| Age | Commit message (Collapse) | Author |
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If changing the page tables in such a way that an invalidation of all
contexts (aka. PCIDs / ASIDs) is required, they can be actively invalidated
by:
1. INVPCID for each PCID (works for single pages too).
2. Load CR3 with each PCID without the NOFLUSH bit set
3. Load CR3 with the NOFLUSH bit set for each and do INVLPG for each address.
But, none of these are really feasible since there are ~6 ASIDs (12 with
PAGE_TABLE_ISOLATION) at the time that invalidation is required.
Instead of actively invalidating them, invalidate the *current* context and
also mark the cpu_tlbstate _quickly_ to indicate future invalidation to be
required.
At the next context-switch, look for this indicator
('invalidate_other' being set) invalidate all of the
cpu_tlbstate.ctxs[] entries.
This ensures that any future context switches will do a full flush
of the TLB, picking up the previous changes.
[ tglx: Folded more fixups from Peter ]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Make VSYSCALLs work fully in PTI mode by mapping them properly to the user
space visible page tables.
[ tglx: Hide unused functions (Patch by Arnd Bergmann) ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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With PTI enabled, the LDT must be mapped in the usermode tables somewhere.
The LDT is per process, i.e. per mm.
An earlier approach mapped the LDT on context switch into a fixmap area,
but that's a big overhead and exhausted the fixmap space when NR_CPUS got
big.
Take advantage of the fact that there is an address space hole which
provides a completely unused pgd. Use this pgd to manage per-mm LDT
mappings.
This has a down side: the LDT isn't (currently) randomized, and an attack
that can write the LDT is instant root due to call gates (thanks, AMD, for
leaving call gates in AMD64 but designing them wrong so they're only useful
for exploits). This can be mitigated by making the LDT read-only or
randomizing the mapping, either of which is strightforward on top of this
patch.
This will significantly slow down LDT users, but that shouldn't matter for
important workloads -- the LDT is only used by DOSEMU(2), Wine, and very
old libc implementations.
[ tglx: Cleaned it up. ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Shrink vmalloc space from 16384TiB to 12800TiB to enlarge the hole starting
at 0xff90000000000000 to be a full PGD entry.
A subsequent patch will use this hole for the pagetable isolation LDT
alias.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The Intel PEBS/BTS debug store is a design trainwreck as it expects virtual
addresses which must be visible in any execution context.
So it is required to make these mappings visible to user space when kernel
page table isolation is active.
Provide enough room for the buffer mappings in the cpu_entry_area so the
buffers are available in the user space visible page tables.
At the point where the kernel side entry area is populated there is no
buffer available yet, but the kernel PMD must be populated. To achieve this
set the entries for these buffers to non present.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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In clone_pgd_range() copy the init user PGDs which cover the kernel half of
the address space, so a process has all the required kernel mappings
visible.
[ tglx: Split out from the big kaiser dump and folded Andys simplification ]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Kernel page table isolation requires to have two PGDs. One for the kernel,
which contains the full kernel mapping plus the user space mapping and one
for user space which contains the user space mappings and the minimal set
of kernel mappings which are required by the architecture to be able to
transition from and to user space.
Add the necessary preliminaries.
[ tglx: Split out from the big kaiser dump. EFI fixup from Kirill ]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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With PAGE_TABLE_ISOLATION the user portion of the kernel page tables is
poisoned with the NX bit so if the entry code exits with the kernel page
tables selected in CR3, userspace crashes.
But doing so trips the p4d/pgd_bad() checks. Make sure it does not do
that.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Add the pagetable helper functions do manage the separate user space page
tables.
[ tglx: Split out from the big combo kaiser patch. Folded Andys
simplification and made it out of line as Boris suggested ]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Add the initial files for kernel page table isolation, with a minimal init
function and the boot time detection for this misfeature.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Many x86 CPUs leak information to user space due to missing isolation of
user space and kernel space page tables. There are many well documented
ways to exploit that.
The upcoming software migitation of isolating the user and kernel space
page tables needs a misfeature flag so code can be made runtime
conditional.
Add the BUG bits which indicates that the CPU is affected and add a feature
bit which indicates that the software migitation is enabled.
Assume for now that _ALL_ x86 CPUs are affected by this. Exceptions can be
made later.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 PTI preparatory patches from Thomas Gleixner:
"Todays Advent calendar window contains twentyfour easy to digest
patches. The original plan was to have twenty three matching the date,
but a late fixup made that moot.
- Move the cpu_entry_area mapping out of the fixmap into a separate
address space. That's necessary because the fixmap becomes too big
with NRCPUS=8192 and this caused already subtle and hard to
diagnose failures.
The top most patch is fresh from today and cures a brain slip of
that tall grumpy german greybeard, who ignored the intricacies of
32bit wraparounds.
- Limit the number of CPUs on 32bit to 64. That's insane big already,
but at least it's small enough to prevent address space issues with
the cpu_entry_area map, which have been observed and debugged with
the fixmap code
- A few TLB flush fixes in various places plus documentation which of
the TLB functions should be used for what.
- Rename the SYSENTER stack to CPU_ENTRY_AREA stack as it is used for
more than sysenter now and keeping the name makes backtraces
confusing.
- Prevent LDT inheritance on exec() by moving it to arch_dup_mmap(),
which is only invoked on fork().
- Make vysycall more robust.
- A few fixes and cleanups of the debug_pagetables code. Check
PAGE_PRESENT instead of checking the PTE for 0 and a cleanup of the
C89 initialization of the address hint array which already was out
of sync with the index enums.
- Move the ESPFIX init to a different place to prepare for PTI.
- Several code moves with no functional change to make PTI
integration simpler and header files less convoluted.
- Documentation fixes and clarifications"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
x86/cpu_entry_area: Prevent wraparound in setup_cpu_entry_area_ptes() on 32bit
init: Invoke init_espfix_bsp() from mm_init()
x86/cpu_entry_area: Move it out of the fixmap
x86/cpu_entry_area: Move it to a separate unit
x86/mm: Create asm/invpcid.h
x86/mm: Put MMU to hardware ASID translation in one place
x86/mm: Remove hard-coded ASID limit checks
x86/mm: Move the CR3 construction functions to tlbflush.h
x86/mm: Add comments to clarify which TLB-flush functions are supposed to flush what
x86/mm: Remove superfluous barriers
x86/mm: Use __flush_tlb_one() for kernel memory
x86/microcode: Dont abuse the TLB-flush interface
x86/uv: Use the right TLB-flush API
x86/entry: Rename SYSENTER_stack to CPU_ENTRY_AREA_entry_stack
x86/doc: Remove obvious weirdnesses from the x86 MM layout documentation
x86/mm/64: Improve the memory map documentation
x86/ldt: Prevent LDT inheritance on exec
x86/ldt: Rework locking
arch, mm: Allow arch_dup_mmap() to fail
x86/vsyscall/64: Warn and fail vsyscall emulation in NATIVE mode
...
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init_espfix_bsp() needs to be invoked before the page table isolation
initialization. Move it into mm_init() which is the place where pti_init()
will be added.
While at it get rid of the #ifdeffery and provide proper stub functions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Put the cpu_entry_area into a separate P4D entry. The fixmap gets too big
and 0-day already hit a case where the fixmap PTEs were cleared by
cleanup_highmap().
Aside of that the fixmap API is a pain as it's all backwards.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Separate the cpu_entry_area code out of cpu/common.c and the fixmap.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Unclutter tlbflush.h a little.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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There are effectively two ASID types:
1. The one stored in the mmu_context that goes from 0..5
2. The one programmed into the hardware that goes from 1..6
This consolidates the locations where converting between the two (by doing
a +1) to a single place which gives us a nice place to comment.
PAGE_TABLE_ISOLATION will also need to, given an ASID, know which hardware
ASID to flush for the userspace mapping.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
First, it's nice to remove the magic numbers.
Second, PAGE_TABLE_ISOLATION is going to consume half of the available ASID
space. The space is currently unused, but add a comment to spell out this
new restriction.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
For flushing the TLB, the ASID which has been programmed into the hardware
must be known. That differs from what is in 'cpu_tlbstate'.
Add functions to transform the 'cpu_tlbstate' values into to the one
programmed into the hardware (CR3).
It's not easy to include mmu_context.h into tlbflush.h, so just move the
CR3 building over to tlbflush.h.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
flush what
Per popular request..
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
atomic64_inc_return() already implies smp_mb() before and after.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Commit:
ec400ddeff20 ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU")
... grubbed into tlbflush internals without coherent explanation.
Since it says its a precaution and the SDM doesn't mention anything like
this, take it out back.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: fenghua.yu@intel.com
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
If the kernel oopses while on the trampoline stack, it will print
"<SYSENTER>" even if SYSENTER is not involved. That is rather confusing.
The "SYSENTER" stack is used for a lot more than SYSENTER now. Give it a
better string to display in stack dumps, and rename the kernel code to
match.
Also move the 32-bit code over to the new naming even though it still uses
the entry stack only for SYSENTER.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
The LDT is inherited across fork() or exec(), but that makes no sense
at all because exec() is supposed to start the process clean.
The reason why this happens is that init_new_context_ldt() is called from
init_new_context() which obviously needs to be called for both fork() and
exec().
It would be surprising if anything relies on that behaviour, so it seems to
be safe to remove that misfeature.
Split the context initialization into two parts. Clear the LDT pointer and
initialize the mutex from the general context init and move the LDT
duplication to arch_dup_mmap() which is only called on fork().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: dan.j.williams@intel.com
Cc: hughd@google.com
Cc: keescook@google.com
Cc: kirill.shutemov@linux.intel.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
The LDT is duplicated on fork() and on exec(), which is wrong as exec()
should start from a clean state, i.e. without LDT. To fix this the LDT
duplication code will be moved into arch_dup_mmap() which is only called
for fork().
This introduces a locking problem. arch_dup_mmap() holds mmap_sem of the
parent process, but the LDT duplication code needs to acquire
mm->context.lock to access the LDT data safely, which is the reverse lock
order of write_ldt() where mmap_sem nests into context.lock.
Solve this by introducing a new rw semaphore which serializes the
read/write_ldt() syscall operations and use context.lock to protect the
actual installment of the LDT descriptor.
So context.lock stabilizes mm->context.ldt and can nest inside of the new
semaphore or mmap_sem.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: dan.j.williams@intel.com
Cc: hughd@google.com
Cc: keescook@google.com
Cc: kirill.shutemov@linux.intel.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
In order to sanitize the LDT initialization on x86 arch_dup_mmap() must be
allowed to fail. Fix up all instances.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: dan.j.williams@intel.com
Cc: hughd@google.com
Cc: keescook@google.com
Cc: kirill.shutemov@linux.intel.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Lots of overlapping changes. Also on the net-next side
the XDP state management is handled more in the generic
layers so undo the 'net' nfp fix which isn't applicable
in net-next.
Include a necessary change by Jakub Kicinski, with log message:
====================
cls_bpf no longer takes care of offload tracking. Make sure
netdevsim performs necessary checks. This fixes a warning
caused by TC trying to remove a filter it has not added.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Linux 4.15-rc4
Daniel requested it to fix some messy conflicts.
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 syscall entry code changes for PTI from Ingo Molnar:
"The main changes here are Andy Lutomirski's changes to switch the
x86-64 entry code to use the 'per CPU entry trampoline stack'. This,
besides helping fix KASLR leaks (the pending Page Table Isolation
(PTI) work), also robustifies the x86 entry code"
* 'WIP.x86-pti.entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
x86/cpufeatures: Make CPU bugs sticky
x86/paravirt: Provide a way to check for hypervisors
x86/paravirt: Dont patch flush_tlb_single
x86/entry/64: Make cpu_entry_area.tss read-only
x86/entry: Clean up the SYSENTER_stack code
x86/entry/64: Remove the SYSENTER stack canary
x86/entry/64: Move the IST stacks into struct cpu_entry_area
x86/entry/64: Create a per-CPU SYSCALL entry trampoline
x86/entry/64: Return to userspace from the trampoline stack
x86/entry/64: Use a per-CPU trampoline stack for IDT entries
x86/espfix/64: Stop assuming that pt_regs is on the entry stack
x86/entry/64: Separate cpu_current_top_of_stack from TSS.sp0
x86/entry: Remap the TSS into the CPU entry area
x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct
x86/dumpstack: Handle stack overflow on all stacks
x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tss
x86/kasan/64: Teach KASAN about the cpu_entry_area
x86/mm/fixmap: Generalize the GDT fixmap mechanism, introduce struct cpu_entry_area
x86/entry/gdt: Put per-CPU GDT remaps in ascending order
x86/dumpstack: Add get_stack_info() support for the SYSENTER stack
...
|
|
Daniel Borkmann says:
====================
pull-request: bpf-next 2017-12-18
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Allow arbitrary function calls from one BPF function to another BPF function.
As of today when writing BPF programs, __always_inline had to be used in
the BPF C programs for all functions, unnecessarily causing LLVM to inflate
code size. Handle this more naturally with support for BPF to BPF calls
such that this __always_inline restriction can be overcome. As a result,
it allows for better optimized code and finally enables to introduce core
BPF libraries in the future that can be reused out of different projects.
x86 and arm64 JIT support was added as well, from Alexei.
2) Add infrastructure for tagging functions as error injectable and allow for
BPF to return arbitrary error values when BPF is attached via kprobes on
those. This way of injecting errors generically eases testing and debugging
without having to recompile or restart the kernel. Tags for opting-in for
this facility are added with BPF_ALLOW_ERROR_INJECTION(), from Josef.
3) For BPF offload via nfp JIT, add support for bpf_xdp_adjust_head() helper
call for XDP programs. First part of this work adds handling of BPF
capabilities included in the firmware, and the later patches add support
to the nfp verifier part and JIT as well as some small optimizations,
from Jakub.
4) The bpftool now also gets support for basic cgroup BPF operations such
as attaching, detaching and listing current BPF programs. As a requirement
for the attach part, bpftool can now also load object files through
'bpftool prog load'. This reuses libbpf which we have in the kernel tree
as well. bpftool-cgroup man page is added along with it, from Roman.
5) Back then commit e87c6bc3852b ("bpf: permit multiple bpf attachments for
a single perf event") added support for attaching multiple BPF programs
to a single perf event. Given they are configured through perf's ioctl()
interface, the interface has been extended with a PERF_EVENT_IOC_QUERY_BPF
command in this work in order to return an array of one or multiple BPF
prog ids that are currently attached, from Yonghong.
6) Various minor fixes and cleanups to the bpftool's Makefile as well
as a new 'uninstall' and 'doc-uninstall' target for removing bpftool
itself or prior installed documentation related to it, from Quentin.
7) Add CONFIG_CGROUP_BPF=y to the BPF kernel selftest config file which is
required for the test_dev_cgroup test case to run, from Naresh.
8) Fix reporting of XDP prog_flags for nfp driver, from Jakub.
9) Fix libbpf's exit code from the Makefile when libelf was not found in
the system, also from Jakub.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Up to f5caf621ee35 ("x86/asm: Fix inline asm call constraints for Clang")
we were able to use x86 headers to build to the 'bpf' clang target, as
done by the BPF code in tools/perf/.
With that commit, we ended up with following failure for 'perf test LLVM', this
is because "clang ... -target bpf ..." fails since 4.0 does not have bpf inline
asm support and 6.0 does not recognize the register 'esp', fix it by guarding
that part with an #ifndef __BPF__, that is defined by clang when building to
the "bpf" target.
# perf test -v LLVM
37: LLVM search and compile :
37.1: Basic BPF llvm compile :
--- start ---
test child forked, pid 25526
Kernel build dir is set to /lib/modules/4.14.0+/build
set env: KBUILD_DIR=/lib/modules/4.14.0+/build
unset env: KBUILD_OPTS
include option is set to -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h
set env: NR_CPUS=4
set env: LINUX_VERSION_CODE=0x40e00
set env: CLANG_EXEC=/usr/local/bin/clang
set env: CLANG_OPTIONS=-xc
set env: KERNEL_INC_OPTIONS= -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h
set env: WORKING_DIR=/lib/modules/4.14.0+/build
set env: CLANG_SOURCE=-
llvm compiling command template: echo '/*
* bpf-script-example.c
* Test basic LLVM building
*/
#ifndef LINUX_VERSION_CODE
# error Need LINUX_VERSION_CODE
# error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig'
#endif
#define BPF_ANY 0
#define BPF_MAP_TYPE_ARRAY 2
#define BPF_FUNC_map_lookup_elem 1
#define BPF_FUNC_map_update_elem 2
static void *(*bpf_map_lookup_elem)(void *map, void *key) =
(void *) BPF_FUNC_map_lookup_elem;
static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) =
(void *) BPF_FUNC_map_update_elem;
struct bpf_map_def {
unsigned int type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
};
#define SEC(NAME) __attribute__((section(NAME), used))
struct bpf_map_def SEC("maps") flip_table = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(int),
.max_entries = 1,
};
SEC("func=SyS_epoll_wait")
int bpf_func__SyS_epoll_wait(void *ctx)
{
int ind =0;
int *flag = bpf_map_lookup_elem(&flip_table, &ind);
int new_flag;
if (!flag)
return 0;
/* flip flag and store back */
new_flag = !*flag;
bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY);
return new_flag;
}
char _license[] SEC("license") = "GPL";
int _version SEC("version") = LINUX_VERSION_CODE;
' | $CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS -DLINUX_VERSION_CODE=$LINUX_VERSION_CODE $CLANG_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf -O2 -o -
test child finished with 0
---- end ----
LLVM search and compile subtest 0: Ok
37.2: kbuild searching :
--- start ---
test child forked, pid 25950
Kernel build dir is set to /lib/modules/4.14.0+/build
set env: KBUILD_DIR=/lib/modules/4.14.0+/build
unset env: KBUILD_OPTS
include option is set to -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h
set env: NR_CPUS=4
set env: LINUX_VERSION_CODE=0x40e00
set env: CLANG_EXEC=/usr/local/bin/clang
set env: CLANG_OPTIONS=-xc
set env: KERNEL_INC_OPTIONS= -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h
set env: WORKING_DIR=/lib/modules/4.14.0+/build
set env: CLANG_SOURCE=-
llvm compiling command template: echo '/*
* bpf-script-test-kbuild.c
* Test include from kernel header
*/
#ifndef LINUX_VERSION_CODE
# error Need LINUX_VERSION_CODE
# error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig'
#endif
#define SEC(NAME) __attribute__((section(NAME), used))
#include <uapi/linux/fs.h>
#include <uapi/asm/ptrace.h>
SEC("func=vfs_llseek")
int bpf_func__vfs_llseek(void *ctx)
{
return 0;
}
char _license[] SEC("license") = "GPL";
int _version SEC("version") = LINUX_VERSION_CODE;
' | $CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS -DLINUX_VERSION_CODE=$LINUX_VERSION_CODE $CLANG_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf -O2 -o -
In file included from <stdin>:12:
In file included from /home/acme/git/linux/arch/x86/include/uapi/asm/ptrace.h:5:
In file included from /home/acme/git/linux/include/linux/compiler.h:242:
In file included from /home/acme/git/linux/arch/x86/include/asm/barrier.h:5:
In file included from /home/acme/git/linux/arch/x86/include/asm/alternative.h:10:
/home/acme/git/linux/arch/x86/include/asm/asm.h:145:50: error: unknown register name 'esp' in asm
register unsigned long current_stack_pointer asm(_ASM_SP);
^
/home/acme/git/linux/arch/x86/include/asm/asm.h:44:18: note: expanded from macro '_ASM_SP'
#define _ASM_SP __ASM_REG(sp)
^
/home/acme/git/linux/arch/x86/include/asm/asm.h:27:32: note: expanded from macro '__ASM_REG'
#define __ASM_REG(reg) __ASM_SEL_RAW(e##reg, r##reg)
^
/home/acme/git/linux/arch/x86/include/asm/asm.h:18:29: note: expanded from macro '__ASM_SEL_RAW'
# define __ASM_SEL_RAW(a,b) __ASM_FORM_RAW(a)
^
/home/acme/git/linux/arch/x86/include/asm/asm.h:11:32: note: expanded from macro '__ASM_FORM_RAW'
# define __ASM_FORM_RAW(x) #x
^
<scratch space>:4:1: note: expanded from here
"esp"
^
1 error generated.
ERROR: unable to compile -
Hint: Check error message shown above.
Hint: You can also pre-compile it into .o using:
clang -target bpf -O2 -c -
with proper -I and -D options.
Failed to compile test case: 'kbuild searching'
test child finished with -1
---- end ----
LLVM search and compile subtest 1: FAILED!
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Yonghong Song <yhs@fb.com>
Link: https://lkml.kernel.org/r/20171128175948.GL3298@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
The MCA_STATUS[ErrorCodeExt] field is very bank type specific.
We currently check if the ErrorCodeExt value is 0x0 or 0x8 in
mce_is_memory_error(), but we don't check the bank number. This means
that we could flag non-memory errors as memory errors.
We know that we want to flag DRAM ECC errors as memory errors, so let's do
those cases first. We can add more cases later when needed.
Define a wrapper function in mce_amd.c so we can use SMCA enums.
[ bp: Remove brackets around return statements. ]
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20171207203955.118171-2-Yazen.Ghannam@amd.com
|
|
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
There is currently no way to force CPU bug bits like CPU feature bits. That
makes it impossible to set a bug bit once at boot and have it stick for all
upcoming CPUs.
Extend the force set/clear arrays to handle bug bits as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.992156574@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
There is no generic way to test whether a kernel is running on a specific
hypervisor. But that's required to prevent the upcoming user address space
separation feature in certain guest modes.
Make the hypervisor type enum unconditionally available and provide a
helper function which allows to test for a specific type.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.912938129@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
The TSS is a fairly juicy target for exploits, and, now that the TSS
is in the cpu_entry_area, it's no longer protected by kASLR. Make it
read-only on x86_64.
On x86_32, it can't be RO because it's written by the CPU during task
switches, and we use a task gate for double faults. I'd also be
nervous about errata if we tried to make it RO even on configurations
without double fault handling.
[ tglx: AMD confirmed that there is no problem on 64-bit with TSS RO. So
it's probably safe to assume that it's a non issue, though Intel
might have been creative in that area. Still waiting for
confirmation. ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bpetkov@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.733700132@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
The existing code was a mess, mainly because C arrays are nasty. Turn
SYSENTER_stack into a struct, add a helper to find it, and do all the
obvious cleanups this enables.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bpetkov@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.653244723@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Now that the SYSENTER stack has a guard page, there's no need for a canary
to detect overflow after the fact.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.572577316@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
The IST stacks are needed when an IST exception occurs and are accessed
before any kernel code at all runs. Move them into struct cpu_entry_area.
The IST stacks are unlike the rest of cpu_entry_area: they're used even for
entries from kernel mode. This means that they should be set up before we
load the final IDT. Move cpu_entry_area setup to trap_init() for the boot
CPU and set it up for all possible CPUs at once in native_smp_prepare_cpus().
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.480598743@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Handling SYSCALL is tricky: the SYSCALL handler is entered with every
single register (except FLAGS), including RSP, live. It somehow needs
to set RSP to point to a valid stack, which means it needs to save the
user RSP somewhere and find its own stack pointer. The canonical way
to do this is with SWAPGS, which lets us access percpu data using the
%gs prefix.
With PAGE_TABLE_ISOLATION-like pagetable switching, this is
problematic. Without a scratch register, switching CR3 is impossible, so
%gs-based percpu memory would need to be mapped in the user pagetables.
Doing that without information leaks is difficult or impossible.
Instead, use a different sneaky trick. Map a copy of the first part
of the SYSCALL asm at a different address for each CPU. Now RIP
varies depending on the CPU, so we can use RIP-relative memory access
to access percpu memory. By putting the relevant information (one
scratch slot and the stack address) at a constant offset relative to
RIP, we can make SYSCALL work without relying on %gs.
A nice thing about this approach is that we can easily switch it on
and off if we want pagetable switching to be configurable.
The compat variant of SYSCALL doesn't have this problem in the first
place -- there are plenty of scratch registers, since we don't care
about preserving r8-r15. This patch therefore doesn't touch SYSCALL32
at all.
This patch actually seems to be a small speedup. With this patch,
SYSCALL touches an extra cache line and an extra virtual page, but
the pipeline no longer stalls waiting for SWAPGS. It seems that, at
least in a tight loop, the latter outweights the former.
Thanks to David Laight for an optimization tip.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bpetkov@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.403607157@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Historically, IDT entries from usermode have always gone directly
to the running task's kernel stack. Rearrange it so that we enter on
a per-CPU trampoline stack and then manually switch to the task's stack.
This touches a couple of extra cachelines, but it gives us a chance
to run some code before we touch the kernel stack.
The asm isn't exactly beautiful, but I think that fully refactoring
it can wait.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.225330557@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
On 64-bit kernels, we used to assume that TSS.sp0 was the current
top of stack. With the addition of an entry trampoline, this will
no longer be the case. Store the current top of stack in TSS.sp1,
which is otherwise unused but shares the same cacheline.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.050864668@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
This has a secondary purpose: it puts the entry stack into a region
with a well-controlled layout. A subsequent patch will take
advantage of this to streamline the SYSCALL entry code to be able to
find it more easily.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bpetkov@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.962042855@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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SYSENTER_stack should have reliable overflow detection, which
means that it needs to be at the bottom of a page, not the top.
Move it to the beginning of struct tss_struct and page-align it.
Also add an assertion to make sure that the fixed hardware TSS
doesn't cross a page boundary.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.881827433@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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A future patch will move SYSENTER_stack to the beginning of cpu_tss
to help detect overflow. Before this can happen, fix several code
paths that hardcode assumptions about the old layout.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.722425540@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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cpu_entry_area
Currently, the GDT is an ad-hoc array of pages, one per CPU, in the
fixmap. Generalize it to be an array of a new 'struct cpu_entry_area'
so that we can cleanly add new things to it.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.563271721@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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We currently have CPU 0's GDT at the top of the GDT range and
higher-numbered CPUs at lower addresses. This happens because the
fixmap is upside down (index 0 is the top of the fixmap).
Flip it so that GDTs are in ascending order by virtual address.
This will simplify a future patch that will generalize the GDT
remap to contain multiple pages.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.471561421@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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get_stack_info() doesn't currently know about the SYSENTER stack, so
unwinding will fail if we entered the kernel on the SYSENTER stack
and haven't fully switched off. Teach get_stack_info() about the
SYSENTER stack.
With future patches applied that run part of the entry code on the
SYSENTER stack and introduce an intentional BUG(), I would get:
PANIC: double fault, error_code: 0x0
...
RIP: 0010:do_error_trap+0x33/0x1c0
...
Call Trace:
Code: ...
With this patch, I get:
PANIC: double fault, error_code: 0x0
...
Call Trace:
<SYSENTER>
? async_page_fault+0x36/0x60
? invalid_op+0x22/0x40
? async_page_fault+0x36/0x60
? sync_regs+0x3c/0x40
? sync_regs+0x2e/0x40
? error_entry+0x6c/0xd0
? async_page_fault+0x36/0x60
</SYSENTER>
Code: ...
which is a lot more informative.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.392711508@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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This will simplify future changes that want scratch variables early in
the SYSENTER handler -- they'll be able to spill registers to the
stack. It also lets us get rid of a SWAPGS_UNSAFE_STACK user.
This does not depend on CONFIG_IA32_EMULATION=y because we'll want the
stack space even without IA32 emulation.
As far as I can tell, the reason that this wasn't done from day 1 is
that we use IST for #DB and #BP, which is IMO rather nasty and causes
a lot more problems than it solves. But, since #DB uses IST, we don't
actually need a real stack for SYSENTER (because SYSENTER with TF set
will invoke #DB on the IST stack rather than the SYSENTER stack).
I want to remove IST usage from these vectors some day, and this patch
is a prerequisite for that as well.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.312726423@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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There are at least two unwinder bugs hindering the debugging of
stack-overflow crashes:
- It doesn't deal gracefully with the case where the stack overflows and
the stack pointer itself isn't on a valid stack but the
to-be-dereferenced data *is*.
- The ORC oops dump code doesn't know how to print partial pt_regs, for the
case where if we get an interrupt/exception in *early* entry code
before the full pt_regs have been saved.
Fix both issues.
http://lkml.kernel.org/r/20171126024031.uxi4numpbjm5rlbr@treble
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bpetkov@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150605.071425003@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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