1. 14 7月, 2011 4 次提交
  2. 07 6月, 2011 1 次提交
    • A
      x86-64: Emulate legacy vsyscalls · 5cec93c2
      Andy Lutomirski 提交于
      There's a fair amount of code in the vsyscall page.  It contains
      a syscall instruction (in the gettimeofday fallback) and who
      knows what will happen if an exploit jumps into the middle of
      some other code.
      
      Reduce the risk by replacing the vsyscalls with short magic
      incantations that cause the kernel to emulate the real
      vsyscalls. These incantations are useless if entered in the
      middle.
      
      This causes vsyscalls to be a little more expensive than real
      syscalls.  Fortunately sensible programs don't use them.
      The only exception is time() which is still called by glibc
      through the vsyscall - but calling time() millions of times
      per second is not sensible. glibc has this fixed in the
      development tree.
      
      This patch is not perfect: the vread_tsc and vread_hpet
      functions are still at a fixed address.  Fixing that might
      involve making alternative patching work in the vDSO.
      Signed-off-by: NAndy Lutomirski <luto@mit.edu>
      Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Cc: Jesper Juhl <jj@chaosbits.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Arjan van de Ven <arjan@infradead.org>
      Cc: Jan Beulich <JBeulich@novell.com>
      Cc: richard -rw- weinberger <richard.weinberger@gmail.com>
      Cc: Mikael Pettersson <mikpe@it.uu.se>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Louis Rilling <Louis.Rilling@kerlabs.com>
      Cc: Valdis.Kletnieks@vt.edu
      Cc: pageexec@freemail.hu
      Link: http://lkml.kernel.org/r/e64e1b3c64858820d12c48fa739efbd1485e79d5.1307292171.git.luto@mit.edu
      [ Removed the CONFIG option - it's simpler to just do it unconditionally. Tidied up the code as well. ]
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      5cec93c2
  3. 06 6月, 2011 7 次提交
  4. 04 6月, 2011 12 次提交
  5. 03 6月, 2011 10 次提交
  6. 02 6月, 2011 6 次提交