1. 30 Jan, 2008 9 commits
  2. 25 Oct, 2007 1 commit
  3. 19 Oct, 2007 5 commits
  4. 16 Oct, 2007 1 commit
    • Christoph Hellwig's avatar
      x86: optimize page faults like all other achitectures and kill notifier cruft · 74a0b576
      Christoph Hellwig authored
      
      
      x86(-64) are the last architectures still using the page fault notifier
      cruft for the kprobes page fault hook.  This patch converts them to the
      proper direct calls, and removes the now unused pagefault notifier bits
      aswell as the cruft in kprobes.c that was related to this mess.
      
      I know Andi didn't really like this, but all other architecture maintainers
      agreed the direct calls are much better and besides the obvious cruft
      removal a common way of dealing with kprobes across architectures is
      important aswell.
      
      [akpm@linux-foundation.org: build fix]
      [akpm@linux-foundation.org: fix sparc64]
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Cc: Andi Kleen <ak@suse.de>
      Cc: <linux-arch@vger.kernel.org>
      Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
      Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
      Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      74a0b576
  5. 11 Oct, 2007 2 commits
  6. 19 Sep, 2007 1 commit
    • Linus Torvalds's avatar
      x86-64: page faults from user mode are always user faults · dbe3ed1c
      Linus Torvalds authored
      
      
      Randy Dunlap noticed an interesting "crashme" behaviour on his dual
      Prescott Xeon setup, where he gets page faults with the error code
      having a zero "user" bit, but the register state points back to user
      mode.
      
      This may be a CPU microcode buglet triggered by some strange instruction
      pattern that crashme generates, and loading a microcode update seems to
      possibly have fixed it.
      
      Regardless, we really should trust the register state more than the
      error code, since it's really the register state that determines whether
      we can actually send a signal, or whether we're in kernel mode and need
      to oops/kill the process in the case of a page fault.
      
      Cc: Randy Dunlap <rdunlap@xenotime.net>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      dbe3ed1c
  7. 22 Jul, 2007 4 commits
  8. 19 Jul, 2007 1 commit
    • Nick Piggin's avatar
      mm: fault feedback #2 · 83c54070
      Nick Piggin authored
      
      
      This patch completes Linus's wish that the fault return codes be made into
      bit flags, which I agree makes everything nicer.  This requires requires
      all handle_mm_fault callers to be modified (possibly the modifications
      should go further and do things like fault accounting in handle_mm_fault --
      however that would be for another patch).
      
      [akpm@linux-foundation.org: fix alpha build]
      [akpm@linux-foundation.org: fix s390 build]
      [akpm@linux-foundation.org: fix sparc build]
      [akpm@linux-foundation.org: fix sparc64 build]
      [akpm@linux-foundation.org: fix ia64 build]
      Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Ian Molton <spyro@f2s.com>
      Cc: Bryan Wu <bryan.wu@analog.com>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Hirokazu Takata <takata@linux-m32r.org>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Cc: Greg Ungerer <gerg@uclinux.org>
      Cc: Matthew Wilcox <willy@debian.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
      Cc: Richard Curnow <rc@rc0.org.uk>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
      Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
      Cc: Chris Zankel <chris@zankel.net>
      Acked-by: default avatarKyle McMartin <kyle@mcmartin.ca>
      Acked-by: default avatarHaavard Skinnemoen <hskinnemoen@atmel.com>
      Acked-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Acked-by: default avatarAndi Kleen <ak@muc.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      [ Still apparently needs some ARM and PPC loving - Linus ]
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      83c54070
  9. 08 Jun, 2007 1 commit
    • Steven Rostedt's avatar
      enable interrupts in user path of page fault. · e5e3c84b
      Steven Rostedt authored
      
      
      This is a minor fix, but what is currently there is essentially wrong.
      In do_page_fault, if the faulting address from user code happens to be
      in kernel address space (int *p = (int*)-1; p = 0xbed;)  then the
      do_page_fault handler will jump over the local_irq_enable with the
      
        goto bad_area_nosemaphore;
      
      But the first line there sees this is user code and goes through the
      process of sending a signal to send SIGSEGV to the user task. This whole
      time interrupts are disabled and the task can not be preempted by a
      higher priority task.
      
      This patch always enables interrupts in the user path of the
      bad_area_nosemaphore.
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e5e3c84b
  10. 08 May, 2007 2 commits
  11. 02 May, 2007 1 commit
  12. 13 Feb, 2007 1 commit
  13. 11 Feb, 2007 1 commit
  14. 07 Dec, 2006 1 commit
  15. 29 Sep, 2006 2 commits
    • Sukadev Bhattiprolu's avatar
      [PATCH] pidspace: is_init() · f400e198
      Sukadev Bhattiprolu authored
      This is an updated version of Eric Biederman's is_init() patch.
      (http://lkml.org/lkml/2006/2/6/280
      
      ).  It applies cleanly to 2.6.18-rc3 and
      replaces a few more instances of ->pid == 1 with is_init().
      
      Further, is_init() checks pid and thus removes dependency on Eric's other
      patches for now.
      
      Eric's original description:
      
      	There are a lot of places in the kernel where we test for init
      	because we give it special properties.  Most  significantly init
      	must not die.  This results in code all over the kernel test
      	->pid == 1.
      
      	Introduce is_init to capture this case.
      
      	With multiple pid spaces for all of the cases affected we are
      	looking for only the first process on the system, not some other
      	process that has pid == 1.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarSukadev Bhattiprolu <sukadev@us.ibm.com>
      Cc: Dave Hansen <haveblue@us.ibm.com>
      Cc: Serge Hallyn <serue@us.ibm.com>
      Cc: Cedric Le Goater <clg@fr.ibm.com>
      Cc: <lxc-devel@lists.sourceforge.net>
      Acked-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      f400e198
    • Jason Baron's avatar
      [PATCH] make PROT_WRITE imply PROT_READ · df67b3da
      Jason Baron authored
      
      
      Make PROT_WRITE imply PROT_READ for a number of architectures which don't
      support write only in hardware.
      
      While looking at this, I noticed that some architectures which do not
      support write only mappings already take the exact same approach.  For
      example, in arch/alpha/mm/fault.c:
      
      "
              if (cause < 0) {
                      if (!(vma->vm_flags & VM_EXEC))
                              goto bad_area;
              } else if (!cause) {
                      /* Allow reads even for write-only mappings */
                      if (!(vma->vm_flags & (VM_READ | VM_WRITE)))
                              goto bad_area;
              } else {
                      if (!(vma->vm_flags & VM_WRITE))
                              goto bad_area;
              }
      "
      
      Thus, this patch brings other architectures which do not support write only
      mappings in-line and consistent with the rest.  I've verified the patch on
      ia64, x86_64 and x86.
      
      Additional discussion:
      
      Several architectures, including x86, can not support write-only mappings.
      The pte for x86 reserves a single bit for protection and its two states are
      read only or read/write.  Thus, write only is not supported in h/w.
      
      Currently, if i 'mmap' a page write-only, the first read attempt on that page
      creates a page fault and will SEGV.  That check is enforced in
      arch/blah/mm/fault.c.  However, if i first write that page it will fault in
      and the pte will be set to read/write.  Thus, any subsequent reads to the page
      will succeed.  It is this inconsistency in behavior that this patch is
      attempting to address.  Furthermore, if the page is swapped out, and then
      brought back the first read will also cause a SEGV.  Thus, any arbitrary read
      on a page can potentially result in a SEGV.
      
      According to the SuSv3 spec, "if the application requests only PROT_WRITE, the
      implementation may also allow read access." Also as mentioned, some
      archtectures, such as alpha, shown above already take the approach that i am
      suggesting.
      
      The counter-argument to this raised by Arjan, is that the kernel is enforcing
      the write only mapping the best it can given the h/w limitations.  This is
      true, however Alan Cox, and myself would argue that the inconsitency in
      behavior, that is applications can sometimes work/sometimes fails is highly
      undesireable.  If you read through the thread, i think people, came to an
      agreement on the last patch i posted, as nobody has objected to it...
      Signed-off-by: default avatarJason Baron <jbaron@redhat.com>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Hugh Dickins <hugh@veritas.com>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Acked-by: default avatarAndi Kleen <ak@muc.de>
      Acked-by: default avatarAlan Cox <alan@lxorguk.ukuu.org.uk>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Acked-by: default avatarPaul Mundt <lethal@linux-sh.org>
      Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
      Cc: Ian Molton <spyro@f2s.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      df67b3da
  16. 26 Sep, 2006 3 commits
    • Dave McCracken's avatar
      [PATCH] Standardize pxx_page macros · 46a82b2d
      Dave McCracken authored
      
      
      One of the changes necessary for shared page tables is to standardize the
      pxx_page macros.  pte_page and pmd_page have always returned the struct
      page associated with their entry, while pte_page_kernel and pmd_page_kernel
      have returned the kernel virtual address.  pud_page and pgd_page, on the
      other hand, return the kernel virtual address.
      
      Shared page tables needs pud_page and pgd_page to return the actual page
      structures.  There are very few actual users of these functions, so it is
      simple to standardize their usage.
      
      Since this is basic cleanup, I am submitting these changes as a standalone
      patch.  Per Hugh Dickins' comments about it, I am also changing the
      pxx_page_kernel macros to pxx_page_vaddr to clarify their meaning.
      Signed-off-by: default avatarDave McCracken <dmccr@us.ibm.com>
      Cc: Hugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      46a82b2d
    • Andi Kleen's avatar
      [PATCH] make fault notifier unconditional and export it · 273819a2
      Andi Kleen authored
      
      
      It's needed for external debuggers and overhead is very small.
      
      Also make the actual notifier chain they use static
      
      Cc: jbeulich@novell.com
      Signed-off-by: default avatarAndi Kleen <ak@suse.de>
      273819a2
    • Andi Kleen's avatar
      [PATCH] Add sparse annotations to quiet sparse in arch/x86_64/mm/fault.c · dd2994f6
      Andi Kleen authored
      
      
      Fixes
      
      linux/arch/x86_64/mm/fault.c:125:7: warning: incorrect type in argument 1 (different address spaces)
      linux/arch/x86_64/mm/fault.c:125:7:    expected void [noderef] *<noident><asn:1>
      linux/arch/x86_64/mm/fault.c:125:7:    got unsigned char *[assigned] instr
      linux/arch/x86_64/mm/fault.c:163:8: warning: incorrect type in argument 1 (different address spaces)
      linux/arch/x86_64/mm/fault.c:163:8:    expected void [noderef] *<noident><asn:1>
      linux/arch/x86_64/mm/fault.c:163:8:    got unsigned char *[assigned] instr
      linux/arch/x86_64/mm/fault.c:179:9: warning: incorrect type in argument 1 (different address spaces)
      linux/arch/x86_64/mm/fault.c:179:9:    expected void [noderef] *<noident><asn:1>
      linux/arch/x86_64/mm/fault.c:179:9:    got unsigned long *<noident>
      Signed-off-by: default avatarAndi Kleen <ak@suse.de>
      dd2994f6
  17. 03 Jul, 2006 1 commit
  18. 30 Jun, 2006 2 commits
  19. 26 Jun, 2006 1 commit