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  1. Apr 19, 2016
    • Yinghai Lu's avatar
      x86/KASLR: Remove unneeded boot_params argument · 206f25a8
      Yinghai Lu authored
      
      
      Since the boot_params can be found using the real_mode global variable,
      there is no need to pass around a pointer to it. This slightly simplifies
      the choose_kernel_location function and its callers.
      
      [kees: rewrote changelog, tracked file rename]
      Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Baoquan He <bhe@redhat.com>
      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: Dmitry Vyukov <dvyukov@google.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: H.J. Lu <hjl.tools@gmail.com>
      Cc: Josh Poimboeuf <jpoimboe@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/1460997735-24785-3-git-send-email-keescook@chromium.org
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      206f25a8
    • Kees Cook's avatar
      x86/KASLR: Rename aslr.c to kaslr.c · 9b238748
      Kees Cook authored
      
      
      In order to avoid confusion over what this file provides, rename it to
      kaslr.c since it is used exclusively for the kernel ASLR, not userspace
      ASLR.
      
      Suggested-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Baoquan He <bhe@redhat.com>
      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: Dmitry Vyukov <dvyukov@google.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: H.J. Lu <hjl.tools@gmail.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Link: http://lkml.kernel.org/r/1460997735-24785-2-git-send-email-keescook@chromium.org
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      9b238748
  2. Mar 29, 2016
    • H.J. Lu's avatar
      x86/build: Build compressed x86 kernels as PIE · 6d92bc9d
      H.J. Lu authored
      
      
      The 32-bit x86 assembler in binutils 2.26 will generate R_386_GOT32X
      relocation to get the symbol address in PIC.  When the compressed x86
      kernel isn't built as PIC, the linker optimizes R_386_GOT32X relocations
      to their fixed symbol addresses.  However, when the compressed x86
      kernel is loaded at a different address, it leads to the following
      load failure:
      
        Failed to allocate space for phdrs
      
      during the decompression stage.
      
      If the compressed x86 kernel is relocatable at run-time, it should be
      compiled with -fPIE, instead of -fPIC, if possible and should be built as
      Position Independent Executable (PIE) so that linker won't optimize
      R_386_GOT32X relocation to its fixed symbol address.
      
      Older linkers generate R_386_32 relocations against locally defined
      symbols, _bss, _ebss, _got and _egot, in PIE.  It isn't wrong, just less
      optimal than R_386_RELATIVE.  But the x86 kernel fails to properly handle
      R_386_32 relocations when relocating the kernel.  To generate
      R_386_RELATIVE relocations, we mark _bss, _ebss, _got and _egot as
      hidden in both 32-bit and 64-bit x86 kernels.
      
      To build a 64-bit compressed x86 kernel as PIE, we need to disable the
      relocation overflow check to avoid relocation overflow errors. We do
      this with a new linker command-line option, -z noreloc-overflow, which
      got added recently:
      
       commit 4c10bbaa0912742322f10d9d5bb630ba4e15dfa7
       Author: H.J. Lu <hjl.tools@gmail.com>
       Date:   Tue Mar 15 11:07:06 2016 -0700
      
          Add -z noreloc-overflow option to x86-64 ld
      
          Add -z noreloc-overflow command-line option to the x86-64 ELF linker to
          disable relocation overflow check.  This can be used to avoid relocation
          overflow check if there will be no dynamic relocation overflow at
          run-time.
      
      The 64-bit compressed x86 kernel is built as PIE only if the linker supports
      -z noreloc-overflow.  So far 64-bit relocatable compressed x86 kernel
      boots fine even when it is built as a normal executable.
      
      Signed-off-by: default avatarH.J. Lu <hjl.tools@gmail.com>
      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: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      [ Edited the changelog and comments. ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      6d92bc9d
  3. Mar 22, 2016
    • Dmitry Vyukov's avatar
      kernel: add kcov code coverage · 5c9a8750
      Dmitry Vyukov authored
      kcov provides code coverage collection for coverage-guided fuzzing
      (randomized testing).  Coverage-guided fuzzing is a testing technique
      that uses coverage feedback to determine new interesting inputs to a
      system.  A notable user-space example is AFL
      (http://lcamtuf.coredump.cx/afl/).  However, this technique is not
      widely used for kernel testing due to missing compiler and kernel
      support.
      
      kcov does not aim to collect as much coverage as possible.  It aims to
      collect more or less stable coverage that is function of syscall inputs.
      To achieve this goal it does not collect coverage in soft/hard
      interrupts and instrumentation of some inherently non-deterministic or
      non-interesting parts of kernel is disbled (e.g.  scheduler, locking).
      
      Currently there is a single coverage collection mode (tracing), but the
      API anticipates additional collection modes.  Initially I also
      implemented a second mode which exposes coverage in a fixed-size hash
      table of counters (what Quentin used in ...
      5c9a8750
  4. Feb 29, 2016
    • Josh Poimboeuf's avatar
      objtool: Mark non-standard object files and directories · c0dd6716
      Josh Poimboeuf authored
      
      
      Code which runs outside the kernel's normal mode of operation often does
      unusual things which can cause a static analysis tool like objtool to
      emit false positive warnings:
      
       - boot image
       - vdso image
       - relocation
       - realmode
       - efi
       - head
       - purgatory
       - modpost
      
      Set OBJECT_FILES_NON_STANDARD for their related files and directories,
      which will tell objtool to skip checking them.  It's ok to skip them
      because they don't affect runtime stack traces.
      
      Also skip the following code which does the right thing with respect to
      frame pointers, but is too "special" to be validated by a tool:
      
       - entry
       - mcount
      
      Also skip the test_nx module because it modifies its exception handling
      table at runtime, which objtool can't understand.  Fortunately it's
      just a test module so it doesn't matter much.
      
      Currently objtool is the only user of OBJECT_FILES_NON_STANDARD, but it
      might eventually be useful for other tools.
      
      Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
      Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Chris J Arges <chris.j.arges@canonical.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Michal Marek <mmarek@suse.cz>
      Cc: Namhyung Kim <namhyung@gmail.com>
      Cc: Pedro Alves <palves@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: live-patching@vger.kernel.org
      Link: http://lkml.kernel.org/r/366c080e3844e8a5b6a0327dc7e8c2b90ca3baeb.1456719558.git.jpoimboe@redhat.com
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      c0dd6716
  5. Feb 16, 2016
  6. Jan 30, 2016
  7. Jan 21, 2016
  8. Dec 04, 2015
    • Kirill A. Shutemov's avatar
      x86/mm: Fix regression with huge pages on PAE · 70f15287
      Kirill A. Shutemov authored
      
      
      Recent PAT patchset has caused issue on 32-bit PAE machines:
      
        page:eea45000 count:0 mapcount:-128 mapping:  (null) index:0x0 flags: 0x40000000()
        page dumped because: VM_BUG_ON_PAGE(page_mapcount(page) < 0)
        ------------[ cut here ]------------
        kernel BUG at /home/build/linux-boris/mm/huge_memory.c:1485!
        invalid opcode: 0000 [#1] SMP
        [...]
        Call Trace:
         unmap_single_vma
         ? __wake_up
         unmap_vmas
         unmap_region
         do_munmap
         vm_munmap
         SyS_munmap
         do_fast_syscall_32
         ? __do_page_fault
         sysenter_past_esp
        Code: ...
        EIP: [<c11bde80>] zap_huge_pmd+0x240/0x260 SS:ESP 0068:f6459d98
      
      The problem is in pmd_pfn_mask() and pmd_flags_mask(). These
      helpers use PMD_PAGE_MASK to calculate resulting mask.
      PMD_PAGE_MASK is 'unsigned long', not 'unsigned long long' as
      phys_addr_t is on 32-bit PAE (ARCH_PHYS_ADDR_T_64BIT). As a
      result, the upper bits of resulting mask get truncated.
      
      pud_pfn_mask() and pud_flags_mask() aren't problematic since we
      don't have PUD page table level on 32-bit systems, but it's
      reasonable to keep them consistent with PMD counterpart.
      
      Introduce PHYSICAL_PMD_PAGE_MASK and PHYSICAL_PUD_PAGE_MASK in
      addition to existing PHYSICAL_PAGE_MASK and reworks helpers to
      use them.
      
      Reported-and-Tested-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
      Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      [ Fix -Woverflow warnings from the realmode code. ]
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Reviewed-by: default avatarToshi Kani <toshi.kani@hpe.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: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Jürgen Gross <jgross@suse.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: elliott@hpe.com
      Cc: konrad.wilk@oracle.com
      Cc: linux-mm <linux-mm@kvack.org>
      Fixes: f70abb0f ("x86/asm: Fix pud/pmd interfaces to handle large PAT bit")
      Link: http://lkml.kernel.org/r/1448878233-11390-2-git-send-email-bp@alien8.de
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      70f15287
  9. Nov 06, 2015
  10. Oct 14, 2015
  11. Oct 12, 2015
    • Matt Fleming's avatar
      efifb: Add support for 64-bit frame buffer addresses · ae2ee627
      Matt Fleming authored
      
      
      The EFI Graphics Output Protocol uses 64-bit frame buffer addresses
      but these get truncated to 32-bit by the EFI boot stub when storing
      the address in the 'lfb_base' field of 'struct screen_info'.
      
      Add a 'ext_lfb_base' field for the upper 32-bits of the frame buffer
      address and set VIDEO_TYPE_CAPABILITY_64BIT_BASE when the field is
      useable.
      
      It turns out that the reason no one has required this support so far
      is that there's actually code in tianocore to "downgrade" PCI
      resources that have option ROMs and 64-bit BARS from 64-bit to 32-bit
      to cope with legacy option ROMs that can't handle 64-bit addresses.
      The upshot is that basically all GOP devices in the wild use a 32-bit
      frame buffer address.
      
      Still, it is possible to build firmware that uses a full 64-bit GOP
      frame buffer address. Chad did, which led to him reporting this issue.
      
      Add support in anticipation of GOP devices using 64-bit addresses more
      widely, and so that efifb works out of the box when that happens.
      
      Reported-by: default avatarChad Page <chad.page@znyx.com>
      Cc: Pete Hawkins <pete.hawkins@znyx.com>
      Acked-by: default avatarPeter Jones <pjones@redhat.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
      ae2ee627
  12. Sep 10, 2015
    • Yinghai Lu's avatar
      lib/decompressors: use real out buf size for gunzip with kernel · 2d3862d2
      Yinghai Lu authored
      
      
      When loading x86 64bit kernel above 4GiB with patched grub2, got kernel
      gunzip error.
      
      | early console in decompress_kernel
      | decompress_kernel:
      |       input: [0x807f2143b4-0x807ff61aee]
      |      output: [0x807cc00000-0x807f3ea29b] 0x027ea29c: output_len
      | boot via startup_64
      | KASLR using RDTSC...
      |  new output: [0x46fe000000-0x470138cfff] 0x0338d000: output_run_size
      |  decompress: [0x46fe000000-0x47007ea29b] <=== [0x807f2143b4-0x807ff61aee]
      |
      | Decompressing Linux... gz...
      |
      | uncompression error
      |
      | -- System halted
      
      the new buffer is at 0x46fe000000ULL, decompressor_gzip is using
      0xffffffb901ffffff as out_len.  gunzip in lib/zlib_inflate/inflate.c cap
      that len to 0x01ffffff and decompress fails later.
      
      We could hit this problem with crashkernel booting that uses kexec loading
      kernel above 4GiB.
      
      We have decompress_* support:
          1. inbuf[]/outbuf[] for kernel preboot.
          2. inbuf[]/flush() for initramfs
          3. fill()/flush() for initrd.
      This bug only affect kernel preboot path that use outbuf[].
      
      Add __decompress and take real out_buf_len for gunzip instead of guessing
      wrong buf size.
      
      Fixes: 1431574a (lib/decompressors: fix "no limit" output buffer length)
      Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
      Cc: Alexandre Courbot <acourbot@nvidia.com>
      Cc: Jon Medhurst <tixy@linaro.org>
      Cc: Stephen Warren <swarren@wwwdotorg.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2d3862d2
    • Dave Young's avatar
      kexec: split kexec_load syscall from kexec core code · 2965faa5
      Dave Young authored
      
      
      There are two kexec load syscalls, kexec_load another and kexec_file_load.
       kexec_file_load has been splited as kernel/kexec_file.c.  In this patch I
      split kexec_load syscall code to kernel/kexec.c.
      
      And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
      use kexec_file_load only, or vice verse.
      
      The original requirement is from Ted Ts'o, he want kexec kernel signature
      being checked with CONFIG_KEXEC_VERIFY_SIG enabled.  But kexec-tools use
      kexec_load syscall can bypass the checking.
      
      Vivek Goyal proposed to create a common kconfig option so user can compile
      in only one syscall for loading kexec kernel.  KEXEC/KEXEC_FILE selects
      KEXEC_CORE so that old config files still work.
      
      Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
      architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
      KEXEC_CORE in arch Kconfig.  Also updated general kernel code with to
      kexec_load syscall.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarDave Young <dyoung@redhat.com>
      Cc: Eric W. Biederman <ebiederm@xmission.com>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Cc: Petr Tesarik <ptesarik@suse.cz>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Cc: Josh Boyer <jwboyer@fedoraproject.org>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2965faa5
  13. Aug 08, 2015
  14. Jul 30, 2015
    • Dmitry Skorodumov's avatar
      x86/efi: Use all 64 bit of efi_memmap in setup_e820() · 7cc03e48
      Dmitry Skorodumov authored
      
      
      The efi_info structure stores low 32 bits of memory map
      in efi_memmap and high 32 bits in efi_memmap_hi.
      
      While constructing pointer in the setup_e820(), need
      to take into account all 64 bit of the pointer.
      
      It is because on 64bit machine the function
      efi_get_memory_map() may return full 64bit pointer and before
      the patch that pointer was truncated.
      
      The issue is triggered on Parallles virtual machine and
      fixed with this patch.
      
      Signed-off-by: default avatarDmitry Skorodumov <sdmitry@parallels.com>
      Cc: Denis V. Lunev <den@openvz.org>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
      7cc03e48
  15. Jul 21, 2015
  16. Jul 07, 2015
    • Kees Cook's avatar
      x86/boot: Add hex output for debugging · 79063a7c
      Kees Cook authored
      
      
      This is useful for reporting various addresses or other values
      while debugging early boot, for example, the recent kernel image
      size vs kernel run size. For example, when
      CONFIG_X86_VERBOSE_BOOTUP is set, this is now visible at boot
      time:
      
      	early console in setup code
      	early console in decompress_kernel
      	input_data: 0x0000000001e1526e
      	input_len: 0x0000000000732236
      	output: 0x0000000001000000
      	output_len: 0x0000000001535640
      	run_size: 0x00000000021fb000
      	KASLR using RDTSC...
      
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Jan Beulich <JBeulich@suse.com>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Joe Perches <joe@perches.com>
      Cc: Josh Triplett <josh@joshtriplett.org>
      Cc: Junjie Mao <eternal.n08@gmail.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Link: http://lkml.kernel.org/r/20150706230620.GA17501@www.outflux.net
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      79063a7c
  17. Jul 06, 2015
  18. May 29, 2015
    • Ingo Molnar's avatar
      x86/boot: Add CONFIG_PARAVIRT_SPINLOCKS quirk to arch/x86/boot/compressed/misc.h · 927392d7
      Ingo Molnar authored
      
      
      Linus reported the following new warning on x86 allmodconfig with GCC 5.1:
      
        > ./arch/x86/include/asm/spinlock.h: In function ‘arch_spin_lock’:
        > ./arch/x86/include/asm/spinlock.h:119:3: warning: implicit declaration
        > of function ‘__ticket_lock_spinning’ [-Wimplicit-function-declaration]
        >    __ticket_lock_spinning(lock, inc.tail);
        >    ^
      
      This warning triggers because of these hacks in misc.h:
      
        /*
         * we have to be careful, because no indirections are allowed here, and
         * paravirt_ops is a kind of one. As it will only run in baremetal anyway,
         * we just keep it from happening
         */
        #undef CONFIG_PARAVIRT
        #undef CONFIG_KASAN
      
      But these hacks were not updated when CONFIG_PARAVIRT_SPINLOCKS was added,
      and eventually (with the introduction of queued paravirt spinlocks in
      recent kernels) this created an invalid Kconfig combination and broke
      the build.
      
      So add a CONFIG_PARAVIRT_SPINLOCKS #undef line as well.
      
      Also remove the _ASM_X86_DESC_H quirk: that undocumented quirk
      was originally added ages ago, in:
      
        099e1377 ("x86: use ELF format in compressed images.")
      
      and I went back to that kernel (and fixed up the main Makefile
      which didn't build anymore) and checked what failure it
      avoided: it avoided an include file dependencies related
      build failure related to our old x86-platforms code.
      
      That old code is long gone, the header dependencies got cleaned
      up, and the build does not fail anymore with the totality of
      asm/desc.h included - so remove the quirk.
      
      Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      927392d7
  19. May 28, 2015
    • Dan Williams's avatar
      e820, efi: add ACPI 6.0 persistent memory types · ad5fb870
      Dan Williams authored
      
      
      ACPI 6.0 formalizes e820-type-7 and efi-type-14 as persistent memory.
      Mark it "reserved" and allow it to be claimed by a persistent memory
      device driver.
      
      This definition is in addition to the Linux kernel's existing type-12
      definition that was recently added in support of shipping platforms with
      NVDIMM support that predate ACPI 6.0 (which now classifies type-12 as
      OEM reserved).
      
      Note, /proc/iomem can be consulted for differentiating legacy
      "Persistent Memory (legacy)" E820_PRAM vs standard "Persistent Memory"
      E820_PMEM.
      
      Cc: Boaz Harrosh <boaz@plexistor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Jens Axboe <axboe@fb.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Matthew Wilcox <willy@linux.intel.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Acked-by: default avatarJeff Moyer <jmoyer@redhat.com>
      Acked-by: default avatarAndy Lutomirski <luto@amacapital.net>
      Reviewed-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
      Acked-by: default avatarChristoph Hellwig <hch@lst.de>
      Tested-by: default avatarToshi Kani <toshi.kani@hp.com>
      Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
      ad5fb870
  20. Apr 17, 2015
    • Roy Franz's avatar
      x86/efi: Store upper bits of command line buffer address in ext_cmd_line_ptr · 98b228f5
      Roy Franz authored
      
      
      Until now, the EFI stub was only setting the 32 bit cmd_line_ptr in
      the setup_header structure, so on 64 bit platforms this could be truncated.
      This patch adds setting the upper bits of the buffer address in
      ext_cmd_line_ptr.  This case was likely never hit, as the allocation
      for this buffer is done at the lowest available address.  Only
      x86_64 kernels have this problem, as the 1-1 mapping mandated
      by EFI ensures that all memory is 32 bit addressable on 32 bit
      platforms.  The EFI stub does not support mixed mode, so the
      32 bit kernel on 64 bit firmware case does not need to be handled.
      
      Signed-off-by: default avatarRoy Franz <roy.franz@linaro.org>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
      98b228f5
  21. Apr 03, 2015
    • Borislav Petkov's avatar
      x86/mm/KASLR: Propagate KASLR status to kernel proper · 78cac48c
      Borislav Petkov authored
      
      
      Commit:
      
        e2b32e67 ("x86, kaslr: randomize module base load address")
      
      made module base address randomization unconditional and didn't regard
      disabled KKASLR due to CONFIG_HIBERNATION and command line option
      "nokaslr". For more info see (now reverted) commit:
      
        f47233c2 ("x86/mm/ASLR: Propagate base load address calculation")
      
      In order to propagate KASLR status to kernel proper, we need a single bit
      in boot_params.hdr.loadflags and we've chosen bit 1 thus leaving the
      top-down allocated bits for bits supposed to be used by the bootloader.
      
      Originally-From: Jiri Kosina <jkosina@suse.cz>
      Suggested-by: default avatarH. Peter Anvin <hpa@zytor.com>
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Cc: Kees Cook <keescook@chromium.org>
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      78cac48c
  22. Apr 02, 2015
  23. Mar 23, 2015
    • Arjun Sreedharan's avatar
      x86/boot: Standardize strcmp() · 1c1d046b
      Arjun Sreedharan authored
      
      
      strcmp() is always expected to return 0 when arguments are equal,
      negative when its first argument @str1 is less than its second argument
      @str2 and a positive value otherwise. Previously strcmp("a", "b")
      returned 1. Now it gives -1, as it is supposed to.
      
      Until now this bug never triggered, because all uses for strcmp() in the
      boot code tested for nonzero:
      
        triton:~/tip> git grep strcmp arch/x86/boot/
        arch/x86/boot/boot.h:int strcmp(const char *str1, const char *str2);
        arch/x86/boot/edd.c:            if (!strcmp(eddarg, "skipmbr") || !strcmp(eddarg, "skip")) {
        arch/x86/boot/edd.c:            else if (!strcmp(eddarg, "off"))
        arch/x86/boot/edd.c:            else if (!strcmp(eddarg, "on"))
      
      should in the future strcmp() be used in a comparative way in the boot
      code, it might have led to (not so subtle) bugs.
      
      Signed-off-by: default avatarArjun Sreedharan <arjun024@gmail.com>
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1426520267-1803-1-git-send-email-arjun024@gmail.com
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      1c1d046b
  24. Mar 16, 2015
    • Borislav Petkov's avatar
      Revert "x86/mm/ASLR: Propagate base load address calculation" · 69797daf
      Borislav Petkov authored
      
      
      This reverts commit:
      
        f47233c2 ("x86/mm/ASLR: Propagate base load address calculation")
      
      The main reason for the revert is that the new boot flag does not work
      at all currently, and in order to make this work, we need non-trivial
      changes to the x86 boot code which we didn't manage to get done in
      time for merging.
      
      And even if we did, they would've been too risky so instead of
      rushing things and break booting 4.1 on boxes left and right, we
      will be very strict and conservative and will take our time with
      this to fix and test it properly.
      
      Reported-by: default avatarYinghai Lu <yinghai@kernel.org>
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: H. Peter Anvin <hpa@linux.intel.com
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Josh Triplett <josh@joshtriplett.org>
      Cc: Junjie Mao <eternal.n08@gmail.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Matt Fleming <matt.fleming@intel.com>
      Link: http://lkml.kernel.org/r/20150316100628.GD22995@pd.tnic
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      69797daf
  25. Feb 19, 2015
  26. Feb 18, 2015
  27. Feb 14, 2015
    • Andrey Ryabinin's avatar
      x86_64: kasan: add interceptors for memset/memmove/memcpy functions · 393f203f
      Andrey Ryabinin authored
      
      
      Recently instrumentation of builtin functions calls was removed from GCC
      5.0.  To check the memory accessed by such functions, userspace asan
      always uses interceptors for them.
      
      So now we should do this as well.  This patch declares
      memset/memmove/memcpy as weak symbols.  In mm/kasan/kasan.c we have our
      own implementation of those functions which checks memory before accessing
      it.
      
      Default memset/memmove/memcpy now now always have aliases with '__'
      prefix.  For files that built without kasan instrumentation (e.g.
      mm/slub.c) original mem* replaced (via #define) with prefixed variants,
      cause we don't want to check memory accesses there.
      
      Signed-off-by: default avatarAndrey Ryabinin <a.ryabinin@samsung.com>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: Konstantin Serebryany <kcc@google.com>
      Cc: Dmitry Chernenkov <dmitryc@google.com>
      Signed-off-by: default avatarAndrey Konovalov <adech.fo@gmail.com>
      Cc: Yuri Gribov <tetra2005@gmail.com>
      Cc: Konstantin Khlebnikov <koct9i@gmail.com>
      Cc: Sasha Levin <sasha.levin@oracle.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: David Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      393f203f
    • Andrey Ryabinin's avatar
      x86_64: add KASan support · ef7f0d6a
      Andrey Ryabinin authored
      
      
      This patch adds arch specific code for kernel address sanitizer.
      
      16TB of virtual addressed used for shadow memory.  It's located in range
      [ffffec0000000000 - fffffc0000000000] between vmemmap and %esp fixup
      stacks.
      
      At early stage we map whole shadow region with zero page.  Latter, after
      pages mapped to direct mapping address range we unmap zero pages from
      corresponding shadow (see kasan_map_shadow()) and allocate and map a real
      shadow memory reusing vmemmap_populate() function.
      
      Also replace __pa with __pa_nodebug before shadow initialized.  __pa with
      CONFIG_DEBUG_VIRTUAL=y make external function call (__phys_addr)
      __phys_addr is instrumented, so __asan_load could be called before shadow
      area initialized.
      
      Signed-off-by: default avatarAndrey Ryabinin <a.ryabinin@samsung.com>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: Konstantin Serebryany <kcc@google.com>
      Cc: Dmitry Chernenkov <dmitryc@google.com>
      Signed-off-by: default avatarAndrey Konovalov <adech.fo@gmail.com>
      Cc: Yuri Gribov <tetra2005@gmail.com>
      Cc: Konstantin Khlebnikov <koct9i@gmail.com>
      Cc: Sasha Levin <sasha.levin@oracle.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Jim Davis <jim.epost@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ef7f0d6a
  28. Feb 13, 2015
    • Matt Fleming's avatar
      x86/efi: Avoid triple faults during EFI mixed mode calls · 96738c69
      Matt Fleming authored
      
      
      Andy pointed out that if an NMI or MCE is received while we're in the
      middle of an EFI mixed mode call a triple fault will occur. This can
      happen, for example, when issuing an EFI mixed mode call while running
      perf.
      
      The reason for the triple fault is that we execute the mixed mode call
      in 32-bit mode with paging disabled but with 64-bit kernel IDT handlers
      installed throughout the call.
      
      At Andy's suggestion, stop playing the games we currently do at runtime,
      such as disabling paging and installing a 32-bit GDT for __KERNEL_CS. We
      can simply switch to the __KERNEL32_CS descriptor before invoking
      firmware services, and run in compatibility mode. This way, if an
      NMI/MCE does occur the kernel IDT handler will execute correctly, since
      it'll jump to __KERNEL_CS automatically.
      
      However, this change is only possible post-ExitBootServices(). Before
      then the firmware "owns" the machine and expects for its 32-bit IDT
      handlers to be left intact to service interrupts, etc.
      
      So, we now need to distinguish between early boot and runtime
      invocations of EFI services. During early boot, we need to restore the
      GDT that the firmware expects to be present. We can only jump to the
      __KERNEL32_CS code segment for mixed mode calls after ExitBootServices()
      has been invoked.
      
      A liberal sprinkling of comments in the thunking code should make the
      differences in early and late environments more apparent.
      
      Reported-by: default avatarAndy Lutomirski <luto@amacapital.net>
      Tested-by: default avatarBorislav Petkov <bp@suse.de>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
      96738c69
  29. Jan 26, 2015
  30. Jan 20, 2015
  31. Jan 13, 2015
  32. Dec 23, 2014
  33. Nov 23, 2014
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