __cpuinit macros from
all C files. x86 only had the one __CPUINIT used in assembly files,
and it wasn't paired off with a .previous or a __FINIT, so we can
delete it directly w/o any corresponding additional change there.
[1] https://lkml.org/lkml/2013/5/20/589
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
We should set X86 to 486 before use cpuid to detect the cpu type, if
we set X86 to 486 after cpuid, then we will get 486 until cpu_detect
runs.
Signed-off-by: Wang YanQing <udknight@gmail.com>
Link: http://lkml.kernel.org/r/20130628144516.GA2177@udknight
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Reimplement FPU detection code in C and drop old, not-so-recommended
detection method in asm. Move all the relevant stuff into i387.c where
it conceptually belongs. Finally drop cpuinfo_x86.hard_math.
[ hpa: huge thanks to Borislav for taking my original concept patch
and productizing it ]
[ Boris, note to self: do not use static_cpu_has before alternatives! ]
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1367244262-29511-2-git-send-email-bp@alien8.de
Link: http://lkml.kernel.org/r/1365436666-9837-2-git-send-email-bp@alien8.de
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull x86 microcode loading update from Peter Anvin:
"This patchset lets us update the CPU microcode very, very early in
initialization if the BIOS fails to do so (never happens, right?)
This is handy for dealing with things like the Atom erratum where we
have to run without PSE because microcode loading happens too late.
As I mentioned in the x86/mm push request it depends on that
infrastructure but it is otherwise a standalone feature."
* 'x86/microcode' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/Kconfig: Make early microcode loading a configuration feature
x86/mm/init.c: Copy ucode from initrd image to kernel memory
x86/head64.c: Early update ucode in 64-bit
x86/head_32.S: Early update ucode in 32-bit
x86/microcode_intel_early.c: Early update ucode on Intel's CPU
x86/tlbflush.h: Define __native_flush_tlb_global_irq_disabled()
x86/microcode_intel_lib.c: Early update ucode on Intel's CPU
x86/microcode_core_early.c: Define interfaces for early loading ucode
x86/common.c: load ucode in 64 bit or show loading ucode info in 32 bit on AP
x86/common.c: Make have_cpuid_p() a global function
x86/microcode_intel.h: Define functions and macros for early loading ucode
x86, doc: Documentation for early microcode loading
We do that once earlier now and cache it into new_cpu_data.cpuid_level
so no need for the EFLAGS.ID toggling dance anymore.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1360592538-10643-4-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
We detect CPUID function support on each CPU and save it for later use,
obviating the need to play the toggle EFLAGS.ID game every time. C code
is looking at ->cpuid_level anyway.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1360592538-10643-3-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Remove code fragments detecting a 386 CPU since we don't support those
anymore. Also, do not do alignment checks because they're done only at
CPL3. Also, no need to preserve EFLAGS.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1360592538-10643-2-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Patch
5a5a51db78 x86-32: Start out eflags and cr4 clean
... made x86-32 match x86-64 in that we initialize %eflags and %cr4
from scratch. This broke OLPC XO-1.5, because the XO enters the
kernel with paging enabled, which the kernel doesn't expect.
Since we no longer support 386 (the source of most of the variability
in %cr0 configuration), we can simply match further x86-64 and
initialize %cr0 to a fixed value -- the one variable part remaining in
%cr0 is for FPU control, but all that is handled later on in
initialization; in particular, configuring %cr0 as if the FPU is
present until proven otherwise is correct and necessary for the probe
to work.
To deal with the XO case sanely, explicitly disable paging in %cr0
before we muck with %cr3, %cr4 or EFER -- those operations are
inherently unsafe with paging enabled.
NOTE: There is still a lot of 386-related junk in head_32.S which we
can and should get rid of, however, this is intended as a minimal fix
whereas the cleanup can be deferred to the next merge window.
Reported-by: Andres Salomon <dilinger@queued.net>
Tested-by: Daniel Drake <dsd@laptop.org>
Link: http://lkml.kernel.org/r/50FA0661.2060400@linux.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Pull x86 BSP hotplug changes from Ingo Molnar:
"This tree enables CPU#0 (the boot processor) to be onlined/offlined on
x86, just like any other CPU. Enabled on Intel CPUs for now.
Allowing this required the identification and fixing of latent CPU#0
assumptions (such as CPU#0 initializations, etc.) in the x86
architecture code, plus the identification of barriers to
BSP-offlining, such as active PIC interrupts which can only be
serviced on the BSP.
It's behind a default-off option, and there's a debug option that
allows the automatic testing of this feature.
The motivation of this feature is to allow and prepare for true
CPU-hotplug hardware support: recent changes to MCE support enable us
to detect a deteriorating but not yet hard-failing L1/L2 cache on a
CPU that could be soft-unplugged - or a failing L3 cache on a
multi-socket system.
Note that true hardware hot-plug is not yet fully enabled by this,
because that requires a special platform wakeup sequence to be sent to
the freshly powered up CPU#0. Future patches for this are planned,
once such a platform exists. Chicken and egg"
* 'x86-bsp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, topology: Debug CPU0 hotplug
x86/i387.c: Initialize thread xstate only on CPU0 only once
x86, hotplug: Handle retrigger irq by the first available CPU
x86, hotplug: The first online processor saves the MTRR state
x86, hotplug: During CPU0 online, enable x2apic, set_numa_node.
x86, hotplug: Wake up CPU0 via NMI instead of INIT, SIPI, SIPI
x86-32, hotplug: Add start_cpu0() entry point to head_32.S
x86-64, hotplug: Add start_cpu0() entry point to head_64.S
kernel/cpu.c: Add comment for priority in cpu_hotplug_pm_callback
x86, hotplug, suspend: Online CPU0 for suspend or hibernate
x86, hotplug: Support functions for CPU0 online/offline
x86, topology: Don't offline CPU0 if any PIC irq can not be migrated out of it
x86, Kconfig: Add config switch for CPU0 hotplug
doc: Add x86 CPU0 online/offline feature
There appear to have been some 486 clones, including the "enhanced"
version of Am486, which have CPUID but not CR4. These 486 clones had
only the FPU flag, if any, unlike the Intel 486s with CPUID, which
also had VME and therefore needed CR4.
Therefore, look at the basic CPUID flags and require at least one bit
other than bit 0 before we modify CR4.
Thanks to Christian Ludloff of sandpile.org for confirming this as a
problem.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
%cr4 is supposed to reflect a set of features into which the operating
system is opting in. If the BIOS or bootloader leaks bits here, this
is not desirable. Consider a bootloader passing in %cr4.pae set to a
legacy paging kernel, for example -- it will not have any immediate
effect, but the kernel would crash when turning paging on.
A similar argument applies to %eflags, and since we have to look for
%eflags.id being settable we can use a sequence which clears %eflags
as a side effect.
Note that we already do this for x86-64.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1348529239-17943-1-git-send-email-hpa@linux.intel.com
Pull x86 trampoline rework from H. Peter Anvin:
"This code reworks all the "trampoline"/"realmode" code (various bits
that need to live in the first megabyte of memory, most but not all of
which runs in real mode at some point) in the kernel into a single
object. The main reason for doing this is that it eliminates the last
place in the kernel where we needed pages to be mapped RWX. This code
separates all that code into proper R/RW/RX pages."
Fix up conflicts in arch/x86/kernel/Makefile (mca removed next to reboot
code), and arch/x86/kernel/reboot.c (reboot code moved around in one
branch, modified in this one), and arch/x86/tools/relocs.c (mostly same
code came in earlier due to working around the ld bugs just before the
3.4 release).
Also remove stale x86-relocs entry from scripts/.gitignore as per Peter
Anvin.
* commit '61f5446169046c217a5479517edac3a890c3bee7': (36 commits)
x86, realmode: Move end signature into header.S
x86, relocs: When printing an error, say relative or absolute
x86, relocs: More relocations which may end up as absolute
x86, relocs: Workaround for binutils 2.22.52.0.1 section bug
xen-acpi-processor: Add missing #include <xen/xen.h>
acpi, bgrd: Add missing <linux/io.h> to drivers/acpi/bgrt.c
x86, realmode: Change EFER to a single u64 field
x86, realmode: Move kernel/realmode.c to realmode/init.c
x86, realmode: Move not-common bits out of trampoline_common.S
x86, realmode: Mask out EFER.LMA when saving trampoline EFER
x86, realmode: Fix no cache bits test in reboot_32.S
x86, realmode: Make sure all generated files are listed in targets
x86, realmode: build fix: remove duplicate build
x86, realmode: read cr4 and EFER from kernel for 64-bit trampoline
x86, realmode: fixes compilation issue in tboot.c
x86, realmode: move relocs from scripts/ to arch/x86/tools
x86, realmode: header for trampoline code
x86, realmode: flattened rm hierachy
x86, realmode: don't copy real_mode_header
x86, realmode: fix 64-bit wakeup sequence
...
Migrated SMP trampoline code to the real mode blob.
SMP trampoline code is not yet removed from
.x86_trampoline because it is needed by the wakeup
code.
[ hpa: always enable compiling startup_32_smp in head_32.S... it is
only a few instructions which go into .init on UP builds, and it makes
the rest of the code less #ifdef ugly. ]
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-6-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
If we get an exception during early boot, walk the exception table to
see if we should intercept it. The main use case for this is to allow
rdmsr_safe()/wrmsr_safe() during CPU initialization.
Since the exception table is currently sorted at runtime, and fairly
late in startup, this code walks the exception table linearly. We
obviously don't need to worry about modules, however: none have been
loaded at this point.
This patch changes the early IDT setup to look a lot more like x86-64:
we now install handlers for all 32 exception vectors. The output of
the early exception handler has changed somewhat as it directly
reflects the stack frame of the exception handler, and the stack frame
has been somewhat restructured.
Finally, centralize the code that can and should be run only once.
[ v2: Use early_fixup_exception() instead of linear search ]
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1334794610-5546-6-git-send-email-hpa@zytor.com
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (27 commits)
x86: Clean up apic.c and apic.h
x86: Remove superflous goal definition of tsc_sync
x86: dt: Correct local apic documentation in device tree bindings
x86: dt: Cleanup local apic setup
x86: dt: Fix OLPC=y/INTEL_CE=n build
rtc: cmos: Add OF bindings
x86: ce4100: Use OF to setup devices
x86: ioapic: Add OF bindings for IO_APIC
x86: dtb: Add generic bus probe
x86: dtb: Add support for PCI devices backed by dtb nodes
x86: dtb: Add device tree support for HPET
x86: dtb: Add early parsing of IO_APIC
x86: dtb: Add irq domain abstraction
x86: dtb: Add a device tree for CE4100
x86: Add device tree support
x86: e820: Remove conditional early mapping in parse_e820_ext
x86: OLPC: Make OLPC=n build again
x86: OLPC: Remove extra OLPC_OPENFIRMWARE_DT indirection
x86: OLPC: Cleanup config maze completely
x86: OLPC: Hide OLPC_OPENFIRMWARE config switch
...
Fix up conflicts in arch/x86/platform/ce4100/ce4100.c
PAGE_SIZE_asm, PAGE_SHIFT_asm, THREAD_SIZE_asm can be safely removed from
asm-offsets.c, and be replaced by their non-'_asm' counterparts in the code
that uses them, since the _AC macro defined in include/linux/const.h makes
PAGE_SIZE/PAGE_SHIFT/THREAD_SIZE work with as.
Signed-off-by: Stratos Psomadakis <psomas@cslab.ece.ntua.gr>
LKML-Reference: <1298666774-17646-2-git-send-email-psomas@cslab.ece.ntua.gr>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Neither CONFIG_OLPC_OPENFIRMWARE nor CONFIG_OLPC_OPENFIRMWARE_DT are
really necessary.
OLPC selects OLPC_OPENFIRMWARE unconditionally, so move the "select
OF" part under OLPC config option and fixup the dependencies in
Makefiles and code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andres Salomon <dilinger@queued.net>
Since checkin ebba638ae7 we call
verify_cpu even in 32-bit mode. Unfortunately, calling a function
means using the stack, and the stack pointer was not initialized in
the 32-bit setup code! This code initializes the stack pointer, and
simplifies the interface slightly since it is easier to rely on just a
pointer value rather than a descriptor; we need to have different
values for the segment register anyway.
This retains start_stack as a virtual address, even though a physical
address would be more convenient for 32 bits; the 64-bit code wants
the other way around...
Reported-by: Matthieu Castet <castet.matthieu@free.fr>
LKML-Reference: <4D41E86D.8060205@free.fr>
Tested-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Fix included-by file reference comments
x86, cpu: Only CPU features determine NX capabilities
x86, cpu: Call verify_cpu during 32bit CPU startup
x86, cpu: Clear XD_DISABLED flag on Intel to regain NX
x86, cpu: Rename verify_cpu_64.S to verify_cpu.S
v2.6.36-rc8-54-gb40827f (x86-32, mm: Add an initial page table
for core bootstrapping) made x86 boot using initial_page_table
and broke lguest.
For 2.6.37 we simply cut & paste the initialization code into
lguest (da32dac101 "lguest: populate initial_page_table"), now
we fix it properly by doing that initialization before the
paravirt jump.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: lguest <lguest@ozlabs.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <201101041720.54535.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Conflicts:
MAINTAINERS
arch/arm/mach-omap2/pm24xx.c
drivers/scsi/bfa/bfa_fcpim.c
Needed to update to apply fixes for which the old branch was too
outdated.
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86-32: Make sure we can map all of lowmem if we need to
x86, vt-d: Handle previous faults after enabling fault handling
x86: Enable the intr-remap fault handling after local APIC setup
x86, vt-d: Fix the vt-d fault handling irq migration in the x2apic mode
x86, vt-d: Quirk for masking vtd spec errors to platform error handling logic
x86, xsave: Use alloc_bootmem_align() instead of alloc_bootmem()
bootmem: Add alloc_bootmem_align()
x86, gcc-4.6: Use gcc -m options when building vdso
x86: HPET: Chose a paranoid safe value for the ETIME check
x86: io_apic: Avoid unused variable warning when CONFIG_GENERIC_PENDING_IRQ=n
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf: Fix off by one in perf_swevent_init()
perf: Fix duplicate events with multiple-pmu vs software events
ftrace: Have recordmcount honor endianness in fn_ELF_R_INFO
scripts/tags.sh: Add magic for trace-events
tracing: Fix panic when lseek() called on "trace" opened for writing
A relocatable kernel can be anywhere in lowmem -- and in the case of a
kdump kernel, is likely to be fairly high. Since the early page
tables map everything from address zero up we need to make sure we
allocate enough brk that we can map all of lowmem if we need to.
Reported-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Tested-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4D0AD3ED.8070607@kernel.org>
Two x86 patches broke lguest:
1) v2.6.35-492-g72d7c3b, which changed x86 to use the memblock allocator.
In lguest, the host places linear page tables at the top of mem, which
used to be enough to get us up to the swapper_pg_dir page tables. With
the first patch, the direct mapping tables used that memory:
Before: kernel direct mapping tables up to 4000000 @ 7000-1a000
After: kernel direct mapping tables up to 4000000 @ 3fed000-4000000
I initially fixed this by lying about the amount of memory we had, so
the kernel wouldn't blatt the lguest boot pagetables (yuk!), but then...
2) v2.6.36-rc8-54-gb40827f, which made x86 boot use initial_page_table.
This was initialized in a part of head_32.S which isn't executed by
lguest; it is then copied into swapper_pg_dir. So we have to initialize
it; and anyway we switch to it before we blatt the old tables, so that
fixes the previous damage as well.
For the moment, I cut & pasted the code into lguest's boot code, but
next merge window I will merge them.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: x86@kernel.org
The XD_DISABLE-clearing side-effect needs to happen for both 32bit
and 64bit, but the 32bit init routines were not calling verify_cpu()
yet. This adds that call to gain the side-effect.
The longmode/SSE tests being performed in verify_cpu() need to happen very
early for 64bit but not for 32bit. Instead of including it in two places
for 32bit, we can just include it once in arch/x86/kernel/head_32.S.
Signed-off-by: Kees Cook <kees.cook@canonical.com>
LKML-Reference: <1289414154-7829-4-git-send-email-kees.cook@canonical.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This patch adds an initial page table with low mappings used exclusively
for booting APs/resuming after ACPI suspend/machine restart. After this,
there's no need to add low mappings to swapper_pg_dir and zap them later
or create own swsusp PGD page solely for ACPI sleep needs - we have
initial_page_table for that.
Signed-off-by: Borislav Petkov <bp@alien8.de>
LKML-Reference: <20101020070526.GA9588@liondog.tnic>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This patch fixes machine crashes which occur when heavily exercising the
CPU hotplug codepaths on a 32-bit kernel. These crashes are caused by
AMD Erratum 383 and result in a fatal machine check exception. Here's
the scenario:
1. On 32-bit, the swapper_pg_dir page table is used as the initial page
table for booting a secondary CPU.
2. To make this work, swapper_pg_dir needs a direct mapping of physical
memory in it (the low mappings). By adding those low, large page (2M)
mappings (PAE kernel), we create the necessary conditions for Erratum
383 to occur.
3. Other CPUs which do not participate in the off- and onlining game may
use swapper_pg_dir while the low mappings are present (when leave_mm is
called). For all steps below, the CPU referred to is a CPU that is using
swapper_pg_dir, and not the CPU which is being onlined.
4. The presence of the low mappings in swapper_pg_dir can result
in TLB entries for addresses below __PAGE_OFFSET to be established
speculatively. These TLB entries are marked global and large.
5. When the CPU with such TLB entry switches to another page table, this
TLB entry remains because it is global.
6. The process then generates an access to an address covered by the
above TLB entry but there is a permission mismatch - the TLB entry
covers a large global page not accessible to userspace.
7. Due to this permission mismatch a new 4kb, user TLB entry gets
established. Further, Erratum 383 provides for a small window of time
where both TLB entries are present. This results in an uncorrectable
machine check exception signalling a TLB multimatch which panics the
machine.
There are two ways to fix this issue:
1. Always do a global TLB flush when a new cr3 is loaded and the
old page table was swapper_pg_dir. I consider this a hack hard
to understand and with performance implications
2. Do not use swapper_pg_dir to boot secondary CPUs like 64-bit
does.
This patch implements solution 2. It introduces a trampoline_pg_dir
which has the same layout as swapper_pg_dir with low_mappings. This page
table is used as the initial page table of the booting CPU. Later in the
bringup process, it switches to swapper_pg_dir and does a global TLB
flush. This fixes the crashes in our test cases.
-v2: switch to swapper_pg_dir right after entering start_secondary() so
that we are able to access percpu data which might not be mapped in the
trampoline page table.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
LKML-Reference: <20100816123833.GB28147@aftab>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Add support for saving OFW's cif, and later calling into it to run OFW
commands. OFW remains resident in memory, living within virtual range
0xff800000 - 0xffc00000. A single page directory entry points to the
pgdir that OFW actually uses, so rather than saving the entire page
table, we grab and install that one entry permanently in the kernel's
page table.
This is currently only used by the OLPC XO. Note that this particular
calling convention breaks PAE and PAT, and so cannot be used on newer
x86 hardware.
Signed-off-by: Andres Salomon <dilinger@queued.net>
LKML-Reference: <20100618174653.7755a39a@dev.queued.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Use symbolic constants rather than hard-coded values when setting
EFER.NX in head_32.S, and do a more rigorous test for the validity of
the response when probing for the extended CPUID range.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
LKML-Reference: <1258154897-6770-2-git-send-email-hpa@zytor.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
