1. 03 Oct, 2018 1 commit
    • Eric W. Biederman's avatar
      signal: Distinguish between kernel_siginfo and siginfo · ae7795bc
      Eric W. Biederman authored
      Linus recently observed that if we did not worry about the padding
      member in struct siginfo it is only about 48 bytes, and 48 bytes is
      much nicer than 128 bytes for allocating on the stack and copying
      around in the kernel.
      
      The obvious thing of only adding the padding when userspace is
      including siginfo.h won't work as there are sigframe definitions in
      the kernel that embed struct siginfo.
      
      So split siginfo in two; kernel_siginfo and siginfo.  Keeping the
      traditional name for the userspace definition.  While the version that
      is used internally to the kernel and ultimately will not be padded to
      128 bytes is called kernel_siginfo.
      
      The definition of struct kernel_siginfo I have put in include/signal_types.h
      
      A set of buildtime checks has been added to verify the two structures have
      the same field offsets.
      
      To make it easy to verify the change kernel_siginfo retains the same
      size as siginfo.  The reduction in size comes in a following change.
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      ae7795bc
  2. 15 Jun, 2018 1 commit
  3. 27 Apr, 2018 3 commits
  4. 25 Apr, 2018 1 commit
  5. 02 Apr, 2018 2 commits
  6. 22 Feb, 2018 1 commit
  7. 11 Feb, 2018 1 commit
    • Linus Torvalds's avatar
      vfs: do bulk POLL* -> EPOLL* replacement · a9a08845
      Linus Torvalds authored
      This is the mindless scripted replacement of kernel use of POLL*
      variables as described by Al, done by this script:
      
          for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
              L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
              for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
          done
      
      with de-mangling cleanups yet to come.
      
      NOTE! On almost all architectures, the EPOLL* constants have the same
      values as the POLL* constants do.  But they keyword here is "almost".
      For various bad reasons they aren't the same, and epoll() doesn't
      actually work quite correctly in some cases due to this on Sparc et al.
      
      The next patch from Al will sort out the final differences, and we
      should be all done.
      Scripted-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a9a08845
  8. 27 Nov, 2017 1 commit
  9. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: default avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  10. 19 Sep, 2017 1 commit
  11. 24 Jul, 2017 1 commit
    • Eric W. Biederman's avatar
      signal: Remove kernel interal si_code magic · cc731525
      Eric W. Biederman authored
      struct siginfo is a union and the kernel since 2.4 has been hiding a union
      tag in the high 16bits of si_code using the values:
      __SI_KILL
      __SI_TIMER
      __SI_POLL
      __SI_FAULT
      __SI_CHLD
      __SI_RT
      __SI_MESGQ
      __SI_SYS
      
      While this looks plausible on the surface, in practice this situation has
      not worked well.
      
      - Injected positive signals are not copied to user space properly
        unless they have these magic high bits set.
      
      - Injected positive signals are not reported properly by signalfd
        unless they have these magic high bits set.
      
      - These kernel internal values leaked to userspace via ptrace_peek_siginfo
      
      - It was possible to inject these kernel internal values and cause the
        the kernel to misbehave.
      
      - Kernel developers got confused and expected these kernel internal values
        in userspace in kernel self tests.
      
      - Kernel developers got confused and set si_code to __SI_FAULT which
        is SI_USER in userspace which causes userspace to think an ordinary user
        sent the signal and that it was not kernel generated.
      
      - The values make it impossible to reorganize the code to transform
        siginfo_copy_to_user into a plain copy_to_user.  As si_code must
        be massaged before being passed to userspace.
      
      So remove these kernel internal si codes and make the kernel code simpler
      and more maintainable.
      
      To replace these kernel internal magic si_codes introduce the helper
      function siginfo_layout, that takes a signal number and an si_code and
      computes which union member of siginfo is being used.  Have
      siginfo_layout return an enumeration so that gcc will have enough
      information to warn if a switch statement does not handle all of union
      members.
      
      A couple of architectures have a messed up ABI that defines signal
      specific duplications of SI_USER which causes more special cases in
      siginfo_layout than I would like.  The good news is only problem
      architectures pay the cost.
      
      Update all of the code that used the previous magic __SI_ values to
      use the new SIL_ values and to call siginfo_layout to get those
      values.  Escept where not all of the cases are handled remove the
      defaults in the switch statements so that if a new case is missed in
      the future the lack will show up at compile time.
      
      Modify the code that copies siginfo si_code to userspace to just copy
      the value and not cast si_code to a short first.  The high bits are no
      longer used to hold a magic union member.
      
      Fixup the siginfo header files to stop including the __SI_ values in
      their constants and for the headers that were missing it to properly
      update the number of si_codes for each signal type.
      
      The fixes to copy_siginfo_from_user32 implementations has the
      interesting property that several of them perviously should never have
      worked as the __SI_ values they depended up where kernel internal.
      With that dependency gone those implementations should work much
      better.
      
      The idea of not passing the __SI_ values out to userspace and then
      not reinserting them has been tested with criu and criu worked without
      changes.
      
      Ref: 2.4.0-test1
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      cc731525
  12. 20 Jun, 2017 1 commit
    • Ingo Molnar's avatar
      sched/wait: Rename wait_queue_t => wait_queue_entry_t · ac6424b9
      Ingo Molnar authored
      Rename:
      
      	wait_queue_t		=>	wait_queue_entry_t
      
      'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
      but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
      which had to carry the name.
      
      Start sorting this out by renaming it to 'wait_queue_entry_t'.
      
      This also allows the real structure name 'struct __wait_queue' to
      lose its double underscore and become 'struct wait_queue_entry',
      which is the more canonical nomenclature for such data types.
      
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      ac6424b9
  13. 18 Apr, 2017 1 commit
    • Paul E. McKenney's avatar
      mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU · 5f0d5a3a
      Paul E. McKenney authored
      A group of Linux kernel hackers reported chasing a bug that resulted
      from their assumption that SLAB_DESTROY_BY_RCU provided an existence
      guarantee, that is, that no block from such a slab would be reallocated
      during an RCU read-side critical section.  Of course, that is not the
      case.  Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire
      slab of blocks.
      
      However, there is a phrase for this, namely "type safety".  This commit
      therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order
      to avoid future instances of this sort of confusion.
      Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: <linux-mm@kvack.org>
      Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
      Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
      [ paulmck: Add comments mentioning the old name, as requested by Eric
        Dumazet, in order to help people familiar with the old name find
        the new one. ]
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      5f0d5a3a
  14. 07 Aug, 2015 1 commit
  15. 05 Nov, 2014 1 commit
  16. 04 Mar, 2013 1 commit
  17. 18 Dec, 2012 1 commit
    • Cyrill Gorcunov's avatar
      fs, epoll: add procfs fdinfo helper · 138d22b5
      Cyrill Gorcunov authored
      This allows us to print out eventpoll target file descriptor, events and
      data, the /proc/pid/fdinfo/fd consists of
      
       | pos:	0
       | flags:	02
       | tfd:        5 events:       1d data: ffffffffffffffff enabled: 1
      
      [avagin@: fix for unitialized ret variable]
      Signed-off-by: default avatarCyrill Gorcunov <gorcunov@openvz.org>
      Acked-by: default avatarPavel Emelyanov <xemul@parallels.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Andrey Vagin <avagin@openvz.org>
      Cc: Al Viro <viro@ZenIV.linux.org.uk>
      Cc: Alexey Dobriyan <adobriyan@gmail.com>
      Cc: James Bottomley <jbottomley@parallels.com>
      Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
      Cc: Alexey Dobriyan <adobriyan@gmail.com>
      Cc: Matthew Helsley <matt.helsley@gmail.com>
      Cc: "J. Bruce Fields" <bfields@fieldses.org>
      Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
      Cc: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      138d22b5
  18. 27 Sep, 2012 1 commit
  19. 30 May, 2012 1 commit
  20. 24 Feb, 2012 2 commits
    • Oleg Nesterov's avatar
      epoll: ep_unregister_pollwait() can use the freed pwq->whead · 971316f0
      Oleg Nesterov authored
      signalfd_cleanup() ensures that ->signalfd_wqh is not used, but
      this is not enough. eppoll_entry->whead still points to the memory
      we are going to free, ep_unregister_pollwait()->remove_wait_queue()
      is obviously unsafe.
      
      Change ep_poll_callback(POLLFREE) to set eppoll_entry->whead = NULL,
      change ep_unregister_pollwait() to check pwq->whead != NULL under
      rcu_read_lock() before remove_wait_queue(). We add the new helper,
      ep_remove_wait_queue(), for this.
      
      This works because sighand_cachep is SLAB_DESTROY_BY_RCU and because
      ->signalfd_wqh is initialized in sighand_ctor(), not in copy_sighand.
      ep_unregister_pollwait()->remove_wait_queue() can play with already
      freed and potentially reused ->sighand, but this is fine. This memory
      must have the valid ->signalfd_wqh until rcu_read_unlock().
      Reported-by: default avatarMaxime Bizon <mbizon@freebox.fr>
      Cc: <stable@kernel.org>
      Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      971316f0
    • Oleg Nesterov's avatar
      epoll: introduce POLLFREE to flush ->signalfd_wqh before kfree() · d80e731e
      Oleg Nesterov authored
      This patch is intentionally incomplete to simplify the review.
      It ignores ep_unregister_pollwait() which plays with the same wqh.
      See the next change.
      
      epoll assumes that the EPOLL_CTL_ADD'ed file controls everything
      f_op->poll() needs. In particular it assumes that the wait queue
      can't go away until eventpoll_release(). This is not true in case
      of signalfd, the task which does EPOLL_CTL_ADD uses its ->sighand
      which is not connected to the file.
      
      This patch adds the special event, POLLFREE, currently only for
      epoll. It expects that init_poll_funcptr()'ed hook should do the
      necessary cleanup. Perhaps it should be defined as EPOLLFREE in
      eventpoll.
      
      __cleanup_sighand() is changed to do wake_up_poll(POLLFREE) if
      ->signalfd_wqh is not empty, we add the new signalfd_cleanup()
      helper.
      
      ep_poll_callback(POLLFREE) simply does list_del_init(task_list).
      This make this poll entry inconsistent, but we don't care. If you
      share epoll fd which contains our sigfd with another process you
      should blame yourself. signalfd is "really special". I simply do
      not know how we can define the "right" semantics if it used with
      epoll.
      
      The main problem is, epoll calls signalfd_poll() once to establish
      the connection with the wait queue, after that signalfd_poll(NULL)
      returns the different/inconsistent results depending on who does
      EPOLL_CTL_MOD/signalfd_read/etc. IOW: apart from sigmask, signalfd
      has nothing to do with the file, it works with the current thread.
      
      In short: this patch is the hack which tries to fix the symptoms.
      It also assumes that nobody can take tasklist_lock under epoll
      locks, this seems to be true.
      
      Note:
      
      	- we do not have wake_up_all_poll() but wake_up_poll()
      	  is fine, poll/epoll doesn't use WQ_FLAG_EXCLUSIVE.
      
      	- signalfd_cleanup() uses POLLHUP along with POLLFREE,
      	  we need a couple of simple changes in eventpoll.c to
      	  make sure it can't be "lost".
      Reported-by: default avatarMaxime Bizon <mbizon@freebox.fr>
      Cc: <stable@kernel.org>
      Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d80e731e
  21. 15 Oct, 2010 1 commit
    • Arnd Bergmann's avatar
      llseek: automatically add .llseek fop · 6038f373
      Arnd Bergmann authored
      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: default avatarArnd Bergmann <arnd@arndb.de>
      Cc: Julia Lawall <julia@diku.dk>
      Cc: Christoph Hellwig <hch@infradead.org>
      6038f373
  22. 08 Oct, 2010 1 commit
  23. 11 Aug, 2010 1 commit
    • Nathan Lynch's avatar
      signalfd: fill in ssi_int for posix timers and message queues · a2a20c41
      Nathan Lynch authored
      If signalfd is used to consume a signal generated by a POSIX interval
      timer or POSIX message queue, the ssi_int field does not reflect the data
      (sigevent->sigev_value) supplied to timer_create(2) or mq_notify(3).  (The
      ssi_ptr field, however, is filled in.)
      
      This behavior differs from signalfd's treatment of sigqueue-generated
      signals -- see the default case in signalfd_copyinfo.  It also gives
      results that differ from the case when a signal is handled conventionally
      via a sigaction-registered handler.
      
      So, set signalfd_siginfo->ssi_int in the remaining cases (__SI_TIMER,
      __SI_MESGQ) where ssi_ptr is set.
      
      akpm: a non-back-compatible change.  Merge into -stable to minimise the
      number of kernels which are in the field and which miss this feature.
      Signed-off-by: default avatarNathan Lynch <ntl@pobox.com>
      Acked-by: default avatarDavide Libenzi <davidel@xmailserver.org>
      Cc: <stable@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a2a20c41
  24. 30 Mar, 2010 1 commit
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  25. 22 Dec, 2009 1 commit
  26. 14 Jan, 2009 1 commit
  27. 24 Jul, 2008 4 commits
    • Ulrich Drepper's avatar
      flag parameters: check magic constants · e38b36f3
      Ulrich Drepper authored
      This patch adds test that ensure the boundary conditions for the various
      constants introduced in the previous patches is met.  No code is generated.
      
      [akpm@linux-foundation.org: fix alpha]
      Signed-off-by: default avatarUlrich Drepper <drepper@redhat.com>
      Acked-by: default avatarDavide Libenzi <davidel@xmailserver.org>
      Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e38b36f3
    • Ulrich Drepper's avatar
      flag parameters: NONBLOCK in signalfd · 5fb5e049
      Ulrich Drepper authored
      This patch adds support for the SFD_NONBLOCK flag to signalfd4.  The
      additional changes needed are minimal.
      
      The following test must be adjusted for architectures other than x86 and
      x86-64 and in case the syscall numbers changed.
      
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      #include <fcntl.h>
      #include <signal.h>
      #include <stdio.h>
      #include <unistd.h>
      #include <sys/syscall.h>
      
      #ifndef __NR_signalfd4
      # ifdef __x86_64__
      #  define __NR_signalfd4 289
      # elif defined __i386__
      #  define __NR_signalfd4 327
      # else
      #  error "need __NR_signalfd4"
      # endif
      #endif
      
      #define SFD_NONBLOCK O_NONBLOCK
      
      int
      main (void)
      {
        sigset_t ss;
        sigemptyset (&ss);
        sigaddset (&ss, SIGUSR1);
        int fd = syscall (__NR_signalfd4, -1, &ss, 8, 0);
        if (fd == -1)
          {
            puts ("signalfd4(0) failed");
            return 1;
          }
        int fl = fcntl (fd, F_GETFL);
        if (fl == -1)
          {
            puts ("fcntl failed");
            return 1;
          }
        if (fl & O_NONBLOCK)
          {
            puts ("signalfd4(0) set non-blocking mode");
            return 1;
          }
        close (fd);
      
        fd = syscall (__NR_signalfd4, -1, &ss, 8, SFD_NONBLOCK);
        if (fd == -1)
          {
            puts ("signalfd4(SFD_NONBLOCK) failed");
            return 1;
          }
        fl = fcntl (fd, F_GETFL);
        if (fl == -1)
          {
            puts ("fcntl failed");
            return 1;
          }
        if ((fl & O_NONBLOCK) == 0)
          {
            puts ("signalfd4(SFD_NONBLOCK) does not set non-blocking mode");
            return 1;
          }
        close (fd);
      
        puts ("OK");
      
        return 0;
      }
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      Signed-off-by: default avatarUlrich Drepper <drepper@redhat.com>
      Acked-by: default avatarDavide Libenzi <davidel@xmailserver.org>
      Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5fb5e049
    • Ulrich Drepper's avatar
      flag parameters: signalfd · 9deb27ba
      Ulrich Drepper authored
      This patch adds the new signalfd4 syscall.  It extends the old signalfd
      syscall by one parameter which is meant to hold a flag value.  In this
      patch the only flag support is SFD_CLOEXEC which causes the close-on-exec
      flag for the returned file descriptor to be set.
      
      A new name SFD_CLOEXEC is introduced which in this implementation must
      have the same value as O_CLOEXEC.
      
      The following test must be adjusted for architectures other than x86 and
      x86-64 and in case the syscall numbers changed.
      
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      #include <fcntl.h>
      #include <signal.h>
      #include <stdio.h>
      #include <unistd.h>
      #include <sys/syscall.h>
      
      #ifndef __NR_signalfd4
      # ifdef __x86_64__
      #  define __NR_signalfd4 289
      # elif defined __i386__
      #  define __NR_signalfd4 327
      # else
      #  error "need __NR_signalfd4"
      # endif
      #endif
      
      #define SFD_CLOEXEC O_CLOEXEC
      
      int
      main (void)
      {
        sigset_t ss;
        sigemptyset (&ss);
        sigaddset (&ss, SIGUSR1);
        int fd = syscall (__NR_signalfd4, -1, &ss, 8, 0);
        if (fd == -1)
          {
            puts ("signalfd4(0) failed");
            return 1;
          }
        int coe = fcntl (fd, F_GETFD);
        if (coe == -1)
          {
            puts ("fcntl failed");
            return 1;
          }
        if (coe & FD_CLOEXEC)
          {
            puts ("signalfd4(0) set close-on-exec flag");
            return 1;
          }
        close (fd);
      
        fd = syscall (__NR_signalfd4, -1, &ss, 8, SFD_CLOEXEC);
        if (fd == -1)
          {
            puts ("signalfd4(SFD_CLOEXEC) failed");
            return 1;
          }
        coe = fcntl (fd, F_GETFD);
        if (coe == -1)
          {
            puts ("fcntl failed");
            return 1;
          }
        if ((coe & FD_CLOEXEC) == 0)
          {
            puts ("signalfd4(SFD_CLOEXEC) does not set close-on-exec flag");
            return 1;
          }
        close (fd);
      
        puts ("OK");
      
        return 0;
      }
      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      
      [akpm@linux-foundation.org: add sys_ni stub]
      Signed-off-by: default avatarUlrich Drepper <drepper@redhat.com>
      Acked-by: default avatarDavide Libenzi <davidel@xmailserver.org>
      Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
      Cc: <linux-arch@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9deb27ba
    • Ulrich Drepper's avatar
      flag parameters: anon_inode_getfd extension · 7d9dbca3
      Ulrich Drepper authored
      This patch just extends the anon_inode_getfd interface to take an additional
      parameter with a flag value.  The flag value is passed on to
      get_unused_fd_flags in anticipation for a use with the O_CLOEXEC flag.
      
      No actual semantic changes here, the changed callers all pass 0 for now.
      
      [akpm@linux-foundation.org: KVM fix]
      Signed-off-by: default avatarUlrich Drepper <drepper@redhat.com>
      Acked-by: default avatarDavide Libenzi <davidel@xmailserver.org>
      Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7d9dbca3
  28. 01 May, 2008 1 commit
    • Al Viro's avatar
      [PATCH] sanitize anon_inode_getfd() · 2030a42c
      Al Viro authored
      a) none of the callers even looks at inode or file returned by anon_inode_getfd()
      b) any caller that would try to look at those would be racy, since by the time
      it returns we might have raced with close() from another thread and that
      file would be pining for fjords.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      2030a42c
  29. 11 Apr, 2008 1 commit
  30. 06 Feb, 2008 1 commit
  31. 03 Feb, 2008 1 commit
  32. 17 Oct, 2007 1 commit
  33. 20 Sep, 2007 1 commit
    • Davide Libenzi's avatar
      signalfd simplification · b8fceee1
      Davide Libenzi authored
      This simplifies signalfd code, by avoiding it to remain attached to the
      sighand during its lifetime.
      
      In this way, the signalfd remain attached to the sighand only during
      poll(2) (and select and epoll) and read(2).  This also allows to remove
      all the custom "tsk == current" checks in kernel/signal.c, since
      dequeue_signal() will only be called by "current".
      
      I think this is also what Ben was suggesting time ago.
      
      The external effect of this, is that a thread can extract only its own
      private signals and the group ones.  I think this is an acceptable
      behaviour, in that those are the signals the thread would be able to
      fetch w/out signalfd.
      Signed-off-by: default avatarDavide Libenzi <davidel@xmailserver.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b8fceee1