1. 08 Aug, 2014 5 commits
    • Vivek Goyal's avatar
      kexec-bzImage64: support for loading bzImage using 64bit entry · 27f48d3e
      Vivek Goyal authored
      
      
      This is loader specific code which can load bzImage and set it up for
      64bit entry.  This does not take care of 32bit entry or real mode entry.
      
      32bit mode entry can be implemented if somebody needs it.
      Signed-off-by: default avatarVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      27f48d3e
    • Vivek Goyal's avatar
      kexec: load and relocate purgatory at kernel load time · 12db5562
      Vivek Goyal authored
      
      
      Load purgatory code in RAM and relocate it based on the location.
      Relocation code has been inspired by module relocation code and purgatory
      relocation code in kexec-tools.
      
      Also compute the checksums of loaded kexec segments and store them in
      purgatory.
      
      Arch independent code provides this functionality so that arch dependent
      bootloaders can make use of it.
      
      Helper functions are provided to get/set symbol values in purgatory which
      are used by bootloaders later to set things like stack and entry point of
      second kernel etc.
      Signed-off-by: default avatarVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      12db5562
    • Vivek Goyal's avatar
      kexec: implementation of new syscall kexec_file_load · cb105258
      Vivek Goyal authored
      
      
      Previous patch provided the interface definition and this patch prvides
      implementation of new syscall.
      
      Previously segment list was prepared in user space.  Now user space just
      passes kernel fd, initrd fd and command line and kernel will create a
      segment list internally.
      
      This patch contains generic part of the code.  Actual segment preparation
      and loading is done by arch and image specific loader.  Which comes in
      next patch.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cb105258
    • Vivek Goyal's avatar
      kexec: make kexec_segment user buffer pointer a union · 815d5704
      Vivek Goyal authored
      
      
      So far kexec_segment->buf was always a user space pointer as user space
      passed the array of kexec_segment structures and kernel copied it.
      
      But with new system call, list of kexec segments will be prepared by
      kernel and kexec_segment->buf will point to a kernel memory.
      
      So while I was adding code where I made assumption that ->buf is pointing
      to kernel memory, sparse started giving warning.
      
      Make ->buf a union.  And where a user space pointer is expected, access it
      using ->buf and where a kernel space pointer is expected, access it using
      ->kbuf.  That takes care of sparse warnings.
      Signed-off-by: default avatarVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      815d5704
    • Vivek Goyal's avatar
      kexec: rename unusebale_pages to unusable_pages · 7d3e2bca
      Vivek Goyal authored
      
      
      Let's use the more common "unusable".
      
      This patch was originally written and posted by Boris. I am including it
      in this patch series.
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Signed-off-by: default avatarVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7d3e2bca
  2. 06 Mar, 2014 1 commit
  3. 24 Jan, 2014 1 commit
    • Kees Cook's avatar
      kexec: add sysctl to disable kexec_load · 7984754b
      Kees Cook authored
      
      
      For general-purpose (i.e.  distro) kernel builds it makes sense to build
      with CONFIG_KEXEC to allow end users to choose what kind of things they
      want to do with kexec.  However, in the face of trying to lock down a
      system with such a kernel, there needs to be a way to disable kexec_load
      (much like module loading can be disabled).  Without this, it is too easy
      for the root user to modify kernel memory even when CONFIG_STRICT_DEVMEM
      and modules_disabled are set.  With this change, it is still possible to
      load an image for use later, then disable kexec_load so the image (or lack
      of image) can't be altered.
      
      The intention is for using this in environments where "perfect"
      enforcement is hard.  Without a verified boot, along with verified
      modules, and along with verified kexec, this is trying to give a system a
      better chance to defend itself (or at least grow the window of
      discoverability) against attack in the face of a privilege escalation.
      
      In my mind, I consider several boot scenarios:
      
      1) Verified boot of read-only verified root fs loading fd-based
         verification of kexec images.
      2) Secure boot of writable root fs loading signed kexec images.
      3) Regular boot loading kexec (e.g. kcrash) image early and locking it.
      4) Regular boot with no control of kexec image at all.
      
      1 and 2 don't exist yet, but will soon once the verified kexec series has
      landed.  4 is the state of things now.  The gap between 2 and 4 is too
      large, so this change creates scenario 3, a middle-ground above 4 when 2
      and 1 are not possible for a system.
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Acked-by: default avatarRik van Riel <riel@redhat.com>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7984754b
  4. 07 Dec, 2013 1 commit
  5. 17 Apr, 2013 1 commit
  6. 30 Jan, 2013 1 commit
    • Yinghai Lu's avatar
      x86: Add Crash kernel low reservation · 0212f915
      Yinghai Lu authored
      
      
      During kdump kernel's booting stage, it need to find low ram for
      swiotlb buffer when system does not support intel iommu/dmar remapping.
      
      kexed-tools is appending memmap=exactmap and range from /proc/iomem
      with "Crash kernel", and that range is above 4G for 64bit after boot
      protocol 2.12.
      
      We need to add another range in /proc/iomem like "Crash kernel low",
      so kexec-tools could find that info and append to kdump kernel
      command line.
      
      Try to reserve some under 4G if the normal "Crash kernel" is above 4G.
      
      User could specify the size with crashkernel_low=XX[KMG].
      
      -v2: fix warning that is found by Fengguang's test robot.
      -v3: move out get_mem_size change to another patch, to solve compiling
           warning that is found by Borislav Petkov <bp@alien8.de>
      -v4: user must specify crashkernel_low if system does not support
           intel or amd iommu.
      Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
      Link: http://lkml.kernel.org/r/1359058816-7615-31-git-send-email-yinghai@kernel.org
      
      
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: Rob Landley <rob@landley.net>
      Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
      0212f915
  7. 13 Oct, 2012 1 commit
  8. 01 Jun, 2012 1 commit
    • maximilian attems's avatar
      kexec: export kexec.h to user space · 29a5c67e
      maximilian attems authored
      
      
      Add userspace definitions, guard all relevant kernel structures.  While at
      it document stuff and remove now useless userspace hint.
      
      It is easy to add the relevant system call to respective libc's, but it
      seems pointless to have to duplicate the data structures.
      
      This is based on the kexec-tools headers, with the exception of just using
      int on return (succes or failure) and using size_t instead of 'unsigned
      long int' for the number of segments argument of kexec_load().
      Signed-off-by: default avatarmaximilian attems <max@stro.at>
      Cc: Simon Horman <horms@verge.net.au>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Cc: Haren Myneni <hbabu@us.ibm.com>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      29a5c67e
  9. 23 Jan, 2012 1 commit
  10. 01 Nov, 2011 1 commit
  11. 30 Oct, 2011 2 commits
  12. 01 Apr, 2011 1 commit
  13. 17 Feb, 2010 1 commit
  14. 16 Dec, 2009 1 commit
  15. 31 Oct, 2008 1 commit
    • Huang Ying's avatar
      kexec/i386: allocate page table pages dynamically · 92be3d6b
      Huang Ying authored
      
      
      Impact: save .text size when kexec is built in but not loaded
      
      This patch adds an architecture specific struct kimage_arch into
      struct kimage. The pointers to page table pages used by kexec are
      added to struct kimage_arch. The page tables pages are dynamically
      allocated in machine_kexec_prepare instead of statically from BSS
      segment. This will save up to 20k memory when kexec image is not
      loaded.
      Signed-off-by: default avatarHuang Ying <ying.huang@intel.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      92be3d6b
  16. 15 Aug, 2008 1 commit
  17. 05 Aug, 2008 1 commit
  18. 26 Jul, 2008 1 commit
    • Huang Ying's avatar
      kexec jump · 3ab83521
      Huang Ying authored
      This patch provides an enhancement to kexec/kdump.  It implements the
      following features:
      
      - Backup/restore memory used by the original kernel before/after
        kexec.
      
      - Save/restore CPU state before/after kexec.
      
      The features of this patch can be used as a general method to call program in
      physical mode (paging turning off).  This can be used to call BIOS code under
      Linux.
      
      kexec-tools needs to be patched to support kexec jump. The patches and
      the precompiled kexec can be download from the following URL:
      
             source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2
             patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2
             binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10
      
      
      
      Usage example of calling some physical mode code and return:
      
      1. Compile and install patched kernel with following options selected:
      
      CONFIG_X86_32=y
      CONFIG_KEXEC=y
      CONFIG_PM=y
      CONFIG_KEXEC_JUMP=y
      
      2. Build patched kexec-tool or download the pre-built one.
      
      3. Build some physical mode executable named such as "phy_mode"
      
      4. Boot kernel compiled in step 1.
      
      5. Load physical mode executable with /sbin/kexec. The shell command
         line can be as follow:
      
         /sbin/kexec --load-preserve-context --args-none phy_mode
      
      6. Call physical mode executable with following shell command line:
      
         /sbin/kexec -e
      
      Implementation point:
      
      To support jumping without reserving memory.  One shadow backup page (source
      page) is allocated for each page used by kexeced code image (destination
      page).  When do kexec_load, the image of kexeced code is loaded into source
      pages, and before executing, the destination pages and the source pages are
      swapped, so the contents of destination pages are backupped.  Before jumping
      to the kexeced code image and after jumping back to the original kernel, the
      destination pages and the source pages are swapped too.
      
      C ABI (calling convention) is used as communication protocol between
      kernel and called code.
      
      A flag named KEXEC_PRESERVE_CONTEXT for sys_kexec_load is added to
      indicate that the loaded kernel image is used for jumping back.
      
      Now, only the i386 architecture is supported.
      Signed-off-by: default avatarHuang Ying <ying.huang@intel.com>
      Acked-by: default avatarVivek Goyal <vgoyal@redhat.com>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Pavel Machek <pavel@ucw.cz>
      Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3ab83521
  19. 07 Feb, 2008 3 commits
  20. 19 Oct, 2007 1 commit
    • Bernhard Walle's avatar
      Extended crashkernel command line · cba63c30
      Bernhard Walle authored
      
      
      This patch adds a extended crashkernel syntax that makes the value of reserved
      system RAM dependent on the system RAM itself:
      
          crashkernel=<range1>:<size1>[,<range2>:<size2>,...][@offset]
          range=start-[end]
      
      For example:
      
          crashkernel=512M-2G:64M,2G-:128M
      
      The motivation comes from distributors that configure their crashkernel
      command line automatically with some configuration tool (YaST, you know ;)).
      Of course that tool knows the value of System RAM, but if the user removes
      RAM, then the system becomes unbootable or at least unusable and error
      handling is very difficult.
      
      This series implements this change for i386, x86_64, ia64, ppc64 and sh.  That
      should be all platforms that support kdump in current mainline.  I tested all
      platforms except sh due to the lack of a sh processor.
      
      This patch:
      
      This is the generic part of the patch.  It adds a parse_crashkernel() function
      in kernel/kexec.c that is called by the architecture specific code that
      actually reserves the memory.  That function takes the whole command line and
      looks itself for "crashkernel=" in it.
      
      If there are multiple occurrences, then the last one is taken.  The advantage
      is that if you have a bootloader like lilo or elilo which allows you to append
      a command line parameter but not to remove one (like in GRUB), then you can
      add another crashkernel value for testing at the boot command line and this
      one overwrites the command line in the configuration then.
      Signed-off-by: default avatarBernhard Walle <bwalle@suse.de>
      Cc: Andi Kleen <ak@suse.de>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Vivek Goyal <vgoyal@in.ibm.com>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cba63c30
  21. 17 Oct, 2007 4 commits
  22. 08 May, 2007 1 commit
    • Simon Horman's avatar
      kdump/kexec: calculate note size at compile time · 6672f76a
      Simon Horman authored
      
      
      Currently the size of the per-cpu region reserved to save crash notes is
      set by the per-architecture value MAX_NOTE_BYTES.  Which in turn is
      currently set to 1024 on all supported architectures.
      
      While testing ia64 I recently discovered that this value is in fact too
      small.  The particular setup I was using actually needs 1172 bytes.  This
      lead to very tedious failure mode where the tail of one elf note would
      overwrite the head of another if they ended up being alocated sequentially
      by kmalloc, which was often the case.
      
      It seems to me that a far better approach is to caclculate the size that
      the area needs to be.  This patch does just that.
      
      If a simpler stop-gap patch for ia64 to be squeezed into 2.6.21(.X) is
      needed then this should be as easy as making MAX_NOTE_BYTES larger in
      arch/asm-ia64/kexec.h.  Perhaps 2048 would be a good choice.  However, I
      think that the approach in this patch is a much more robust idea.
      Acked-by: default avatarVivek Goyal <vgoyal@in.ibm.com>
      Signed-off-by: default avatarSimon Horman <horms@verge.net.au>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      6672f76a
  23. 16 Feb, 2007 1 commit
    • Richard Purdie's avatar
      [ARM] 4137/1: Add kexec support · c587e4a6
      Richard Purdie authored
      
      
      Add kexec support to ARM.
      
      Improvements like commandline handling could be made but this patch gives
      basic functional support. It uses the next available syscall number, 347.
      
      Once the syscall number is known, userspace support will be
      finalised/submitted to kexec-tools, various patches already exist.
      
      Originally based on a patch by Maxim Syrchin but updated and forward
      ported by various people.
      Signed-off-by: default avatarRichard Purdie <rpurdie@rpsys.net>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      c587e4a6
  24. 07 Dec, 2006 2 commits
    • Zou Nan hai's avatar
      [IA64] IA64 Kexec/kdump · a7956113
      Zou Nan hai authored
      
      
      Changes and updates.
      
      1. Remove fake rendz path and related code according to discuss with Khalid Aziz.
      2. fc.i offset fix in relocate_kernel.S.
      3. iospic shutdown code eoi and mask race fix from Fujitsu.
      4. Warm boot hook in machine_kexec to SN SAL code from Jack Steiner.
      5. Send slave to SAL slave loop patch from Jay Lan.
      6. Kdump on non-recoverable MCA event patch from Jay Lan
      7. Use CTL_UNNUMBERED in kdump_on_init sysctl.
      Signed-off-by: default avatarZou Nan hai <nanhai.zou@intel.com>
      Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
      a7956113
    • Magnus Damm's avatar
      [PATCH] Kexec / Kdump: Unify elf note code · 85916f81
      Magnus Damm authored
      
      
      The elf note saving code is currently duplicated over several
      architectures.  This cleanup patch simply adds code to a common file and
      then replaces the arch-specific code with calls to the newly added code.
      
      The only drawback with this approach is that s390 doesn't fully support
      kexec-on-panic which for that arch leads to introduction of unused code.
      Signed-off-by: default avatarMagnus Damm <magnus@valinux.co.jp>
      Cc: Vivek Goyal <vgoyal@in.ibm.com>
      Cc: Andi Kleen <ak@suse.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      85916f81
  25. 30 Nov, 2006 1 commit
  26. 23 Jun, 2006 1 commit
  27. 10 Feb, 2006 1 commit
    • Haren Myneni's avatar
      [PATCH] kexec: fix in free initrd when overlapped with crashkernel region · 9c15e852
      Haren Myneni authored
      
      
      It is possible that the reserved crashkernel region can be overlapped with
      initrd since the bootloader sets the initrd location.  When the initrd
      region is freed, the second kernel memory will not be contiguous.  The
      Kexec_load can cause an oops since there is no contiguous memory to write
      the second kernel or this memory could be used in the first kernel itself
      and may not be part of the dump.  For example, on powerpc, the initrd is
      located at 36MB and the crashkernel starts at 32MB.  The kexec_load caused
      panic since writing into non-allocated memory (after 36MB).  We could see
      the similar issue even on other archs.
      
      One possibility is to move the initrd outside of crashkernel region.  But,
      the initrd region will be freed anyway before the system is up.  This patch
      fixes this issue and frees only regions that are not part of crashkernel
      memory in case overlaps.
      Signed-off-by: default avatarHaren Myneni <haren@us.ibm.com>
      Acked-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Vivek Goyal <vgoyal@in.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      9c15e852
  28. 17 Jan, 2006 1 commit
  29. 10 Jan, 2006 1 commit