1. 12 Jul, 2017 1 commit
  2. 10 Jul, 2017 1 commit
  3. 09 May, 2017 1 commit
    • Hari Bathini's avatar
      crash: move crashkernel parsing and vmcore related code under CONFIG_CRASH_CORE · 692f66f2
      Hari Bathini authored
      Patch series "kexec/fadump: remove dependency with CONFIG_KEXEC and
      reuse crashkernel parameter for fadump", v4.
      
      Traditionally, kdump is used to save vmcore in case of a crash.  Some
      architectures like powerpc can save vmcore using architecture specific
      support instead of kexec/kdump mechanism.  Such architecture specific
      support also needs to reserve memory, to be used by dump capture kernel.
      crashkernel parameter can be a reused, for memory reservation, by such
      architecture specific infrastructure.
      
      This patchset removes dependency with CONFIG_KEXEC for crashkernel
      parameter and vmcoreinfo related code as it can be reused without kexec
      support.  Also, crashkernel parameter is reused instead of
      fadump_reserve_mem to reserve memory for fadump.
      
      The first patch moves crashkernel parameter parsing and vmcoreinfo
      related code under CONFIG_CRASH_CORE instead of CONFIG_KEXEC_CORE.  The
      second patch reuses the definitions of append_elf_note() & final_note()
      functions under CONFIG_CRASH_CORE in IA64 arch code.  The third patch
      removes dependency on CONFIG_KEXEC for firmware-assisted dump (fadump)
      in powerpc.  The next patch reuses crashkernel parameter for reserving
      memory for fadump, instead of the fadump_reserve_mem parameter.  This
      has the advantage of using all syntaxes crashkernel parameter supports,
      for fadump as well.  The last patch updates fadump kernel documentation
      about use of crashkernel parameter.
      
      This patch (of 5):
      
      Traditionally, kdump is used to save vmcore in case of a crash.  Some
      architectures like powerpc can save vmcore using architecture specific
      support instead of kexec/kdump mechanism.  Such architecture specific
      support also needs to reserve memory, to be used by dump capture kernel.
      crashkernel parameter can be a reused, for memory reservation, by such
      architecture specific infrastructure.
      
      But currently, code related to vmcoreinfo and parsing of crashkernel
      parameter is built under CONFIG_KEXEC_CORE.  This patch introduces
      CONFIG_CRASH_CORE and moves the above mentioned code under this config,
      allowing code reuse without dependency on CONFIG_KEXEC.  There is no
      functional change with this patch.
      
      Link: http://lkml.kernel.org/r/149035338104.6881.4550894432615189948.stgit@hbathini.in.ibm.comSigned-off-by: 's avatarHari Bathini <hbathini@linux.vnet.ibm.com>
      Acked-by: 's avatarDave Young <dyoung@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
      Cc: Vivek Goyal <vgoyal@redhat.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      692f66f2
  4. 25 Feb, 2017 1 commit
  5. 02 Aug, 2016 2 commits
  6. 08 Dec, 2015 1 commit
  7. 04 Dec, 2015 1 commit
    • Paul E. McKenney's avatar
      rcu: Add rcu_normal kernel parameter to suppress expediting · 5a9be7c6
      Paul E. McKenney authored
      Although expedited grace periods can be quite useful, and although their
      OS jitter has been greatly reduced, they can still pose problems for
      extreme real-time workloads.  This commit therefore adds a rcu_normal
      kernel boot parameter (which can also be manipulated via sysfs)
      to suppress expedited grace periods, that is, to treat requests for
      expedited grace periods as if they were requests for normal grace periods.
      If both rcu_expedited and rcu_normal are specified, rcu_normal wins.
      This means that if you are relying on expedited grace periods to speed up
      boot, you will want to specify rcu_expedited on the kernel command line,
      and then specify rcu_normal via sysfs once boot completes.
      Signed-off-by: 's avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      5a9be7c6
  8. 10 Sep, 2015 1 commit
    • 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: 's 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: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      2965faa5
  9. 25 Apr, 2014 1 commit
  10. 07 Apr, 2014 1 commit
  11. 26 Feb, 2014 1 commit
  12. 24 Jan, 2014 1 commit
    • Vivek Goyal's avatar
      kdump: fix exported size of vmcoreinfo note · 77019967
      Vivek Goyal authored
      Right now we seem to be exporting the max data size contained inside
      vmcoreinfo note.  But this does not include the size of meta data around
      vmcore info data.  Like name of the note and starting and ending elf_note.
      
      I think user space expects total size and that size is put in PT_NOTE elf
      header.  Things seem to be fine so far because we are not using vmcoreinfo
      note to the maximum capacity.  But as it starts filling up, to capacity,
      at some point of time, problem will be visible.
      
      I don't think user space will be broken with this change.  So there is no
      need to introduce vmcoreinfo2.  This change is safe and backward
      compatible.  More explanation on why this change is safe is below.
      
      vmcoreinfo contains information about kernel which user space needs to
      know to do things like filtering.  For example, various kernel config
      options or information about size or offset of some data structures etc.
      All this information is commmunicated to user space with an ELF note
      present in ELF /proc/vmcore file.
      
      Currently vmcoreinfo data size is 4096.  With some elf note meta data
      around it, actual size is 4132 bytes.  But we are using barely 25% of that
      size.  Rest is empty.  So even if we tell user space that size of ELf note
      is 4096 and not 4132, nothing will be broken becase after around 1000
      bytes, everything is zero anyway.
      
      But once we start filling up the note to the capacity, and not report the
      full size of note, bad things will start happening.  Either some data will
      be lost or tools will be confused that they did not fine the zero note at
      the end.
      
      So I think this change is safe and should not break existing tools.
      Signed-off-by: 's avatarVivek Goyal <vgoyal@redhat.com>
      Cc: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
      Cc: Dan Aloni <da-x@monatomic.org>
      Cc: Greg KH <greg@kroah.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      77019967
  13. 12 Sep, 2013 1 commit
  14. 28 Nov, 2012 1 commit
  15. 23 Oct, 2012 1 commit
  16. 31 Oct, 2011 2 commits
  17. 19 Apr, 2011 1 commit
  18. 21 May, 2010 1 commit
  19. 05 Feb, 2010 1 commit
  20. 21 Jan, 2010 1 commit
  21. 16 Dec, 2009 1 commit
  22. 06 Jan, 2009 1 commit
  23. 16 Oct, 2008 1 commit
  24. 25 Jan, 2008 6 commits
  25. 17 Oct, 2007 2 commits
  26. 15 Oct, 2007 1 commit
  27. 20 Jul, 2007 1 commit
    • David Howells's avatar
      FRV: Fix linkage problems · 0b1937ac
      David Howells authored
      Make it possible to use __start_notes and __stop_notes without getting a GPREL
      overflow error from the FRV linker.
      
      Small variables that would otherwise be in .data or .bss may, depending on the
      arch, be placed in special sections (.sdata or .sbss) that permit single
      instruction references on fixed instruction width machines.
      
      __start_notes and __stop_notes aren't really char variables, and certainly
      don't refer to data in .data or .bss.  Making them type "void" fools the
      compiler into not assuming anything about them.
      Signed-off-by: 's avatarDavid Howells <dhowells@redhat.com>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      0b1937ac
  28. 19 Jul, 2007 1 commit
    • Roland McGrath's avatar
      Add /sys/kernel/notes · da1a679c
      Roland McGrath authored
      This patch adds the /sys/kernel/notes magic file.  Reading this delivers the
      contents of the kernel's .notes section.  This lets userland easily glean any
      detailed information about the running kernel's build that was stored there at
      compile time.
      Signed-off-by: 's avatarRoland McGrath <roland@redhat.com>
      Cc: Andi Kleen <ak@suse.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
      da1a679c
  29. 03 May, 2007 1 commit
  30. 30 Jun, 2006 1 commit
  31. 23 Jun, 2006 1 commit
  32. 24 Mar, 2006 1 commit