1. 06 2月, 2016 3 次提交
    • N
      um: asm/page.h: remove the pte_high member from struct pte_t · 012a4163
      Nicolai Stange 提交于
      Commit 16da3068 ("um: kill pfn_t") introduced a compile warning for
      defconfig (SUBARCH=i386):
      
        arch/um/kernel/skas/mmu.c:38:206:
            warning: right shift count >= width of type [-Wshift-count-overflow]
      
      Aforementioned patch changes the definition of the phys_to_pfn() macro
      from
      
        ((pfn_t) ((p) >> PAGE_SHIFT))
      
      to
      
        ((p) >> PAGE_SHIFT)
      
      This effectively changes the phys_to_pfn() expansion's type from
      unsigned long long to unsigned long.
      
      Through the callchain init_stub_pte() => mk_pte(), the expansion of
      phys_to_pfn() is (indirectly) fed into the 'phys' argument of the
      pte_set_val(pte, phys, prot) macro, eventually leading to
      
        (pte).pte_high = (phys) >> 32;
      
      This results in the warning from above.
      
      Since UML only deals with 32 bit addresses, the upper 32 bits from
      'phys' used to be always zero anyway.  Also, all page protection flags
      defined by UML don't use any bits beyond bit 9.  Since the contents of a
      PTE are defined within architecture scope only, the ->pte_high member
      can be safely removed.
      
      Remove the ->pte_high member from struct pte_t.
      Rename ->pte_low to ->pte.
      Adapt the pte helper macros in arch/um/include/asm/page.h.
      
      Noteworthy is the pte_copy() macro where a smp_wmb() gets dropped.  This
      write barrier doesn't seem to be paired with any read barrier though and
      thus, was useless anyway.
      
      Fixes: 16da3068 ("um: kill pfn_t")
      Signed-off-by: NNicolai Stange <nicstange@gmail.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Nicolai Stange <nicstange@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      012a4163
    • V
      mm, hugetlb: don't require CMA for runtime gigantic pages · 080fe206
      Vlastimil Babka 提交于
      Commit 944d9fec ("hugetlb: add support for gigantic page allocation
      at runtime") has added the runtime gigantic page allocation via
      alloc_contig_range(), making this support available only when CONFIG_CMA
      is enabled.  Because it doesn't depend on MIGRATE_CMA pageblocks and the
      associated infrastructure, it is possible with few simple adjustments to
      require only CONFIG_MEMORY_ISOLATION instead of full CONFIG_CMA.
      
      After this patch, alloc_contig_range() and related functions are
      available and used for gigantic pages with just CONFIG_MEMORY_ISOLATION
      enabled.  Note CONFIG_CMA selects CONFIG_MEMORY_ISOLATION.  This allows
      supporting runtime gigantic pages without the CMA-specific checks in
      page allocator fastpaths.
      Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
      Cc: Luiz Capitulino <lcapitulino@redhat.com>
      Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
      Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: Davidlohr Bueso <dave@stgolabs.net>
      Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
      Cc: Mike Kravetz <mike.kravetz@oracle.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      080fe206
    • S
      m32r: fix build failure due to SMP and MMU · af1ddcb5
      Sudip Mukherjee 提交于
      One of the randconfig build failed with the error:
      
        arch/m32r/kernel/smp.c: In function 'smp_flush_tlb_mm':
        arch/m32r/kernel/smp.c:283:20: error: subscripted value is neither array nor pointer nor vector
          mmc = &mm->context[cpu_id];
                            ^
        arch/m32r/kernel/smp.c: In function 'smp_flush_tlb_page':
        arch/m32r/kernel/smp.c:353:20: error: subscripted value is neither array nor pointer nor vector
          mmc = &mm->context[cpu_id];
                            ^
        arch/m32r/kernel/smp.c: In function 'smp_invalidate_interrupt':
        arch/m32r/kernel/smp.c:479:41: error: subscripted value is neither array nor pointer nor vector
          unsigned long *mmc = &flush_mm->context[cpu_id];
      
      It turned out that CONFIG_SMP was defined but CONFIG_MMU was not
      defined.  But arch/m32r/include/asm/mmu.h only defines mm_context_t as
      an array when both CONFIG_SMP and CONFIG_MMU are defined.  And
      arch/m32r/kernel/smp.c is always using context as an array.  So without
      MMU SMP can not work.
      Signed-off-by: NSudip Mukherjee <sudip@vectorindia.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      af1ddcb5
  2. 05 2月, 2016 2 次提交
  3. 04 2月, 2016 1 次提交
  4. 02 2月, 2016 7 次提交
  5. 01 2月, 2016 1 次提交
  6. 29 1月, 2016 3 次提交
    • M
      x86/mm/pat: Avoid truncation when converting cpa->numpages to address · 74256377
      Matt Fleming 提交于
      There are a couple of nasty truncation bugs lurking in the pageattr
      code that can be triggered when mapping EFI regions, e.g. when we pass
      a cpa->pgd pointer. Because cpa->numpages is a 32-bit value, shifting
      left by PAGE_SHIFT will truncate the resultant address to 32-bits.
      
      Viorel-Cătălin managed to trigger this bug on his Dell machine that
      provides a ~5GB EFI region which requires 1236992 pages to be mapped.
      When calling populate_pud() the end of the region gets calculated
      incorrectly in the following buggy expression,
      
        end = start + (cpa->numpages << PAGE_SHIFT);
      
      And only 188416 pages are mapped. Next, populate_pud() gets invoked
      for a second time because of the loop in __change_page_attr_set_clr(),
      only this time no pages get mapped because shifting the remaining
      number of pages (1048576) by PAGE_SHIFT is zero. At which point the
      loop in __change_page_attr_set_clr() spins forever because we fail to
      map progress.
      
      Hitting this bug depends very much on the virtual address we pick to
      map the large region at and how many pages we map on the initial run
      through the loop. This explains why this issue was only recently hit
      with the introduction of commit
      
        a5caa209 ("x86/efi: Fix boot crash by mapping EFI memmap
         entries bottom-up at runtime, instead of top-down")
      
      It's interesting to note that safe uses of cpa->numpages do exist in
      the pageattr code. If instead of shifting ->numpages we multiply by
      PAGE_SIZE, no truncation occurs because PAGE_SIZE is a UL value, and
      so the result is unsigned long.
      
      To avoid surprises when users try to convert very large cpa->numpages
      values to addresses, change the data type from 'int' to 'unsigned
      long', thereby making it suitable for shifting by PAGE_SHIFT without
      any type casting.
      
      The alternative would be to make liberal use of casting, but that is
      far more likely to cause problems in the future when someone adds more
      code and fails to cast properly; this bug was difficult enough to
      track down in the first place.
      Reported-and-tested-by: NViorel-Cătălin Răpițeanu <rapiteanu.catalin@gmail.com>
      Acked-by: NBorislav Petkov <bp@alien8.de>
      Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      Link: https://bugzilla.kernel.org/show_bug.cgi?id=110131
      Link: http://lkml.kernel.org/r/1454067370-10374-1-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      74256377
    • P
      perf/x86: De-obfuscate code · 8f04b853
      Peter Zijlstra 提交于
      Get rid of the 'onln' obfuscation.
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      8f04b853
    • P
      perf/x86: Fix uninitialized value usage · e01d8718
      Peter Zijlstra 提交于
      When calling intel_alt_er() with .idx != EXTRA_REG_RSP_* we will not
      initialize alt_idx and then use this uninitialized value to index an
      array.
      
      When that is not fatal, it can result in an infinite loop in its
      caller __intel_shared_reg_get_constraints(), with IRQs disabled.
      
      Alternative error modes are random memory corruption due to the
      cpuc->shared_regs->regs[] array overrun, which manifest in either
      get_constraints or put_constraints doing weird stuff.
      
      Only took 6 hours of painful debugging to find this. Neither GCC nor
      Smatch warnings flagged this bug.
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Kan Liang <kan.liang@intel.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Fixes: ae3f011f ("perf/x86/intel: Fix SLM MSR_OFFCORE_RSP1 valid_mask")
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      e01d8718
  7. 28 1月, 2016 13 次提交
  8. 27 1月, 2016 9 次提交
  9. 26 1月, 2016 1 次提交
    • M
      arm64: mm: avoid calling apply_to_page_range on empty range · 57adec86
      Mika Penttilä 提交于
      Calling apply_to_page_range with an empty range results in a BUG_ON
      from the core code. This can be triggered by trying to load the st_drv
      module with CONFIG_DEBUG_SET_MODULE_RONX enabled:
      
        kernel BUG at mm/memory.c:1874!
        Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
        Modules linked in:
        CPU: 3 PID: 1764 Comm: insmod Not tainted 4.5.0-rc1+ #2
        Hardware name: ARM Juno development board (r0) (DT)
        task: ffffffc9763b8000 ti: ffffffc975af8000 task.ti: ffffffc975af8000
        PC is at apply_to_page_range+0x2cc/0x2d0
        LR is at change_memory_common+0x80/0x108
      
      This patch fixes the issue by making change_memory_common (called by the
      set_memory_* functions) a NOP when numpages == 0, therefore avoiding the
      erroneous call to apply_to_page_range and bringing us into line with x86
      and s390.
      
      Cc: <stable@vger.kernel.org>
      Reviewed-by: NLaura Abbott <labbott@redhat.com>
      Acked-by: NDavid Rientjes <rientjes@google.com>
      Signed-off-by: NMika Penttilä <mika.penttila@nextfour.com>
      Signed-off-by: NWill Deacon <will.deacon@arm.com>
      57adec86