1. 07 Aug, 2015 1 commit
  2. 05 Nov, 2014 1 commit
  3. 04 Mar, 2013 1 commit
  4. 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
  5. 27 Sep, 2012 1 commit
  6. 30 May, 2012 1 commit
  7. 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
  8. 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
  9. 08 Oct, 2010 1 commit
  10. 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
  11. 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
  12. 22 Dec, 2009 1 commit
  13. 14 Jan, 2009 1 commit
  14. 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
  15. 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
  16. 11 Apr, 2008 1 commit
  17. 06 Feb, 2008 1 commit
  18. 03 Feb, 2008 1 commit
  19. 17 Oct, 2007 1 commit
  20. 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
  21. 23 Aug, 2007 1 commit
    • Oleg Nesterov's avatar
      signalfd: make it group-wide, fix posix-timers scheduling · f9ee228b
      Oleg Nesterov authored
      With this patch any thread can dequeue its own private signals via signalfd,
      even if it was created by another sub-thread.
      
      To do so, we pass "current" to dequeue_signal() if the caller is from the same
      thread group. This also fixes the scheduling of posix timers broken by the
      previous patch.
      
      If the caller doesn't belong to this thread group, we can't handle __SI_TIMER
      case properly anyway. Perhaps we should forbid the cross-process signalfd usage
      and convert ctx->tsk to ctx->sighand.
      Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Davide Libenzi <davidel@xmailserver.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Michael Kerrisk <mtk-manpages@gmx.net>
      Cc: Roland McGrath <roland@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: <stable@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f9ee228b
  22. 26 Jul, 2007 1 commit
  23. 28 Jun, 2007 1 commit
  24. 24 May, 2007 1 commit
  25. 11 May, 2007 1 commit
    • Davide Libenzi's avatar
      signal/timer/event: signalfd core · fba2afaa
      Davide Libenzi authored
      This patch series implements the new signalfd() system call.
      
      I took part of the original Linus code (and you know how badly it can be
      broken :), and I added even more breakage ;) Signals are fetched from the same
      signal queue used by the process, so signalfd will compete with standard
      kernel delivery in dequeue_signal().  If you want to reliably fetch signals on
      the signalfd file, you need to block them with sigprocmask(SIG_BLOCK).  This
      seems to be working fine on my Dual Opteron machine.  I made a quick test
      program for it:
      
      http://www.xmailserver.org/signafd-test.c
      
      The signalfd() system call implements signal delivery into a file descriptor
      receiver.  The signalfd file descriptor if created with the following API:
      
      int signalfd(int ufd, const sigset_t *mask, size_t masksize);
      
      The "ufd" parameter allows to change an existing signalfd sigmask, w/out going
      to close/create cycle (Linus idea).  Use "ufd" == -1 if you want a brand new
      signalfd file.
      
      The "mask" allows to specify the signal mask of signals that we are interested
      in.  The "masksize" parameter is the size of "mask".
      
      The signalfd fd supports the poll(2) and read(2) system calls.  The poll(2)
      will return POLLIN when signals are available to be dequeued.  As a direct
      consequence of supporting the Linux poll subsystem, the signalfd fd can use
      used together with epoll(2) too.
      
      The read(2) system call will return a "struct signalfd_siginfo" structure in
      the userspace supplied buffer.  The return value is the number of bytes copied
      in the supplied buffer, or -1 in case of error.  The read(2) call can also
      return 0, in case the sighand structure to which the signalfd was attached,
      has been orphaned.  The O_NONBLOCK flag is also supported, and read(2) will
      return -EAGAIN in case no signal is available.
      
      If the size of the buffer passed to read(2) is lower than sizeof(struct
      signalfd_siginfo), -EINVAL is returned.  A read from the signalfd can also
      return -ERESTARTSYS in case a signal hits the process.  The format of the
      struct signalfd_siginfo is, and the valid fields depends of the (->code &
      __SI_MASK) value, in the same way a struct siginfo would:
      
      struct signalfd_siginfo {
      	__u32 signo;	/* si_signo */
      	__s32 err;	/* si_errno */
      	__s32 code;	/* si_code */
      	__u32 pid;	/* si_pid */
      	__u32 uid;	/* si_uid */
      	__s32 fd;	/* si_fd */
      	__u32 tid;	/* si_fd */
      	__u32 band;	/* si_band */
      	__u32 overrun;	/* si_overrun */
      	__u32 trapno;	/* si_trapno */
      	__s32 status;	/* si_status */
      	__s32 svint;	/* si_int */
      	__u64 svptr;	/* si_ptr */
      	__u64 utime;	/* si_utime */
      	__u64 stime;	/* si_stime */
      	__u64 addr;	/* si_addr */
      };
      
      [akpm@linux-foundation.org: fix signalfd_copyinfo() on i386]
      Signed-off-by: default avatarDavide Libenzi <davidel@xmailserver.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      fba2afaa