1. 27 7月, 2015 2 次提交
  2. 19 7月, 2015 1 次提交
  3. 18 7月, 2015 1 次提交
  4. 11 7月, 2015 1 次提交
    • J
      parisc: Fix some PTE/TLB race conditions and optimize __flush_tlb_range based on timing results · 01ab6057
      John David Anglin 提交于
      The increased use of pdtlb/pitlb instructions seemed to increase the
      frequency of random segmentation faults building packages. Further, we
      had a number of cases where TLB inserts would repeatedly fail and all
      forward progress would stop. The Haskell ghc package caused a lot of
      trouble in this area. The final indication of a race in pte handling was
      this syslog entry on sibaris (C8000):
      
       swap_free: Unused swap offset entry 00000004
       BUG: Bad page map in process mysqld  pte:00000100 pmd:019bbec5
       addr:00000000ec464000 vm_flags:00100073 anon_vma:0000000221023828 mapping: (null) index:ec464
       CPU: 1 PID: 9176 Comm: mysqld Not tainted 4.0.0-2-parisc64-smp #1 Debian 4.0.5-1
       Backtrace:
        [<0000000040173eb0>] show_stack+0x20/0x38
        [<0000000040444424>] dump_stack+0x9c/0x110
        [<00000000402a0d38>] print_bad_pte+0x1a8/0x278
        [<00000000402a28b8>] unmap_single_vma+0x3d8/0x770
        [<00000000402a4090>] zap_page_range+0xf0/0x198
        [<00000000402ba2a4>] SyS_madvise+0x404/0x8c0
      
      Note that the pte value is 0 except for the accessed bit 0x100. This bit
      shouldn't be set without the present bit.
      
      It should be noted that the madvise system call is probably a trigger for many
      of the random segmentation faults.
      
      In looking at the kernel code, I found the following problems:
      
      1) The pte_clear define didn't take TLB lock when clearing a pte.
      2) We didn't test pte present bit inside lock in exception support.
      3) The pte and tlb locks needed to merged in order to ensure consistency
      between page table and TLB. This also has the effect of serializing TLB
      broadcasts on SMP systems.
      
      The attached change implements the above and a few other tweaks to try
      to improve performance. Based on the timing code, TLB purges are very
      slow (e.g., ~ 209 cycles per page on rp3440). Thus, I think it
      beneficial to test the split_tlb variable to avoid duplicate purges.
      Probably, all PA 2.0 machines have combined TLBs.
      
      I dropped using __flush_tlb_range in flush_tlb_mm as I realized all
      applications and most threads have a stack size that is too large to
      make this useful. I added some comments to this effect.
      
      Since implementing 1 through 3, I haven't had any random segmentation
      faults on mx3210 (rp3440) in about one week of building code and running
      as a Debian buildd.
      Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
      Cc: stable@vger.kernel.org # v3.18+
      Signed-off-by: NHelge Deller <deller@gmx.de>
      01ab6057
  5. 25 6月, 2015 1 次提交
    • L
      mm: new mm hook framework · 2ae416b1
      Laurent Dufour 提交于
      CRIU is recreating the process memory layout by remapping the checkpointee
      memory area on top of the current process (criu).  This includes remapping
      the vDSO to the place it has at checkpoint time.
      
      However some architectures like powerpc are keeping a reference to the
      vDSO base address to build the signal return stack frame by calling the
      vDSO sigreturn service.  So once the vDSO has been moved, this reference
      is no more valid and the signal frame built later are not usable.
      
      This patch serie is introducing a new mm hook framework, and a new
      arch_remap hook which is called when mremap is done and the mm lock still
      hold.  The next patch is adding the vDSO remap and unmap tracking to the
      powerpc architecture.
      
      This patch (of 3):
      
      This patch introduces a new set of header file to manage mm hooks:
      - per architecture empty header file (arch/x/include/asm/mm-arch-hooks.h)
      - a generic header (include/linux/mm-arch-hooks.h)
      
      The architecture which need to overwrite a hook as to redefine it in its
      header file, while architecture which doesn't need have nothing to do.
      
      The default hooks are defined in the generic header and are used in the
      case the architecture is not defining it.
      
      In a next step, mm hooks defined in include/asm-generic/mm_hooks.h should
      be moved here.
      Signed-off-by: NLaurent Dufour <ldufour@linux.vnet.ibm.com>
      Suggested-by: NAndrew Morton <akpm@linux-foundation.org>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Ingo Molnar <mingo@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2ae416b1
  6. 08 6月, 2015 1 次提交
  7. 19 5月, 2015 2 次提交
  8. 13 5月, 2015 2 次提交
    • T
      arch: Remove __ARCH_HAVE_CMPXCHG · a22e5f57
      Thomas Gleixner 提交于
      We removed the only user of this define in the rtmutex code. Get rid
      of it.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
      a22e5f57
    • H
      parisc,metag: Fix crashes due to stack randomization on stack-grows-upwards architectures · d045c77c
      Helge Deller 提交于
      On architectures where the stack grows upwards (CONFIG_STACK_GROWSUP=y,
      currently parisc and metag only) stack randomization sometimes leads to crashes
      when the stack ulimit is set to lower values than STACK_RND_MASK (which is 8 MB
      by default if not defined in arch-specific headers).
      
      The problem is, that when the stack vm_area_struct is set up in fs/exec.c, the
      additional space needed for the stack randomization (as defined by the value of
      STACK_RND_MASK) was not taken into account yet and as such, when the stack
      randomization code added a random offset to the stack start, the stack
      effectively got smaller than what the user defined via rlimit_max(RLIMIT_STACK)
      which then sometimes leads to out-of-stack situations and crashes.
      
      This patch fixes it by adding the maximum possible amount of memory (based on
      STACK_RND_MASK) which theoretically could be added by the stack randomization
      code to the initial stack size. That way, the user-defined stack size is always
      guaranteed to be at minimum what is defined via rlimit_max(RLIMIT_STACK).
      
      This bug is currently not visible on the metag architecture, because on metag
      STACK_RND_MASK is defined to 0 which effectively disables stack randomization.
      
      The changes to fs/exec.c are inside an "#ifdef CONFIG_STACK_GROWSUP"
      section, so it does not affect other platformws beside those where the
      stack grows upwards (parisc and metag).
      Signed-off-by: NHelge Deller <deller@gmx.de>
      Cc: linux-parisc@vger.kernel.org
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: linux-metag@vger.kernel.org
      Cc: stable@vger.kernel.org # v3.16+
      d045c77c
  9. 06 5月, 2015 1 次提交
  10. 22 4月, 2015 2 次提交
  11. 17 4月, 2015 1 次提交
  12. 15 4月, 2015 1 次提交
  13. 13 4月, 2015 1 次提交
  14. 23 3月, 2015 2 次提交
  15. 01 3月, 2015 1 次提交
    • K
      mm: add missing __PAGETABLE_{PUD,PMD}_FOLDED defines · c07af4f1
      Kirill A. Shutemov 提交于
      Core mm expects __PAGETABLE_{PUD,PMD}_FOLDED to be defined if these page
      table levels folded.  Usually, these defines are provided by
      <asm-generic/pgtable-nopmd.h> and <asm-generic/pgtable-nopud.h>.
      
      But some architectures fold page table levels in a custom way.  They
      need to define these macros themself.  This patch adds missing defines.
      
      The patch fixes mm->nr_pmds underflow and eliminates dead __pmd_alloc()
      and __pud_alloc() on architectures without these page table levels.
      Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c07af4f1
  16. 17 2月, 2015 5 次提交
  17. 13 2月, 2015 1 次提交
    • A
      all arches, signal: move restart_block to struct task_struct · f56141e3
      Andy Lutomirski 提交于
      If an attacker can cause a controlled kernel stack overflow, overwriting
      the restart block is a very juicy exploit target.  This is because the
      restart_block is held in the same memory allocation as the kernel stack.
      
      Moving the restart block to struct task_struct prevents this exploit by
      making the restart_block harder to locate.
      
      Note that there are other fields in thread_info that are also easy
      targets, at least on some architectures.
      
      It's also a decent simplification, since the restart code is more or less
      identical on all architectures.
      
      [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
      Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: David Miller <davem@davemloft.net>
      Acked-by: NRichard Weinberger <richard@nod.at>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Guenter Roeck <linux@roeck-us.net>
      Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f56141e3
  18. 12 2月, 2015 1 次提交
  19. 11 2月, 2015 1 次提交
  20. 13 1月, 2015 2 次提交
  21. 27 12月, 2014 1 次提交
  22. 11 12月, 2014 1 次提交
  23. 06 12月, 2014 1 次提交
    • A
      net: sock: allow eBPF programs to be attached to sockets · 89aa0758
      Alexei Starovoitov 提交于
      introduce new setsockopt() command:
      
      setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd, sizeof(prog_fd))
      
      where prog_fd was received from syscall bpf(BPF_PROG_LOAD, attr, ...)
      and attr->prog_type == BPF_PROG_TYPE_SOCKET_FILTER
      
      setsockopt() calls bpf_prog_get() which increments refcnt of the program,
      so it doesn't get unloaded while socket is using the program.
      
      The same eBPF program can be attached to multiple sockets.
      
      User task exit automatically closes socket which calls sk_filter_uncharge()
      which decrements refcnt of eBPF program
      Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      89aa0758
  24. 12 11月, 2014 1 次提交
    • E
      net: introduce SO_INCOMING_CPU · 2c8c56e1
      Eric Dumazet 提交于
      Alternative to RPS/RFS is to use hardware support for multiple
      queues.
      
      Then split a set of million of sockets into worker threads, each
      one using epoll() to manage events on its own socket pool.
      
      Ideally, we want one thread per RX/TX queue/cpu, but we have no way to
      know after accept() or connect() on which queue/cpu a socket is managed.
      
      We normally use one cpu per RX queue (IRQ smp_affinity being properly
      set), so remembering on socket structure which cpu delivered last packet
      is enough to solve the problem.
      
      After accept(), connect(), or even file descriptor passing around
      processes, applications can use :
      
       int cpu;
       socklen_t len = sizeof(cpu);
      
       getsockopt(fd, SOL_SOCKET, SO_INCOMING_CPU, &cpu, &len);
      
      And use this information to put the socket into the right silo
      for optimal performance, as all networking stack should run
      on the appropriate cpu, without need to send IPI (RPS/RFS).
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2c8c56e1
  25. 11 11月, 2014 4 次提交
  26. 21 10月, 2014 1 次提交
  27. 12 10月, 2014 1 次提交
    • H
      parisc: Reduce SIGRTMIN from 37 to 32 to behave like other Linux architectures · 1f25df2e
      Helge Deller 提交于
      This patch reduces the value of SIGRTMIN on PARISC from 37 to 32, thus
      increasing the number of available RT signals and bring it in sync with other
      Linux architectures.
      
      Historically we wanted to natively support HP-UX 32bit binaries with the
      PA-RISC Linux port.  Because of that we carried the various available signals
      from HP-UX (e.g. SIGEMT and SIGLOST) and folded them in between the native
      Linux signals.  Although this was the right decision at that time, this
      required us to increase SIGRTMIN to at least 37 which left us with 27 (64-37)
      RT signals.
      
      Those 27 RT signals haven't been a problem in the past, but with the upcoming
      importance of systemd we now got the problem that systemd alloctes (hardcoded)
      signals up to SIGRTMIN+29 which is beyond our NSIG of 64. Because of that we
      have not been able to use systemd on the PARISC Linux port yet.
      
      Of course we could ask the systemd developers to not use those hardcoded
      values, but this change is very unlikely, esp. with PA-RISC being a niche
      architecture.
      
      The other possibility would be to increase NSIG to e.g. 128, but this would
      mean to duplicate most of the existing Linux signal handling code into the
      parisc specific Linux kernel tree which would most likely introduce lots of new
      bugs beside the code duplication.
      
      The third option is to drop some HP-UX signals and shuffle some other signals
      around to bring SIGRTMIN to 32.  This is of course an ABI change, but testing
      has shown that existing Linux installations are not visibly affected by this
      change - most likely because we move those signals around which are rarely used
      and move them to slots which haven't been used in Linux yet. In an existing
      installation I was able to exchange either the Linux kernel or glibc (or both)
      without affecting the boot process and installed applications.
      
      Dropping the HP-UX signals isn't an issue either, since support for HP-UX was
      basically dropped a few months back with Kernel 3.14 in commit
      f5a408d5 already, when we changed EWOULDBLOCK
      to be equal to EAGAIN.
      
      So, even if this is an ABI change, it's better to change it now and thus bring
      PARISC Linux in sync with other architectures to avoid other issues in the
      future.
      Signed-off-by: NHelge Deller <deller@gmx.de>
      Cc: Carlos O'Donell <carlos@systemhalted.org>
      Cc: John David Anglin <dave.anglin@bell.net>
      Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
      Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
      Cc: PARISC Linux Kernel Mailinglist <linux-parisc@vger.kernel.org>
      Tested-by: NAaro Koskinen <aaro.koskinen@iki.fi>
      1f25df2e