1. 10 Sep, 2015 1 commit
    • 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
  2. 08 Aug, 2014 1 commit
    • Yinghai Lu's avatar
      initramfs: support initramfs that is bigger than 2GiB · d97b07c5
      Yinghai Lu authored
      Now with 64bit bzImage and kexec tools, we support ramdisk that size is
      bigger than 2g, as we could put it above 4G.
      
      Found compressed initramfs image could not be decompressed properly.  It
      turns out that image length is int during decompress detection, and it
      will become < 0 when length is more than 2G.  Furthermore, during
      decompressing len as int is used for inbuf count, that has problem too.
      
      Change len to long, that should be ok as on 32 bit platform long is
      32bits.
      
      Tested with following compressed initramfs image as root with kexec.
      	gzip, bzip2, xz, lzma, lzop, lz4.
      run time for populate_rootfs():
         size        name       Nehalem-EX  Westmere-EX  Ivybridge-EX
       9034400256 root_img     :   26s           24s          30s
       3561095057 root_img.lz4 :   28s           27s          27s
       3459554629 root_img.lzo :   29s           29s          28s
       3219399480 root_img.gz  :   64s           62s          49s
       2251594592 root_img.xz  :  262s          260s         183s
       2226366598 root_img.lzma:  386s          376s         277s
       2901482513 root_img.bz2 :  635s          599s
      Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Rashika Kheria <rashika.kheria@gmail.com>
      Cc: Josh Triplett <josh@joshtriplett.org>
      Cc: Kyungsik Lee <kyungsik.lee@lge.com>
      Cc: P J P <ppandit@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
      Cc: "Daniel M. Weeks" <dan@danweeks.net>
      Cc: Alexandre Courbot <acourbot@nvidia.com>
      Cc: Jan Beulich <JBeulich@suse.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d97b07c5
  3. 20 Feb, 2013 1 commit
  4. 13 Jan, 2012 1 commit
  5. 13 Jan, 2011 5 commits
  6. 24 Apr, 2010 1 commit
  7. 11 Jan, 2010 1 commit
    • Albin Tonnerre's avatar
      lib: add support for LZO-compressed kernels · 7dd65feb
      Albin Tonnerre authored
      This patch series adds generic support for creating and extracting
      LZO-compressed kernel images, as well as support for using such images on
      the x86 and ARM architectures, and support for creating and using
      LZO-compressed initrd and initramfs images.
      
      Russell King said:
      
      : Testing on a Cortex A9 model:
      : - lzo decompressor is 65% of the time gzip takes to decompress a kernel
      : - lzo kernel is 9% larger than a gzip kernel
      :
      : which I'm happy to say confirms your figures when comparing the two.
      :
      : However, when comparing your new gzip code to the old gzip code:
      : - new is 99% of the size of the old code
      : - new takes 42% of the time to decompress than the old code
      :
      : What this means is that for a proper comparison, the results get even better:
      : - lzo is 7.5% larger than the old gzip'd kernel image
      : - lzo takes 28% of the time that the old gzip code took
      :
      : So the expense seems definitely worth the effort.  The only reason I
      : can think of ever using gzip would be if you needed the additional
      : compression (eg, because you have limited flash to store the image.)
      :
      : I would argue that the default for ARM should therefore be LZO.
      
      This patch:
      
      The lzo compressor is worse than gzip at compression, but faster at
      extraction.  Here are some figures for an ARM board I'm working on:
      
      Uncompressed size: 3.24Mo
      gzip  1.61Mo 0.72s
      lzo   1.75Mo 0.48s
      
      So for a compression ratio that is still relatively close to gzip, it's
      much faster to extract, at least in that case.
      
      This part contains:
       - Makefile routine to support lzo compression
       - Fixes to the existing lzo compressor so that it can be used in
         compressed kernels
       - wrapper around the existing lzo1x_decompress, as it only extracts one
         block at a time, while we need to extract a whole file here
       - config dialog for kernel compression
      
      [akpm@linux-foundation.org: coding-style fixes]
      [akpm@linux-foundation.org: cleanup]
      Signed-off-by: default avatarAlbin Tonnerre <albin.tonnerre@free-electrons.com>
      Tested-by: default avatarWu Zhangjin <wuzhangjin@gmail.com>
      Acked-by: default avatar"H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarRussell King <rmk@arm.linux.org.uk>
      Acked-by: default avatarRussell King <rmk@arm.linux.org.uk>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7dd65feb