1. 15 10月, 2010 1 次提交
    • A
      llseek: automatically add .llseek fop · 6038f373
      Arnd Bergmann 提交于
      All file_operations should get a .llseek operation so we can make
      nonseekable_open the default for future file operations without a
      .llseek pointer.
      
      The three cases that we can automatically detect are no_llseek, seq_lseek
      and default_llseek. For cases where we can we can automatically prove that
      the file offset is always ignored, we use noop_llseek, which maintains
      the current behavior of not returning an error from a seek.
      
      New drivers should normally not use noop_llseek but instead use no_llseek
      and call nonseekable_open at open time.  Existing drivers can be converted
      to do the same when the maintainer knows for certain that no user code
      relies on calling seek on the device file.
      
      The generated code is often incorrectly indented and right now contains
      comments that clarify for each added line why a specific variant was
      chosen. In the version that gets submitted upstream, the comments will
      be gone and I will manually fix the indentation, because there does not
      seem to be a way to do that using coccinelle.
      
      Some amount of new code is currently sitting in linux-next that should get
      the same modifications, which I will do at the end of the merge window.
      
      Many thanks to Julia Lawall for helping me learn to write a semantic
      patch that does all this.
      
      ===== begin semantic patch =====
      // This adds an llseek= method to all file operations,
      // as a preparation for making no_llseek the default.
      //
      // The rules are
      // - use no_llseek explicitly if we do nonseekable_open
      // - use seq_lseek for sequential files
      // - use default_llseek if we know we access f_pos
      // - use noop_llseek if we know we don't access f_pos,
      //   but we still want to allow users to call lseek
      //
      @ open1 exists @
      identifier nested_open;
      @@
      nested_open(...)
      {
      <+...
      nonseekable_open(...)
      ...+>
      }
      
      @ open exists@
      identifier open_f;
      identifier i, f;
      identifier open1.nested_open;
      @@
      int open_f(struct inode *i, struct file *f)
      {
      <+...
      (
      nonseekable_open(...)
      |
      nested_open(...)
      )
      ...+>
      }
      
      @ read disable optional_qualifier exists @
      identifier read_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      expression E;
      identifier func;
      @@
      ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
      {
      <+...
      (
         *off = E
      |
         *off += E
      |
         func(..., off, ...)
      |
         E = *off
      )
      ...+>
      }
      
      @ read_no_fpos disable optional_qualifier exists @
      identifier read_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      @@
      ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
      {
      ... when != off
      }
      
      @ write @
      identifier write_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      expression E;
      identifier func;
      @@
      ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
      {
      <+...
      (
        *off = E
      |
        *off += E
      |
        func(..., off, ...)
      |
        E = *off
      )
      ...+>
      }
      
      @ write_no_fpos @
      identifier write_f;
      identifier f, p, s, off;
      type ssize_t, size_t, loff_t;
      @@
      ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
      {
      ... when != off
      }
      
      @ fops0 @
      identifier fops;
      @@
      struct file_operations fops = {
       ...
      };
      
      @ has_llseek depends on fops0 @
      identifier fops0.fops;
      identifier llseek_f;
      @@
      struct file_operations fops = {
      ...
       .llseek = llseek_f,
      ...
      };
      
      @ has_read depends on fops0 @
      identifier fops0.fops;
      identifier read_f;
      @@
      struct file_operations fops = {
      ...
       .read = read_f,
      ...
      };
      
      @ has_write depends on fops0 @
      identifier fops0.fops;
      identifier write_f;
      @@
      struct file_operations fops = {
      ...
       .write = write_f,
      ...
      };
      
      @ has_open depends on fops0 @
      identifier fops0.fops;
      identifier open_f;
      @@
      struct file_operations fops = {
      ...
       .open = open_f,
      ...
      };
      
      // use no_llseek if we call nonseekable_open
      ////////////////////////////////////////////
      @ nonseekable1 depends on !has_llseek && has_open @
      identifier fops0.fops;
      identifier nso ~= "nonseekable_open";
      @@
      struct file_operations fops = {
      ...  .open = nso, ...
      +.llseek = no_llseek, /* nonseekable */
      };
      
      @ nonseekable2 depends on !has_llseek @
      identifier fops0.fops;
      identifier open.open_f;
      @@
      struct file_operations fops = {
      ...  .open = open_f, ...
      +.llseek = no_llseek, /* open uses nonseekable */
      };
      
      // use seq_lseek for sequential files
      /////////////////////////////////////
      @ seq depends on !has_llseek @
      identifier fops0.fops;
      identifier sr ~= "seq_read";
      @@
      struct file_operations fops = {
      ...  .read = sr, ...
      +.llseek = seq_lseek, /* we have seq_read */
      };
      
      // use default_llseek if there is a readdir
      ///////////////////////////////////////////
      @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier readdir_e;
      @@
      // any other fop is used that changes pos
      struct file_operations fops = {
      ... .readdir = readdir_e, ...
      +.llseek = default_llseek, /* readdir is present */
      };
      
      // use default_llseek if at least one of read/write touches f_pos
      /////////////////////////////////////////////////////////////////
      @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier read.read_f;
      @@
      // read fops use offset
      struct file_operations fops = {
      ... .read = read_f, ...
      +.llseek = default_llseek, /* read accesses f_pos */
      };
      
      @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier write.write_f;
      @@
      // write fops use offset
      struct file_operations fops = {
      ... .write = write_f, ...
      +	.llseek = default_llseek, /* write accesses f_pos */
      };
      
      // Use noop_llseek if neither read nor write accesses f_pos
      ///////////////////////////////////////////////////////////
      
      @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier read_no_fpos.read_f;
      identifier write_no_fpos.write_f;
      @@
      // write fops use offset
      struct file_operations fops = {
      ...
       .write = write_f,
       .read = read_f,
      ...
      +.llseek = noop_llseek, /* read and write both use no f_pos */
      };
      
      @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier write_no_fpos.write_f;
      @@
      struct file_operations fops = {
      ... .write = write_f, ...
      +.llseek = noop_llseek, /* write uses no f_pos */
      };
      
      @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      identifier read_no_fpos.read_f;
      @@
      struct file_operations fops = {
      ... .read = read_f, ...
      +.llseek = noop_llseek, /* read uses no f_pos */
      };
      
      @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
      identifier fops0.fops;
      @@
      struct file_operations fops = {
      ...
      +.llseek = noop_llseek, /* no read or write fn */
      };
      ===== End semantic patch =====
      Signed-off-by: NArnd Bergmann <arnd@arndb.de>
      Cc: Julia Lawall <julia@diku.dk>
      Cc: Christoph Hellwig <hch@infradead.org>
      6038f373
  2. 16 9月, 2010 2 次提交
  3. 11 9月, 2010 2 次提交
  4. 10 9月, 2010 8 次提交
  5. 09 9月, 2010 4 次提交
  6. 08 9月, 2010 8 次提交
  7. 05 9月, 2010 2 次提交
    • A
      x86, mcheck: Avoid duplicate sysfs links/files for thresholding banks · 1389298f
      Andreas Herrmann 提交于
      kobject_add_internal failed for threshold_bank2 with -EEXIST,
      don't try to register things with the same name in the same
      directory:
      
        Pid: 1, comm: swapper Tainted: G        W  2.6.31 #1
        Call Trace:
        [<ffffffff81161b07>] ? kobject_add_internal+0x156/0x180
        [<ffffffff81161cc0>] ? kobject_add+0x66/0x6b
        [<ffffffff81161793>] ? kobject_init+0x42/0x82
        [<ffffffff81161cf9>] ? kobject_create_and_add+0x34/0x63
        [<ffffffff81393963>] ? threshold_create_bank+0x14f/0x259
        [<ffffffff8139310a>] ? mce_create_device+0x8d/0x1b8
        [<ffffffff81646497>] ? threshold_init_device+0x3f/0x80
        [<ffffffff81646458>] ? threshold_init_device+0x0/0x80
        [<ffffffff81009050>] ? do_one_initcall+0x4f/0x143
        [<ffffffff816413a0>] ? kernel_init+0x14c/0x1a2
        [<ffffffff8100c8da>] ? child_rip+0xa/0x20
        [<ffffffff81641254>] ? kernel_init+0x0/0x1a2
        [<ffffffff8100c8d0>] ? child_rip+0x0/0x20
        kobject_create_and_add: kobject_add error: -17
      
      (Probably the for_each_cpu loop should be entirely removed.)
      Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
      LKML-Reference: <20100827092006.GB5348@loge.amd.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      1389298f
    • F
      x86: Fix the address space annotations of iomap_atomic_prot_pfn() · cc1a8e52
      Francisco Jerez 提交于
      This patch fixes the sparse warnings when the return pointer of
      iomap_atomic_prot_pfn() is used as an argument of iowrite32()
      and friends.
      Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
      LKML-Reference: <1283633804-11749-1-git-send-email-currojerez@riseup.net>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      cc1a8e52
  8. 03 9月, 2010 3 次提交
    • R
      perf, x86: Try to handle unknown nmis with an enabled PMU · 4177c42a
      Robert Richter 提交于
      When the PMU is enabled it is valid to have unhandled nmis, two
      events could trigger 'simultaneously' raising two back-to-back
      NMIs. If the first NMI handles both, the latter will be empty
      and daze the CPU.
      
      The solution to avoid an 'unknown nmi' massage in this case was
      simply to stop the nmi handler chain when the PMU is enabled by
      stating the nmi was handled. This has the drawback that a) we
      can not detect unknown nmis anymore, and b) subsequent nmi
      handlers are not called.
      
      This patch addresses this. Now, we check this unknown NMI if it
      could be a PMU back-to-back NMI. Otherwise we pass it and let
      the kernel handle the unknown nmi.
      
      This is a debug log:
      
       cpu #6, nmi #32333, skip_nmi #32330, handled = 1, time = 1934364430
       cpu #6, nmi #32334, skip_nmi #32330, handled = 1, time = 1934704616
       cpu #6, nmi #32335, skip_nmi #32336, handled = 2, time = 1936032320
       cpu #6, nmi #32336, skip_nmi #32336, handled = 0, time = 1936034139
       cpu #6, nmi #32337, skip_nmi #32336, handled = 1, time = 1936120100
       cpu #6, nmi #32338, skip_nmi #32336, handled = 1, time = 1936404607
       cpu #6, nmi #32339, skip_nmi #32336, handled = 1, time = 1937983416
       cpu #6, nmi #32340, skip_nmi #32341, handled = 2, time = 1938201032
       cpu #6, nmi #32341, skip_nmi #32341, handled = 0, time = 1938202830
       cpu #6, nmi #32342, skip_nmi #32341, handled = 1, time = 1938443743
       cpu #6, nmi #32343, skip_nmi #32341, handled = 1, time = 1939956552
       cpu #6, nmi #32344, skip_nmi #32341, handled = 1, time = 1940073224
       cpu #6, nmi #32345, skip_nmi #32341, handled = 1, time = 1940485677
       cpu #6, nmi #32346, skip_nmi #32347, handled = 2, time = 1941947772
       cpu #6, nmi #32347, skip_nmi #32347, handled = 1, time = 1941949818
       cpu #6, nmi #32348, skip_nmi #32347, handled = 0, time = 1941951591
       Uhhuh. NMI received for unknown reason 00 on CPU 6.
       Do you have a strange power saving mode enabled?
       Dazed and confused, but trying to continue
      
      Deltas:
      
       nmi #32334 340186
       nmi #32335 1327704
       nmi #32336 1819      <<<< back-to-back nmi [1]
       nmi #32337 85961
       nmi #32338 284507
       nmi #32339 1578809
       nmi #32340 217616
       nmi #32341 1798      <<<< back-to-back nmi [2]
       nmi #32342 240913
       nmi #32343 1512809
       nmi #32344 116672
       nmi #32345 412453
       nmi #32346 1462095   <<<< 1st nmi (standard) handling 2 counters
       nmi #32347 2046      <<<< 2nd nmi (back-to-back) handling one
       counter nmi #32348 1773      <<<< 3rd nmi (back-to-back)
       handling no counter! [3]
      
      For  back-to-back nmi detection there are the following rules:
      
      The PMU nmi handler was handling more than one counter and no
      counter was handled in the subsequent nmi (see [1] and [2]
      above).
      
      There is another case if there are two subsequent back-to-back
      nmis [3]. The 2nd is detected as back-to-back because the first
      handled more than one counter. If the second handles one counter
      and the 3rd handles nothing, we drop the 3rd nmi because it
      could be a back-to-back nmi.
      Signed-off-by: NRobert Richter <robert.richter@amd.com>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      [ renamed nmi variable to pmu_nmi to avoid clash with .nmi in entry.S ]
      Signed-off-by: NDon Zickus <dzickus@redhat.com>
      Cc: peterz@infradead.org
      Cc: gorcunov@gmail.com
      Cc: fweisbec@gmail.com
      Cc: ying.huang@intel.com
      Cc: ming.m.lin@intel.com
      Cc: eranian@google.com
      LKML-Reference: <1283454469-1909-3-git-send-email-dzickus@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      4177c42a
    • P
      perf, x86: Fix handle_irq return values · de725dec
      Peter Zijlstra 提交于
      Now that we rely on the number of handled overflows, ensure all
      handle_irq implementations actually return the right number.
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: NDon Zickus <dzickus@redhat.com>
      Cc: peterz@infradead.org
      Cc: robert.richter@amd.com
      Cc: gorcunov@gmail.com
      Cc: fweisbec@gmail.com
      Cc: ying.huang@intel.com
      Cc: ming.m.lin@intel.com
      Cc: eranian@google.com
      LKML-Reference: <1283454469-1909-4-git-send-email-dzickus@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      de725dec
    • D
      perf, x86: Fix accidentally ack'ing a second event on intel perf counter · 2e556b5b
      Don Zickus 提交于
      During testing of a patch to stop having the perf subsytem
      swallow nmis, it was uncovered that Nehalem boxes were randomly
      getting unknown nmis when using the perf tool.
      
      Moving the ack'ing of the PMI closer to when we get the status
      allows the hardware to properly re-set the PMU bit signaling
      another PMI was triggered during the processing of the first
      PMI.  This allows the new logic for dealing with the
      shortcomings of multiple PMIs to handle the extra NMI by
      'eat'ing it later.
      
      Now one can wonder why are we getting a second PMI when we
      disable all the PMUs in the begining of the NMI handler to
      prevent such a case, for that I do not know.  But I know the fix
      below helps deal with this quirk.
      
      Tested on multiple Nehalems where the problem was occuring.
      With the patch, the code now loops a second time to handle the
      second PMI (whereas before it was not).
      Signed-off-by: NDon Zickus <dzickus@redhat.com>
      Cc: peterz@infradead.org
      Cc: robert.richter@amd.com
      Cc: gorcunov@gmail.com
      Cc: fweisbec@gmail.com
      Cc: ying.huang@intel.com
      Cc: ming.m.lin@intel.com
      Cc: eranian@google.com
      LKML-Reference: <1283454469-1909-2-git-send-email-dzickus@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      2e556b5b
  9. 02 9月, 2010 5 次提交
  10. 01 9月, 2010 5 次提交