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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
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()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm updates from Ingo Molnar:
"This is another big update. Main changes are:
- lots of x86 system call (and other traps/exceptions) entry code
enhancements. In particular the complex parts of the 64-bit entry
code have been migrated to C code as well, and a number of dusty
corners have been refreshed. (Andy Lutomirski)
- vDSO special mapping robustification and general cleanups (Andy
Lutomirski)
- cpufeature refactoring, cleanups and speedups (Borislav Petkov)
- lots of other changes ..."
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
x86/cpufeature: Enable new AVX-512 features
x86/entry/traps: Show unhandled signal for i386 in do_trap()
x86/entry: Call enter_from_user_mode() with IRQs off
x86/entry/32: Change INT80 to be an interrupt gate
x86/entry: Improve system call entry comments
x86/entry: Remove TIF_SINGLESTEP entry work
x86/entry/32: Add and check a stack canary for the SYSENTER stack
x86/entry/32: Simplify and fix up the SYSENTER stack #DB/NMI fixup
x86/entry: Only allocate space for tss_struct::SYSENTER_stack if needed
x86/entry: Vastly simplify SYSENTER TF (single-step) handling
x86/entry/traps: Clear DR6 early in do_debug() and improve the comment
x86/entry/traps: Clear TIF_BLOCKSTEP on all debug exceptions
x86/entry/32: Restore FLAGS on SYSEXIT
x86/entry/32: Filter NT and speed up AC filtering in SYSENTER
x86/entry/compat: In SYSENTER, sink AC clearing below the existing FLAGS test
selftests/x86: In syscall_nt, test NT|TF as well
x86/asm-offsets: Remove PARAVIRT_enabled
x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled
uprobes: __create_xol_area() must nullify xol_mapping.fault
x86/cpufeature: Create a new synthetic cpu capability for machine check recovery
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RAS updates from Ingo Molnar:
"Various RAS updates:
- AMD MCE support updates for future CPUs, fixes and 'SMCA' (Scalable
MCA) error decoding support (Aravind Gopalakrishnan)
- x86 memcpy_mcsafe() support, to enable smart(er) hardware error
recovery in NVDIMM drivers, based on an extension of the x86
exception handling code. (Tony Luck)"
* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
EDAC/sb_edac: Fix computation of channel address
x86/mm, x86/mce: Add memcpy_mcsafe()
x86/mce/AMD: Document some functionality
x86/mce: Clarify comments regarding deferred error
x86/mce/AMD: Fix logic to obtain block address
x86/mce/AMD, EDAC: Enable error decoding of Scalable MCA errors
x86/mce: Move MCx_CONFIG MSR definitions
x86/mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries
x86/mm: Expand the exception table logic to allow new handling options
x86/mce/AMD: Set MCAX Enable bit
x86/mce/AMD: Carve out threshold block preparation
x86/mce/AMD: Fix LVT offset configuration for thresholding
x86/mce/AMD: Reduce number of blocks scanned per bank
x86/mce/AMD: Do not perform shared bank check for future processors
x86/mce: Fix order of AMD MCE init function call
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull read-only kernel memory updates from Ingo Molnar:
"This tree adds two (security related) enhancements to the kernel's
handling of read-only kernel memory:
- extend read-only kernel memory to a new class of formerly writable
kernel data: 'post-init read-only memory' via the __ro_after_init
attribute, and mark the ARM and x86 vDSO as such read-only memory.
This kind of attribute can be used for data that requires a once
per bootup initialization sequence, but is otherwise never modified
after that point.
This feature was based on the work by PaX Team and Brad Spengler.
(by Kees Cook, the ARM vDSO bits by David Brown.)
- make CONFIG_DEBUG_RODATA always enabled on x86 and remove the
Kconfig option. This simplifies the kernel and also signals that
read-only memory is the default model and a first-class citizen.
(Kees Cook)"
* 'mm-readonly-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
ARM/vdso: Mark the vDSO code read-only after init
x86/vdso: Mark the vDSO code read-only after init
lkdtm: Verify that '__ro_after_init' works correctly
arch: Introduce post-init read-only memory
x86/mm: Always enable CONFIG_DEBUG_RODATA and remove the Kconfig option
mm/init: Add 'rodata=off' boot cmdline parameter to disable read-only kernel mappings
asm-generic: Consolidate mark_rodata_ro()
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Currently on i386 and on X86_64 when emulating X86_32 in legacy mode, only
the stack and the executable are randomized but not other mmapped files
(libraries, vDSO, etc.). This patch enables randomization for the
libraries, vDSO and mmap requests on i386 and in X86_32 in legacy mode.
By default on i386 there are 8 bits for the randomization of the libraries,
vDSO and mmaps which only uses 1MB of VA.
This patch preserves the original randomness, using 1MB of VA out of 3GB or
4GB. We think that 1MB out of 3GB is not a big cost for having the ASLR.
The first obvious security benefit is that all objects are randomized (not
only the stack and the executable) in legacy mode which highly increases
the ASLR effectiveness, otherwise the attackers may use these
non-randomized areas. But also sensitive setuid/setgid applications are
more secure because currently, attackers can disable the randomization of
these applications by setting the ulimit stack to "unlimited". This is a
very old and widely known trick to disable the ASLR in i386 which has been
allowed for too long.
Another trick used to disable the ASLR was to set the ADDR_NO_RANDOMIZE
personality flag, but fortunately this doesn't work on setuid/setgid
applications because there is security checks which clear Security-relevant
flags.
This patch always randomizes the mmap_legacy_base address, removing the
possibility to disable the ASLR by setting the stack to "unlimited".
Signed-off-by: Hector Marco-Gisbert <hecmargi@upv.es>
Acked-by: Ismael Ripoll Ripoll <iripoll@upv.es>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org
Cc: kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1457639460-5242-1-git-send-email-hecmargi@upv.es
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Because Linux might use bigger pages than the 4K pages to handle those mmio
ioremaps, the kmmio code shouldn't rely on the pade id as it currently does.
Using the memory address instead of the page id lets us look up how big the
page is and what its base address is, so that we won't get a page fault
within the same page twice anymore.
Tested-by: Pierre Moreau <pierre.morrow@free.fr>
Signed-off-by: Karol Herbst <nouveau@karolherbst.de>
Cc: Andrew Morton <akpm@linux-foundation.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: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-mm@kvack.org
Cc: linux-x86_64@vger.kernel.org
Cc: nouveau@lists.freedesktop.org
Cc: pq@iki.fi
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/1456966991-6861-1-git-send-email-nouveau@karolherbst.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Andrey Wagin reported that a simple test case was broken by:
2b5f7d013fc ("mm/core, x86/mm/pkeys: Add execute-only protection keys support")
This test case creates an unreadable VMA and my patch assumed
that all writes must be to readable VMAs.
The simplest fix for this is to remove the pkey-related bits
in access_error(). For execute-only support, I believe the
existing version is sufficient because the permissions we
are trying to enforce are entirely expressed in vma->vm_flags.
We just depend on pkeys to get *an* exception, it does not
matter that PF_PK was set, or even what state PKRU is in.
I will re-add the necessary bits with the full pkeys
implementation that includes the new syscalls.
The three cases that matter are:
1. If a write to an execute-only VMA occurs, we will see PF_WRITE
set, but !VM_WRITE on the VMA, and return 1. All execute-only
VMAs have VM_WRITE clear by definition.
2. If a read occurs on a present PTE, we will fall in to the "read,
present" case and return 1.
3. If a read occurs to a non-present PTE, we will miss the "read,
not present" case, because the execute-only VMA will have
VM_EXEC set, and we will properly return 0 allowing the PTE to
be populated.
Test program:
int main()
{
int *p;
p = mmap(NULL, 4096, PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
p[0] = 1;
return 0;
}
Reported-by: Andrey Wagin <avagin@gmail.com>,
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Cc: linux-next@vger.kernel.org
Fixes: 62b5f7d013fc ("mm/core, x86/mm/pkeys: Add execute-only protection keys support")
Link: http://lkml.kernel.org/r/20160301194133.65D0110C@viggo.jf.intel.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 fixes from Thomas Gleixner:
"This update contains:
- Hopefully the last ASM CLAC fixups
- A fix for the Quark family related to the IMR lock which makes
kexec work again
- A off-by-one fix in the MPX code. Ironic, isn't it?
- A fix for X86_PAE which addresses once more an unsigned long vs
phys_addr_t hickup"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mpx: Fix off-by-one comparison with nr_registers
x86/mm: Fix slow_virt_to_phys() for X86_PAE again
x86/entry/compat: Add missing CLAC to entry_INT80_32
x86/entry/32: Add an ASM_CLAC to entry_SYSENTER_32
x86/platform/intel/quark: Change the kernel's IMR lock bit to false
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Replace calls to get_random_int() followed by a cast to (unsigned long)
with calls to get_random_long(). Also address shifting bug which, in
case of x86 removed entropy mask for mmap_rnd_bits values > 31 bits.
Signed-off-by: Daniel Cashman <dcashman@android.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nick Kralevich <nnk@google.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Mark Salyzyn <salyzyn@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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In the unlikely event that regno == nr_registers then we get an array
overrun on regoff because the invalid register check is currently
off-by-one. Fix this with a check that regno is >= nr_registers instead.
Detected with static analysis using CoverityScan.
Fixes: fcc7ffd67991 "x86, mpx: Decode MPX instruction to get bound violation information"
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1456512931-3388-1-git-send-email-colin.king@canonical.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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"d1cd12108346: x86, pageattr: Prevent overflow in slow_virt_to_phys() for
X86_PAE" was unintentionally removed by the recent "34437e67a672: x86/mm: Fix
slow_virt_to_phys() to handle large PAT bit".
And, the variable 'phys_addr' was defined as "unsigned long" by mistake -- it should
be "phys_addr_t".
As a result, Hyper-V network driver in 32-PAE Linux guest can't work again.
Fixes: commit 34437e67a672: "x86/mm: Fix slow_virt_to_phys() to handle large PAT bit"
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Toshi Kani <toshi.kani@hpe.com>
Cc: olaf@aepfle.de
Cc: gregkh@linuxfoundation.org
Cc: jasowang@redhat.com
Cc: driverdev-devel@linuxdriverproject.org
Cc: linux-mm@kvack.org
Cc: apw@canonical.com
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Link: http://lkml.kernel.org/r/1456394292-9030-1-git-send-email-decui@microsoft.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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set_memory_nx() (and set_memory_x()) currently differ in behavior from
all other set_memory_*() functions when encountering a virtual address
space hole within the kernel address range: They stop processing at the
hole, but nevertheless report success (making the caller believe the
operation was carried out on the entire range). While observed to be a
problem - triggering the CONFIG_DEBUG_WX warning - only with out of
tree code, I suspect (but didn't check) that on x86-64 the
CONFIG_DEBUG_PAGEALLOC logic in free_init_pages() would, when called
from free_initmem(), have the same effect on the set_memory_nx() called
from mark_rodata_ro().
This unexpected behavior is a result of change_page_attr_set_clr()
special casing changes to only the NX bit, in that it passes "false" as
the "checkalias" argument to __change_page_attr_set_clr(). Since this
flag becomes the "primary" argument of both __change_page_attr() and
__cpa_process_fault(), the latter would so far return success without
adjusting cpa->numpages. Success to the higher level callers, however,
means that whatever cpa->numpages currently holds is the count of
successfully processed pages. The cases when __change_page_attr() calls
__cpa_process_fault(), otoh, don't generally mean the entire range got
processed (as can be seen from one of the two success return paths in
__cpa_process_fault() already adjusting ->numpages).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/56BB0AD402000078000D05BF@prv-mh.provo.novell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: trivial@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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This removes the CONFIG_DEBUG_RODATA option and makes it always enabled.
This simplifies the code and also makes it clearer that read-only mapped
memory is just as fundamental a security feature in kernel-space as it is
in user-space.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Brown <david.brown@linaro.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-hardening@lists.openwall.com
Cc: linux-arch <linux-arch@vger.kernel.org>
Link: http://lkml.kernel.org/r/1455748879-21872-4-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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As part of the preparation for the EFI_MEMORY_RO flag added in the UEFI
2.5 specification, we need the ability to map pages in kernel page
tables without _PAGE_RW being set.
Modify kernel_map_pages_in_pgd() to require its callers to pass _PAGE_RW
if the pages need to be mapped read/write. Otherwise, we'll map the
pages as read-only.
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
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: Hugh Dickins <hughd@google.com>
Cc: Lee, Chun-Yi <jlee@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1455712566-16727-12-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Since EFI page tables can be treated as kernel page tables they should
be global. All the other page mapping functions in pageattr.c set the
_PAGE_GLOBAL bit and we want to avoid inconsistencies when we map a page
in the EFI code paths, for example when that page is split in
__split_large_page(), etc. It also makes it easier to validate that the
EFI region mappings have the correct attributes because there are fewer
differences compared with regular kernel mappings.
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
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: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1455712566-16727-4-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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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 fixes from Ingo Molnar:
"This is unusually large, partly due to the EFI fixes that prevent
accidental deletion of EFI variables through efivarfs that may brick
machines. These fixes are somewhat involved to maintain compatibility
with existing install methods and other usage modes, while trying to
turn off the 'rm -rf' bricking vector.
Other fixes are for large page ioremap()s and for non-temporal
user-memcpy()s"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Fix vmalloc_fault() to handle large pages properly
hpet: Drop stale URLs
x86/uaccess/64: Handle the caching of 4-byte nocache copies properly in __copy_user_nocache()
x86/uaccess/64: Make the __copy_user_nocache() assembly code more readable
lib/ucs2_string: Correct ucs2 -> utf8 conversion
efi: Add pstore variables to the deletion whitelist
efi: Make efivarfs entries immutable by default
efi: Make our variable validation list include the guid
efi: Do variable name validation tests in utf8
efi: Use ucs2_as_utf8 in efivarfs instead of open coding a bad version
lib/ucs2_string: Add ucs2 -> utf8 helper functions
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is_hypervisor_range() can simply check if the PGD index is
within ffff800000000000 - ffff87ffffffffff which is the range
reserved for a hypervisor. That range is practically an ABI, see
Documentation/x86/x86_64/mm.txt.
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> # Under Xen, as PV guest
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1455825641-19585-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Commit 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings") has
moved up the pte_page(pte) in x86's fast gup_pte_range(), for no
discernible reason: put it back where it belongs, after the pte_flags
check and the pfn_valid cross-check.
That may be the cause of the NULL pointer dereference in
gup_pte_range(), seen when vfio called vaddr_get_pfn() when starting a
qemu-kvm based VM.
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Michael Long <Harn-Solo@gmx.de>
Tested-by: Michael Long <Harn-Solo@gmx.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Protection keys provide new page-based protection in hardware.
But, they have an interesting attribute: they only affect data
accesses and never affect instruction fetches. That means that
if we set up some memory which is set as "access-disabled" via
protection keys, we can still execute from it.
This patch uses protection keys to set up mappings to do just that.
If a user calls:
mmap(..., PROT_EXEC);
or
mprotect(ptr, sz, PROT_EXEC);
(note PROT_EXEC-only without PROT_READ/WRITE), the kernel will
notice this, and set a special protection key on the memory. It
also sets the appropriate bits in the Protection Keys User Rights
(PKRU) register so that the memory becomes unreadable and
unwritable.
I haven't found any userspace that does this today. With this
facility in place, we expect userspace to move to use it
eventually. Userspace _could_ start doing this today. Any
PROT_EXEC calls get converted to PROT_READ inside the kernel, and
would transparently be upgraded to "true" PROT_EXEC with this
code. IOW, userspace never has to do any PROT_EXEC runtime
detection.
This feature provides enhanced protection against leaking
executable memory contents. This helps thwart attacks which are
attempting to find ROP gadgets on the fly.
But, the security provided by this approach is not comprehensive.
The PKRU register which controls access permissions is a normal
user register writable from unprivileged userspace. An attacker
who can execute the 'wrpkru' instruction can easily disable the
protection provided by this feature.
The protection key that is used for execute-only support is
permanently dedicated at compile time. This is fine for now
because there is currently no API to set a protection key other
than this one.
Despite there being a constant PKRU value across the entire
system, we do not set it unless this feature is in use in a
process. That is to preserve the PKRU XSAVE 'init state',
which can lead to faster context switches.
PKRU *is* a user register and the kernel is modifying it. That
means that code doing:
pkru = rdpkru()
pkru |= 0x100;
mmap(..., PROT_EXEC);
wrpkru(pkru);
could lose the bits in PKRU that enforce execute-only
permissions. To avoid this, we suggest avoiding ever calling
mmap() or mprotect() when the PKRU value is expected to be
unstable.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chen Gang <gang.chen.5i5j@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Piotr Kwapulinski <kwapulinski.piotr@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: keescook@google.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210240.CB4BB5CA@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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As discussed earlier, we attempt to enforce protection keys in
software.
However, the code checks all faults to ensure that they are not
violating protection key permissions. It was assumed that all
faults are either write faults where we check PKRU[key].WD (write
disable) or read faults where we check the AD (access disable)
bit.
But, there is a third category of faults for protection keys:
instruction faults. Instruction faults never run afoul of
protection keys because they do not affect instruction fetches.
So, plumb the PF_INSTR bit down in to the
arch_vma_access_permitted() function where we do the protection
key checks.
We also add a new FAULT_FLAG_INSTRUCTION. This is because
handle_mm_fault() is not passed the architecture-specific
error_code where we keep PF_INSTR, so we need to encode the
instruction fetch information in to the arch-generic fault
flags.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210224.96928009@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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We might not strictly have to make modifictions to
access_error() to check the VMA here.
If we do not, we will do this:
1. app sets VMA pkey to K
2. app touches a !present page
3. do_page_fault(), allocates and maps page, sets pte.pkey=K
4. return to userspace
5. touch instruction reexecutes, but triggers PF_PK
6. do PKEY signal
What happens with this patch applied:
1. app sets VMA pkey to K
2. app touches a !present page
3. do_page_fault() notices that K is inaccessible
4. do PKEY signal
We basically skip the fault that does an allocation.
So what this lets us do is protect areas from even being
*populated* unless it is accessible according to protection
keys. That seems handy to me and makes protection keys work
more like an mprotect()'d mapping.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210222.EBB63D8C@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Today, for normal faults and page table walks, we check the VMA
and/or PTE to ensure that it is compatible with the action. For
instance, if we get a write fault on a non-writeable VMA, we
SIGSEGV.
We try to do the same thing for protection keys. Basically, we
try to make sure that if a user does this:
mprotect(ptr, size, PROT_NONE);
*ptr = foo;
they see the same effects with protection keys when they do this:
mprotect(ptr, size, PROT_READ|PROT_WRITE);
set_pkey(ptr, size, 4);
wrpkru(0xffffff3f); // access disable pkey 4
*ptr = foo;
The state to do that checking is in the VMA, but we also
sometimes have to do it on the page tables only, like when doing
a get_user_pages_fast() where we have no VMA.
We add two functions and expose them to generic code:
arch_pte_access_permitted(pte_flags, write)
arch_vma_access_permitted(vma, write)
These are, of course, backed up in x86 arch code with checks
against the PTE or VMA's protection key.
But, there are also cases where we do not want to respect
protection keys. When we ptrace(), for instance, we do not want
to apply the tracer's PKRU permissions to the PTEs from the
process being traced.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dominik Dingel <dingel@linux.vnet.ibm.com>
Cc: Dominik Vogt <vogt@linux.vnet.ibm.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Shachar Raindel <raindel@mellanox.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20160212210219.14D5D715@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The current get_user_pages() code is a wee bit more complicated
than it needs to be for pte bit checking. Currently, it establishes
a mask of required pte _PAGE_* bits and ensures that the pte it
goes after has all those bits.
This consolidates the three identical copies of this code.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210218.3A2D4045@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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This fills in the new siginfo field: si_pkey to indicate to
userspace which protection key was set on the PTE that we faulted
on.
Note though that *ALL* protection key faults have to be generated
by a valid, present PTE at some point. But this code does no PTE
lookups which seeds odd. The reason is that we take advantage of
the way we generate PTEs from VMAs. All PTEs under a VMA share
some attributes. For instance, they are _all_ either PROT_READ
*OR* PROT_NONE. They also always share a protection key, so we
never have to walk the page tables; we just use the VMA.
Note that _pkey is a 64-bit value. The current hardware only
supports 4-bit protection keys. We do this because there is
_plenty_ of space in _sigfault and it is possible that future
processors would support more than 4 bits of protection keys.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210213.ABC488FA@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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During a page fault, we look up the VMA to ensure that the fault
is in a region with a valid mapping. But, in the top-level page
fault code we don't need the VMA for much else. Once we have
decided that an access is bad, we are going to send a signal no
matter what and do not need the VMA any more. So we do not pass
it down in to the signal generation code.
But, for protection keys, we need the VMA. It tells us *which*
protection key we violated if we get a PF_PK. So, we need to
pass the VMA down and fill in siginfo->si_pkey.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210211.AD3B36A3@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Note: "PK" is how the Intel SDM refers to this bit, so we also
use that nomenclature.
This only defines the bit, it does not plumb it anywhere to be
handled.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210207.DA7B43E6@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Huge amounts of help from Andy Lutomirski and Borislav Petkov to
produce this. Andy provided the inspiration to add classes to the
exception table with a clever bit-squeezing trick, Boris pointed
out how much cleaner it would all be if we just had a new field.
Linus Torvalds blessed the expansion with:
' I'd rather not be clever in order to save just a tiny amount of space
in the exception table, which isn't really criticial for anybody. '
The third field is another relative function pointer, this one to a
handler that executes the actions.
We start out with three handlers:
1: Legacy - just jumps the to fixup IP
2: Fault - provide the trap number in %ax to the fixup code
3: Cleaned up legacy for the uaccess error hack
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
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/f6af78fcbd348cf4939875cfda9c19689b5e50b8.1455732970.git.tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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A kernel page fault oops with the callstack below was observed
when a read syscall was made to a pmem device after a huge amount
(>512GB) of vmalloc ranges was allocated by ioremap() on a x86_64
system:
BUG: unable to handle kernel paging request at ffff880840000ff8
IP: vmalloc_fault+0x1be/0x300
PGD c7f03a067 PUD 0
Oops: 0000 [#1] SM
Call Trace:
__do_page_fault+0x285/0x3e0
do_page_fault+0x2f/0x80
? put_prev_entity+0x35/0x7a0
page_fault+0x28/0x30
? memcpy_erms+0x6/0x10
? schedule+0x35/0x80
? pmem_rw_bytes+0x6a/0x190 [nd_pmem]
? schedule_timeout+0x183/0x240
btt_log_read+0x63/0x140 [nd_btt]
:
? __symbol_put+0x60/0x60
? kernel_read+0x50/0x80
SyS_finit_module+0xb9/0xf0
entry_SYSCALL_64_fastpath+0x1a/0xa4
Since v4.1, ioremap() supports large page (pud/pmd) mappings in
x86_64 and PAE. vmalloc_fault() however assumes that the vmalloc
range is limited to pte mappings.
vmalloc faults do not normally happen in ioremap'd ranges since
ioremap() sets up the kernel page tables, which are shared by
user processes. pgd_ctor() sets the kernel's PGD entries to
user's during fork(). When allocation of the vmalloc ranges
crosses a 512GB boundary, ioremap() allocates a new pud table
and updates the kernel PGD entry to point it. If user process's
PGD entry does not have this update yet, a read/write syscall
to the range will cause a vmalloc fault, which hits the Oops
above as it does not handle a large page properly.
Following changes are made to vmalloc_fault().
64-bit:
- No change for the PGD sync operation as it handles large
pages already.
- Add pud_huge() and pmd_huge() to the validation code to
handle large pages.
- Change pud_page_vaddr() to pud_pfn() since an ioremap range
is not directly mapped (while the if-statement still works
with a bogus addr).
- Change pmd_page() to pmd_pfn() since an ioremap range is not
backed by struct page (while the if-statement still works
with a bogus addr).
32-bit:
- No change for the sync operation since the index3 PGD entry
covers the entire vmalloc range, which is always valid.
(A separate change to sync PGD entry is necessary if this
memory layout is changed regardless of the page size.)
- Add pmd_huge() to the validation code to handle large pages.
This is for completeness since vmalloc_fault() won't happen
in ioremap'd ranges as its PGD entry is always valid.
Reported-by: Henning Schild <henning.schild@siemens.com>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: <stable@vger.kernel.org> # 4.1+
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-mm@kvack.org
Cc: linux-nvdimm@lists.01.org
Link: http://lkml.kernel.org/r/1455758214-24623-1-git-send-email-toshi.kani@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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We will soon modify the vanilla get_user_pages() so it can no
longer be used on mm/tasks other than 'current/current->mm',
which is by far the most common way it is called. For now,
we allow the old-style calls, but warn when they are used.
(implemented in previous patch)
This patch switches all callers of:
get_user_pages()
get_user_pages_unlocked()
get_user_pages_locked()
to stop passing tsk/mm so they will no longer see the warnings.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: jack@suse.cz
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210156.113E9407@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Provide a stable basis for the pkeys patches, which touches various
x86 details.
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 fixes from Thomas Gleixner:
"Two small fixlets for x86:
- Prevent a KASAN false positive in thread_saved_pc()
- Fix a 32-bit truncation problem in the x86 numa code"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm/numa: Fix 32-bit memblock range truncation bug on 32-bit NUMA kernels
x86: Fix KASAN false positives in thread_saved_pc()
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track_pfn_insert() overwrites the pgprot that is passed in with a value
based on the VMA's page_prot. This is a problem for people trying to
do clever things with the new vm_insert_pfn_prot() as it will simply
overwrite the passed protection flags. If we use the current value of
the pgprot as the base, then it will behave as people are expecting.
Also fix track_pfn_remap() in the same way.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1453742717-10326-2-git-send-email-matthew.r.wilcox@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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After kasan_init() executed, no one is allowed to write to kasan_zero_page,
so write protect it.
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1452516679-32040-3-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Currently we clear kasan_zero_page before __flush_tlb_all(). This
works with current implementation of native_flush_tlb[_global]()
because it doesn't cause do any writes to kasan shadow memory.
But any subtle change made in native_flush_tlb*() could break this.
Also current code seems doesn't work for paravirt guests (lguest).
Only after the TLB flush we can be sure that kasan_zero_page is not
used as early shadow anymore (instrumented code will not write to it).
So it should cleared it only after the TLB flush.
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1452516679-32040-2-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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numa_clear_kernel_node_hotplug() uses memblock_set_node() without
checking for failures.
memblock_set_node() is a complex function that might extend the
memblock array - which extension might fail - so check for this
possibility.
It's not supposed to happen (because realistically if we have so
little memory that this fails then we likely won't be able to
boot anyway), but do the check nevertheless.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Chen Tang <imtangchen@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: y14sg1 <y14sg1@comcast.net>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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So we fixed an overflow bug in numa_clear_kernel_node_hotplug():
2b54ab3c66d4 ("x86/mm/numa: Fix memory corruption on 32-bit NUMA kernels")
... and the bug was indirectly caused by poor coding style,
such as using start/end local variables unnecessarily, which
lost the physaddr_t type.
So make the code more readable and try to fully comment all
the thinking behind the logic.
No change in functionality.
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Chen Tang <imtangchen@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: y14sg1 <y14sg1@comcast.net>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The following commit:
a0acda917284 ("acpi, numa, mem_hotplug: mark all nodes the kernel resides un-hotpluggable")
Introduced numa_clear_kernel_node_hotplug(), which function is executed
during early bootup, and which marks all currently reserved memblock
regions as hot-memory-unswappable as well.
y14sg1 <y14sg1@comcast.net> reported that when running 32-bit NUMA kernels,
the grsecurity/PAX kernel patch flagged a size overflow in this function:
PAX: size overflow detected in function x86_numa_init arch/x86/mm/numa.c:691 [...]
... the reason for the overflow is that memblock_clear_hotplug() takes physical
addresses as arguments, while the start/end variables used by
numa_clear_kernel_node_hotplug() are 'unsigned long', which is 32-bit on PAE
kernels, but which has 64-bit physical addresses.
So on 32-bit PAE kernels that have physical memory above the 4GB boundary,
we truncate a 64-bit physical address range to 32 bits and pass it to
memblock_clear_hotplug(), which at minimum prevents the original memory-hotplug
bugfix from working, but might have other side effects as well.
The fix is to use the proper type to handle physical addresses, phys_addr_t.
Reported-by: y14sg1 <y14sg1@comcast.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Chen Tang <imtangchen@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Commit 944d9fec8d7a ("hugetlb: add support for gigantic page allocation
at runtime") has added the runtime gigantic page allocation via
alloc_contig_range(), making this support available only when CONFIG_CMA
is enabled. Because it doesn't depend on MIGRATE_CMA pageblocks and the
associated infrastructure, it is possible with few simple adjustments to
require only CONFIG_MEMORY_ISOLATION instead of full CONFIG_CMA.
After this patch, alloc_contig_range() and related functions are
available and used for gigantic pages with just CONFIG_MEMORY_ISOLATION
enabled. Note CONFIG_CMA selects CONFIG_MEMORY_ISOLATION. This allows
supporting runtime gigantic pages without the CMA-specific checks in
page allocator fastpaths.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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recent fixes
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 fixes from Thomas Gleixner:
"A bit on the largish side due to a series of fixes for a regression in
the x86 vector management which was introduced in 4.3. This work was
started in December already, but it took some time to fix all corner
cases and a couple of older bugs in that area which were detected
while at it
Aside of that a few platform updates for intel-mid, quark and UV and
two fixes for in the mm code:
- Use proper types for pgprot values to avoid truncation
- Prevent a size truncation in the pageattr code when setting page
attributes for large mappings"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
x86/mm/pat: Avoid truncation when converting cpa->numpages to address
x86/mm: Fix types used in pgprot cacheability flags translations
x86/platform/quark: Print boundaries correctly
x86/platform/UV: Remove EFI memmap quirk for UV2+
x86/platform/intel-mid: Join string and fix SoC name
x86/platform/intel-mid: Enable 64-bit build
x86/irq: Plug vector cleanup race
x86/irq: Call irq_force_move_complete with irq descriptor
x86/irq: Remove outgoing CPU from vector cleanup mask
x86/irq: Remove the cpumask allocation from send_cleanup_vector()
x86/irq: Clear move_in_progress before sending cleanup IPI
x86/irq: Remove offline cpus from vector cleanup
x86/irq: Get rid of code duplication
x86/irq: Copy vectormask instead of an AND operation
x86/irq: Check vector allocation early
x86/irq: Reorganize the search in assign_irq_vector
x86/irq: Reorganize the return path in assign_irq_vector
x86/irq: Do not use apic_chip_data.old_domain as temporary buffer
x86/irq: Validate that irq descriptor is still active
x86/irq: Fix a race in x86_vector_free_irqs()
...
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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>
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There are a couple of nasty truncation bugs lurking in the pageattr
code that can be triggered when mapping EFI regions, e.g. when we pass
a cpa->pgd pointer. Because cpa->numpages is a 32-bit value, shifting
left by PAGE_SHIFT will truncate the resultant address to 32-bits.
Viorel-Cătălin managed to trigger this bug on his Dell machine that
provides a ~5GB EFI region which requires 1236992 pages to be mapped.
When calling populate_pud() the end of the region gets calculated
incorrectly in the following buggy expression,
end = start + (cpa->numpages << PAGE_SHIFT);
And only 188416 pages are mapped. Next, populate_pud() gets invoked
for a second time because of the loop in __change_page_attr_set_clr(),
only this time no pages get mapped because shifting the remaining
number of pages (1048576) by PAGE_SHIFT is zero. At which point the
loop in __change_page_attr_set_clr() spins forever because we fail to
map progress.
Hitting this bug depends very much on the virtual address we pick to
map the large region at and how many pages we map on the initial run
through the loop. This explains why this issue was only recently hit
with the introduction of commit
a5caa209ba9c ("x86/efi: Fix boot crash by mapping EFI memmap
entries bottom-up at runtime, instead of top-down")
It's interesting to note that safe uses of cpa->numpages do exist in
the pageattr code. If instead of shifting ->numpages we multiply by
PAGE_SIZE, no truncation occurs because PAGE_SIZE is a UL value, and
so the result is unsigned long.
To avoid surprises when users try to convert very large cpa->numpages
values to addresses, change the data type from 'int' to 'unsigned
long', thereby making it suitable for shifting by PAGE_SHIFT without
any type casting.
The alternative would be to make liberal use of casting, but that is
far more likely to cause problems in the future when someone adds more
code and fails to cast properly; this bug was difficult enough to
track down in the first place.
Reported-and-tested-by: Viorel-Cătălin Răpițeanu <rapiteanu.catalin@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=110131
Link: http://lkml.kernel.org/r/1454067370-10374-1-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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The value (once we initialize it) is a foregone conclusion.
Make it a #define to save a tiny amount of text and data size
and to make it more comprehensible.
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/0850eb0213de9da88544ff7fae72dc6d06d2b441.1453239349.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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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>
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